Classical early human studies estimated total mechanical LV efficiency at 20–30%, whereas the remaining energy is dissipated as heat. Total mechanical efficiency is a joint effect of the efficiency of energy transfer at three sequential stages. The first step, from MVO2 to adenosine triphosphate (ATP), reflects the yield of oxidative phosphorylation . The second step, from ATP split to pressure–volume area, represents the proportion of the energy liberated during ATP hydrolysis which is converted to total mechanical energy. Total mechanical energy generated per beat—represented by pressure–volume area—consists of EW (corresponding to PVLA) and potential energy, which is needed to develop tension during isovolumic contraction. The efficiency of the third step of energy transfer, i.e., from pressure–volume area to EW, decreases with depressed LV contractility, increased afterload, more concentric LV geometry with diastolic dysfunction and lower LV preload reserve. As practical assessment of LV efficiency poses methodological problems, De Simone et al. proposed a simple surrogate measure of myocardial efficiency, i.e., mechano-energetic efficiency index (MEEi) calculated from LV stroke volume, heart rate and LV mass. In two independent cohorts, including a large group of hypertensive subjects and a population-based cohort , low MEEi independently predicted composite adverse cardiovascular events and incident heart failure. It was hypothesized that the prognostic ability of low MEEi can result from its association with both metabolic and hemodynamic alterations, i.e., metabolic syndrome components, the degree of insulin resistance, concentric LV geometry, LV diastolic and discrete systolic dysfunction. On the one part, an increased reliance of cardiomyocytes on the oxidation of free fatty acids, typical for insulin-resistant states, is associated with both a lower yield of ATP per oxygen molecule and lesser availability of ATP for contraction, which might decrease energetic efficiency of the first and second step of energy transfer from MVO2 to EW. On the other part, concentric LV remodeling and LV dysfunction despite preserved ejection fraction can impair the efficiency of the third energy transfer step. In conclusion, the association of low MEEi with adverse cardiovascular outcome might be related to a multi-step impairment of energy transfer from MVO2 to EW in various clinical settings, including metabolic syndrome, diabetes, hypertension and heart failure. Irrespective of theoretical considerations, MEEi appears an attractive simple tool which couldt improve risk stratification in hypertensive and diabetic patients for primary prevention purposes. Further clinical studies are warranted to estimate the predictive ability of MEEi and its post-treatment changes, especially in patients on novel antidiabetic drugs and subjects with common metabolic diseases and concomitant chronic coronary syndromes, in whom the potential relevance of MEE can be potentiated by myocardial ischemia.Cardiac mechanical energetic efficiency is the ratio of external work (EW) to the total energy consumption. EW performed by the left ventricle (LV) during a single beat is represented by LV stroke work and may be calculated from the pressure–volume loop area (PVLA), while energy consumption corresponds to myocardial oxygen consumption (MVO The prevalence of cardiovascular (CV) diseases remains high in the modern world, regardless of well-recognized modifiable CV risk factors. Despite rigorous treatment goals and lifestyle modifications recommended by practice guidelines, these targets are not achieved in the majority of patients with most common CV risk factors, such as hypertension, obesity and type 2 diabetes (DM), constituting major public health concerns. In order to improve primary prevention strategy, there is a need to optimally use easily accessible parameters to ameliorate risk stratification and enhance implementation of aggressive prophylactic measures. In this review, we focus on a non-invasive index of cardiac mechanical efficiency which, despite its simplicity, has proved its predictive ability in prospective clinical studies with regard to the risk of major adverse CV events or new-onset heart failure (HF).2) assuming a constant energy equivalent per amount of oxygen metabolized. MVO2 can accurately be measured by coronary sinus catheterization as a product of myocardial blood flow and the coronary arteriovenous difference in oxygen content, expressed on a per-beat basis. Early studies estimated mechanical efficiency of the human LV at about 20–25% [Mechanical energetic efficiency of a system can be universally defined as the ratio of external work performed by the system to the total energy consumption ,2,3,4. It 20–25%  Figure  assumingTotal mechanical efficiency is a joint effect of the efficiency of energy transfer at several sequential stages ,8 Figur. The fir2 [2+-ATPase in the sarcoplasmic reticulum and sarcolemmal Na+-K+-ATPase), various protein phosphorylation pathways and synthetic purposes, and its majority is converted to heat [The second step, from ATP split to pressure–volume area (PVA) , represe2 ,8. The r to heat ,8  and potential energy (PE) . PE is t2 with positron emission tomography poses methodological problems [11C-labelled acetate and 15O-labelled water  enter equations depicting estimates of MVO2, while LV mass (LVM) and volumes may be derived from echocardiography, magnetic resonance or nuclear imaging, and brachial blood pressure is measured by a sphygmomanometer [11C-acetate-based method to equivalents of absolute units, the variability of the metabolic fate of 11C-acetate, tracer spill-over artifacts and the need of arterial blood sampling [15O2-based method appears to be a golden standard of MVO2 estimation, its feasibility is profoundly limited by technical problems related to the multiple tracer usage and challenging data analysis [Coronary sinus catheterization is rarely performed and the assessment of MVOproblems , which panometer ,10,11,12sampling . Althouganalysis .Therefore, in 2009, De Simone et al. [According to this concept , stroke -meters” ,13.2 may be approximated by calculating the so-called double product, i.e., SBP multiplied by heart rate (HR)—Equation (2):MVOThus, MEE is presented as a simplified formula—Equation (3):Following the initial concept by De Simone et al. , MEE is Since a linear positive correlation between MEE and LVM was found in the initial report, MEE index (MEEi) was computed as MEE divided by LVM . ObviousIn a report from the Campania Salute Network Registry , 12,353 During the follow-up, 136 incident 3-point MACE and 359 composite CV events were observed. The association of low MEEi at baseline  with the risk of either 3-point MACE or composite CV events remained significant upon adjustment for demographical characteristics, baseline and follow-up blood pressure, antihypertensive treatment, obesity, DM and LVH . AlthougIn a population-based cohort, 1912 American Indians participating in the Strong Heart Study (SHS)  free of prevalent CV disease and with preserved EF were followed for a median of 9.9 years  . Low MEEIn the seminal study performed in newly diagnosed, untreated patients with hypertension and without CV disease, De Simone et al.  comparedThe hemodynamic alterations are likely to decrease the efficiency of the third step of energy transfer from oxygen consumption to EW, i.e., from TME (PVA) to EW. In particular, the proportion of EW relative to TME  decreases with depressed LV contractility (via higher PE) , increasIn addition to hemodynamic alterations, reports from three independent cohorts suggested the association of low MEEi with metabolic risk factors, such as obesity, insulin resistance (IR), metabolic syndrome and DM ,15,16,17IR hinders the usage of glucose and lactate as energy sources and favors FFA utilization, which is associated with impaired energetic efficiency due to a lower yield of ATP per mole of oxygen consumed  ,18, whicA total of 3128 non-diabetic participants of the SHS and the Strong Heart Family Study free of CV disease, with available data on fasting glucose and insulin concentrations, were divided into four groups based on the quartiles of HOMA-IR (Homeostatic Model Assessment for Insulin Resistance) index, an estimate of the magnitude of IR . With inIn another cohort, 12,503 participants of the previously mentioned Campania Salute Network Registry (of whom women represented 44%), with available glucose levels, were divided into four groups according to the presence of DM or metabolic syndrome . Both DMRecently, Fiorentino et al.  reportedMechanistically, the joint contribution of IR and impaired glucose tolerance to low MEEi might be attributed to the competition between FFA and glucose/lactate for oxidation via the Randle cycle-related pathways . In insuWhen IR is paralleled by hyperinsulinemia, these abnormalities are partially compensated by higher insulin levels. In contrast, when IR is accompanied by developing beta-cell dysfunction, the IR-dependent shift of myocardial metabolism in favor of FFA is potentiated, which decreases the rate of ATP production at a given rate of oxygen consumption. Thus, the additive contribution of IR and beta-cell dysfunction to depressed MEE might explain joint effects of the metabolic syndrome (associated with IR) and DM (presumably with coexistent beta-cell dysfunction) on MEEi in the Campania Salute Network Registry .Finally, the proposed concept is consistent with independent additive associations of incident HF with both reduced glucose disposal rate  and fasting intact proinsulin levels and 2-h post-challenge glucose concentrations (estimates of beta-cell dysfunction) in 1187 community-based elderly subjects without prevalent HF participating in the Uppsala Longitudinal Study of Adult Men . NotablyBeyond the lower maximal achievable ATP yield per oxygen molecule for FFA than glucose ,18, exceIn mitochondria, electrons from glucose and FFA pass through the electron transport chain, which generates a proton gradient across the inner mitochondrial membrane, a driving force for ATP synthesis. If electrons leave the electron transport chain before oxygen is reduced to water, superoxide is generated. The electron leak is the predominant mechanism of the formation of reactive oxygen species (ROS) in mitochondria, accounting for the vast majority of cellular ROS production . On the + influx and consequent Ca2+ accumulation via the Ca/Na exchanger operating in the reverse mode [+ and Ca2+ homeostasis, so that less ATP is available for contraction [Recently, an acute inhibition of malonyl-CoA decarboxylase (MCD)  resulted in a switch from FFA to glucose utilization in normal rat hearts, and improved EF and SV in post-infarction failing hearts . Additiorse mode ,28. Constraction ,28.Thus, an increased reliance of cardiomyocytes on the oxidation of FFA at the expense of glucose, typical for IR, is associated not only with a lower yield of ATP per oxygen molecule , but also lower mechanical energy per ATP molecule, which decreases energetic efficiency of the first and second step of energy transfer from oxygen consumption to EW.Regardless of the above-summarized evidence, it can also be argued that the predictive value of MEEi might—at least in part—actually result from a combination of three established outcome predictors, i.e., increased HR, decreased SV and higher LVM into a single index. Obviously, low MEEi is likely to reflect the amplified prognostic ability of the integrated parameters. Indeed, De Marco et al.  describeThese findings may be interpreted as a consequence of the association between low SVI and low LVM, as pointed out by the authors , so thatNevertheless, LVM and LVH were not included in the multivariate analysis in the former report  of SHS IAccordingly, based on these reports ,14,29, a2 and better noninvasive indices of myocardial oxygen demand would be more appropriate, such as a so-called triple product, i.e., the product of heart rate, LV mass and end-systolic circumferential LV wall stress [Admittedly, it can be argued that MEEi calculation represents a too simplified approach to the estimation of MEE. First, mean arterial pressure, not SBP, is frequently used in the formulas for LV stroke work ,11,12. Sl stress . Notablyl stress  demonstrOn the other hand, MEEi seems to be a stronger predictor of incident HF than SVI. On multivariate analysis, low MEEi was associated with a more pronounced increase of the risk of incident HF   comparedIrrespective of detailed mechanisms underlying its prognostic capability in the given patient, MEEi elegantly integrates SV, HR and LVM into a simple estimate. Thus, this index also reflects mechanistic pathways, underlying predictive value of low SV and high LVM in hypertensive and diabetic patients. These pathways include restrictive LV remodeling, diastolic dysfunction and interrelated abnormalities, such as subtle circumferential and longitudinal systolic dysfunction despite preserved EF ,36,37,38These abnormalities—jointly contributing to LV concentric geometry, diastolic and subtle systolic dysfunction—decrease the efficiency of the third step of energy transfer from oxygen consumption to EW, as discussed previously. In addition, the association of low MEEi with metabolic risk factors ,15,16,17+ and Ca2+ overload [Metabolic effects have been implicated in the antianginal activity of trimetazidine and perhexiline in patients with ischemic heart disease . Trimetaoverload . Perhexioverload . Howeveroverload .Among established drugs for HF, beta-blockers were reportedly shown to improve cardiac metabolism, which could contribute to their recognized energy-sparing effect, primarily linked to a drop in heart rate and myocardial contractility. Early studies suggested that possible direct metabolic effects of beta-blockerst could result from decreased availability of circulating FFA for myocardial uptake and beta-oxidation through the inhibition of hormone-sensitive lipase in adipocytes .2 (estimated by means of 11C-acetate positron emission tomography) at unchanged LV stroke work [Metformin, a first-line antidiabetic drug, is known to inhibit mitochondrial complex I and up-regulate 5′-adenosine monophosphate-activated protein kinase, a pivotal energy sensor in mammalian cells ,48,49,50oke work .Cardiac metabolism has recently regained attention with the introduction of novel antidiabetic drugs. Among multiple possible pleiotropic effects of sodium-glucose cotransporter-2 inhibitors (SGLT2i), increased concentrations of ketone bodies, termed a “thrifty substrate”  or “supe2 dropped and the EW-to-TME ratio increased immediately after transcatheter aortic valve implantation (TAVI), and over-median post-TAVI rises in the ratio  were associated with a lower risk of all-cause death over an approximately 3-year follow up [The impact of therapeutic interventions on MEEi was rarely investigated in clinical studies. In patients with mild systolic HF and metabolic syndrome, MEEi increased after 12 months in patients randomized to an aldosterone receptor antagonist on the top of optimal therapy, which was associated with improved LV diastolic function and decreased levels of B-type natriuretic peptide compared to placebo . Recentlollow up .2 to external work in various clinical setting, including metabolic syndrome, diabetes, hypertension and HF. Irrespective of theoretical considerations, MEEi appears an attractive simple tool which could improve risk stratification in hypertensive and diabetic subjects for primary prevention purposes. Further clinical studies are warranted to estimate the predictive ability of MEEi and its post-treatment changes, especially in patients on novel antidiabetic drugs and subjects with common metabolic diseases and concomitant chronic coronary syndromes, in whom the potential relevance of MEE can be potentiated by myocardial ischemia.The association of low MEEi with adverse CV outcome might be related to multi-step impairment of energy transfer from MVO


Propionic Acidemia (PA) is characterized by the accumulation of propionic acid (PPA), its toxic derivatives, and ammonia. The disease causes multiorgan damage, especially in heart, pancreas, and brain; seizures and intellectual disability are often described. Some PA children also show autism spectrum disorders (ASD). In this study, we have compiled data from 62 individuals from the Propionic Acidemia International Patient Registry and compared it to the published literature on the prevalence of autism in PA. The PA registry shows a significant proportion of ASD diagnoses that is consistent with the combined prevalence reported in the literature. It also shows that ASD in PA is gender balanced and it is diagnosed at older ages (median age 8 years) than in the national registry for autism (median age 4.3 years), which raises the possibility, among others, of PA specific risk factors affecting the natural history of ASD. Data from patient registries provide valuable information on studying the mechanisms involved in a rare disease, although more outreach effort must be done to increase participation and consistency in data entry. The disease is characterized by the systemic accumulation of propionic acid (PPA) and its toxic derivatives. Children with PA are at high risk of developing low muscle tone, cardiomyopathy, neutropenia, pancreatitis, and ultimately death.Some studies have reported an increased frequency of autism spectrum disorder (ASD)Despite these evidences, the true prevalence of ASD in PA and other inborn errors of metabolism has been difficult to assess given the high variability in the number of affected patients, in the testing tools reported in the literature, in the large number of comorbid factors that affect PA and, above all, in the heterogeneity in testing protocols. Moreover, the changing diagnostic criteria for ASD in the various versions of the Diagnostic and statistical manual of mental disorders  has also made it difficult to obtain reliable estimates of the prevalence of this condition in PA.In this study, we collected information from the PA International Patient Registry maintained by the PA Foundation and compared it to the published prevalence of ASD in PA to obtain an improved estimate of the prevalence of this condition in this patient population.2Data from PA and UCD‐affected patients were collected from the UCD/PA International Patient Registries, created in 2012, and maintained by the Propionic Acidemia Foundation (IL) and the National Urea Cycle Disorders Foundation (CA), respectively. All data were obtained in accordance with IRB‐approved protocols of the UCD/PA Registries. All registry entries are self‐reported either by the patients themselves, or by the parents/guardians in the case of a minor or a cognitively impaired person. Information is collected through a web‐based questionnaire consisting of 52 questions related to initial diagnosis and medical history of which a subset related to hospitalizations, hyperammonemia, cardiac, developmental or neurological diagnoses  was included. For ASD, the registry had three possible answers: “Asperger's,” “Pervasive developmental disorder ‐not otherwise specified (PDD‐NOS)” and “Autism spectrum.” A positive answer to any of these entries was considered as a single instance of the self‐reported diagnosis of autism spectrum disorder. In each category, all the answers were structured: either with Yes/No type of answers or a list of possible answers from which the last option (“other”) is free text to capture an event or diagnosis not specified in the set of possible answers. For questions related to diagnoses, the questions required that the parent/caregiver reported only if the affected individual had been diagnosed by a medical professional about each specific condition.For this manuscript, we have used the subset of questions that are common to both the UCD and the PA registries.To calculate the percentage of cases for each diagnosis we divided the number of positive answers by the number of responders to that particular question. To compare the rates of ASD diagnosis between PA and UCD, we used Fisher's exact test at a level of confidence of 0.05.To obtain an estimate of the published prevalence of ASD in PA, we carried out a literature search in PubMed using the keywords “autism/ASD and PA,” “autism/ASD and IEMs,” “cognitive delays and PA,” “developmental delays and PA,” “language impairment and PA.” For other IEMs, we performed a similar search including the terms “IEMs” (Inborn Error of Metabolisms), “UCDs” or “OAs” (Organic Acidemias). Inclusion criteria were set for any study referring to the neurological manifestations in propionic acidemia, UCDs or any of the other OAs or IEMs .33.1The PA international registry currently contains data from 104 participant families of which 62  self‐reported information related to neurological and developmental impairments in an affected family member and were used in this study. Table 3.2We next examined the comorbid conditions present in the PA patients who were diagnosed with ASD as reported in the PA registry, and the relationship with their metabolic stability and other neurological and developmental manifestations Table . Most suWe also observed that PA patients were substantially older at age of ASD diagnosis (40% were 9 years of age or older at time of diagnosis with a median age of 12.5 years) than children in the general population (4.3 years old at age of diagnosis), even though PA children tend to be carefully monitored since birth.3.3P < .05).To explore whether propionic acidemia is a risk factor for the prevalence of ASD, we compared the data from the PA registry to data reported in the UCD International Patient Registry because, similar to the PA patients, UCD patients typically exhibit hyperammonemia. As seen in Table 44.1The data collected from the PA registry shows that about 21% of the PA population is diagnosed with ASD at some point in their lives and that this number is consistent with both the PA registry and the literature.From this cohort we observed (a) that the age of diagnosis of ASD in PA obtained from the registry data is greater than the one reported in the national data, (b) that patients diagnosed with ASD often have concomitant intellectual impairment, as opposed to stroke or basal‐ganglia damage, and (c) that there was no higher prevalence of diagnoses in males over females, a difference from the known prevalence of ASD diagnoses in the general population, which tend to affect more boys than girls ratio 4:1. AlthougConsistent with de la Batie et alde la Batie et alImportantly, none of these reports found association between ASD and higher levels of 3‐hydroxypropionate (3‐OHP) in urine either. This is in contrast to the association found at early ages between higher 3‐OHP levels and intellectual disability.When we compared ASD prevalence in PA vs the general population, we found a much higher prevalence of ASD in PA  compared to the age of the patients reported in the literature. It is possible that a younger cohort with earlier diagnoses (73% of the registry has been diagnosed under 1 month of age) means that less time has passed to observe the chronic consequences of the disease. Improved dietary management may also result in less comorbid conditions in this younger population. Self‐reported bias and the relatively small number of participants in the registry can also be added as other confounding factors.It is expected that a higher participation in the registry will unmask the true prevalence of these comorbid conditions in PA.4.3The UCD International Registry provided a valuable comparative tool for the prevalence of ASD in other IEMs. Unfortunately, data from the UCD literature proved to be complex to interpret because the reports compile information from eight different UCD subtypes, each with early and late presentations, and with clear variations in neurological outcomes. It is worth mentioning that some of the outcomes reported tend to improve with treatments that diminish brain ammonia levels.4.4We have shown that the two registries utilized in this work have provided valuable information on the prevalence of ASD in a rare disease, but our work also highlights the complexity in evaluating a neurological disease like ASD in the PA population. There are limitations imposed by interobserver variation and more accurate and precise methodologies for both testing and comparing across studies are necessary.Improvements can also be made to further increase the value of the patient registries: a stronger outreach effort must be done to involve families in the process of registry participation and families need to be empowered with clearer information about their child's diagnosis which, in turn, will increase accuracy in data entry in the databases.Independently of the above caveats, the registries provide the unique capability to follow the same cohort over time as an initial and inexpensive source for longitudinal data.The authors declare that they have no conflict of interest.M.L.C. and P.S. conceived the idea, designed and supervised the project. M.L.C. and S.F. carried out all the investigation. M.L.C., P.S., and S.F. discussed the results and contributed to the final manuscript, written by M.L.C.All procedures followed were in accordance with the ethical standards of the responsible committee on human experimentation  and with the Helsinki Declaration of 1975, as revised in 2000 (5). Informed consent was obtained from all patients for being included in the study. All data were obtained in accordance with IRB‐approved protocols of the UCD/PA Registries. No animals were used for this study.All data presented in this manuscript are deidentified so no personal information about the patients was used. All patients signed an informed consent form as part of the requirement for participation in the registries.Supplemental Table S1 Neurological and developmental sequelae of PA affected patients − prevalence of autism/ASD − Number (%)Click here for additional data file.


Long‐lasting athletic training induces an overload on the heart that leads to structural, functional, and electrical adaptive changes known as the “athlete's heart.” The amount of this heart remodeling has been traditionally considered balanced between the left and the right heart chambers. However, during intense exercise, the right heart is exposed to a disproportional afterload and wall stress which over a long period of time could lead to more pronounced exercise‐induced changes. Highly trained athletes, especially those involved in endurance sport disciplines, can develop marked right ventricular (RV) remodeling that could raise the suspicion of an underlying RV pathology including arrhythmogenic cardiomyopathy (ACM). The distinction between physiological and pathological RV remodeling is essential as ACM is a common cause of sudden cardiac death in athletes, and high‐intensity exercise training has demonstrated to accelerate its phenotypic expression and worsen its prognosis. The distinction between physiological and pathological RV remodeling is essential since ACM is a common cause of sudden cardiac death in athletes, and high‐intensity exercise training has demonstrated to accelerate the phenotypic expression and worsen the prognosis. This article outlines the physiological adaptation of the RV to acute exercise, the subsequent physiological structural and functional changes induced by athletic training and provides useful tips of how to differentiate between physiological RV remodeling and a cardiomyopathy phenotype. In contrast, the systemic circulation works with moderate compliance, higher vascular resistance, and higher afterload. During exercise, both the pulmonary and systemic circulations have to accommodate the same increase in cardiac output (CO) which can be 3 to 5 times higher with high‐intensity exercise and even rise to 40 L/min in highly trained athletes.2Understanding the athlete's history is one of the strongest factors that either increases or decreases the likelihood of disease. RV remodeling in athletes should be interpreted in the context of each athlete training characteristics.Recently, a new classification of sport disciplines has been proposed, based on the relative isotonic and isometric components and subsequent cardiovascular adaptations: Skill disciplines (such as golf or horse‐riding), Power disciplines (such as weight‐lifting or short distance running), mixed disciplines , and endurance disciplines .Endurance sports disciplines, weekly training load, years of training, and male gender have been identified as predictors of greater RV remodeling.A family history of unexplained or unexpected sudden cardiac death before the age of 50, sudden infant death syndrome, drowning or near‐drowning, or unexplained car accident should raise the suspicionThe occurrence of prodromal symptoms or signs  should prompt further diagnostic investigations. Some athletes, however, display nonspecific symptoms  and are regarded as asymptomatic; high level of suspicion and deep history taking is needed.3P < .001). In addition, in specific cases, anterior TWI may also be a manifestation of the physiological electrical changes induced by the exercise stimulus as it is present in up to 7% of endurance Caucasian athletes,The ECG is one of the most important tools for the screening of athletes and for the identification of inherited cardiac conditions at risk of sudden cardiac death. A recently published international panel of experts released the new criteria for ECG interpretation in athletes. A correct definition of which ECG changes are physiological  and which are pathological  is essential for an accurate cardiovascular evaluation, preventing from false positive diagnosis, and facilitating cost savings.Voltage criteria for RV hypertrophy and incomplete RBBB are common ECG findings in athletes. Zaidi et al44.1Cardiovascular imaging should be performed after careful understanding of the athlete's characteristics. To rule out ACM in athletes, an accurate assessment of RV dimensional and functional parameters should be performed including the use of focused RV views.2 in long axis view and >21 mm/m2 in short axis view are reported as cutoff value.The athletic training promotes a global dilation of the RV cavity, with proportional increases in RV outflow (RVOT) and inflow. Up to 28% of athletes fulfill the RVOT dimensional major criteria for ACM, but the ratio RV outflow/inflow is unchanged with respect to the general population.RV systolic function in athletes does not usually differ from nonathletes.Exercise echocardiography may be considered in athletes with prominent RV dilation and borderline or reduced systolic RV function in resting conditions. During exercise, healthy athletes are expected to effectively increase stroke volume and overall RV function, reflecting a good contractile reserve.4.22 for male and ≥100 mL/m2 for females).Imaging allows an accurate and reproducible estimation of ventricular mass, volumes, and is considered the standard of reference for the evaluation of global and regional RV contractile function.In resting conditions, RV ejection fraction in highly trained athletes was shown to be slightly lower (52%) than in the general populationLate gadolinium enhancement (LGE) imaging aids in detecting myocardial inflammation and fibrosis of the LV. Currently, it is also applied for RV analysis, although its interpretation is more challenging due to the thin RV wall. Recently, three‐dimensional LGE has been applied for RV fibrosis evaluation with promising results.Table 55.1It can be extremely difficult to determine the significance of palpitations, isolated premature ventricular beats (PVBs), or non‐sustained ventricular tachycardia (NSVT) in athletes coming from RV, particularly when an extensive morphological and functional evaluation of RV was considered as normal in an athlete. The most common ventricular arrhythmias seen in athletes are PVBs.5.2When diagnosis is still uncertain, an invasive approach may be considered. However, electrophysiological testing in athletes sometimes reveals controversial results. Sustained ventricular tachyarrhythmias are rarely induced even when NSVT are present in the ECG monitoring, and thus their clinical interpretation is not clear.5.3The role of genetic testing has been gaining interest in recent decades. Although indications are the same for athletes and nonathletes, it may have additional utility in athletes by contributing to the early detection of genetic cardiac conditions that may increase the risk of experiencing life‐threatening arrhythmias and sudden cardiac death.6The following algorithm Figure  summarizClinical traits are the framework where any parameter should be acknowledged and include training load , male gender, and increasing age. ECG is considered the first supplementary exam to perform in pre‐participation screening in athletes. Second step aims to assess with echocardiographic measurements if RV dimensions exceed values expected in the athlete's population. If so (third step), functional RV parameters and the ratio LV/RV should be further evaluated. When any of these functional parameters are under normal limits and/or RV dimensions exceed the upper limits provided for the athlete's population, an underlying disease should be excluded. In inconclusive cases, further assessment (step 4) is required. Exercise ECG might help in the assessment of PVBs, exercise‐induced arrhythmias, abnormal blood pressure responses as well as in the detection of repolarization changes suggestive of ischemia or an underlying disease. An impaired RV contractile reserve, a significant decrease of RV global function and/or the presence of wall motion abnormalities (by CMR and/or exercise echocardiography) as well as positive LGE (CMR) should be considered pathological signs.


TnI and NT-proBNP were significantly increased compared to nCA . In CA patients we found an increased LDH compared to nCA (p = 0.0011). CA patients were also found to have an increased interventricular septum thickness compared to nCA (p = 0.002), a decreased Ejection Fraction % (p = 0.0018) and Doppler velocity E/e’ ratio (p = 0.0095). Moreover, CA patients had an enhanced right atrium area (p = 0.0179), right ventricle basal diameter (p = 0.0112) and wall thickness (p = 0.0471) compared to nCA, and an increased inferior cava vein diameter (p = 0.0495) as well. TAPSE was the method chosen to evaluate systolic function of the right heart. In CA subjects very poor TAPSE levels were found compared to nCA patients (p = 0.0495). Additionally, we found a significant positive correlation between TAPSE and lymphocyte count  as well as Gamma globulins , Monoclonal components  and IgG values . Conversely, a significant negative correlation with LDH , IVS  and diastolic function evaluated as E/e’  were verified. CA patients had very poor survival rates compared to controls . Mean survival of CA individuals was worse also when stratified according to NT-proBNP levels, using 2500 pg/mL as class boundary . In much the same way, a decreased right heart systolic function was correlated with a worse prognosis . Finally, our data highlight the potential prognostic and predictive value of right heart alterations characterizing amyloidosis, as a novel clinical parameter correlated to increased LDH and immunoglobulins levels. Overall, we confirm the clinical relevance of cardiac involvement suggests that right heart evaluation may be considered as a new marker for clinical risk stratification in patients with amyloidosis.Amyloidosis is due to deposition of an excessive amount of protein in many parenchymal tissues, including myocardium. The onset of cardiac Amyloidosis (CA) is an inauspicious prognostic factor, which can lead to sudden death. We retrospectively analyzed 135 patients with systemic amyloidosis, admitted to our ward between 1981 and 2019. Among them, 54 patients  presented CA at baseline. In 53 patients, it was associated with a multiorgan involvement, while in one there was a primary myocardial deposition. As a control group, we enrolled 81 patients  who did not meet the criteria for CA. In 44/54 of patients CA was associated with AL, 5/54 with AA and 3/54 of patients with ATTR, and in 1/54 AL was related to hemodialysis and in 1/54 to Gel-Amyloidosis. The most common AL type was IgG (28/44); less frequent forms were either IgA (7/44) or IgD (2/44), while seven patients had a λ free light chain form. The 32 AL with complete Ig were 31 λ-chain and just one k-chain. CA patients presented normal BP , while those with nCA had an increased proteinuria ( The term “Amyloidosis” includes a group of protein folding disorders in which there is a deposition of an insoluble protein material that Rudolph Virchow in 1854 called “amyloid substance”. Stacked protein monomers are rich in β-sheets. They form proto-filaments measuring 2 to 5 nm in diameter. These filaments bind each other through hydrogen bonds creating complex insoluble polymers .The most common form of systemic amyloidosis in western countries is derived from the light chains of Immunoglobulin (AL amyloidosis) , with an estimated incidence of 0.8 per 100,000 person/year and a prevalence of 40.5 cases per million in 2015 ,4. RarelThe second most important type of acquired amyloidosis is the AA form, a rare complication of persistent inflammatory states. AA amyloid deposits are a consequence of an increase in N-terminal proteolytic fragments serum amyloid A (SAA) protein, which is an apolipoprotein of high-density lipoproteins (HDL) acting as an acute-phase reactant. During persistent chronic inflammatory disorders, sustained deposition of SAA occurs. In western countries, rheumatoid arthritis, inflammatory bowel disease and untreated familial Mediterranean fever are some of the diseases inducing the production of this secondary misfolding protein. On the contrary, in developing countries, infectious diseases such as tuberculosis, bronchiectasis and osteomyelitis are more commonly implicated . NowadayFrom a clinical standpoint, cardiac involvement is very common in AL amyloidosis, involving up to 90% of patients during disease evolution ,8, charaSymptoms and signs are mostly non-specific, which is a further obstacle to making an early ,11 diagnOf note, the most commonly referred to symptoms of cardiac amyloidosis can be clinically associated with right heart (RH) failure, including atypical chest pain, dyspnea on exertion, fatigue, peripheral edema and palpitations.Electrocardiography shows the characteristic feature of low QRS voltage  in up toLeft ventricular (LV) performance deteriorates in step with the disease progression. Characteristic echocardiography findings of cardiac amyloid represent a continuum of diastolic dysfunction repertories that progress from an impaired relaxation through a pseudonormal pattern to a restrictive pattern, due to the increased deposition of amyloid in the myocardium. Two-dimensional trans-thoracic echocardiography (2D-TTE) is a valuable tool for structural anatomy and ventricular function assessment in the diagnosis of cardiac amyloid. Echocardiographic studies have reported abnormalities in left ventricular (LV) function ranging from mild diastolic dysfunction with minimal other echocardiographic findings in early disease to LV hypertrophy and LV systolic dysfunction in late disease . HoweverEchocardiographic evidence for a mean left ventricular wall thickness of >12 mm, in absence of other causes, and a tissue biopsy demonstrating amyloid at an alternative site might also be sufficient.Current management of Cardiac Amyloidosis (CA) other than AL remains symptomatic, based on diuretics, cardiovascular medications and anticoagulation drugs when atrial fibrillation occurs. However, CA is the most frequent heart amyloid disease and negatively impacts patients’ prognosis, being characterized by a median survival of 6 months when untreated ,14.The aim of this case-control retrospective study was to evaluate the difference between patients who presented CA with the ones who did not (nCA). Moreover, we investigated the potential role played by both CA and the CA-related RH involvement in patients’ prognosis.We retrospectively evaluated 166 consecutive patients discharged with a diagnosis of amyloidosis from our Internal Medicine unit between 1 January 1981 and 31 December 2019. We excluded patients who had no histological diagnosis, those without complete clinical records, and the ones who had neither undergone heart ultrasound nor the other necessary basic tests for diagnosis. We selected 135 patients who had detailed records of their clinical history available, at presentation and throughout follow-up.Study patients underwent a complete assessment including physical examination at the first visit. Complete blood counts, erythrocyte sedimentation rate, C-reactive protein, liver and renal function tests and serum protein electrophoresis were carried out as baseline investigations in all patients. Additional tests included typing for immunocharacterization of monoclonal components, proteinuria and Bence–Jones. Free light chain (FLC) λ and κ monitoring on serum and urine was performed in 30 patients. All patients underwent electrocardiogram and echocardiography. Other instrumental exams, such as chest x-ray, chest computed tomography, ultrasound examination of the upper and lower abdomen, radiographs of the skeleton and magnetic resonance imaging of brain and spine were performed whenever an association between Amyloidosis and systemic diseases (such as multiple myeloma or lymphoma) was suspected or if the exam was deemed clinically useful. Echocardiography results were obtained on exams recorded over the years, performing a post-processing evaluation using parameters and methods already described elsewhere .All patients provided written informed consent to take part in the study. The study protocol was approved by the Ethics Committee of the University of Bari Medical School  and conformed to the good clinical practice guidelines of the Italian Ministry of Health and the ethical guidelines of the Declaration of Helsinki, as revised and amended in 2004.Amyloidosis was diagnosed by performing biopsy on periumbelical fat (109), rectum mucosa (7), heart (2), liver (7) and kidney (10). All patients underwent ultrasound evaluation of the heart, an electrocardiogram and laboratory tests to characterize the disease.We questioned the Apulian regional patients’ database of the health care system Edotto©  to identify the date of death of patients who were lost to follow-up.Data were plotted for the type of amyloid protein, organ involvement, and associated diseases. Then heart deposition was analyzed, as detailed in the consensus symposium ,17. In pAmong all the patients, we selected the 54 who met the above-mentioned criteria for a diagnosis of CA . Patients who did not meet the criteria used to define cardiac involvement in amyloidosis were classified as non-cardiac amyloidosis (nCA) and included in the control group .p-values are shown for statistically significant differences, defined as p values < 0.05. Statistical analyses were performed using GraphPad Prism software, Version 8.0 .To analyze the distribution of dichotomous values we used the chi-squared test. Non-normally distributed data were analyzed using non-parametric statistics. The Mann–Whitney test was used for comparisons between the groups and the Spearman rank test for correlations. Normally distributed data were analyzed using parametric statistics; group comparisons were carried out using unpaired t tests. Correlation of normally distributed values was performed with the Pearson method. Survival comparison was made with the log-rank method (presented as Kaplan–Meier curves). In CA, amyloid deposition was associated with a systemic form of amyloidosis with multiorgan involvement in 53 patients, while just one had an amyloid localization only in the heart. Comparing incidence per age plotted per decade, the heart appears to be an involvement typically described in the elderly , althougp = ns)  had AL amyloidosis, while the 10 other cases included 5 AA amyloidosis, 3 ATTR, one Gel-amyloidosis and one dialysis-related Amyloidosis. CA had an increased incidence of AL compared to nCA  . In C-ALWe observed that in 8/54 patients no disease was associated to heart involvement, while 13/54 presented a hematologic disease (Multiple Myeloma or MGUS), 4/54 a solid tumor , 4/54 a connective tissue disorder , 8/54 were affected by HCV and 25/54 presented other diseases .Bone marrow plasmacytosis was 12.2 ± 8.1% in all AL-CA: in Amyloidosis secondary to Myeloma plasmacytosis it was 22.5 ± 12.3% while in the remaining patients it was 2.1 ± 1.2%.Other than heart, the organs most frequently involved were kidneys  and liver . Less frequent deposition was demonstrated in nodes or spleen (9/54 16.67%), the Peripheral Nervous System (PNS) , skin , eyes , lung  and breast .CA patients had normal blood pressure (BP): mean systolic BP was 118.0 ± 13.05 mmHg and diastolic BP was 72.92 ± 8.31 mmHg. Comparing values of CA patients to the nCA population, no significant differences were found for Hemoglobin (Hb), Mean corpuscular volume (MCV), white blood cells (WBC) while CA had a significantly decreased platelet (PLT) count . There wp = 0.0307) while no difference was found in PLR   or platelets (Platelet-to-lymphocyte ratio: PLR) has been proposed as an indicator of the systemic inflammatory response that is widely investigated in cardiovascular diseases ,19. NLR  p = ns) .In AL amyloidosis, hematological tests were performed. CD20 positive lymphocyte percentages were increased in CA patients . The monp = 0.047) and the N-terminal fragment of brain natriuretic peptide  were significantly increased in CA compared to nCA patients  abnormalities found were Atrial Fibrillation (12/54), Extrasystoles (7/54), Q waves in two or more leads (5/54) and diffused low voltages (16/54), while 14 were considered to show a normal sinus rhythm.p < 0.0001), PWd , and LVedD . Consequently, there was a significant increase in relative wall thickness .Echocardiography results were interpreted considering both heart ultrasound guidelines  and hearp = 0.015). Similarly, there was a significant increase in LVM when it was indexed for body surface area  and height elevated to 2.7 .Left ventricle mass (LVM) was dramatically increased in CA in terms of the absolute value ; left ventricle end diastolic volume (LVedVol) was decreased . As a consequence, left atrial volume (LAV) was increased in CA in both absolute values  and when indexed for body surface area  and height elevated to 2.7  (Ejection fraction (EF%) was reduced in CA  .Heart ultrasound images in CA patients revealed an inhomogeneity of the interventricular septum, that appeared as “ground glass” in 20/54 patients or “sparkling” in 28/54 patients. All Left ventricles appeared as hypertrophic. Normal contractive function was also described in 10/54 CA patients but more frequently, the heart showed global or segment hypokinesia (28/54), segmental akinesia (4/54) or dyskinesia (4/54), whereas 6/54 patients had a combination of different patterns. Three patients also showed dilated myocardiopathy with marked wall hypertrophy.p = 0.0085) while no significant difference was found in the A velocity. Diastolic dysfunction was constant in CA with an increased incidence of a severe pattern (p < 0.0001). Similarly, e’ velocity of the Tissue Doppler Imaging (TDI) analysis result dramatically decreased  with a clear increase in the E/e’ ratio Mitral Doppler analysis of blood in-flow  revealed2; p = 0.0179). Similar to this finding, there was an increase in the Right ventricle (RV) basal diameter (RVd1)  and the diameter of the inferior cava vein (IVC) at rest . We also found an increase in RV wall thickness (RVWt) in CA , resulting in a reduced total RV volume evaluated as biplane area . RV also showed a reduced systolic function. To achieve its quantification, we measured the tricuspid annular plane excursion (TAPSE). This parameter proved to be reduced in CA compared to nCA patients . Finally, the continuous-wave (CW) evaluation of tricuspid regurgitation velocity (TRV) did not reveal any difference between patients affected and not affected by CA  despite the fact that semi-quantitative evaluation of the estimated pulmonary arterial pressure (PAPs) was increased in CA   .p = 0.031), Gamma globulins , Monoclonal component  and IgG values . At the same time, this parameter showed a significant negative correlation with LDH , IVS  and diastolic function evaluated as E/e’  (p = 0.043) while no other correlation was found between ICV, PAPs, TRV and RA area and the parameters examined (p = 0.048). Cardiac biomarkers present different correlations. NT-proBNP and TnI were negatively correlated to the monoclonal component (p = 0.013).We examined the data of all 135 patients for a possible correlation between right heart parameters and immunological patterns. TAPSE indicated a significant positive correlation with lymphocyte count  . RA area= 0.003) . Only PAexamined . On the omponent  but onlyp = 0.020) and to indirect evaluation of RV pressure overload such as IVC diameter  and PAPs . LDH was showed to be negatively related to RV area . Both NT-proBNP and LDH were negatively related to TAPSE , while there was no correlation between cardiac and RA areas, TRV and RVd1  , LVM , IAS  and presented a negative correlation with EF% , while no correlation was found with E/e’. On the contrary, RWt presented no correlation with LV mass, volume and EF%, but was positively correlated with E/e’ (p = 0.049) and LV  but also with IAS thickness   .P = 0.0.075) (p < 0.0001). Similar results were obtained when stratifying CA patients according to TnI levels and using 0.10 ng/mL as class boundary . In much the same way, decreased TAPSE, an indirect expression of right heart systolic function, was correlated with worse prognosis . Moreover, patients showed a lower life expectancy with an increased inferior cava vein diameter, considering 20 mm maximum diameter as class boundary . The above findings are the only two right heart parameters that proved to be indicative of a worse prognosis (p = 0.0427) (P = ns) but this value was not significantly different  . CA indirognosis . CA surv 0.0427) . In AL-Cifferent .Cardiac involvement represents a truncal clinical event, impacting amyloidosis clinical outcome ,26. LeftAn ancillary finding, from a pathophysiologic standpoint, is the production of highly dynamic light chains that overcome the chaperon’s ability to control the misfolding while a dynamic interaction with the matrix component, shear forces and endoproteinases lead to oligomers. These molecules display toxicity, organ dysfunction and reduced survival formation ,34,35. MFinally, from an immunological perspective, immunoparesis in newly diagnosed AL amyloidosis represents a marker for response and survival along with the increased risk of infections; immunoparesis has been shown to be a response and survival marker and patients with full suppression of the uninvolved immunoglobulins are less likely to achieve an optimal response . MoreoveIn previous reports, a low plasma cell burden (median 10%) and proliferative rate characterized the amyloidogenic clone  and a diThis study has clear limitations, due to the retrospective design and the sample size. Weaknesses warrant future statistically powered studies in order to evaluate, in a proper prospective analysis, the impact on clinical outcome in terms of survival. Another consequence of the retrospective nature of this study is the outdated classification of Amyloid substance origin. In fact, although the amyloid diagnosis was histologically made, there was no possibility to have a second-look analysis of the samples taken before 1999. Regarding AL amyloidosis, the presence of a small, but dangerous, B cell clone producing misfolded free light chains  stimulatOverall, our and previous data prompt deeper basic research aiming to understanding the mechanisms of disease and heart involvement in both AL and non-AL amyloidosis, in order to efficiently identify biomarkers and imaging-based diagnostic tools that may quite likely improve disease management.


Tricuspid regurgitation (TR) is a frequent complication in various cardiovascular diseases. However, few studies have reported the prevalence of TR especially the moderate to severe or significant TR (ms-TR) maintenance dialysis patients. Thus, we aimed to identify the prevalence of ms-TR and its associated factors.n = 283) also received routine blood tests, renal function examinations, and electrolyte analysis. We first compared the differences in abovementioned parameters among groups with various TR areas (TRAs). Finally, univariate and adjusted regression were also used to identify factors that were independently associated with ms-TR.A total of 491 maintenance dialysis patients underwent echocardiographic examinations, while a subgroup  was negatively correlated with TRA. After adjusted, only Na+ , RA , and FS  were independently associated with ms-TR.The incidence of TR jets was 62.6%, which included a mildly increased TRA (47.8%), moderately increased TRA (10.4%), and severely increased TRA (3.5%). Most of the cardiac structures and functional parameters, such as the end-diastolic internal diameters of the left atrium (LA), left ventricle (LVDD), right atrium (RA), right ventricle (RV), left ventricular ejection fraction (LVEF), and fractional shortening (FS), were significantly associated with ms-TR. Among serum ions, only total CO+ FS and RA were independently associated with ms-TR, and these parameters may be potential risk factors/predictors for ms-TR.Tricuspid regurgitation occurs in maintenance hemodialysis patients with ESRD. Na End-stage renal disease (ESRD) has been demonstrated to be accompanied by various cardiovascular complications, which usually have poor outcomes . It has However, the structure and function of the right heart in ESRD patients, especially those who underwent dialysis treatment, have not been extensively studied. Tricuspid regurgitation (TR), which includes functional or mild TR, moderate TR and significant severe TR, is one of the most important functions of the right heart and is highly prevalent in various populations . HoweverMany previous studies have been studied the roles of tricuspid regurgitation in right heart failure in hemodialysis patients . Part ofn = 491) at the Nephrology of Chongqing and Kidney Center of PLA, Xinqiao Hospital, and Army Medical University  were included in this retrospective study. These hemodialysis patients underwent echocardiographic examinations, while a subgroup (n = 283) of this population also received routine blood tests, renal function examinations, and electrolyte analysis, which are shown in From March 2011 to June 2019, ESRD patients who received maintenance dialysis  and Army Medical University  approved the study.The echocardiographic examinations of each patient were carried out by a skilled echocardiographer, Dr. Rongsheng Rao, according to the American Society of Echocardiography recommendations . EchocarAmong the echocardiographic parameters, our trained physicians recorded the left atrial end-diastolic internal diameter (LA), left ventricular end-diastolic internal diameter (LVDD), right atrial end-diastolic internal diameter (RA), right ventricular end-diastolic internal diameter (RV), and pulmonary arterial end-diastolic internal diameter (PA).Additionally, the mobility and size of the left ventricular posterior wall (LVPW), the mobility and the size of the interventricular septum (IVS), fractional shortening (FS) and left ventricular ejection fraction (LVEF) and stroke volume (SV) were also recorded. Finally, TR-related parameters, such as TR area (TRA), TR velocity (TRV), and TR pressure, were also measured and recorded.After admission to the hospital, we collected venous blood samples early in the morning after patients had fasted for more than 12 h before dialysis. The blood samples have also been obtained after dialysis in order to assess the effect of dialysis.First, renal function, such as eGFR, plasma creatinine (Cr) and the blood urea nitrogen (BUN) concentration, was examined. Cr was also tested with Roche Diagnostics GmbH products . BUN was also measured with ferene methods .Then, we performed routine blood examinations. An automated hematology chemistry analyzer was used to examine the hemoglobin concentration (Hb), red blood cell (RBC) count (RBC), hematocrit (HCT), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), and red blood cell distribution width (RDW) . Furthermore, we also examined the white blood cell (WBC) and platelet (PLT) counts. The lymphocyte ratio (LYM), basophil ratio (BAS), neutrophil ratio (NEU), eosinophil ratio (EO), and monocyte ratio (MONO) were also tested and recorded.+, indirect ion selective electrode assay with EX-Z, JOKOH, Japan), serum calcium concentration , and phosphate concentration . In addition, we also measured the serum potassium concentration .Finally, we also performed an electrolyte examination, which included the sodium concentration (Na2) and the moderately to severely increased TRA group  which is also called significant TR (ms-TR in this study).First, patients were divided into the non-TR group (without a TR jet), the mildly increased TRA group (0 < TRA < 5 cm2) = 1.41 × minα × max–1.209 × 0.993age × 1.018 .We calculated the estimated glomerular filtration rate (eGFR) by using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formula: eGFR . We employed one-way ANOVA to compare differences among the non-TR, mildly increased TRA and moderately to severely increased TRA groups. Further analysis comparing two groups was performed using least significant difference (LSD) methods after one-way ANOVA.If one variable was non-normally distributed, it is presented as the median (25–75%). Comparisons among the non-TR, mildly increased TRA and moderately to severely increased TRA groups of variables with non-normal distributions were performed by one-way ANOVA after being transformed to achieve normality.p value less than 0.1 in the univariate logistic regression were included in multivariate (adjusted) logistic regression analyses to identify factors that were independently associated with moderate to severe TR. Our statistical analyses were performed by using the statistical software SPSS 22.0  for Mac.We performed univariate logistic regression analyses with each variable to screen for factors associated with moderate to severe TR. Variables with a 2. The incidence of a TR jet was 62.6%, which included a mildly increased TRA (47.8%), a moderately increased TRA (10.4%), and a severely increased TRA (3.5%). Thus, the incidence of ms-TR was 13.9%. These results are shown in In our study, 491 ESRD patients were included. The mean age was 52.95 ± 14.21 years, and the mean body-mass index (BMI) was 21.89 ± 4.89 kg/mp > 0.05) among the non-TR, mildly increased TRA and ms-TR groups.First, we did not find any differences in the demographic data . These parameters were also significantly higher in the ms-TR group than in the mildly increased TRA group . However, there were no differences in LA and LVDD between the mildly increased TRA and non-TR groups . Though there were no differences in IVS and LVPW thickness among the three subpopulations, and their mobility was significantly different among the various TRA groups. ms-TR patients had worse IVS mobility [3.00 (6.00–6.00)] and a more dispersive LVPW mobility [10.00 (7.00–10.00)] than the other two groups , p < 0.001] populations. The left heart functions, including LVEF, were significantly different among the three groups. The ms-TR group was characterized by a lower LVEF (50.28 ± 13.93%) than the other two subgroups . However, SV was similar in the three groups . In addition, PA was also significantly higher in the ms-TR group than in the other groups  and LVDD (54.11 ± 7.18 vs. 48.80 ± 5.25) were significantly higher in the ms-TR group than in the non-TR group  were significantly different among the three groups of patients , and P]. However, none of these ions were significantly different among the non-TR, mildly increased TRA and ms-TR groups , LVDD , RA , RV , and PA  were closely positively related to TRA. Meanwhile, the IVS mobility , LVPW mobility , LVEF , and FS  as well as TCO2  were negatively correlated with TRA. We did not find other associations between TRA and the rest of the parameters   were not associated with ms-TR  .p < 0.001], LVDD , RA , RV , and PA  were associated with ms-TR : 1.281, 95% confidence interval (CI): 1.166–1.408, th ms-TR .p < 0.001), LVPW mobility , FS , and LVEF  may also have been associated with ms-TR  and TCO2  were potentially related to ms-TR , RA , and FS  were independently associated with ms-TR  logistic regression. We found that only Nath ms-TR .2 and other renal functions were potentially associated with TR, adjusted regression showed that only Na+, FS, and RA were independently associated with ms-TR; thus, further cohort studies are warranted to confirm their causality.In our present study, we found that TR was prevalent (62.6%) in 491 ESRD patients who received maintenance dialysis treatment. Though TCO2; these patients needed further examination or treatment by the cardiovascular disease department. In the past, few studies had investigated the roles of TR, as well as the function and structure of the left heart, in renal function in heart failure patients  and TR jets. First, there were no significant differences in the abovementioned ions in the various TRA groups. Then, we found that TCO2 was closely negatively correlated with TRA. In the past several decades, researchers have found that TCO2 levels changed in uremia, indicating that renal dysfunction may alter TCO2 levels, resulting in changes in respiration and oxygen usage. If this situation is persistent, it may cause hypoxia-induced cardiac injury or changes in cardiac structure and function. Through further univariate regression analysis, we found that TCO2 and Na+ were potentially associated with an ms-TR jet. However, in the adjusted regression analysis, these factors were excluded by other variables and did not show independent associations with ms-TR.Ions are known to play numerous key roles in signal transduction, protein synthesis, cell proliferation and differentiation. In ESRD patients, serum ion disturbances are the most common clinical manifestations. Thus, we also investigated the associations between serum ions  (Our present study found that Nafailure) .+ was independently associated with TR which was in concordant with the previous studies that Na+ was correlated to the cardiovascular diseases in ERSD dialysis patients. This may be caused by the roles of Na+ in the vascular systems. In according to the previous studies, cardiovascular diseases are the common complications in ESRD patients especially in the maintenance dialysis subset populations  and Army Medical University . The patients/participants provided their written informed consent to participate in this study.S-ZB and YZ designed the study, drafted the manuscript, and performed the statistical analysis. S-ZB and X-HD critically reviewed and revised the manuscript for important intellectual content. RR performed the echocardiographic examinations and LZ recorded the measurements of TR-related parameters. YZ and X-HD collected the demographic data and performed routine blood examinations. YW, FP, and LZ performed the laboratory measurements. YW and WW obtained the dialysis-related data. All authors contributed to the article and approved the submitted version.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


Heart failure (HF) screening strategies require biomarkers to predict disease manifestation to aid HF surveillance and management programmes. The aim of this study was to validate a previous proteomics discovery programme that identified Tetranectin as a potential HF biomarker candidate based on expression level changes in asymptomatic patients at future risk for HF development. The initial study consisted of 132 patients, comprising of HF (n = 40), no-HF controls (n = 60), and cardiac surgery patients (n = 32). Serum samples were quantified for circulating levels of Tetranectin and a panel of circulating fibro-inflammatory markers. Cardiac tissue served as a resource to investigate the relationship between cardiac Tetranectin levels and fibrosis and inflammation within the myocardium. An independent cohort of 224 patients with or without HF was used to validate serum Tetranectin levels. Results show that circulating Tetranectin levels are significantly reduced in HF patients (p < 0.0001), and are associated with HF more closely than B-type natriuretic peptide . Serum Tetranectin negatively correlated with circulating fibrosis markers, whereas cardiac tissue Tetranectin correlated positively with fibrotic genes and protein within the myocardium. In conclusion, we report for the first time that Tetranectin is a promising HF biomarker candidate linked with fibrotic processes within the myocardium. A major component of HF disease management is diagnosis and monitoring of disease progression and there is increasing application of biomarker tools such as B-type natriuretic peptide (BNP)5. One biomarker discovery approach that we previously adopted was to examine the coronary sinus proteome of asymptomatic hypertensive patients with high and low risk of future development of HF, based on their BNP levels6. Numerous biomarkers of interest were identified in this discovery study that may be further investigated to determine their value as a single biomarker or in combination with BNP. Herein we describe a protein with limited known function called Tetranectin that was significantly reduced in coronary sinus serum of asymptomatic patients with elevated BNP. Tetranectin, gene name CLEC3B, is a calcium-binding homotrimeric protein from the C-type lectin family of proteins. It is primarily found in serum and in the extracellular matrix (ECM) during development, tissue regeneration and cancer, with low levels in normal adult tissue8. Tetranectin potentially has an important role in tissue remodelling due to its ability to bind ECM components , stimulate proteolytic activation of proteases and growth factors, and regulate ECM proteolysis. It has been suggested to have a protective function within the muscle, bone, and the circulatory system. Serum concentrations of Tetranectin decrease in pathological conditions such as cancer, inflammatory diseases, and coronary artery disease16. Tetranectin knockout (null) mice have shown to develop features consistent with Parkinson’s disease when aged, and to have impaired fracture and wound healing processes;19 however data from a cardiac phenotype in these mice is lacking.Heart failure (HF) is a major public health problem and will directly impact the lives of approximately 2% of the population, extending to up to 10% within the over 65 year old demographicTetranectin was identified in our biomarker discovery study and given previous limited literature we hypothesised that it could be associated with cardiac remodelling and HF. To investigate this, we studied Tetranectin expression in human cardiac tissue and examined serum Tetranectin levels in at-risk non-HF patients and patients with established HF.20, who are asymptomatic and have at least one cardiovascular risk factor for the future development of heart failure, as well as 40 stable HF patients from the Heart Failure Unit. To be eligible for inclusion in the STOP-HF no heart failure (no-HF) population, patients must have been deemed asymptomatic following assessment at the time of presentation by an experienced attending cardiologist and were required to have had an ejection fraction ≥50% on echocardiography. To be eligible for inclusion in the HF population, patients were required to have had a hospitalisation for proven New York Heart Association (NYHA) Class IV heart failure (confirmed by an attending cardiologist), continued symptoms of at least NYHA Class II heart failure, and left ventricular ejection fraction ≥50% with Doppler abnormalities of diastolic dysfunction but no evidence of significant valvular heart disease.This study utilised three different patient cohorts with a total population of 356. Firstly, 100 patients were recruited from the Chronic Cardiovascular Disease Management department at St Vincent’s University Hospital, Dublin. This cohort was the validation cohort. Sixty patients were included from the STOP-HF populationThe second cohort, the re-validation cohort, consisted of additional 224 patients with heart failure (n = 60) or risk factors for heart failure risk (hypertension and/or diabetes) (n = 164). This additional heart failure cohort was used for the mass spectrometry study.The third cohort consisted of 32 patients undergoing elective cardiac surgery for coronary artery by-pass grafting or valve replacement at the Cardiology Department, Blackrock Clinic, Dublin. Right atrial appendage tissue was collected from this cohort. All subjects gave written informed consent to participate in this study. The Ethics Committee at St Vincent’s University Hospital approved all study protocols which conformed to the principles of the Helsinki Declaration.Study patients underwent a full physical examination, and phlebotomy was performed by a blinded observer. Physical examination included assessment of waist circumference, body mass index (BMI) calculation, and a heart rate and blood pressure measurement. Peripheral venous blood samples were analysed for B-type natriuretic peptide . All patients had electrocardiograms (ECGs) and Doppler echocardiographic assessment. Left ventricular mass was calculated using the Devereux method and was indexed to body surface area. Left atrial volume was calculated using the biplane area length method and was also indexed to body surface area. Left ventricular filling pressures were non-invasively assessed by E/e′ with tissue Doppler measurements taken at the lateral mitral annulus.Peripheral venous blood samples were obtained at the time of clinical assessment, 24 hours before cardiac surgery. Serum samples were obtained following centrifugation at 2500 g for 10 min at 4 °C. Samples were aliquoted and stored at –80 °C until required. Each serum sample underwent no more than three freeze–thaw cycles prior to its use in enzyme-linked immunosorbent assays (ELISA), radioimmuno assays (RIA), and mass spectrometry (SRM).Full details of SRM assay are included in the supplementary methods.Pooled patient serum samples from the re-validation cohort (n = 224) were used for development of the SRM method. Samples were depleted of the 14 most abundant proteins using Multiple Affinity Removal LC (MARS) , according to the manufacturer’s instructions. Both crude and depleted samples were digested with trypsin and de-salted using C18 resin ZipTips® (Millipore) prior to SRM analysis.Skyline  and Spectrum Mill Peptide Selector  software were both used for selection of suitable proteotypic peptides with properties compatible with detection by mass spectrometry. No fewer than 2 peptides were selected for each protein. To aid in method development, synthetic crude peptides were purchased from Thermo Fisher Scientific (PEPotecTM SRM unmodified peptide in plate). Spectral libraries were generated using raw data generated from LC-MS/MS analysis of crude synthetic peptides on an Agilent 6460 Q-TOF mass spectrometer. Five transitions per peptide, with the highest MS signals in the available MS spectral libraries, were used for the initial SRM development. SRM analysis was carried out on a nanoflow reverse phase C18 chromatographic Chip Cube based separation coupled to an Agilent 6460 triple quadrupole mass spectrometer (QqQ). In order to prevent carry over between samples, ‘blank’ samples (buffer only) were loaded at the start and end of each SRM run and between each sample injection. In order to maintain reproducibility and confirm optimum instrument performance, Pierce TM Peptide Retention Time Calibration Mixture (Thermo Scientific) was used as a ‘quality control’ (QC) standard. This QC was loaded to a final concentration of 250 fmol/µl at the beginning, middle and end of each of the SRM runs in order to monitor and normalise QqQ performance between samples and over time.Data analysis was performed using both Qualitative Mass Hunter Software  and Skyline . Using this software, peak quality and signal intensity was recorded for each measured peptide as well as the quality of the overall total ion chromatogram (TIC).23. Peripheral serum Tetranectin levels in surgical patients, and in the non-HF vs. HF patient cohort were measured with a human Tetranectin/CLEC3B ELISA kit (Biorbyt).Peripheral serum levels of interleukin (IL) 6, IL8, monocyte chemotactic protein 1 (MCP1), tumor necrosis factor alpha (TNFα), high sensitivity C-reactive protein (hsCRP), matrix metalloproteinase (MMP) 2, MMP9, and tissue inhibitor of metalloproteinases 1 (TIMP1) in the atrial appendage patient cohort were analysed using the electro-chemiluminescent ultrasensitive assay kits (MSD). For each of the inflammatory markers  the assay sensitivity of was <0.7 pg/ml; for MMP2 – assay sensitivity was 120 pg/ml, for MMP9 – 99 pg/ml, and for TIMP1 – 17.8 pg/ml. Signal detection was performed with SECTOR Imager 2400 (MSD). Procollagen I C-terminal propeptide (PICP) (assay sensitivity 2.0 ng/ml) was measured using ELISA . Procollagen type I N-terminal propeptide (PINP) (assay sensitivity 13.0 ng/ml), type III procollagen peptide (PIIINP) (assay sensitivity 1.9 ng/ml), and C-telopeptide for type I collagen (CITP) (assay sensitivity 0.5 ng/ml) were measured using radioimmunoassay (Orion Diagnostica). The intra-assay variations for determining PINP, PIIINP, and CITP were 7%, <5%, and <8%, respectively. Assays were performed according to manufacturer’s protocol or as previously describedRight atrial appendage tissue was collected from 32 patients with ischemic heart disease and/or valvular heart disease undergoing coronary artery bypass surgery or valve replacement surgery (study cohort 3). Immediately after biopsy collection, samples were divided into two parts with one part used for RNA isolation and another part for histological staining.Tissues (30-35 mg) were stored in Allprotect Tissue Reagent (Qiagen), homogenised using an Ultra Turrax T25 Dispersing Instrument (IKA) with a rotor–stator mechanism, and RNA was subsequently isolated using AllPrep DNA/RNA Mini-Kit (Qiagen) according to the manufacturer’s instructions. This included a DNase treatment step to remove potentially contaminating genomic DNA. RNA (600 ng) was reverse-transcribed to cDNA using SuperScript II RT (Invitrogen) before use in a quantitative real-time polymerase chain reaction (QPCR) using Platinum SYBR Green qPCR SuperMix-UDG (Invitrogen). Amplification and detection were performed in a 40-cycle reaction  using Mx3000P according to the manufacturer’s instructions (Stratagene). This included the generation of a melt curve at the end of each QPCR run to ensure single product formation. Gene-specific primers used are listed in Table Tissues were formalin-fixed and paraffin-embedded, cut into 8 µm thick sections, and stored at 4 °C until used in histological immunostaining. Before staining, sections were deparaffinised and rehydrated using a Leica Autostainer XL, incubated in citrate buffer antigen retrieval solution , and blocked . Sections were subsequently stained for 1 h with either a rabbit anti-human monoclonal antibody against Tetranectin (Abcam), or a mouse anti-human monoclonal antibody against CD68 (Dako), or for 2 h with Picrosirius red solution (0.01% Direct red 80 and 0.01% Fast green diluted in Picric acid aqueous solution (Sigma)) for histological visualization of collagen 1 and 3 fibers, i.e. collagen deposition within the cardiac tissue. For Tetranectin staining, the Dako Real Envision detection system, Peroxidase/DAB + , rabbit/mouse (Dako) was used according to the manufacture’s instruction. For CD68 staining, a non-HRP, anti-mouse alkaline phosphatase secondary antibody (Abcam) was used. Stained sections were counterstained with Haematoxylin using Leica Autostainer XL and imaged at 40-fold magnification using Aperio ScanScope digital scanner and VisionScope V10 (Aperio Technologies). A positive pixel count algorithm was applied to analyse the area and intensity of the stain. For picrosirius red staining, sections were rinsed in water, dehydrated with increasing concentrations of alcohol using Leica Autostainer XL and imaged also at 40-fold magnification. For Tetranectin/picrosirius red and Tetranectin/CD68 double stainings, sections were first stained for Tetranectin and then counterstained with either picrosirius red or CD68 as described above.th percentiles. Categorical variables are presented as frequencies and percentages (in parenthesis). Comparisons between the low- and high-Tetranectin groups were made using independent t-test or Mann-Whitney test where appropriate. The relationships between Tetranectin, markers of collagen turnover and markers of inflammation were assessed using Pearson or Spearman correlation coefficients for variables that were normally or non-normally distributed. A p-value of less than 0.05 was considered statistically significant.For continuous variables, summary statistics are presented as the mean ± standard deviation (SD) or median and 25–756, the expression of serum Tetranectin was quantified in a validation cohort (study cohort 1), consisting of 100 patients visiting the heart failure and STOP-HF clinics: 60 no-HF patients and 40 symptomatic HF patients. Patient characteristics of study cohort 1 are described in Table To confirm previous proteomics findingsRe-validation of reduced Tetranectin levels was achieved in a second, independent cohort of 224 patients with risk factors (hypertension and/or diabetes) for heart failure n = 164) or with heart failure (n = 60) using a mass spectrometry approach, designed to target the specific Tetranectin peptide fragment LDTLAQEVALLK. Patient characteristics of the study cohort are included in Supplementary Table 64 or witArea under the receiver operating characteristic (ROC) curve (AUC) for the diagnosis of HF in the validation cohort of patients without and with HF  demonstrated a significantly higher diagnostic specificity and sensitivity of serum Tetranectin in univariate analysis (AUC = 96.6% 93.2–99.9%]) compared to the gold-standard marker BNP (AUC = 83.7% [74.8–92.6%]), p = 0.011, Fig. –99.9%) cSerum from study cohort 3  and 3 , MMP2 , MMP9 , and TIMP1  . In two cohorts totalling 324 patients with either risk factors for heart failure (hypertension and/or diabetes) or with heart failure, we demonstrate that circulating levels of Tetranectin are significantly decreased in those with HF. Serum Tetranectin demonstrated higher diagnostic specificity and sensitivity for heart failure than the gold-standard biomarker BNP. Indeed, a combination of Tetranectin with BNP achieved high performance characteristics for HF diagnosis (not further improved by controlling for age and gender). Although circulating serum Tetranectin levels correlated negatively with circulating markers of fibrosis, an opposite relationship was found within cardiac tissue of 32 patients with ischemic or valvular heart disease, where expression levels correlated positively with fibrosis and fibrotic genes.Within the literature, serum concentrations of Tetranectin have been shown to be reduced in non-cardiac pathological conditions , possibly indicating a common underlying disease process among these diseases. However, none of these studies have compared circulating vs. organ-specific tissue levels to provide a direct link of Tetranectin with a certain disease pathology. It would be of great interest to investigate this to see if a similar inverse pattern is observed in other diseases. Relevant to the biomarker potential of Tetranectin for heart failure, combining Tetranectin with other novel heart failure biomarkers may improve disease specificity in a multi-morbid condition.24. Higher plasma Tetranectin levels were inversely associated with risk of atherosclerotic cardiovascular disease16. Chen et al. previously reported lower serum Tetranectin levels in patients with coronary artery disease  compared to healthy subjects and hypothesized that atherosclerosis-related endothelial damage might lead to intimal accumulation of Tetranectin in atherosclerotic plaque complexes with Lipoprotein (a) and/or fibrin, thus diminishing serum Tetranectin levels25. Of note, they performed immuno-histochemical staining for Tetranectin in human normal internal mammary artery and atherosclerotic coronary artery and found significantly higher expression in patients with coronary artery disease compared with healthy controls. The model proposed by Weber et al. for the development of interstitial fibrosis includes pathophysiological processes such as endothelial damage  as an inciting factor, not distinct from atherosclerosis26. In this study Tetranectin was found to co-localise with areas of collagen deposition and we hypothesize that reduced Tetranectin levels in the circulation could either indicate cardiac uptake to help combat myocardial interstitial fibrosis or that perhaps reduced circulating Tetranectin might predispose to the development of heart failure. More recently, a 2018 biomarker analysis of the Framingham cohort in the US has shown that reduced circulating levels of Tetranectin (CLEC3B) are significantly associated with all‐cause mortality and with cardiovascular disease death27. In further support of a role for Tetranectin in heart disease, a small study (n = 10 per group) was published last year reporting than circulating levels are significantly reduced within three hours following an acute myocardial infarction28. All of these scenarios would point towards a cardioprotective role for Tetranectin and require further investigation.From a cardiovascular perspective, prior literature has demonstrated an anti-thrombotic role (via enhanced plasminogen activation) and an anti-proliferative role (regarding the endothelium) for platelet-released TetranectinIn conclusion, we report for the first time that Tetranectin is a promising candidate HF biomarker associated with fibrotic processes within the myocardium. Further investigations into the mechanisms and consequences for altered circulatory and cardiac tissue Tetranectin are needed. In addition, it is important to expand our novel biomarker findings into other independent heart failure cohorts across a range of geographical locations, and to compare the diagnostic and clinical value with existing heart failure biomarkers and cardiac imaging data, as well as investigate the dynamic response of Tetranectin to change in cardiac status in a longitudinal study.ex vivo model by which to assess for tissue specific associations of Tetranectin with fibrosis and inflammation. Further work would be required to examine Tetranectin in this context from ventricular tissue, however access to this material in humans is challenging.Although this is the first study to report on Tetranectin as a potential heart failure biomarker, these observations were made on a relatively small cohort, and validation studies in additional representative screening populations harbouring multiple different diagnoses, such as cardiomyopathy and acute decompensated HF (ADHF), would help confirm the cardiac specificity of Tetranectin as a prospective biomarker. BNP may also perform better in the acute HF setting. Given the data presented further research in this area would be of value. The tissue analysis conducted in this study was on human cardiac samples, however, these were derived from atrial samples from patients undergoing cardiothoracic surgery. This human cardiac tissue served as an Supplemental File.


Hypertrophic cardiomyopathy (HCM) is thought to be associated with microvascular dysfunction. Adenosine stress-perfusion cardiovascular magnetic resonance imaging (CMR) is a sensitive method for assessing microvascular perfusion abnormalities. We evaluated the prevalence and clinical characteristics of HCM patients with adenosine-induced perfusion defects on CMR.Among 189 consecutive patients with HCM who underwent adenosine-stress perfusion CMR, 115 patients who had clinical, echocardiography, 24-h Holter monitoring and treadmill exercise test data were analyzed. We calculated myocardial perfusion ratio index from the intensity-over-time curve to quantify perfusion defects. The presence and extent of the stress-induced perfusion defect were compared with clinical characteristics, presence and extent of late gadolinium enhancement (LGE), left ventricular (LV) mass index and volume, presence of non-sustained ventricular tachycardia (NSVT) and results of treadmill exercise test.P = 0.008), presence of apical aneurysm and NSVT , and LV mass index (P = 0.022) to be independently associated with adenosine stress-induced perfusion defects.The mean age of enrolled patients was 51.8 ± 11.3 years. Most patients were asymptomatic except 25 subjects presented with New York Heart Association Class II dyspnea and 16 patients with atypical non-exertional chest discomfort. LGE was present in 103 (89.6%) subjects. Adenosine stress-induced perfusion defects were present in 48 (42%) subjects. None of the perfusion defects corresponded with a single or multiple coronary artery territories, showing a multiple patchy pattern in 24 (50.0%), a concentric subendocardial pattern in 20 subjects (41.7%), and as a single blot-like defect in the remaining 4 (8.3%). A perfusion defect was associated with NSVT, LV apical aneurysm, higher LV mass index, and higher LGE volume on univariate analysis. Multivariate analysis revealed female gender (In patients with HCM, adenosine-stress perfusion defects on CMR are present in more than 40% of subjects. This perfusion defect is associated with NSVT, higher LV mass index, and apical aneurysms. The prognostic value of this finding needs further elucidation. Hypertrophic cardiomyopathy (HCM) is a primarily myocardial disease with inappropriate growth and disarray of myocardial cells as well as interstitial fibrosis . Since iCardiovascular magnetic resonance (CMR) has generated a great interest for assessing the myocardial abnormalities in HCM, especially for the presence of fibrosis in the hypertrophied myocardium with late gadolinium enhancement (LGE) in the myocardium –14. AdenOur study sought to evaluate the frequency of microvascular perfusion abnormality in HCM assessed by adenosine-stress perfusion CMR and to elucidate its relationship with clinical characteristics as well as risk factors associated with HCM.We prospectively enrolled 189 consecutive subjects diagnosed with HCM between December 2008 and November 2012 who underwent CMR with adenosine stress perfusion study that were included in the HCM registry of our cardiovascular imaging center as part of a research protocol. The diagnosis of HCM was based on the conventional guideline ; echocarClinical information including history of syncope or heart failure, and family (defined as first-degree relative) history of HCM or sudden cardiac death were collected, as well as cardiac risk factors. Twenty-four-hour ECG monitoring and symptom-limited treadmill exercise stress test were performed within a month of the CMR in subjects who were available for the tests. Results of the treadmill exercise test analyzed were; duration of exercise, adequacy of blood pressure response to exercise (defined as blood pressure increase of 20 mmHg or more), and presence of significant ST segment changes during exercise. The presence of LV outflow tract obstruction was assessed by echocardiography, with a characteristic late peaking velocity of > 3 m/sec as the definition of flow obstruction at rest or with Valsalva maneuver.3, 30 heart phases) to evaluate the LV function and myocardial mass. After the 2-chamber, 3-chamber, and 4-chamber long-axis views were obtained, short-axis stack cine-CMR images were obtained to cover the whole LV from the apex to the base with a slice thickness of 6 mm with 4 mm gaps. Stress perfusion CMR was performed with a 3-min continuous intravenous infusion of adenosine with a rate of 140 μg/kg/min. After the 3-min infusion, 0.1 mmol/kg of gadobutrol  was injected as a bolus application with a rate of 3.0 ml/sec followed by a 20 ml saline flush. Four short-axis slices were obtained with TurboFLASH sequence without breath-hold for 1 min and the adenosine infusion was terminated subsequently. Fifteen minutes after termination of the adenosine infusion, an identical perfusion sequence was applied at rest. LGE images were obtained 10 min after the second contrast injection using a 2-dimensional TurboFLASH phase-sensitive inversion-recovery sequence  in short-and long-axis planes.CMR was performed using a 1.5 T CMR system  with a standardized CMR protocol with subjects in the supine position using a 32-element-phased-array cardiac coil. In detail, breath-held cine-CMR images of the whole heart were obtained with a ECG-gated balanced steady-state free precession sequence  by manually tracing the endocardial and epicardial contours in the short-axis stacks of end-diastolic and end-systolic images. For perfusion analysis, stress and rest perfusion scans were magnified and displayed and read simultaneously. The presence of perfusion defect was defined by regional hypoenhancements that persist for more than 10 frames after maximal myocardial enhancement . PerfusiStructural stenosis of the epicardial coronary arteries were evaluated in a proportion among the subjects in the stress CMR positive groups who agreed to receive the tests. Invasive coronary angiography was performed in 3 and coronary computed tomography angiography was performed in 21 subjects. All of the studies revealed normal or unremarkable findings of less than 10% diameter epicardial coronary artery stenosis.P value of less than 0.05 was considered significant.The subjects were divided into two groups: stress CMR positive and negative. All analyses were performed with PASW statistics 18 . The inter-observer agreement analysis between the original two readers was performed by obtaining the intraclass correlation coefficient  by reliability analysis. Chi-square association analysis was performed for evaluation of association of the stress-induced perfusion defects and the collected clinical information, type of HCM, the presence of LGE, and presence of apical aneurysm. Association between the stress-induced perfusion defect and LV volume, LV ejection fraction (LVEF), LV mass index, LGE volume, and LGE percentage was evaluated by the Mann-Whitney analysis. Multivariate analysis was performed with binary logistic regression analysis for evaluation of independent association of factors. Data are represented in frequency or mean ± standard deviation, and a After exclusion of subjects according to the exclusion criteria, a total of 115 subjects were included in our analysis. Their mean age was 51.8 ± 11.3 years and male was predominant (83.5%). A history of diabetes was present in 4 (3.5%), current smoking in 30 (26.1%), and 28 (24.3%) were ex-smokers (defined as abstinence from smoking for at least 1 year). Twenty-five subjects presented with NYHA Class II dyspnea (21.7%), 16 presented with atypical non-exertional chest discomfort (13.9%), and the remaining were asymptomatic. History of syncope was present in 9 (7.8%), and family history of HCM and sudden cardiac death was present in 8 (7.0%) and 13 (11.3%), respectively.Non-sustained ventricular tachycardia (NSVT) was detected in 11 (10.7%) of the 103 subjects who received 24-h ECG monitoring. Treadmill exercise stress test was performed in 102 subjects, and the mean duration of exercise was 9.4 ± 2.3 min. Inadequate blood pressure response to exercise was detected in 24 subjects (23.5%).HCM was of septal type in 40 (34.8%), septal/apical type in 32 (27.8%), apical type in 28 (24.3%), concentric type in 13 (11.3%), and others in 2 (1.7%). LV outflow obstruction with systolic anterior motion of the mitral valve on echocardiography was present in 31 (27.0%) subjects.2, respectively. LGE was present in 103 (89.6%) subjects, and mean LGE volume and percentage were 20.0 ± 20.5 ml and 11.6 ± 8.9%, respectively. An apical aneurysm was found in 13 (11.3%) subjects.None of the patients had an abnormal blood pressure response to adenosine Table . None exp = 0.046). However, when the stress-negative group was divided into two groups (no perfusion defect group and perfusion-defect-corresponding-to-LGE-site group), significant differences were found between the no perfusion defect group and the perfusion-defect-corresponding-to-LGE-site group , and also between the stress-positive group and the no perfusion defect group (p = 0.001). There was no significant difference in MPRI between the stress-positive group and the perfusion-defect-corresponding-to-LGE-site group.Visually assessed stress-induced perfusion defects were present in 48 41.7%) patients. None of the defects corresponded with a single or multiple coronary artery territories, showing a multiple patchy pattern in 24 (50.0%), a concentric subendocardial pattern in 20 subjects (41.7%), and as a single blot-like defect in the remaining 4 8.3%) , but exercise duration on treadmill test or the frequency of abnormal blood pressure response to exercise were not different between the two groups . The presence or absence of LGE was not significantly different between the two groups, with 45 subjects (93.8%) in the stress-positive group and 58 (86.6%) subjects in the stress-negative group showing LGE. However, the presence of stress-induced perfusion defects was significantly associated with higher LGE volume and also with LGE volume percentage . Apical aneurysm on CMR .Data from CMR are summarized in Table p = 0.008), presence of apical aneurysm , NSVT on 24-h ECG , and higher LV mass index  to be independently associated with presence of stress-induced perfusion defects  of the study subjects that showed perfusion defects on stress CMR received invasive coronary angiography or coronary computed tomography angiography within 3 months of the CMR, although all of them showed normal or insignificant results. Hence, the co-existence of epicardial coronary artery disease cannot be completely excluded. However, the stress-induced perfusion defects did not correspond to a coronary artery territory, and subjects who showed significant ECG changes on the symptom-limited treadmill exercise ECG tests performed in about 90% of the subjects were all excluded. Furthermore, coronary artery disease cannot account for the perfusion defect rate of 40% in Korean patients with a mean age of 50. Secondly, 24-h ECG monitoring and treadmill exercise ECG were performed in most, but not in all subjects. However, subjects who did not undergo these tests were very few, and the proportion of the subjects who did not receive the test was similar between the stress-positive and negative groups, this limitation may not be critical to our analysis. Lastly, parametric mapping data could not be analyzed as the CMR in our study was performed before parametric mapping was incorporated into wide clinical use. Future studies using native T1 mapping and extracellular volume may be warranted to obtain additional information on the association between myocardial ischemia and LGE.Adenosine-stress-induced perfusion defects on CMR are frequently found in subjects with HCM. The finding is associated with increased LV mass index, presence of apical aneurysm, and inadequate hemodynamic response to exercise. The clinical significance and prognostic value of the finding need further elucidation.