A subclinical left ventricular systolic dysfunction was evidenced by two-dimensional speckle tracking technique before and after liver transplantation, even when compared to normal values of the last pediatric meta-analysis.To evaluate the ventricular function of patients with biliary atresia (BA) before and after liver transplantation using two-dimensional speckle tracking. Observational, analytical study with healthy control group, volunteers. We recruited patients from 0 to 18 years old who were candidates for liver transplantation and patients after six months of liver transplantation performed for BA from January 1997 to August 2015 at Children’s Institute of São Paulo University Medical School. The patients were submitted to a complete conventional echocardiographic study. After that, the images were captured for global longitudinal strain (GLS). A blood sample was collected for brain natriuretic peptide (BNP) level. Ejection fraction obtained by Simpson’s method was significantly higher in the hepatic pre-transplantation group (p < 0.001), as well as left atrial size (p < 0.001) and left ventricle size (p = 0.039). The left ventricular mass index was significantly higher in pre-transplantation group (p < 0.001). The left atrium volume (p = 0.008) and the left ventricular mass index (p t = 0.035) were higher in the post-transplant group. It was observed that the lower the BNP, the lower/more negative the GLS in the post-transplant group (p = 0.038 and r = 0.427). Significant reduction in the overall longitudinal  Currently, BA is the most frequent indication for liver transplantation in most pediatric centers.Biliary atresia (BA) is an obstructive cholangiopathy and the main cause of neonatal cholestasis. It progresses fast to secondary biliary cirrhosis, leading to death in the first two years of life when untreated1 A working group meeting at the World Congress of Gastroenterology in 2005, elaborated a proposal for the definition of cirrhotic myocardiopathy and described a serie of abnormalities to the resting Doppler echocardiogram in adults: E/A ratio < 1,: E-wave deceleration time > 200 ms, isovolumetric relaxation time > 80 ms, left atrial volume increase, decreased left ventricular contractility, hypokinesis and / or wall akinesia, increased myocardial mass, lower ejection fraction (< 55%), increased brain natriuretic peptide and troponin levels2. The diagnostic criteria for children are not well established or validated.Cirrhotic cardiomyopathy, initially described in 1989, is defined by the following criteria: normal or increased systolic left ventricular contractility at rest; attenuated systolic contraction or diastolic relaxation in the presence of pharmacological, physiological or surgical stress, cardiac electrical abnormalities and myocardial hypertrophy.4. The main objective of this study is to evaluate the ventricular function of patients with biliary atresia before and after pediatric liver transplantation using new echocardiographic techniques such as two-dimensional speckle tracking. The deformation analysis by speckle tracking is based on the tracking of natural acoustic markers present in the two-dimensional gray scale image. The speckles function as a “fingerprint” of that determined myocardial segment and it is possible to calculate the deformation and the speed with which the deformation occurs from the displacement of these markers.According to current recommendations, echocardiography is the first-line imaging method in the evaluation of patients with suspected cirrhotic cardiomyopathy, providing structural and functional information. However, many patients may have preserved resting systolic function assessed by conventional techniques. New echocardiographic methods may overcome some of these limitations, allowing a quantitative analysis of the myocardial deformationThis is an observational, analytical, cross-sectional study with a control group, which included patients from zero to eighteen years old who were candidates for liver transplantation due to BA with severe cirrhosis, patients from zero to eighteen years admitted to liver transplantation due to BA from 1989 to 2015 at Children’s Institute of University of São Paulo Medical School and healthy volunteers controls of primary care units paired by sex and age. From July 2016 to May 2018, 120 patients were included. The selected children were divided into four groups, each one with 30 participants: patients who were candidates for liver transplantation, healthy controls in the pre-transplant group, patients post-liver transplantation who had any of the following altered parameters on hepatic pre-transplant echocardiography: dilated cardiac chambers, ventricular hypertrophy, systolic dysfunction, diastolic alteration; and healthy controls in the post-transplant group. Of the thirty patients who were candidates for liver transplantation, ten patients underwent a Kasai portoenterostomy surgery, with surgery performed at an average of 60 days of life, all with jaundice clearance failure.The diagnosis of cirrhosis was established by a combination of biochemical, clinical, liver biopsy, and ultrasonographic findings. Patients with congenital and other acquired heart diseases such as structural heart diseases, pericardial effusion, arrhythmia, systemic arterial hypertension, other systemic conditions that could affect cardiac function, hepatic retransplantation, hospitalization in the last month prior to the examination and inadequate echocardiographic image were excluded from the study. Informed consent was obtained from all included patients and controls. The study was approved by the Research Ethics Committee of the Faculty of Medicine of University of São Paulo Medical School. All experiments were performed in accordance with relevant guidelines and regulations.5, as well as anthropometric evaluation .The patients were interviewed based on a structured questionnaire containing the date of birth, sex, age at the time of the liver transplantation, PELD (Pediatric End-Stage Liver Disease), current medications, comorbidities such as renal failure and traditional risks for cardiovascular disease such as: positive family history, presence of hypertension, diabetes, obesity, arrhythmias. A detailed cardiovascular physical examination including heart rate measurement and noninvasive blood pressure was performed by means of an oscillometric method after five minutes of rest according to the norms of the 4th Consensus on the diagnosis, evaluation and treatment of hypertension in children and adolescents7. The equipment used was a Vivid E9 GE Vingmed Ultrasound AS, with multifrequency transducers (with frequencies of 4.5–1.5 MHz and 8–2.7 MHz). Cardiac chamber dimensions were obtained using two-dimensional mode, and left ventricle ejection fraction (LV EF) was calculated by Simpson’s method. LV mass (g) was estimated using Devereaux’s formula according to the Penn convention and indexed for height (m) raised to an exponential power of 2.79. Evaluation of LV diastolic function included conventional as well as tissue Doppler-based measurements: mitral E and A velocities, E/A ratio, deceleration time (DT), E/E’ ratio, with E’ being the average of values obtained by tissue Doppler at the septal and lateral annulus. Left atrial volume was estimated using the biplane area-length method (Simpson´s method), and values were indexed to the BSA.Standard transthoracic echocardiography was performed according to the recommendations of the American Society of Echocardiography and included M-mode, two-dimensional imaging, conventional, and tissue Doppler evaluation at the septal, lateral mitral annulus and lateral tricuspid annulus6.The isovolumic relaxation time (IVRT) was measured for both LV and RV lateral walls. Calculation of global myocardial performance index (MPI index) was performed according to the recommendations of the American Society of EchocardiographyFor strain assessment, two-dimensional grey-scale images were acquired in the apical four, three and two-chamber views, with a frame rate of 60–80 fps. In the same way the acquisition of the images in the parasternal window was performed, transverse short axis of the left ventricle in its 03 main cuts: basal, middle and apical. The time "systolic event" was determined by marking the opening and closing moments of the aortic valve. Three cardiac cycles were digitally stored and analyzed using the EchoPAC program BT10 (GE Vingmed Ultrasound AS)  test.The software used for the calculations was SPSS 17.0 for windows. The level of significance used for the tests was 5%. For the quantitative variables, this analysis was done by observing the minimum and maximum values, and the calculation of means, standard deviations and median. Absolute and relative frequencies were calculated for the qualitative variables.For the comparison of means of two groups, Student's t-test was used. In order to test the homogeneity between the proportions, the chi-square test was used. Correlation between variables was assessed using the Pearson correlation coefficient.The study was approved by the Institutional Ethical Committee.Informed consent was obtained from legal guardians.Patients in the pre-transplant group and in the control group had similar ages . There were seventeen female patients in the pre-transplant group (56.7%) and seventeen in the control group .Patients from the post-transplant group and from respective control group had similar ages . There were sixteen (53.3%) female patients in each group   than controls, although it was not below the expected values for normal children. The thickness of the interventricular septum was significantly higher  as well as the posterior wall thickness , the left ventricle diastolic diameter , the systolic diameter of the left ventricle  and the right ventricle diastolic diameter (14.70 ± 1.97 vs. 13.08 ± 1.98)  were significantly higher in the liver pre-transplant group than controls. In fact, 20 (66.6%) of the 30 pre-transplant patients had Z Score >  + 2.0 when the diameter of the left atrium was analyzed.Both the two-dimensional left atrial diameter  and the left atrium volume , possibly secondary to of increase the thickness of the septum and the posterior wall. Thus, 20 (66.6%) of the 30 patients had ventricular mass index > 95th percentile for age and sex.The left ventricular mass was higher in the hepatic pre-transplant group than in the control group , as well as the relative wall thickness (0.39 ± 0.10 vs. 0.30 ± 0.05). When the left ventricular mass index was evaluated, it remained significantly higher in the pre-transplantation group   and the pulmonary VTI  were significantly different between the hepatic pre-transplant group and the control group. Pulmonary artery systolic pressure (PASP), estimated through tricuspid reflux, although still within normal values, was higher in pre-liver transplant patients . In the pulsed Doppler of the mitral valve, there was a difference in the peak of the A wave velocity (80.57 ± 21.59 vs. 71.10 ± 13.77) and the E wave deceleration time   of the left ventricular free wall , final diastolic velocity (a wave)  and in IVRT , between groups pre-transplant and controls , according to the fraction by Teichholz’s method  and with shortening fraction  comparing to control group  were higher in the post-transplant group compared to controls. In this group also, 07 (23.3%) of the 30 patients after hepatic transplantation presented Z Score >  + 2.0 of the left atrium diameter. The difference of the diameter of the interventricular septum  and the posterior wall  between the two groups was also statistically significant higher.The left atrial diameter  as well as left atrium volume . Therefore, 7 (23.3%) of the 30 patients presented ventricular mass index > 95th percentile for age and sex. Relative wall thickness was significantly higher in the post-transplant group (0.34 ± 0.08 vs. 0.27 ± 0.04).In the post-transplant group only PSAP was higher than the controls  . Therefore, the lower the BNP value, the lower the GLS value (more negative)  for interobserver variability. Regarding intraobserver variability, the intraclass correlation of the LV global longitudinal strain was 0.93 . The intraclass correlations of the RV longitudinal strain were 0.90  and 0.92  for inter variability and intraobserver, respectively.This study is the first to identify left ventricular and right ventricular subclinical dysfunction through two-dimensional speckle tracking in pediatric patients with severe cirrhosis due to BA, listed for liver transplantation. In this group, there were no major cardiac complications in the postoperative period despite left ventricular subclinical dysfunction. It was also possible to evaluate another group of patients, already after liver transplantation, who had also left ventricular subclinical systolic dysfunction, too.The median age of transplantation was 12.5 months. The inclusion of very young patients in the pre-liver transplant group (< five years) made the results even more impactful, making it possible to infer that even patients with a short time of cirrhosis may already have myocardial involvement, even if it is subclinical. The fact that the patients from this study were not hospitalized, and did not present clinical decompensation in the last 30 days of the study, resulted in lower PELD. However, even these patients had a lower global longitudinal strain compared to healthy controls. This raises the hypothesis that a longer exposure to a hyperdynamic circulatory stage could make this systolic dysfunction be diagnosed in the usual methods, which do not have the same sensitivity as the strain.In this study, changes in the longitudinal, circumferential and radial strain were verified pre-liver transplantation, as well as changes in the longitudinal and radial strain post-liver transplantation. It is interesting to note that even post-liver transplantation, the values of the longitudinal strain from the right and left ventricles are lower than in control patients.10, we observed that 33.3% of the patients had values below expected before liver transplantation and 36.3% post-liver transplantation. There are no cohort studies with these patients demonstrating whether these persistently reduced strain values could be related as a risk factor for cardiovascular morbidity and mortality in adults or the time after liver transplantation could cause changes in these parameters, which may affect survival in the future.When comparing the results of the global longitudinal strain obtained in the study with the values suggested by the most recent pediatric meta-analysis and systematic review on the subject12. Grose et al. showed that final systolic and diastolic volumes increased in cirrhosis and attributed this fact to the decrease in cardiac contractility13.As previously described in others studies in pediatric populations with hepatic cirrhosis, conventional echocardiography showed an increase in ventricular mass index as the main structural alteration, associated with dilation of the left chambers, probably due to the hyperdynamic circulation state of these patients and difficulty in ventricular filling14.In 2011, Desai et al. reported cardiac structural and functional alterations in infants and children with biliary atresia, listed for liver transplantation. In Desai’s report, two-dimensional echocardiography of infants with biliary atresia, listed for liver transplantation, were reviewed and compared with age and sex-matched infants without cardiac or liver disease as controls. Compared to controls, children with BA of this study had significant increases in multiple parameters, notably left ventricle wall thickness and left ventricle mass indexed, similar to the findings of our study15. Our data are in compliance with this study, which has found alterations in conventional echocardiography in 66.6% of the pre-liver transplant patients. There was a significant increase in the diastolic diameter of the right ventricle, also cited in other studies, especially in decompensated patients, what can be attributed to prolonged volume overload.Studies report this change in up to 70% of pre-liver transplant patients9. This data is important because can be used in the stratification of cardiovascular risk and may change treatment decisions16.The LV indexed mass value was higher in patients before liver transplantation. A more recent study has chosen to calculate the LV mass through high height to 2.7 because this calculation approaches more to the lean body mass17.In the post-liver transplantation group, there was also a significant increase in the volume of the left atrium, out dilation of the left ventricle. Additionally, an increase in the ventricular mass index was also observed in these patients. Although it has been reported in studies that there is a reduction in the size of the left heart chambers and a reduction in left ventricular mass after transplantation, in our sample there was still a significant difference when compared to normal controls, despite of the values were still within normal limitsAlthough no patient in the study had left ventricular systolic dysfunction, the ejection fraction value by Simpson´s method was significantly lower in pre-liver transplant patients than in controls, even though these values were still within the normal range. This fact was not verified when analyzed the systolic function by Teichholz´s method, which method has the disadvantage of undergoing changes with ventricular geometry. Even in patients after hepatic transplantation, this alteration was maintained with statistical significancy, without an apparent clinical significance. It is speculated that perhaps this dysfunction could become clinically visible if subjected to pharmacological or physical stress tests. The systolic function is generally preserved until a very late course, so it should not be considered for the early diagnosis of cirrhotic cardiomyopathy. Our patients may have had better cardiac reserves, being able to mask the manifestations of cirrhotic cardiomyopathy more than in adults, especially those with cardiovascular risk factors.18. In patients after liver transplantation, a lower e '/ a' ratio was found in the septum and in the LV lateral wall, lower e’ septal velocity and higher a' wave velocity in the left ventricular lateral wall. This finding was described in a previous study in patients with cirrhosis due to chronic hepatitis B19.The LV peak systolic velocity measured by TDI was not reduced in pre-liver transplant patients, however there was a higher velocity of the S’ wave in the left ventricular lateral wall, and these factors can be attributed to the hyperdynamic state that accompanies cirrhosis. The left IVRT was significantly more prolonged in pre-liver transplant patients than in controls, as well as the increase in the a' wave velocity, which may suggest a loss of left ventricular diastolic function in this subclinical stage. The underlying mechanism of diastolic dysfunction in cirrhosis is probably due to the increase in myocardial wall stiffness caused by myocardial hypertrophy, fibrosis and subendothelial edema, and subsequently resulting in high left ventricular and atrial filling pressures20.The present study demonstrated a significant increase in aortic and pulmonary VTI in the hepatic pre-transplant group, probably due to the hyperdynamic circulation presented by these patients, with no statistical significance in the post-transplant group. Likewise, pulmonary artery systolic pressure, estimated through tricuspid reflux, even within normal range, was shown to be significantly increased in the pre and post-transplant groups. Pulmonary hypertension has recently been shown to develop in a substantial proportion of patients with cirrhosis. The mechanism of increased pulmonary artery pressure is not fully understood, but previous studies have suggested an increase in the levels of vasoactive substances in the pulmonary circulation and the likely toxic effect of these substances on endothelial cells. Some authors have suggested that microthrombi can migrate to the pulmonary vascular bed along portosystemic shunts and can cause an increase in vascular resistance20.Pulmonary artery systolic pressure on transthoracic echocardiography may be elevated for many reasons other than portopulmonary hypertension, including venous pulmonary hypertension secondary to left ventricular dysfunction, volume overload, or increased cardiac output17. Other researchers reported an association between the level of BNP and pro BNP with the severity of the liver disease, or with the thickness of the posterior wall and the interventricular septum, including changes in tissue Doppler22.The study of cardiac function was complemented in patients pre and post-liver transplantation using biomarkers such as BNP, who had normal values for age in all patients in this study, probably because the patients were not decompensated at the time of the examination. BNP is an excellent marker of myocardial damage and atrial distension, and although left atrial dilation was present in 66.6% of pre-liver transplant patients, the value of this marker remained within normal limits. However, in the correlation analysis, there was a significant difference, with higher BNP values associated with lower longitudinal strain values (less negative) in the group after liver transplantation. This fact indicates the need of further studies to correlate BNP with clinical cardiac alterations in these patients, maybe serving as a routine biomarker in the future. Some studies have shown that BNP was significantly higher in cirrhotic patients than in controlsProspective studies will be needed to establish whether subclinical left ventricular and right ventricular dysfunction detected through two-dimensional speckle tracking in cirrhosis due to BA will predict adverse cardiovascular events in the future. In addition, the inclusion of two-dimensional speckle tracking in the routine echocardiographic evaluation of patients listed for liver transplantation may help to determine if any early therapeutic intervention could modify the cardiovascular prognosis.As a limitation of the present research, this was a relatively small observational study and conducted in a single call center, which may hinder the generalization of our conclusions for larger populations. In addition, patients evaluated before liver transplantation are not part of the same cohort as patients post-liver transplantation, which makes it difficult to infer whether the changes found in the post-transplantation would be due to changes already established before the transplant or acquired (cumulative effect) during treatment.The present study demonstrated the presence of a significant reduction in the values of the global longitudinal strain of the left and right ventricles in the group before and after liver transplantation. It also demonstrated a reduction in the radial and circumferential strain in the pre-transplant group and a reduction in the radial strain in the post-liver transplant, through the assessment of myocardial deformation using the two-dimensional speckle tracking technique. Lower BNP levels were associated with lower longitudinal strain values in the group after liver transplantation.


The progressive risk of graft failure in pediatric heart transplantation (PHT) necessitates close surveillance for rejection and coronary allograft vasculopathy (CAV). The current gold standard of surveillance via invasive coronary angiography is costly, imperfect and associated with complications. Our goal was to assess the safety and feasibility of a comprehensive multi-parametric CMR protocol with regadenoson stress perfusion in PHT and evaluate for associations with clinical history of rejection and CAV.We performed a retrospective review of 26 PHT recipients who underwent stress CMR with tissue characterization and compared with 18 age-matched healthy controls. CMR protocol included myocardial T2, T1 and extracellular volume (ECV) mapping, late gadolinium enhancement (LGE), qualitative and semi-quantitative stress perfusion  and strain imaging. Clinical, demographics, rejection score and CAV history were recorded and correlated with CMR parameters.Mean age at transplant was 9.3 ± 5.5 years and median duration since transplant was 5.1 years (IQR 7.5 years). One patient had active rejection at the time of CMR, 11/26 (42%) had CAV 1 and 1/26 (4%) had CAV 2. Biventricular volumes were smaller and cardiac output higher in PHT vs. healthy controls. Global T1  and ECV  were higher in PHT compared to helathy controls. Significant relationships between changes in myocardial tissue structure and function were noted in PHT: increased T2 correlated with reduced LVEF , reduced global circumferential strain  and reduced global longitudinal strain . In addition, significant relationships were noted between higher rejection score and global T1 , T2  and ECV . The presence of even low-grade CAV was associated with higher global T1, global ECV and maximum segmental T2. No major side effects were noted with stress testing. MPRI was analyzed with good interobserver reliability and was lower in PHT compared to healthy controls .In a PHT population with low incidence of rejection or high-grade CAV, CMR demonstrates important differences in myocardial structure, function and perfusion compared to age-matched healthy controls. Regadenoson stress perfusion CMR could be safely and reliably performed. Increasing T2 values were associated with worsening left ventricular function and increasing T1/ECV values were associated with rejection history and low-grade CAV. These findings warrant larger prospective studies to further define the role of CMR in PHT graft surveillance. Pediatric heart transplantation (PHT) is the definitive treatment for end-stage heart disease associated with various pediatric and congenital cardiac diagnoses. Although improving over time, the long-term outcome from the most recent analysis of the International Society for Heart and Lung Transplantation’s (ISHLT) registry shows that overall survival 25 years post-PHT is 37%  with graEndomyocardial biopsy and invasive coronary angiography remain the gold standard for detection of acute rejection and CAV, respectively, but are invasive procedures with imperfect disease detection and several potential complications that multiply over repeated exposures, especially in younger patients –9. SurveCardiovascular magnetic resonance imaging (CMR) has emerged as a tool for comprehensive assessment of myocardial structure and function. Compared to echocardiography, CMR more accurately represents ventricular volumes and function . SimilarIn this study, we aimed to (1) describe the safety and feasibility of performing vasodilator stress regadenoson CMR in the PHT population (2) characterize myocardial tissue, function and perfusion in a cohort of PHT and compare with healthy controls and (3) explore associations of CMR parameters with history of rejection or CAV.We conducted a single-center retrospective cross-sectional case–control study that was IRB approved and HIPAA compliant. Informed consent was waived. PHT recipients who underwent a clinically ordered comprehensive stress perfusion structure–function CMR between May 2016 and January 2019 were identified. Eighteen historical institutional controls who had a normal structure–function CMR (without stress perfusion) for various indications including abnormal electrocardiogram (ECG) (n = 9), chest pain (n = 2), syncope (n = 2), family history of cardiomyopathy (n = 1), obesity (n = 1), suspected atrial mass (n = 1) and other systemic diseases (n = 2) were age and sex-matched to the PHT. Since there were no institutional healthy control patients who had undergone stress perfusion imaging, we identified a separate cohort of 16 non-transplant patients who underwent stress perfusion CMR with negative results performed for various indications where suspicion for microvascular dysfunction was minimal. Indications for CMR in this cohort were: post-coronary artery unroofing with chest pain (n = 4), single coronary artery (n = 2), history of arterial switch procedure (n = 1), failing Fontan (n = 1), remote history of Kawasaki disease with normal coronaries (n = 6), congenital coronary artery aneurysm (n = 1) and aortic stenosis with syncope (n = 1).Demographic and clinical data collection included transplant surgical history, number of rejection episodes and history of CAV per clinical history or cardiac catheterization report. A Rejection Score (RS) was devised to quantify the clinical rejection history by adding the total number of rejection episodes  based on endomyocardial biopsy (EMB) as per ISHLT criteria  or any eCMR was performed on a 1.5 T scanner . A comprehensive protocol including structure and function assessment and stress perfusion testing was followed . T2 mapping was performed prior to contrast injection. Three T2-prepared bSSFP images with varying T2-prep times  were acquired in a breath-held fashion in three short axis orientations  through the LV . These levels were pre-selected by the technologist at the time of the scan: basal level defined at the mitral valve leaflet tips, apical level near the apex where the ventricular cavity was still visible at end-systole and mid ventricular level mid-way between those. Next, T1 mapping with a modified Look-Locker inversion recovery (MOLLI) sequence was used to measure native (pre-contrast) longitudinal relaxation T1 times of myocardium at the same three levels as well as within the blood pool. Pre-contrast T1 maps were obtained using a single-breath-hold, ECG-triggered, MOLLI sequence . Myocardial stress perfusion was then performed using regadenoson at a dose of 6–10 mcg/kg (up to a maximum dose of 400 mcg) [2). Following image acquisition, a single dose of 75 mg of intravenous aminophylline was given to reverse the effects of regadenoson. Between stress and rest perfusion, ECG-gated 2-D Cine bSSFP imaging of the ventricles in short-axis from base to apex was obtained. Contrast-enhanced first pass perfusion imaging at rest was obtained following a second 0.05 mmol/kg dose of gadobutrol. Finally, a third dose of 0.05 mmol/kg dose of gadobutrol was injected with post-contrast T1 mapping. LGE was then obtained using segmented inversion-recovery sequences in three orientations: 4-chamber, 2-chamber and short axis from base to apex  around 20–30 min from the time of the initial contrast injection. For LGE sequences, the inversion time was selected using an inversion time scout scan to optimally null the normal myocardium.Following image localizer scans, 2D cine balanced steady-state free-precession (bSSFP) images in the two-chamber, three-chamber and four-chamber planes were obtained in standard clinical fashion   with cloPatients were advised to refrain from the use of caffeine containing products for 24 h prior to the study. A baseline ECG was obtained prior to start of the exam. Heart rate and blood pressure were recorded at the start of the CMR and monitored during the test. A pediatric cardiologist, pediatric radiologist, a technologist and a nurse were present during induction of stress. Following administration of regadenoson, vitals were recorded every minute for 5 min, every 5 min for the next 20 min and then every 10–15 min until an hour from the time of stress.Adverse events were documented and classified as major or minor. Major adverse events would result in need for termination of the study, and included arrhythmia, hypotension, atrioventricular block and bronchoconstriction. Minor adverse events would not typically result in termination of the test and included anxiety, chest pain, tingling in the limbs and gastrointestinal effects such as nausea and abdominal pain. Patients were monitored for an hour after the completion of the study prior to discharge.Volumetric and functional data analysis from the 2D cine bSSFP short-axis stack was performed using dedicated software  by manual segmentation of the epicardial and endocardial borders. LV and right ventricular (RV) volumes, ejection fraction and cardiac output and LV mass were calculated.Endocardial and epicardial contours were traced on each T2 map excluding blood, epicardial fat or artifact. Images were motion corrected. An automated pixel-wise fit was used to generate a color map and analysis was done by drawing overlying regions of interest by dividing the myocardium into 16 segments as standardized by the American Heart Association (AHA) . SegmentEndocardial and epicardial contours were traced on each pre- and post-contrast T1 map to exclude blood, epicardial fat or artifact. Images were motion corrected. Similar to T2 mapping, color maps were generated, and analysis was done by drawing overlying regions of interest by dividing the myocardium into 16 segments as standardized by AHA. Extracellular volume fractio (ECV) was calculated for all 16 segments using the pre- and post-contrast maps and hematocrit using standard methodology . SegmentFor LGE analysis, we identified the presence or absence of focal myocardial fibrosis based on visual assessment as areas of relatively increased signal intensity following administration of gadolinium contrast. Myocardial fibrosis was noted only if LGE was seen in two orthogonal planes. LGE distribution patterns were classified as subepicardial, mid-myocardial, subendocardial or transmural and by AHA segment involved. This was confirmed by two experienced CMR readers at the time of the study interpretation.Qualitative myocardial perfusion was assessed by two experienced CMR readers, one pediatric cardiologist and one pediatric radiologist, at the time of the clinical study interpretation and presence of perfusion defect determined by consensus review. If a deficit was present at stress but not at rest, it was described as an inducible, reversible perfusion deficit. If the defect was present both at rest and stress, and LGE was seen in the same myocardial region, it was described as fixed perfusion deficit. If the defect was present at rest and stress, and there was no LGE noted, it was considered an artifact. The presence of any regional wall motion abnormalities was used as an additional tool to aid in making the determination. Presence of dark rim artifacts were noted if present. Timing of hypointensity, symmetry of the lesion and comparison to resting perfusion were used to distinguish artifact from true perfusion defects. These were described as subendocardial or transmural  in pattern.Semi-quantitative analysis by calculation of a myocardial perfusion reserve index (MPRI) was performed with the commercially available software . The software was used to obtain time signal intensity (TSI) curves for each AHA segment in the basal, mid and apical slices during stress and rest states. Maximum upslope was calculated as the maximum rate of signal intensity increase per unit time (au/s) and relative upslope was obtained by dividing the maximum upslope of the segment TSI curve with the maximum upslope of the myocardial blood pool TSI curve. The MPRI was then calculated as the ratio of the stress and rest relative upslopes for each segment and a global MPRI was calculated as the mean MPRI of all segments. A subset of PHT subjects (n = 9) were re-analyzed by a blinded second reviewer to assess for inter-observer differences.Feature tracking (FT) analysis was performed using dedicated post-processing software . Standard 2-D cine bSSFP images in long and short axis which had 20 phases per cardiac cycle were used. Endocardial borders were manually drawn in end-diastole and end-systole. Four, three and two-chamber views were used to derive the peak global LV longitudinal strain (GLS) and peak systolic and diastolic strain rates. Three short-axis cine imaging slices  were used to derive peak global LV circumferential strain (GCS) and peak systolic and diastolic strain rates. The AHA 16 segment LV model was used to create a map of LV segmental systolic and diastolic strain and strain rate in order to register myocardial tissue and function data on the same anatomic map. A subset of PHT subjects (n = 5) were re-analyzed by a blinded second reviewer to assess for inter-observer differences in global longitudinal and circumferential strain.Data are reported as means ± standard deviations or median  as appropriate. Intraclass correlation coefficient was calculated to assess inter-observer variability in MPRI and FT strain in a subset of patients. To assess significant group differences, an unpaired t-test  or a Wilcoxon rank-sum test  was performed between cases and controls. Segmental differences in the CMR parametric data were displayed as AHA 16-segment maps. Additionally, Pearson’s correlation coefficients (r) were obtained to determine the relationships between clinical variables and CMR structure/function variables. Univariate and multivariable logistic regression model was used to determine association of CMR parameters with the rejection score. Significance was determined by p < 0.05.Twenty-six PHT patients underwent 30 clinician-ordered CMRs during the study period . Individual patients were used as subjects with the most recent CMR used for evaluation. All patients underwent CMR around the time of their annual surveillance catheterization with a median of 28 days (IQR 42 days) between the procedures. All CMR exams in PHT and controls were performed without the use of anesthesia. Demographic differences are highlighted in Table Ventricular volumes were smaller and cardiac output was higher in PHT compared to controls Table . BaselinGLS rate and GCS rate were higher in this cohort of PHT Table . All midStress perfusion was reliably performed in 24/26 (92.3%) CMR exams. Deviation from standard protocol with exclusion of stress perfusion testing occurred because of the clinical situation (1 with active rejection) or patient factors (1 for limited scan due to difficulty lying in scanner). There were no major adverse reactions and 1/24 (4.1%) PHT reported a minor adverse reaction with nausea and gastrointestinal discomfort. Two of 16 (12.5%) perfusion controls had minor adverse reactions including limb numbness and chest discomfort that self-resolved. Qualitative inducible subendocardial defects were noted in 3/12 (25%) of PHT with known CAV: 1/1 (100%) with CAV2 and 2/11 (18%) with CAV1. These qualitative perfusion defects overlapped the CAV coronary territory in 3/3 (100%) PHT with positive findings. Compared to the control group, PHT were found to have a significantly lower global MPRI  with no significant differences between CAV 0 versus CAV 1. MPRI did not correlate with ischemic time during heart transplant surgery. A Bland–Altman analysis between two blinded reviewers showed agreement with no significant bias in MPRI measurement  , reduced GCS  and lower GLS   and ECV values  in PHT recipients. There was higher GCS noted in those who were further out in years post-transplant . No correlations were noted between age and T2, T1 and ECV or MPRI.There were modest correlations between higher rejection scores and elevated global T1 , T2  and ECV . Significant structural differences were also noted between CAV 0 versus CAV 1: CAV 1 showed higher global T1: , higher global ECV (25.4 ± 1.9 vs 28.9 ± 4.6% p = 0.02) and higher maximum segmental T2   showed positive LGE. Studies in adult transplant recipients demonstrate that presence and severity of LGE predict long-term outcomes such as mortality and major adverse cardiac events , 57, andCMR stress perfusion testing was reliably and safely performed in our study. Only one PHT in our cohort had a minor adverse event and no serious adverse events were noted. This low incidence is similar to that reported in other pediatric cohorts . Three oThe safety profile, clinical findings and good reproducibility of MPRI measurements shown across observers, should motivate further studies to better quantify myocardial perfusion as an indicator of CAV in PHT.Despite similar body sizes between PHT and age-matched controls, ventricular volumes in PHT were smaller even though cardiac output was overall higher. This has been previously described in pediatric cohorts , 60 in wEchocardiography-derived strain and CMR derived myocardial velocities are often abnormal during an acute rejection episode or with cumulative history of repetitive rejections , 62, 63.In our cohort, we noted that while GLS and GCS were not significantly different between PHT and healthy controls, there were significant differences in strain rate. We also observed higher GCS in PHT further from transplant. These differences could be due to a variety of factors including differences in age, heart rate, cardiac size, donor-recipient size mismatch or loading conditions. Importantly, the mechanistic and clinical implications are unclear given the cross-sectional nature of our study design and prospective, longitudinal studies could answer some of these questions and clarify significance.This was a retrospective chart review with limitations inherent to this type of a study design. We had a small sample size with only 26 PHT and 18 age-matched healthy controls, which may have limited the strength of associations between clinical and CMR variables. In addition, true controls were not available for myocardial stress perfusion comparisons and therefore, we selected non-PHT subjects with other diagnoses who had undergone stress perfusion CMR with negative results and had minimal suspicion for microvascular dysfunction. Complete CMR protocol was not performed in all patients, leading to missing T2 data in five PHT, ECV data in one and MPRI in two patients. PHT recipients presented for their CMR following variable time since heart transplantation which somewhat limited evaluation of temporal relationships between clinical and CMR variables.In a PHT population with low incidence of CAV and rejection, CMR demonstrates important differences in myocardial structure, function and perfusion compared to age-matched controls. Increasing T2 values were associated with worsening LV function and increasing T1/ECV and T2 values were associated with rejection burden and low-grade CAV. These myocardial structure–function relationships may indicate early graft dysfunction. Larger, prospective studies are warranted to define the role of CMR in PHT graft surveillance.


In the regression analysis, 19 diseases were significantly associated with heart failure. Non-cardiovascular diagnoses strongly associated with HF were obesity (HR = 1.46), chronic bronchitis and COPD (HR = 1.41), gout (HR: 1.41), and chronic kidney disease (HR = 1.27). In the present study, we identified a variety of cardiac and extracardiac diseases associated with heart failure. Our data underscore the immense importance of comorbidities, even as early as at the stage of initial diagnosis of heart failure.The prognosis of heart failure (HF) patients is determined to a decisive extent by comorbidities. The present study investigates the association between a broad spectrum of diseases and the occurrence of HF in a large collective of outpatients. This retrospective case control study assessed the prevalence of 37 cardiac and extracardiac diseases in patients with an initial diagnosis of heart failure (ICD-10: I50) in 1,274 general practices in Germany between January 2005 and December 2019. The study is based on the Disease Analyzer database (IQVIA), which contains drug prescriptions, diagnoses, and basic medical and demographic data. Patients with and without heart failure were matched by sex, age, and index year. Hazard regression models were conducted to evaluate the association between different disease entities and heart failure. The present study included 162,246 patients with heart failure and 162,246 patients without heart failure. Mean age [SD] was 73.7 [12.1] years; 52.6% were women. Out of 37 predefined diagnoses, 36 were more prevalent in HF patients. The highest prevalence was primary hypertension (63.4% in HF patients vs. 53.3% in controls,  Although important innovative therapeutic approaches have been established in recent years, the prognosis of heart failure is still poor6. In this context, comorbidities or concomitant diseases of heart failure patients play a decisive role. Concomitant diseases and comorbidities are diagnostically definable clinical pictures that are present in addition to an underlying disease or index disease8. In the case of heart failure, these can significantly aggravate the prognosis of the underlying disease, but also and above all significantly worsen the subjective feeling of illness9. Heart failure is usually diagnosed at older age, which may partly explain the high frequency of comorbidities. A third of patients report that other medical conditions are primarily responsible for their clinical condition. While heart failure with reduced ejection fraction (HFrEF) is often associated with comorbidities, heart failure with preserved ejection fraction (HFpEF) appears to be mainly defined by these conditions10. In this context, intracardiac and extracardiac can be differentiated9. Some intracardiac comorbidities such as coronary artery disease are clearly identified as precipitating or risk factors for heart failure11. Extracardiac comorbidities such as arterial hypertension are also known risk factors for the development of heart failure11. Other conditions such as renal failure are so frequently associated with the prognosis of heart failure that common pathomechanisms are discussed12. In this large case–control study, we assess the prevalence of intra- and extracardiac diseases that were diagnosed within 12 months prior to the diagnosis of heart failure in comparison to patients without heart failure.Heart Failure has recently been defined as a clinical syndrome with symptoms and/or signs caused by a structural and/or functional cardiac abnormality and corroborated by elevated natriuretic peptide levels and/or objective evidence of pulmonary or systemic congestionOur objective is to gain a comprehensive profile of comorbidities commonly present at the initial diagnosis of heart failure.13. The database covers approximately 3% of all outpatient practices in Germany. Diagnoses , prescriptions , and the quality of reported data are being monitored by IQVIA. In Germany, the sampling methods used to select physicians’ practices are appropriate for obtaining a representative database of general and specialized practices. It has previously been shown that the panel of practices included in the Disease Analyzer database is representative of general and specialized practices in Germany14. For example, Rathmann et al. were able to show a good agreement of the incidence or prevalence of cancer diagnoses between the outpatient DA database with German reference data14. Finally, this database has already been used in previous studies focusing on cardiovascular disorders17.This study was based on data from the Disease Analyzer database (IQVIA), which contains drug prescriptions, diagnoses, and basic medical and demographic data obtained directly and in anonymous format from computer systems used in the practices of general practitioners and specialistsThis retrospective cohort study included adult patients ≥ 18 years) with an incident diagnosis of heart failure (ICD-10: I50) in 1,274 general practices in Germany between January 2005 and December 2019 , iron deficiency anemia (ICD-10: D50), hypothyroidism (ICD-10: E03), hyperthyroidism (ICD-10: E05), diabetes mellitus type 2 (ICD-10: E11), obesity (ICD-10: E66), lipid metabolism disorders (ICD-10: E78), dementia , depression , anxiety disorder (ICD-10: F41), sleep disorders (ICD-10: G47), hearing loss , primary hypertension (ICD-10: I10), hypertensive heart disease (ICD-10: I11), angina pectoris (ICD-10: I20), myocardial infarction (ICD-10: I21-I23), coronary heart disease , nonrheumatic aortic valve disorders (ICD-10: I35), atrial fibrillation and flutter (ICD-10: I48), ischemic stroke , atherosclerosis , venous embolism and thrombosis (ICD-10: I80-I82), chronic bronchitis and COPD (ICD-10: J42-J44), asthma (ICD-10: J45), gastro-esophageal reflux disease (ICD-10: K21), gastritis and duodenitis (ICD-10: K29), diverticular disease (ICD-10: K57), hemorrhoids (ICD-10: K64), NALFD , cholelithiasis (ICD-10: K80), gout (M10), osteoarthritis (M15-M19), spondylopathies (ICD-10: M45-M49), osteoporosis , chronic kidney disease , benign prostatic hyperplasia in men (ICD-10: N40).Differences in the sample characteristics and diagnosis prevalence between those with and those without heart failure were tested using chi-squared tests for categorical variables and Wilcoxon tests for age. Multivariable logistic regression models were conducted to study the association between the pre-defined diagnoses and heart failure. This model contained 37 diagnoses which were adjusted for each other. A Bonferroni correction for p-value was performed, and a p-value of < 0.001  was considered statistically significant. Analyses were performed separately for women and men. Analyses were carried out using SAS version 9.4 .18. Since only anonymized data were used which could not be traced back to individual persons, the research protocol did not have to be approved by the local ethics committee, and it was not necessary to obtain informed consent from individual patients to participate in the study. This was confirmed by the local ethics committee of the Christian-Albrechts-University (CAU) of Kiel, Kiel, Germany (File reference D413/21).Only aggregated, anonymized patient data were used in these analyses. This study was performed in accordance with the Declaration of Helsinki and the guidelines for Good Practice of Secondary Data AnalysisPatients and the public were not involved in the generation of this research paper.p < 0.001) and diabetes mellitus type II . In men, no significant difference was observed between patients with and without heart failure for cancer and hemorrhoids.The present study included 162,246 patients with heart failure and 162,246 patients without heart failure. The basic characteristics of study patients are displayed in Table In our regression analyses, 19 diseases were significantly associated with heart failure Fig. . The strAssociations between diagnoses with the highest risks (OR > 1.20) and HF were similar in females and males Table .Table 3A2, the importance of comorbidities in the development, course, and prognosis of heart failure has also been recognized in recent years3. In our analysis, we identified 19 diseases that were significantly associated with the incidence of heart failure. We consider only diagnoses that were present within 12 months prior to the initial diagnosis of heart failure, not those that were newly diagnosed during the course of heart failure. This explains, for example, why the proportion of patients with dementia was not higher in the HF group than in the control group. The risk of new-onset heart failure among patients with dementia does not appear to be increased. Conversely, it has been clearly demonstrated that the risk of new-onset dementia is increased during the course of heart failure19. Like heart failure, dementia is a huge problem today, with incidence and prevalence continuing to rise20. This may explain why the prevalence in our cohort is higher than that reported in the first EuroHeart Failure Survey21 from 2003, for example. Both are diseases found mainly in older patients. Common mechanisms of disease are proposed, e.g., frailty22. The coincidence of both diseases is certainly an issue that impacts the care of those affected as well as patient quality of life and prognosis23, meaning that special importance will have to be placed on this issue in the future, including in the area of scientific work19.Although heart failure is defined primarily by an elevation of the heart-specific marker (NT) pro BNP, even in the most recent definitions25. Our data underline this very clearly.In our analysis, the strongest association with the incidence of heart failure was observed for hypertensive heart disease. The association between primary arterial hypertension and heart failure was also significant, but significantly less pronounced (HR 1.13). Especially in light of the considerable prevalence of arterial hypertension in our collective (63.4% in the cardiac efficiency group vs. 53.3% in the control group), our results highlight the importance of effectively breaking the pathological sequence of arterial hypertension-hypertensive heart disease-heart failure. The improvement of the medicinal adjustment of arterial hypertension and thus the prevention of end organ damage to the heart offers an excellent opportunity to protect many patients from developing heart failure26. Obesity may have deletive effects on myocardial remodelling similar to those of diabetes. Research into the stand-alone effects of obesity on the heart is still in its infancy; pericardial adipose tissue, for example, could play an important role as an endocrine organ. The strong association of obesity with heart failure in our study suggests the importance of further research in this area. This is an important key to the prevention of heart failure, given the enormous and increasing prevalence of obesity in industrialised countries26. Obesity and diabetes in particular have been linked to HFpEF, which is a disease diagnosed mainly in older individuals10. The median age in our study (and control) group was 73 years, which is lower than that in other Western European datasets27. This may be due in part to the fact that we studied outpatients with an initial diagnosis of heart failure and many other studies enrol patients as the disease progresses or those admitted to hospital for heart failure27. The possibility that the proportion of HFpEF patients is lower in our heart failure cohort because of the slightly younger age of our cohort and the lower proportion of obese patients cannot be excluded. Due to missing information in our database, which is based on ICD-10 codes, we were unable to determine the ejection fraction in our HF patients (see Limitations part of the Discussion section).The prevalence of obesity in our collectives is relatively low. The possibility of a recording bias cannot be ruled out here. Nevertheless, this extracardiac comorbidity was strongly associated with heart failure in our study. Interestingly, the respective hazard ratio was higher than that of diabetes. The two conditions of obesity and diabetes are considered so closely linked that they are also referred to as a parallel coepidemic of the western world, and the term diabesity has been coined in response28. In addition, certain drugs such as beta sympathomimetics can have significant side effects in heart failure patients, and overall, the large group of patients with COPD and heart failure should be considered particularly at risk29.The association between COPD and new-onset heart failure is strong, with COPD being very prevalent in our study population , which also reflects the high prevalence in the general population. Clinically, this association is particularly problematic as both conditions can present with similar symptoms, which can significantly delay the diagnosis of heart failure30. Recent hypotheses on the genesis of heart failure place gout in a series with other chronic inflammatory conditions such as rheumatoid arthritis and chronic inflammatory bowel diseases31. It is well established that heart failure is also a state of chronic inflammation, and it has been postulated that there may be a cardioinflammatory subtype of heart failure that is particularly associated with chronic inflammation. This would potentially provide intriguing treatment options for some heart failure patients31. However, the fact that gout was significantly more strongly associated with heart failure than rheumatoid arthritis in our study may suggest that gout-specific pathomechanisms also contribute to the occurrence of heart failure beyond general inflammatory conditions.Another strong association was shown in our study between gout and the occurrence of heart failure. It must be emphasised again that our study describes statistical associations and does not prove causal relationships. A clear causal relationship between these diseases has not yet been described; however, gout has been associated with coronary heart disease and cardiovascular mortality in generalNo significant differences were found between the heart failure and control groups with regard to cancer in general and specific cancers. Cardio-oncology is an emerging field in the area of cardiology. Initially considered to include the risk of recurrence of heart failure in oncology patients treated with cardiotoxic therapies, increasingly heart failure is also being inversely linked to cancer. Recent data suggest that heart failure is also a prooncogenic entity, with an increased rate of cancer in heart failure patients. Low-grade inflammation and neurohumoral activation are cited as mechanisms linking the two conditions. In addition, there are, of course, common risk factors, such as nicotine. Our study does not show an increased cancer rate at the onset of heart failure. Other studies which focus more on the long-term course of the disease, are likely to show this association.33. In both study groups, we found significant differences between men and women in the prevalence of dementia, anxiety disorders, and depression, with an overall higher prevalence in women both with and without heart failure. Clear differences in the respective gender-specific distribution between heart failure patients and control patients were not found. However, further studies such as ours will certainly be needed to identify gender differences that could also explain different responses to therapies32.Due to the large size of our collective, the analysis of possible differences between the sexes with regard to comorbidities/risk factors is of possible interest and warranted. Recent work has shown that there are important differences between women and men in clinical characteristics, comorbidities, and response to therapyAs a caveat, secondary data analyses such as ours are generally limited by a lack of completeness of the data on which they are based. For example, we cannot provide information on the individual disease stages of disease entities, or on the guideline-based therapy of the diseases and the course of the disease. As such, we are unable to differentiate between different subtypes of heart failure (HFrEF vs. HFpEF). Furthermore, no data were available in the database on the individual left ventricle ejection fraction. In addition, identification of patients was based on officially coded diagnoses only, most likely resulting in a recording bias. The possibility that diagnoses have been misclassified within the ICD-10 coding system cannot be excluded. However, we used data from a large database with over 162,000 patients for our case–control study. We are therefore confident that the associations shown are reliable and clinically meaningful.In summary, we can give a very comprehensive and broad picture of associations of various internal diseases with the new onset of heart failure in a case–control study. Comorbidities are risk factors for the occurrence of heart failure as well as aggravating factors for the course of the disease. However, they could also offer new starting points for multimodal innovative therapy approaches for heart failure in the future.


In cemented primary total knee arthroplasty (TKA), aseptic loosening remains a major cause for failure. Cementing techniques and characteristics of a chosen cement play a key role for good fixation and implant survival. A pastry bone cement was developed to facilitate the cement preparation and to rule out most of preparation-associated application errors. The pastry bone cement was compared to a conventional polymethyl methacrylate cement in a TKA setting.Standardized implantations of total knee endoprostheses were performed in bilateral knee cadavers to investigate handling properties, variables of cement application, working time, and temperature development. Mechanical aspects and cementation quality were assessed by pull-out trials and microscopic interface analysis.Both cements expressed similar characteristics during preparation and application, only the curing time of the pastry cement was about 3 min longer and the temperature peak was lower. Fractures of the conventional cement specimens differed from the pastry cement specimens in the tibial part, while no differences were found in the femoral part. Penetration depth of the pastry cement was similar (tibia) or deeper (femur) compared to the conventional cement.The pastry cement facilitates the feasibility of cemented TKA. The pre-clinical tests indicate that the pastry bone cement fulfills the requirements for bone cement in the field of knee arthroplasty. A clinical trial is needed to further investigate the approach and ensure patient safety.The online version contains supplementary material available at 10.1186/s13018-021-02436-z. In the field of joint replacement surgery, cemented and cement-less (“press-fit”) techniques are used for implant fixation . Even thWhile some studies show that cemented TKAs have lower failure rates and greater functional outcomes compared to uncemented TKAs –6, otherThe widespread use of cemented TKA is supported by extensive clinical experience and provides the advantage of local antibiotic protection, if required. Advancements in cementing are usually referred to as first-, second-, or third-generation techniques. The developments include vast improvements in bone bed preparation, cement preparation, and cement delivery .Although the underlying mechanism of aseptic loosening after TKA is not fully understood, it is commonly accepted that it has a multifactorial etiology  that canFor the optimal outcome, knowledge about the bone cement is of paramount importance and a precise, standardized cementing technique is essential . VariousIn contrast to the conventional cement consisting of a powder and a fluid component, the pastry bone cement  is prepaThe objective of this pre-clinical investigation was to evaluate the quality of cementation, handling and product properties, as well as the mechanical characteristics of this pastry bone cement compared to a conventional cement in a TKA setting.This pre-clinical investigation was conducted in the Anatomical Institute of the University of Basel, which furnished 16 medically prepared knees of 8 deceased persons without obvious pathological findings. Pre-trials were conducted on artificial and cadaver material in the sense of feasibility.Standardized implantations of total knee endoprostheses with a bone cement paste and an established bone cement were performed in bilateral knee cadavers . On one side, the prostheses components were implanted with the conventional powder/liquid cement, while on the opposite side, the bone cement paste was applied under otherwise equal conditions. The selection was performed randomly and alternating.A pasty two-component bone cement  and the The implants used for the tibial and femoral parts were Duracon® (Stryker) and porous-coated anatomic (PCA) prosthesis (Howmedica), both with an identical porous coating. Either sample implants, or implants obtained by explantation during revision surgery were used. The components were purified thoroughly, adherent cement remnants were removed by incubation in acetone and mechanical post-processing, and final sterilization was achieved by gamma radiation.For both knee implants, 60 g of conventional cement (40 g powder + 20 g fluid) or of pastry cement (30 g paste A + 30 g paste B) were initially mixed according to the manufacturer specifications. The mixing procedure was performed by using the Palamix®  System (hand mixing) without a vacuum. Cement application was executed by a conventional cement gun.Investigation was executed on prepared isolated cadaver material (knee joints) that was fixed with a buffered formaldehyde solution. Detailed instructions were given during an onsite training performed by specialists from Heraeus Medical. Tendons, ligaments, and cartilage structures of the knee joint were removed. Bone was prepared without patella.The surgical handling of the experiments was executed by two fully trained orthopedic surgeons specialized in TKA. Preparation of the bone surfaces: the valgus angle of the femur was 5°, femur size was measured, and the final preparation of the femur with the bevel saw cuts took place. Dorsal condyles were sawed off. The required tibial resection template was applied; a correct slope and the physiological tibial axis to the second (2°) toe were aligned. The tibial plateau was sectioned, the size was measured, and the prosthesis chosen. To remove loose cancellous bone, blood, fat, and marrow, all bone surfaces were washed with pulsatile lavage using warm tap water. Washing time (3 min) and water temperature (40–43 °C) were monitored.The correct handling of the cement preparation was taken over by the Heraeus team. The tibial component was cemented first. Cement was applied early during its working phase onto the bone-side surface of the metal implant , not on the bone surface Fig. . As soonThe femoral component was cemented separately, but the procedure was analogous to the tibial component Fig. .Fig. 2FTo determine the total amount of used cement, the surplus of cement was measured, as well as all equipment in contact with cement before and after use, and subtracted from the initial amount.Variables of cement application and working time were investigated. Maximum temperature was measured at the bone-cement interface with an implanted thermo-sensor  that was fixed by a clamp to keep it in place during the cementation process. The thermo-sensor was fixed at the location with the thickest layer of cement, where the highest curing temperatures were to be expected Figs.  and 2. B2 is achieved after a setting time of 3 days at room temperature.Trials were conducted in the Center of Biomechanics, University of Basel. A servo-hydraulic testing machine (Typ MTS Bionix 858) was used to measure the maximum tractive force of 5 knee implants for each cement. Femur and tibia were fixed on a pipe socket by bolting and by applying a two-component adhesive based on epoxy resin . Remaining space between bone and pipe socket was filled with the adhesive. According to the manufacturer, a tensile strength of 17–23 N/mmTo test the tibial component, the tibia-plateau was linked to the connecting element of the femur condyle. Similarly, the femur condyle was used with the corresponding connecting element for the femoral component trials. To allow proper fixation, plastic shims were inserted into little notches of the prostheses medially and laterally of the tibia-plateau and femur condyle during cementation. They were removed after curing of the cement, to allow the positioning of the pincers.Surgical tools (Stryker) were used as joints to connect the implants with the testing machine. The tractive force and the displacement speed of the axial cylinder were recorded at sampling rate of 1000 Hz, and the whole process was documented with high-speed filming (300 frames per second). After fixation on the testing machine, human preparations were exposed to tractive forces of 20 N. Subsequently, tractive forces were increased constantly (1 m/min) until implant-cement-bone anchoring failed.One cadaver was used for analysis . Pastry cement was applied at the left side, and conventional powder/liquid cement at the right side.All preparations were sectioned with a diamond tipped bend saw. To prevent melting of the cement, cutting was water-cooled and slow (about 12 h per sample). The femoral longitudinal cut was frontal through the anchorage pins. The tibial longitudinal cut was frontal, right behind the frontal metal anchor. All segments were analyzed with a Keyence microscope.Only descriptive statistical methods were used in the present pre-clinical investigation. Continuous parameters are presented with their means, standard deviations (SDs), medians, and minimum and maximum values. Frequencies were calculated for categorical variables.Sixteen knee joints from eight prepared cadavers were used for the evaluation of TKA. The demographic data are shown in Table The mean valgus angle was 8.1 ± 1.57° for the pastry cement and 6.8 ± 3.33° for the conventional cement. Mean values for the length of caput femoris–condyles medialis femoralis and condyles medialis tibiae–pilon tibiale are shown in Table For both cement types, the mainly used implant for the tibial part was Duracon® (Stryker) (six implants [75%] each). The other used implant was the PCA prosthesis (Howmedica) (two implants [25%] each). In case of the pastry cement, Duracon® was used during all surgical preparations of the femoral part (eight implants [100%]), while Duracon® (seven implants [87.5%]) and PCA (one implant [12.5%]) were used for the conventional cement.The mean preparation time of the tibial condyles was about 5.5 min , and about twice as long for the femoral condyles . In all cases, mean lavage washing time was 3 min, and mean temperature was approximately 43.5 °C, except for the pastry cement during the preparation of the tibial part (40.4 ± 8.25 °C). The mean preparation time for the device ready to use was shorter for the powder/liquid cement compared to the pastry cement for both tibial  and femoral condyles . The mean weight of the application system plus cement (ready to apply) for both condyles was around 179 g for the powder/liquid cement and 188 g for the pastry cement. Immediate loss of stickiness after extrusion was documented for both cement types during all surgical preparations of the tibial and femoral part.A mean duration of cement application of 0.60 ± 0.17 min for the pastry cement and 0.62 ± 0.19 min for the powder/liquid cement was revealed. The mean time to implant set for the pastry cement was 1.77 ± 0.37 min and 1.48 ± 0.71 min for the powder/liquid cement. A longer time from start of the application to curing (trocar test) of about 3 min was shown for the pastry cement  compared to the powder/liquid cement . The mean really applied amount of cement during the surgical preparations of the tibial part was 9.06 ± 1.43 g for the pastry cement and 11.04 ± 1.55 g for the powder/liquid cement.For both cement types, the time to place the metal implant was sufficient during all surgical preparations of the tibial part. The mean maximum temperature before the cementation process was 24.78 ± 1.79 °C for the pastry, and 25.49 ± 1.39 °C for the powder/liquid cement. Mean temperature peaks of 33.90 ± 4.15°C (9 min) and 36.28 ± 1.91 °C (6.5 min) were measured for the pastry and powder/liquid cement, respectively. The mean maximum temperature after the cementation process was 29.10 ± 1.93 °C for the pastry cement and for the powder/liquid cement it was 29.24 ± 1.28 °C  of about 3 min was shown for the pastry cement  than for the powder/liquid cement . The mean really applied amount of cement during the surgical preparations of the femoral part was 10.96 ± 2.35 g for the pastry cement and 12.41 ± 1.46 g for the powder/liquid cement.For both cement types, the time to place the metal implant was sufficient during all surgical preparations of the tibial part. The mean maximum temperature before the cementation process was 25.71 ± 1.55 °C for the pastry, and 26.16 ± 1.64 °C for the powder/liquid cement. Mean temperature peaks of 35.93 ± 9.16 °C (8.5 min) and 36.93 ± 5.91 °C (7.5 min) were measured for the pastry and powder/liquid cement, respectively. The mean maximum temperature after the cementation process was 27.39 ± 3.88 °C for the pastry cement and for the powder/liquid cement it was 29.51 ± 1.61°C , followed by excellent (2 implanted cadaver sides [25%]), and poor (1 implanted cadaver side [12.5%]).For both cement types, it was easy to remove the surplus cement and the prosthesis was assessed to be in position at all implanted cadaver sides. It was easy to manually transfer and mold the cement from gloves onto the implant surface. Only non-latex gloves (Biogel®) were used during the implantations.The stress level for the user was low and the handling of the cement was easy at all implanted cadaver sides for both cement types.A higher percentage of unproblematic methyl methacrylate (MMA) odor was revealed for the pastry cement (87.5%) compared to the predicate device (62.5%). The MMA odor was assessed to be tolerable for both cement types at the remaining implanted cadaver sides.In the tibial part Fig. a, fractuIn the femoral part Fig. b, the frThe cut surface of the tibia had a slightly concave shape Fig. . Both ceIn the femoral part Fig. , penetraIn the present study, a pastry bone cement was introduced and compared to a conventional PMMA cement, aiming to refine cemented TKA. Regarding the cementing technique, bone preparation and surgical approach, initial conditions were simulated as closely as possible.Both cements expressed similar characteristics during preparation and application, only the curing time of the pastry cement was about 3 min longer for the tibial and femoral parts. The prolonged curing time may increase cement flow, thereby facilitating penetration. However, this was not confirmed by the present results.The temperature was measured where cement was the thickest and heat development produced by PMMA curing was expected to be maximal. Temperature peaks were about 34 to 36 °C for the pastry cement and about 36 to 37 °C for the powder/liquid cement, the peaks were rather short-lived. In an animal model, it was shown that bone formation is reduced after 1-min exposure to a temperature between 47 and 50 °C, while no effects were observed at 44 °C . ThermalIn earlier pull-out trials, it was shown that less dense bones with wide cancellous clefts allowed large cement pegs extending into the cancellous bone, entailing interface fractures that predominantly occurred within the bone. In dense bones, fractures occurred rather in the cement , 22. In PMMA is used to tightly fill the space between the irregular bone surface and the implant. The penetration depth of cement into bone is supposed to be crucial for increased implant stability , 24. PenPull-out trials and microscopic interface analysis indicate that the cement-bone/cement implant contact area is important for the interfacial strength as well. The findings are in line with Waanders et al., showing that cement penetration depth as well as contact area are key elements for optimizing the interfacial strength .This study has several limitations. Obviously, the knee is exposed to a variety of motions, shear forces, and tensile or compressive loadings that cannot be assessed by pull-out trials. Moreover, the present study does not consider biological reactions due to polymerization heat, trauma, or monomer toxicity and clinical tests are needed to address these issues.The pre-clinical tests reported here show equal or even slightly improved properties of the pastry cement compared to the powder/liquid cement, indicating that the pastry bone cement fulfills the requirements for bone cement in the field of knee arthroplasty. As an elaborate mixing procedure  is not needed for the pastry cement and the operator needs to perform only a few simple steps, the potential risk of cement-related failures is reduced. A clinical trial is needed to further verify the system.Additional file 1. Tibial part; powder/liquid cement. Pull-out forces of single specimens and correlating surface pictures after fractures. *Pipe socket moved slightly.Additional file 2. Tibial part; pastry cement. Pull-out forces of single specimens and correlating surface pictures after fractures. *Pipe socket moved slightly.Additional file 3. Femoral part; powder/liquid cement. Pull-out forces of single specimens and correlating surface pictures after fractures. *Pipe socket moved slightly; **failure of the implant .Additional file 4. Femoral part; pastry cement. Pull-out forces of single specimens and correlating surface pictures after fractures. *Pipe socket moved slightly.


The aim of this study was to characterize determinants of left ventricular mechanical dyssynchrony (LVMD) in patients with coronary artery disease (CAD).Medical records and results of myocardial perfusion SPECT/CT studies were evaluated in 326 patients with previously diagnosed CAD. LVMD was assessed with the phase analysis of ECG-gated myocardial SPECT. Dyssynchrony was described with phase histogram bandwidth (PHBW), standard deviation (PHSD) or entropy (PHE) values above limit of the highest normal.P < 0.001 for all). Independent predictors of LVMD were myocardial infarction scar (P = 0.004), ischemia extent (P = 0.003), and QRS duration (P = 0.003). Previous percutaneous coronary intervention and coronary artery bypass grafting did not independently predict dyssynchrony.Prevalence of LVMD was 29% in CAD patients. Size of the infarction scar and ischemia extent correlated significantly with PHBW, PHSD and PHE  contains supplementary material, which is available to authorized users. Understanding of mechanisms behind development of heart failure progression and therefore, characterization of risk factors predicting left ventricular (LV) dysfunction is important in patients with incipient heart failure. Left ventricular mechanical dyssynchrony (LVMD), asynchronous and dyscoordinate contraction of the LV, has found to be a significant determinant of systolic dysfunction in patients with heart failure.3Myocardial perfusion imaging (MPI) with ECG-gated single-photon emission computed tomography (SPECT) is widely used to assess possible myocardial ischemia and to study viability of myocardium to optimize treatments of coronary artery disease (CAD) patients.8LVMD has been found to occur even without signs or symptoms of heart disease and it may help to identify patients at higher risk for progression of heart failure.In the present study, the aim was to investigate the relationship between LVMD and myocardial ischemia, myocardial infarction and previous invasive treatments such as PCI and CABG in a population of established CAD.This study was approved by the Research Ethics Committee of the Northern Savo Hospital District.We analyzed medical records of 1191 patients who underwent SPECT/CT examination during January 2009-May 2011 in the Department of Clinical Physiology and Nuclear Medicine, Kuopio University Hospital. Of this population, we included all patients with earlier diagnosis of CAD and with both rest and stress MPI data available to use. Additionally, the 12-lead electrocardiogram (ECG) available from the same MPI examination was the third inclusion criteria. Patients with atrial fibrillation were excluded to avoid bias to LVMD measurements. A total of 326 patients fulfilled all inclusion criteria.We collected basic characteristics , previous invasive cardiac procedures, such as PCI and CABG, chronic underlying diseases, medications and history of smoking from the medical records. In addition, we analyzed the ECG recordings and MPI data and retrospectively performed the phase analysis. All the information was collected and converted to a single, non-identifiable data set. We verified the whole population as a CAD group and divided the CAD group for subgroups to examine the effects of ischemia or infarct scars. Patients who did not exceed the reference values of phase histogram measurements were defined as non-LVMD subgroup (n = 232) and those who exceeded belonged to LVMD subgroup (n = 94). In addition to that, patients with summed rest score (SRS) points two or more in MPI (described later) were classified into infarct scar subgroup (n = 131) and ischemia% three or more were classified into ischemia subgroup (n = 244). For more precise selection, we studied the effects of location of myocardial infarct scar and the location of myocardial ischemia based on the coronary artery areas to find out, whether there is correlation between increased LVMD and the location of the infarct scar or the ischemic area in myocardium.Finally, an additional reference group of 52 patients without diagnosed cardiac diseases and normal myocardial perfusion in SPECT imaging was shown in electronic supplementary material in comparison with CAD group. The selection criteria and formation of the reference group is described in details in our previous work.22Patients were instructed to avoid caffeine-containing beverages and medications for 24 hours before MPI. Adenosine stress MPI with 99m-Tc-tetrofosmin was performed using 1-day protocol and all patients were studied with both stress and rest phases. At stress phase, adenosine  was administered intravenously for 6 minutes with injection of tracer  at 4 minutes from the onset of adenosine infusion. Low-level exercise was used in combination with adenosine infusion when possible, to avoid influence of extracardial tracer accumulation. Thirty minutes after the tracer injection, ECG-gated SPECT MPI was acquired. For the rest study, patients received an intravenous injection of tracer  and were imaged 45 minutes afterwards.> 100 kg). Reconstructions were made retrospectively with HERMES Hybrid Recon Cardiology . Analyses were carried out using automated QPS/QGS2012 software .MPI scans were performed in a supine position with a dual detector SPECT/CT system  with detectors in 90° configurations using 180° body contour orbits with 64 projections and images were acquired with 128 × 128 matrix size. The gated data was acquired with 16 time bins, and with 25 second per angle (patient weight < 100 kg) or 30 second per angle . The summed rest score (SRS), summed stress score (SSS), and summed difference score (SDS) for perfusion were obtained automatically by software.Furthermore, co-registration of rest and stress images and voxel-by-voxel estimation of differences described by Slomka et al. was also used in quantification of ischemia percentage.19In the QGS algorithm, the mid-myocardial LV surface was first computed and endo- and epicardial surfaces were computed subsequently. The end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV) and ejection fraction (EF) were calculated from the volumes determined by the endocardial surface in different time frames.LVMD was assessed from the ECG-gated SPECT with the phase analysis method. Phase analysis detects regional count changes in 16 time bins to observe the variation in LV wall thickness throughout the cardiac cycle. This is done for 1008 spatial points covering the whole LV area. The onset of mechanical contraction is assessed for each spatial points and the information is presented as a phase histogram which describes distribution of the timing of LV regional onset of mechanical contraction as a function of the length of the R-R-interval.21The definition of having LVMD was the values of PHBW, PHSD and/or PHE above the limit of the highest normal based on our reference material .22T test was used to test the statistical significance of difference between two independent samples. One-way ANOVA with least significant difference post hoc algorithm was used to test the differences between the mean values of the more than two groups. For categorical variables the Chi square test or Fisher´s exact test, when the expected value in each cell was less than 5, were used. Correlations were tested using Pearson´s bivariate correlations.One-sample Kolmogorov–Smirnov test was used to test the normality of distribution for continuous variables. Descriptive statistics is presented as mean ± standard deviation. In the case of continuous variables Logistic regression analysis was performed to find out the predictors of LVMD. At first, the logistic regression model included age, sex and variables which differed between non-LVMD and LVMD subgroups and therefore were possible predictors of LVMD.P < 0.05. All statistical calculations were performed with the SPSS for Windows program .Tests were two-sided and significance was present if P < 0.001) and they were more frequently males compared to those without LVMD (P = 0.048). PCI had been done for 39% of the patients in both LVMD and non-LVMD group (P = 0.924).The characteristics of overall patient population are summarized in Table About one-third (29%) of all CAD patients had LVMD. The prevalence of LVMD raised to 45% in subpopulation with infarct scar in MPI. In the subgroup of patients with earlier PCI (n = 127), the prevalence of LVMD was 29% and in patients with earlier CABG (n = 111) the prevalence of LVMD was 36%.Table Patients in CAD group had statistically significantly increased amount of ischemia, larger infarction scars and LVMD as well as decreased volume parameters compared to reference group .P < 0.05). The same was detected between the infarct and non-infarct groups. LVMD was significantly increased in stress compared to rest study in the whole CAD group (P < 0.001), as well as other subgroups except for in the LVMD group (NS). The change in phase analysis measurements  between the rest and stress studies was not statistically significant between the non-infarct and infarct patients (P > 0.05) or between the non-ischemic or ischemic patients . In LVMD group, this change seemed to be smaller than in non-LVMD patients .Table Figure P = 0.054). After excluding the mixed group from the analysis, there were not statistically significant difference in the prevalence of LVMD between LAD, LCX or RCA areal infarct scar (P = 0.442 NS). To elaborate the effects of vessel distribution of infarction more precisely, the regression analysis showed that if infarction (described by SRS points) was located in only 1 vessel distribution, it had less effect to increased LVMD  compared to 2 or more vessel distribution location . Moreover, there were no statistically significant differences in phase analysis measurements in patients with detected ischemia in different arterial areas based on SDS points.In the subanalysis, there were 33 patients with an infarct scar only in LAD area, 21 patients with LCX areal infarct, 28 patients with RCA areal infarct and 37 patients with mixed areas infarcts. PHBW was highest in the mixed infarct group (68.3 ± 36°) and second highest in the LAD infarct group (58.8 ± 33°) and smallest in the LCX infarct group (52.5 ± 28°). However, phase histogram measurements did not differ statistically significantly between the groups. Chi Square test showed no statistically significant difference in the prevalence of LVMD between these four infarct groups . Remodeling related to CAD was characterized by EDV and electrical dyssynchrony by QRS duration. According to the analysis, larger infarction extent%, larger ischemia%, and longer QRS duration independently predicted LVMD Table . PreviouB = 1.11, P = 0.015), ischemia , larger EDV , low EF  and longer QRS duration , but not infarct scar extent .In additional logistic regression analysis in which EF was also added into the model, significant predictors of LVMD were male sex .10Logistic regression analysis of this study showed that significant predictors of LVMD were myocardial ischemia, infarction scar extent and QRS duration. In additional analysis, when EF was included in the model, significant predictors of LVMD were male sex, ischemia, larger end-diastolic volume, low ejection fraction and longer QRS duration, but not infarct scar extent. The latter model indicates how well the entire bundle of predictors predicts LVMD but it does not indicate that infarct scar would be redundant information. When including EF into the model, the analysis meets the problem of multicollinearity; patients with infarction scar have often decreased EF.It has been acknowledged, that the greater the amount of LVMD was, the more perfusion defects and infarct scars were present, and myocardial infarction size was an independent predictor of LVMD.In addition to previous myocardial infarction, the correlation between LVMD parameters and ischemia% was statistically significant whereas correlation between SDS and LVMD was not. That suggests that ischemia% might be more sensitive parameter to describe the functional significance of ischemia in the myocardium than SDS. One reason for that might be the fact that voxel-by-voxel estimation technique  compared to traditional technique has shown better ability to detect borderline-abnormal findings in patients who had coronary stenosis confirmed by coronary angiography.15In multivessel CAD, more advanced LVMD have been detected at stress compared to rest, as in our study.In the present study, earlier PCI did not independently predict dyssynchrony. “Earlier PCI” in this study meant that according to medical history, PCI had been done before SPECT, but the precise timeline between PCI and SPECT was not known. Although this study did not find statistically significant association between earlier PCI and LVMD in long term, this does not prove that that PCI does not contribute to LV synchronicity. Earlier, even the protective value of PCI to LVMD is supported by the studies in which the most of are focused on examining the acute effects of PCI and have been done mostly with tissue Doppler echocardiography.In addition to PCI, it is commonly known, that CABG surgery induces paradoxical septal wall motion; about 60.5% of patients who had undergone CABG, had paradoxical septal motion quantified by SPECT.35To conclude, LVMD seems to be in close relation with CAD, myocardial infarct and ischemia. This connection expresses the importance of CAD in the pathophysiology of heart failure. The adequate prevention and treatment of CAD might prevent LVMD and thus decrease the risk for upcoming heart failure.The most important limitation was the retrospective nature of the study. All patients were sent to SPECT MPI for medical reasons and CAD patient selection was made based on the previous medical records and written diagnosis of CAD. This made the CAD patient group a versatile group, which might have introduced some bias in the patient selection. However, the present data represent a picture of the actual population of subjects submitted to MPI.A considerable part of CAD patients had significant LVMD. In this study, CABG or PCI did not independently predict dyssynchrony, but previous myocardial infarct, myocardial ischemia as well as large EDV did.LVMD is common in CAD patients and is associated with presence of both reversible and irreversible perfusion defects. This connection highlights the importance of detecting and treating of CAD to prevent possible upcoming heart failure.Electronic supplementary material 1 (PPTX 248 kb)Below is the link to the electronic supplementary material.