Keyword searches of databases were performed per PRISMA-NMA guidelines. Frequentist network meta-analysis were conducted with 16 head-to-head randomized controlled trials. The effect sizes of dichotomous and continuous variables were estimated with odds ratio (OR) and standard mean differences (SMD), respectively. The protocol is registered in PROSPERO (CRD42022365927). Dual antihypertensive regimens with combination of angiotensin receptor blockers (ARB) and calcium channel blockers (CCB) demonstrated substantially reduced odd of major cardiovascular disease (CVD) events over other regimens including angiotensin converting enzyme inhibitor (ACEI) monotherapy (OR 3.19) and ARB monotherapy (OR 2.64). Most significant reductions in systolic (SBP) and diastolic blood pressure (DBP) were observed with ARB-based CCB dual regimen over ACEI monotherapy (SMD 17.60 SBP and 9.40 for DBP), ACEI-based CCB regimen (SMD 12.90 for SBP and 9.90 for DBP), and ARB monotherapy (SMD 13.20 for SBP and 5.00 for DBP). However, insignificant differences were noticed for the odds of hyperkalemia, end stage renal disease progression, and all-cause mortality. ARB-based CCB regimen has the greatest benefits on BP reduction as well as major CVD risks in non-dialysis CKD patients.This study comprehensively investigated clinical outcomes associated with renin angiotensin system inhibitor-based dual antihypertensive regimens in non-dialysis chronic kidney disease (CKD) patients Among numerous comorbidities, hypertension is one of the most common etiologic factors for CKD, and the prevalence increases with declining renal function, accounting for 60 to 90% of CKD patients4. Hypertension is considered as a dominant attributed comorbidity for end stage renal disease (ESRD), defined as eGFR < 15 mL/min/1.73 m2 or renal failure, as blood pressure (BP) increases with worsening renal insufficiency, which subsequently accelerates the disease progression5. Moreover, uncontrolled hypertension increases the risks of significant adverse cardiovascular outcomes such as myocardial infarction (MI), stroke, or sudden cardiac death, and CVD is designated for the leading cause of mortality in CKD patients indeed6. Thus, maintaining target BP goals in CKD patients is critical to improve clinical prognoses.Chronic kidney disease (CKD) is a progressive disorder characterized by renal insufficiency with an estimated glomerular filtration rate (eGFR) less than 60 mL/min/1.73 m7. According to the previous studies, both ACEI and ARB not only delayed CKD progression but also reduced CVD events including heart failure and cardiac death in patients with renal insufficiency8. However, most CKD patients require additional antihypertensive agents to RASi to maintain optimal BP as the disease progresses. According to a nationwide population study9, more than 50% of CKD patients were prescribed with at least 2 antihypertensive agents to manage hypertension. Although the current guidelines suggest dual antihypertensive treatment with RASi, either ACEIs or ARBs, in CKD patients with uncontrolled BP by the primary antihypertensive agent, the valid evidences on the optimal selection of add-on agent for RASi-based dual hypertension treatment regimens in CKD patients are currently limited10, and considering increased risk of adverse events (AE) secondary to substantial changes in pharmacokinetic and pharmacodynamic characteristics, there is an urgent need for the establishment of evidence-based guidance on optimal pharmacotherapy in patients with renal insufficiency11. Nevertheless, as CKD patients are considered as vulnerable patient populations, the clinical studies to support the selection of optimal RASi-based dual antihypertensive regimens in patients with renal insufficiency are currently lacking, consequently making clinical decision more perplex12. Therefore, this study aims to comprehensively assess clinical outcomes of diverse RASi-based dual antihypertensive regimens in non-dialysis CKD patients by conducting pair-wise comparisons utilizing Frequentist network meta-analysis methods to evaluate clinical benefits of each RASi-based dual antihypertensive regimen, thereby providing supporting evidences on the optimal RASi-based dual antihypertensive regimens in non-dialysis CKD patients to enhance prognosis.The updated 2021 Kidney Disease Improving Global Outcomes (KDIGO) guideline for the management of blood pressure in CKD recommends renin-angiotensin system inhibitors (RASi), either angiotensin converting enzyme inhibitors (ACEI) or angiotensin receptor blockers (ARB), as the first-line antihypertensive agents for non-dialysis CKD patients with elevated BP to inhibit markedly increased renin angiotensin aldosterone system (RAAS) activity induced by renal insufficiency21, ARB monotherapy25, CCB monotherapy14, ARB and ACEI combination21, ARB and CCB combination27, ARB and thiazide combination (TZD)26, ARB and renin inhibitor (RI) combination25, ACEI-based CCB combination28, ACEI and SPR combination20, ACEI and TZD combination28, CCB and beta-blocker combination (BB)27, and CCB and TZD combination27. The network plot of eligible studies is described in Fig. P values < 0.05). All study outcomes had I2 index < 50% and P values > 0.05 for Cochran Q statistics, implying low risk of heterogeneity and inconsistency.The primary database search and study selection process per PRISMA and PRISMA-NMA guidelines are described in Fig. p = 0.0156), ACEI and SPR combination , ARB monotherapy , and ARB and ACEI combination  than ARB-based CCB combination therapy  (Table P = 0.0035), ACEI and CCB combination , ARB monotherapy , ARB and ACEI combination  and CCB monotherapy  , ACEI-based CCB combination regimen , ARB monotherapy , ARB and ACEI combination  and CCB monotherapy    and non-RASi-based antihypertensive treatment including CCB monotherapy , CCB and BB combination  and CCB and TZD combination  in this study. Although the evident mechanism for similar hyperkalemia risks regardless of the diverse combination of antihypertensive agents is yet to be determined, disease-specific factor may have superior influences on hyperkalemia risk over RASi use in CKD patients34. Renal insufficiency itself is a compelling risk factor of hyperkalemia as the hyperkalemia incidence and severity increase with CKD progression, and a previous study revealed that the degree of renal insufficiency manifested by elevated serum creatinine level was the strongest positive correlation factor with serum potassium over other contributing factors such as diabetes, RASi use, and age35. However, the scarcity of evidences in CKD patients may hinder investigation of evident hyperkalemia risk from pharmacotherapy notwithstanding renal function. Hence, further studies investigating hyperkalemia risk associated with antihypertensive combination regimens including RASi-based dual antihypertensive treatment in CKD patients are warranted to improve patient prognosis.One of the concerns associated with RASi treatment is elevated risk of hyperkalemia36. However, the time to ESRD diagnosis may be different as numerous patient- and disease-specific factors play crucial roles in ESRD progressions, and the studies suggest that those with younger age, female sex, diabetes, or dyslipidemia are more likely to have accelerated progression to ESRD38. Considering the substantial clinical adverse outcomes in ESRD patients, delaying ESRD progression itself may be acknowledged as valuable clinical benefits in CKD patients39. Thus, further studies investigating the impact of various antihypertensive treatment regimens on the time to ESRD diagnosis are warranted to ensure favorable prognoses in CKD patients.The risk of ESRD diagnosis was statistically insignificant among antihypertensive treatment regimens. As CKD being a progressive chronic disorder, disease progression to ESRD may inevitable in many patients with the estimated probability of 52% in 10 years40. The guidelines recommend RASi-based antihypertensive treatment regimens regardless of diabetes status10. However, despite the significant influence of diabetes on accelerated disease progression in CKD patients, the studies investigating clinical outcomes of diverse antihypertensive treatment regimens are still limited38. Among 16 clinical trials included in this study, 9 clinical trials evaluated outcomes from 7 different antihypertensive regimen in CKD patients with diabetes: ACEI monotherapy, ARB monotherapy, ACEI-based spironolactone, ARB-based spironolactone, ARB and ACEI combination, and ARB-based renin inhibitor. The risk of major CVD events was substantially higher in ACEI + SPR  when compared to ARB monotherapy (reference), the most prescribed antihypertensive regimen in Korea , and Scopus were searched from the inception to March 7 2023. The prespecified Medical Subject Headings (MeSH) and keywords were utilized for the initial database search: ‘angiotensin-converting enzyme inhibitors’, ‘angiotensin receptor antagonists’, ‘chronic kidney disease’, ‘hypertension’, and ‘renal insufficiency’. We also used ‘combin*’ as keyword to identify studies evaluating efficacy and safety of antihypertensive combination therapy containing either ACEI or ARB. The full database search terms and strategies are listed in Supplementary Table This study was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) 2020 and PRISMA-Network Meta-Analyses (PRISMA-NMA) guidelines  is prespecified as follows: patients with HTN and non-dialysis CKD (stage 3 to 5), intervention with RASi-based (either ACEI or ARB) dual antihypertensive treatment, both inpatient and outpatients with treatment duration ≥ 24 weeks, and head-to-head RCT. Control was prespecified as any hypertensive treatment regimens including monotherapy and dual antihypertensive therapy that were directly compared with the intervention in the head-to-head RCT. Two reviewers independently screened titles/abstracts for eligibility of all identified studies from the initial database. The prespecified eligibility criteria of study inclusion included (1) head-to-head randomized controlled trials (RCT), (2) studies evaluating efficacy and safety of dual antihypertensive treatment regimens containing either ACEIs or ARBs as intervention in non-dialysis patients with CKD stage 3 to 5, (3) antihypertensive medications prescribed for ≥ 24 weeks, and (4) studies published in English. Duplicated studies, placebo-controlled RCTs, case reports, cross-over designed studies, observational studies, preclinical studies (in-vivo or in-vitro), abstracts including conference abstracts, study protocols, proceedings, reviews, and studies without available full-texts were excluded. Any disagreements on study eligibility were discussed until a consensus was reached. Cohen’s kappa statistic was calculated to determine interrater reliability for study selection and revealed kappa value of 0.88, implying strong level of agreement6. Moreover, other clinical outcomes including reduction in systolic blood pressure (SBP) and diastolic blood pressure (DBP), hyperkalemia, newly diagnosed ESRD (ESRD progression), and all-cause mortality, otherwise referred to as death of any cause were also investigated. Following information was extracted from the eligible study: study characteristics (author and year of publication), study population (number of patients and comorbidities), study intervention and comparators, and treatment duration. We extracted the number of patients experienced the outcomes of the study for dichotomous outcomes. For continuous outcomes such as SBP and DBP, we extracted the mean and standard deviation (SD) of each intervention.The primary outcome of interest was major CVD events identified as MI, stroke, cardiovascular (CV) death, and CV-related hospitalization due to heart failure or angina as these have been identified as the most significant cause of mortality in CKD patient46, and each study were scored as low, some concerns (unclear), or high risk in the following domains: randomization process, deviations from the intended interventions, missing outcome data, measurements of the outcomes, and selection of the reported results. Any disagreements on the quality assessments were discussed until a consensus was reached. Studies were classified as low risk of bias if three or more domains were identified as low risk, whereas studies with at least two domains with high risk were classified as high-risk studies. The quality of evidences was assessed based on Cochrane GRADE guideline for each outcome47.Two reviewers assessed the quality of included studies, and any disagreements on study eligibility were resolved by the third reviewer (SJR). Risk of bias of included studies was assessed in accordance with Cochrane Risk of Bias version 2.0 (RoB 2) tool48. ARB-based dual antihypertensive regimen with calcium channel blocker (CCB) was applied as the control antihypertensive treatment regimen for network analysis41. Dichotomous variables including major CVD events, ESRD diagnosis, all-cause mortality, and hyperkalemia were analyzed with a Mantel–Haenszel random effects model and odds ratio (OR) with 95% confidence intervals (CI) were calculated for each antihypertensive regimen. Changes in SBP and DBP were evaluated as weighted standard mean differences (SMD) with 95% CI. The heterogeneity and inconsistency of included studies were assessed with I2 index and Cochran’s Q, respectively. I2 index > 50% was considered as high heterogeneity and any P value < 0.05 was considered as significant inconsistency49. Egger’s test was performed to detect any publication of bias, and any P value > 0.05 implies a low risk of publication bias. The “netrank” function was utilized to assess the ranking of relative efficacy and safety of antihypertensive regimens in CKD patients, and the calculated P value was equivalent to the Surface Under the Cumulative Ranking (SCURA): the higher the P value, the better the rank of the antihypertensive treatment regimen50. The “netleague” function was utilized to create league tables for each outcome. All P values were calculated by two-sided tests, and statistical significance was determined by P values < 0.05.Pooled traditional pair-wise analyses on the outcomes were performed using ‘netmeta’ package in R (version 4.1.0.). Frequentist network meta-analyses were conducted to simultaneously compare the outcomes of interest by integrating direct and indirect effects of each RASi-based dual antihypertensive treatment regimen against a control group generated by the network meta-analysis in CKD patientsSupplementary Information 1.


In the last decades, noninvasive ventilation (NIV) has been increasingly used to support patients with hypercapnic and hypoxemic acute respiratory failure. Pressure ulcers are a frequently observed NIV-related adverse effect, directly related to interface type and exposure time. Switching to a different interface has been proposed as a solution to improve patient comfort. However, large studies investigating the benefit of this strategy are not available. Thus, the aim of the ROTAtional-USE of interface STUDY (ROTA-USE STUDY) is to investigate whether a protocolized rotational use of interfaces during NIV is effective in reducing the incidence of pressure ulcers.The ROTA-USE STUDY is a pragmatic, parallel arm, open-label, multicenter, spontaneous, non-profit, randomized controlled trial requiring non-significant risk medical devices, with the aim to determine whether a rotational strategy of NIV interfaces is associated with a lower incidence of pressure ulcers compared to the standard of care. In the intervention group, NIV mask will be randomly chosen and rotated every 6 h. In the control group, mask will be chosen according to the standard of care of the participating centers and changed in case of discomfort or in the presence of new pressure sores. In both groups, the skin underneath the mask will be inspected every 12 h for any possible damage by blinded assessors. The primary outcome is the proportion of patients developing new pressure sores at 36 h from randomization. The secondary outcomes are (i) onset of pressure sores measured at different time points, i.e., 12, 24, 36, 48, 60, 72, 84, and 96 h; (ii) number and stage of pressure sores and comfort measured at 12, 24, 36, 48, 60, 72, 84, and 96 h; and (iii) the economic impact of the protocolized rotational use of interfaces. A sample size of 239 subjects per group (intervention and control) is estimated to detect a 10% absolute difference in the proportion of patients developing pressure sores at 36 h.The development of pressure ulcers is a common side effect of NIV that negatively affects the patients’ comfort and tolerance, often leading to NIV failure and adverse outcomes. The ROTA-USE STUDY will determine whether a protocolized rotational approach can reduce the incidence, number, and severity of pressure ulcers in NIV-treated patients.ClinicalTrials.gov NCT05513508. Registered on August 24, 2022. The order of the items has been modified to group similar items  has increasingly become a common approach for the treatment of hypercapnic , 2 and hAs patient comfort is a major factor for NIV success , the selThe development of pressure ulcers is associated with adverse outcomes that may contribute to patient pain and suffering, impaired quality of life , and incPrevention is usually considered the most efficient solution to address pressure ulcers caused by NIV. Recommended preventative measures for skin damage due to pressure, friction, or shear include the following: (1) correct choice of interface and ventilator (2) reducing the time of uninterrupted NIV administration, (3) application of wound care dressing, and (4) absence of humidification. In particular, the interface should be chosen according to size and attachment. On the one hand, it should not be too loose to cause unintentional leakage, which would worsen patient-ventilator interaction. On the other hand, it should not be too tight to increase the risk of skin breakdown.x̅ = 28.4 h) for oronasal masks and from 24.75 to 98 h (x̅ = 61.37 h) for total face masks [As for the exposure time to the interface, a previous study assessing the incidence, location, and stage of pressure ulcers in ICU patients requiring NIV for > 24 h showed that the average exposure time for pressure ulcer development ranged from 1.25 to 74 h  with NIV administered (i) to avoid intubation (ii) as an alternative to invasive ventilation, (iii) to avoid reintubation after early extubation, or (iv) to prevent reintubation.The ROTA-USE STUDY is designed as a pragmatic, parallel arm, open-label, multicenter, spontaneous, no-profit, randomized, controlled, trial requiring non-significant risk medical devices. Figure Data will be collected from ICUs, intermediate respiratory care units, respiratory medicine, or internal medicine services in 23 centers in Italy.Age ≥ 18 years old;2) > 45 mmHg and an arterial partial pressure of oxygen (PaO2) < 65 mmHg at room air plus respiratory rate > 25 breaths/min with clinical signs of respiratory muscle distress) or (ii) as an alternative to invasive ventilation  (iii) to avoid reintubation after early extubation in patients who present the readiness to wean criteria but failed a spontaneous breathing trial or (iv) to prevent reintubation;Patients with chronic obstructive pulmonary disease (COPD) exacerbation or with hypercapnic ARF of a different etiology receiving NIV (i) to avoid intubation ; status post-upper gastrointestinal surgery;Patients entering the hospital with asthma or cardiogenic pulmonary edema;Patients with tracheostomy;Patients receiving NIV only for palliation of symptoms . These patients belong to category 3 as defined by the Society of Critical Care Medicine (SCCM) Task Force assessing the palliative use of noninvasive positive pressure ventilation ;Use of high-flow nasal cannula integrated with NIV to prevent reintubation;Pre-existing skin erythematosus disorders;Known hypersensitivity to skin protective devices ;More than 2 h of NIV application before randomization;Patients already included in the study protocol at an earlier stage of their hospital stay; andRefuse to wear NIV interface due to comfort.Local principal investigators, sub-investigators, trained research nurses, or residents will introduce the trial to the patients or to their legal representatives in case the patients are unable to understand due to communicative or cognitive limitations. The same operators will obtain written consent before randomization from all eligible patients or their legal representatives. Informed consent will be collected according to current national regulations. If patients with legal representatives regain their ability to consent, a second written consent will be requested. In circumstances where patients are unable to consent due to the nature of the underlying disease process  or treatments , in the absence of a legal representative, patients will be randomized, and written consent will be obtained once patients regain their ability to consent. If patients understand and consent to the study, but they are not able to sign a written consent, they will be allowed to verbally agree in the presence of a witness. This verbal consent will then be documented in the medical records. Once the clinical situation improves, the patient will be asked to sign the consent form before being discharged. If a patient dies before a written informed consent can be obtained, his/her data may also potentially be used.At any time during the clinical study, patients can freely withdraw their informed consent. In this case, no further data will be collected, and the data already collected will be deleted. Participants who abandon the study will be replaced with the aim of reaching the number of subjects envisaged by the sample size, with the possible need to extend the inclusion period.No ancillary studies have been planned so far, and no biological specimens will be collected.Two groups will be compared. In the control group , interface rotation during NIV will be allowed only in case patients develop pressure ulcer or become intolerant to the interface. In the treatment group, patients will rotate two interfaces, chosen among those used in that center, every 6 h.In the control group, mask will be chosen among the three types of masks available: oronasal, total face, or hybrid mask, according to the standard of care of the participating centers. Patients wearing oronasal masks will receive protective dressing on their nasal bridges before starting NIV. Interface will be changed in case of discomfort, referred by the patient as unbearable, or in the presence of a pressure sore.In the intervention group, the mask initially applied to the patient will be randomly chosen between the two most used masks in that center among those available . Thereafter, NIV mask will be changed every 6 h, alternating the two different interfaces. Patients wearing oronasal masks will receive a protective dressing on the nasal bridge before starting NIV. In case of discomfort, referred by the patient as unbearable related to one of the two interfaces, NIV will be continued with the other mask.In both arms, the treatment will be continued until patients require NIV according to the assigned protocol.Prior to patient recruitment, the candidate assessors (doctors and nurses) will be trained to recognize and stage pressure sores through a specific standardized education module. At the end of this course, the trainees will be asked to take a final test where they have to correctly stage 10 pressure sores. Only those trainees able to identify and stage all 10 sores will be qualified as assessors. To minimize detection bias, assessors will not participate in patient care and will be blinded to treatment allocation.The skin underneath the mask and occipital region will be inspected every 12 h for possible damage by the assessors. If a pressure sore is detected, the physician in charge of the patient will be promptly informed, and a note will be written on the nursing record. Pressure sores will be staged according to the classification of the National Pressure Ulcer Advisory Panel, European Pressure Ulcer Advisory Panel, and Pan Pacific Pressure Injury Alliance   application of a wound care dressing or a different kind of wound care dressing; (2) reduction of the time spent on NIV; and (3) change interface.Patients will discontinue NIV treatments in case of improvement, worsening leading to intubation, or in case of death.Prior to study protocol initiation, an investigator meeting will be held in each center to detail the study protocol and encourage the staff to adhere to it;The enrolling centers will be selected according to a similar protocol on NIV interface rotation  that represents a common standard of care.Adherence to interventions will be improved by means of the following strategies:To monitor the adherence to the study protocol, the effective time of ventilation derived from the ventilator counter, the exact time of interface change, and the adherence to the skincare bundle protocol will be recorded as well.In both arms, diagnostic tests, administration of systemic therapy , and hemodynamic management will be performed according to the best clinical practice at enrolling centers. The right size of the mask will be selected according to the indications provided by the manufacturer. The mask straps will be adjusted in compliance with the “two-finger rule” so as to not tighten too hard the headgear .2 > 45 mmHg persist or develop despite optimal medical therapy, targeting an oxygen saturation of 88–92%. Blood gas exchange will be performed before starting NIV treatment, 2 h after NIV institution, and thereafter, when clinically indicated. NIV will be initially set to pressure support mode with a ventilator designed specifically to deliver NIV or with an ICU ventilator equipped with an NIV mode. Positive end-expiratory pressure (PEEP) will be set at 3–5 cmH2O, while inspiratory pressure support (PS) will be titrated to achieve adequate augmentation of chest/abdomen movement with an expiratory tidal volume of 6-8 ml/kg and a reduction of respiratory rate (< 30 breaths/min). A good patient-ventilator interaction will be also assessed by checking pressure-flow curve monitoring and the patient’s respiratory pattern. The presence of active humidification will be left to the choice of the patient’s attending physician, although heated humidification should be considered if the patient complains of mucosal dryness or if respiratory secretions are thick and tenacious. The weaning strategy will be documented in the medical and nursing records. The following suggested protocol will be given as a general indication for weaning: continue NIV for 16 h on day 2; 12 h on day 3, including 6–8 h overnight use; NIV may be discontinued on day 4 unless continuation is clinically indicated [2 and pH, and ECG monitoring in patients with a pulse rate > 120 bpm or with dysrhythmia or possible cardiomyopathy. As the international guidelines recommend keeping the skin in contact with the medical equipment dry and clean, a skincare bundle protocol will be adopted by all centers. If a patient needs prolonged continuous NIV, brakes will be programmed and annotated in the case report form (CRF). In case of instability, the interface will be removed for about 10 min solely to ensure oxygenation [In accordance with international guidelines , patientndicated . The suggenation . In both2 are normalized in the presence of neurological, hemodynamic, and respiratory stability, patients will be extubated and subjected to NIV. The ventilator will be initially set at the same PEEP and inspiratory PS level applied during invasive mechanical ventilation, setting it at the fastest pressure rise time. Successively, NIV setting will be titrated to maintain arterial blood gas in a normal range, a tidal volume between 6 and 8 ml/kg of predicted body weight, and a respiratory rate below 25 breaths/min. In patients tolerating spontaneous breathing. NIV will be gradually tapered off until they can permanently sustain spontaneous breathing.For patients intubated due to hypercapnic ARF secondary to COPD or other causes related to hypercapnic ARF, NIV might be applied during early extubation and weaning. According to the international guidelines, NIV is recommended to aid weaning from invasive mechanical ventilation, when local expertise in its use exists , 14. PatNIV is extensively used in clinical practice. All patients included in the study deserve NIV treatment according to their clinical symptoms and pathology. Major complications due to NIV treatment are not expected. If any complications occur, they will be treated according to the best clinical practice.The primary effectiveness outcome is the proportion of patients developing at least one pressure sore of any stage at 36 h from randomization. The reason why this measure of effectiveness was chosen is that it is more clinically relevant than the overall number of pressure sores. Furthermore, 36 h seems to be an appropriate time point given that the time it takes for pressure sores to develop is extremely variable, but it might as well be very short.Secondary outcomes will be the onset, number, and stage of pressure sores and comfort during NIV measured at different time points . At the same time points, the location of pressure sores per patient will also be recorded, i.e., forehead, nose bridge, left cheek, right cheek, chin, left periauricular, right periauricular, and occipital. The study will also monitor the number of patients that interrupts NIV due to discomfort, the presence/absence of eye irritation in relation to both oronasal and full face/hybrid mask, poor adherence to the protocol  and the presence/absence and types of vasoactive medications, i.e., epinephrine, norepinephrine, vasopressin, dobutamine, dopamine, other. Further outcomes include the costs for intervention implementation  and those related to the care of pressure sores .Patients will be screened for eligibility criteria. Consent will be obtained from the patients, if possible, or their legal representative. Thereafter, patients will be randomized into the treatment or control group. After randomization, the skin underneath the mask and the auricle and occipital regions will be inspected to check for any possible pressure sores every 12 h for the following 4 days. Patient status at hospital discharge will also be evaluated  or standard of care (control) group. Moreover, following the same procedure, patients in the interface rotation group will be assigned to start their treatment wearing an oronasal mask or full face/hybrid masks. The randomization list will be uploaded into the research electronic data capture (REDCap) system that will provide the assigned arm of the patients. Investigators will have no access to the randomization list.To ensure allocation concealment, the randomization list will be uploaded directly into REDCap. Allocation will take place after the patient is recruited to the trial.The statistician (LS) will prepare the randomization list that will be uploaded into REDCap. Once the staff members enroll a new patient, he/she will access REDCap that will provide the randomization arm and mask sequence after filling out the inclusion criteria form.Due to the nature of the intervention tested, trial participants and care providers will not be blinded after being assigned to an intervention. However, assessors and data analysts will not participate in the care of the patient and will be blinded to patient group assignment.Unblinding procedure is not required.Baseline characteristics: age, sex, hospitalization date, nutritional status, body mass index, Braden scale, frailty index, sensorium (Kelly score), Charlson index, chronic steroids therapy, domiciliary NIV or CPAP, NIV treatment goal.Outcome assessment: presence and number of pressure sores, location, comfort score , stage for each lesion, fever, humidification, vasoactive medication, NIV interruption, daily NIV duration, hygiene protocol application, eye irritation, interface change, time interface change, NIV ventilator, circuit type, expiratory positive airway pressure, inspiratory positive airway pressure, leaks, medical treatment for the pressure lesions and eventual skin specialist consult.Discharge: discharge date, length of hospital stay, discharge status.A REDCap database will be set up to collect the information needed for the study. The database will consist of ten sheets. The first one will contain the baseline demographic and clinical characteristics of the patients. Eight sheets will store information on primary and secondary outcomes at each time point. The last one will enlist information on patient discharge and the overall treatment. More specifically, the following variables will be recorded:Once a patient is enrolled or randomized, the study investigators will make every reasonable effort to follow the patient for the entire study period. This trial does not entail a long follow-up period, thus the rate of loss-to-follow-up is anticipated to be negligible.Data entry will be carried out by the investigators of each study center after the participation in training session before the beginning of the study to standardize procedures, including data collection.Investigators may contact the coordinating center to solve issues that may arise.Only authorized staff will be able to access the REDCap system. A two-step login procedure is needed to access the system. The first step requires the login with username and password. After the completion of the first step, an e-mail is sent to the user by the system with a verification code to be entered in the second step login, which expires after two minutes.Investigators will only be granted access to the records of their own patients but not to those stored in the entire database.The data will be automatically stored by REDCap, with backups planned every 4 h.During the creation of data collection sheets, when possible, the data format and range of plausible values will be set. If the input value is outside the defined range, a warning message will automatically appear to the researcher.Data will first be collected with a paper support and, after having checked for completeness and consistency, will be entered in REDCap.After the end of data collection:Data provided by the centers will be checked for missing data, plausible, possible, or non-permitted value ranges. When necessary, centers will be asked to correct them;Statistical techniques to identify inconsistencies will be applied periodically. The centers will be notified about eventual inconsistencies to correct them;The coordinating center will review detailed reports on screening, inclusion, follow-up, and data consistency and completeness. The coordinating center will take immediate action to solve any problems that may arise.Data will be entered in the final electronic database only after the CRFs have been cleared by the coordinating center.The electronic CRF, which will not include any names, initials, dates of birth, or local hospital patient numbers, is identified by a unique subject identifier. Data protection in the database will be guaranteed through encoding and the use of a secured database with restricted access by individual login and gradated user rights. Lastly, only encrypted data will be centrally stored.No biological specimens will be collected.The analysis will be performed according to the intention-to-treat (ITT) principle. Descriptive statistics will be calculated to summarize patient characteristics collected at study entry according to the randomization group. Categorical variables will be reported as absolute frequencies and percentages. Continuous variables will be represented as mean and standard deviation or median first and third quartiles if not normally distributed according to the Shapiro–Wilk test.The raw risk of pressure sore will be calculated at each time point as the ratio between the number of subjects who developed a pressure sore at a given time point divided by the number of subjects undergoing NIV at that time point. Patients having a planned break at the time point considered, but not weaned off NIV, will be considered as patients undergoing NIV.Mixed effect logistic regression models will be used to estimate the risk of pressure sores and the difference between interfaces, including a random intercept to account for clustering of the subjects within the center and repeated measures within patients. The response variable will be the presence/absence of pressure sores, whereas the independent variables will be the treatment, time , and their interaction. The marginal predicted probabilities estimated by the model will provide the incidence of pressure sores at different times as well as overall. The inclusion of time as a covariate will allow to test the presence of a time trend in the incidence of pressure sores and to investigate the variation of time trends according to treatment group.If the descriptive statistics will detect unbalanced characteristics between randomization groups , the corresponding variables will be added as covariates in the logistic regression model.Regarding the number of pressure sores, different mixed effect Poisson regression models will be applied: one for each time point to estimate the average number of pressure sores at each time point and a model in which only the highest number of pressure sores will be considered for each patient. Time will be included as offset to evaluate the average number of pressure sores per day.The grade and location of pressure sores will be summarized using descriptive statistics at each time point.The analyses will be also performed according to the modified intention-to-treat approach (mITT) excluding subjects with a NIV duration shorter than 12 h to ensure patients in the rotational group performed at least one rotation of the interface.th and 9.75th percentiles of the bootstrap distribution of ICER will be considered as the lower and higher limits of the confidence interval. The cost-effectiveness acceptability curve will also be drawn to evaluate the probability of the intervention to be cost-effective, considering different thresholds.Regarding the economic evaluation, the incremental cost-effectiveness ratio (ICER) will be calculated considering two outcomes: (i) the proportion of pressure sores and (ii) the patient comfort. ICER, which is the ratio between the difference of each outcome in the two groups  and the difference in the average cost for each treatment will allow to evaluate the incremental costs needed to reduce of 1 point the outcomes thanks to interface rotation. The confidence intervals of the ICER will be calculated using the non-parametric bootstrap method. Specifically, the 2.5p-value < 0.01 for the rejection of the null hypothesis that the strategies are equivalent in terms of pressure sore incidence rate.A single interim analysis will be performed when two-thirds of the predefined sample are randomized and completed the study. Early stopping criteria will be a predetermined 2-sided When possible , the analyses will be performed stratified by center.Protocol non-adherence will be handled by performing the analyses according to the ITT principle, specifically, patients will be analyzed considering their allocation group regardless of the intervention they will follow. Moreover, deviation from the protocol will be registered as well as the reason for deviation. The missing rate is expected to be very low, therefore no specific analyses to handle missing data are planned. However, if needed  multiple imputation through expectation–maximization algorithm will be applied and the results obtained from analysis of the new data will be considered as sensitivity analysis.Public access to the full protocol and statistical methods will be obtained by publishing the study protocol in an open-access journal. Study protocol has been submitted to ClinicalTrials.gov (identifier: NCT05513508).The coordinator center is based at the Università del Piemonte Orientale and includes Rosanna Vaschetto , Nello De Vita (research physician), Eduardo Rocca (research physician), Alberto Dal Molin (research nurse) e Lorenza Scotti (methodologist). Coordinator center tasks will consist in preparing protocol and revisions; designing CRFs; organizing steering committee meetings; managing and controlling data quality; designing, testing, and maintaining the electronic data capture system; assisting the steering committee; managing the research centers; selecting and training the research centers; helping the centers prepare all the necessary documents to be submitted to research ethics boards (REBs) and assisting centers with submission; monitoring recruitment rates; sending study materials to the research centers; complete statistical analysis; and writing and publication of study protocol and final manuscript.The trial steering committee is composed by Cesare Gregoretti (lead investigator), Annalisa Carlucci (lead investigator), Andrea Cortegiani (lead investigator), Claudia Crimi (lead investigator), Alessio Mattei (lead investigator), Raffaele Scala (lead investigator), Federico Longhini (lead investigator), Gianmaria Cammarota (lead investigator), Giovanni Misseri (lead investigator), and Paolo Navalesi (senior lead investigator). The trial steering committee responsibilities will be agreement on the final protocol, recruitment of patients and liaising with the principal investigator, reviewing the progress of the study, and if necessary agreeing on changes to the protocol and/or investigators brochure to facilitate the smooth running of the study, agreement on the final manuscripts.The data monitoring group is composed by Stefano Nava (lead investigator), Sabino Scolletta (lead investigator), and Salvatore Maurizio Maggiore (lead investigator). The role of the data monitoring committee is to independently review the study protocol, recruitment of patients and liaising with the principal investigator to be involved in the safety monitoring interim analysis, and agreement on the final manuscripts. The Data Quality Assurance group is composed by Eduardo Rocca, Federico Longhini, Gianmaria Cammarota, Giovanni Misseri, and Alberto Dal Molin and will be responsible for monitoring data for inconsistency and missing data.Interfaces for noninvasive ventilation should be considered as a non-significant risk device according to the definition given from the Food and Drug Administration. Besides, the present randomized controlled trial does not intend to investigate a new interface but the protocolized rotational use of commercially available interfaces. As patients with contraindications to NIV/with known hypersensitivity to skin protective devices will be excluded from the study, the potential for serious adverse events related to a protocolized rotation use of interfaces appears remote. Possible minor adverse events consequent to the use of noninvasive ventilation interfaces consist of pressure sores, dryness of the mouth, eye redness, and discomfort. All these information will be recorded and reported as primary and secondary outcomes of the study.At the start of the trial, the coordinating center will conduct a tutorial on the web-based data entry system. Overall quality and completeness of the data will be checked every six months.Any modifications to the protocol that may impact the conduct of the trial will require a formal amendment to the protocol. All amendments to the protocol must be approved by the internal review board of each participating center. Administrative changes to the protocol, minor corrections, and/or clarifications that have no effect on the way the trial is to be conducted will be agreed upon among the participating centers.The ROTA-USE STUDY group will publish the study findings, whatever they are. The main manuscript will be submitted by the writing committee on behalf of the research group. The principal investigators of the three top enrolling centers will be included and engaged in the writing process. Collaborative authorship  will be offered to the principal investigators and research nurses of all the centers including at least 20 patients.All the issues have been covered in the above sections.The ROTA-USE protocol, version I (01/07/22), has been approved by the research ethics committee of the coordinator center on the 16/09/22, and recruitment has started in December 2022 at the coordinating center. The remaining centers are undergoing ethics committee evaluation. Recruitment is expected to be completed within September 2024.


BackgroundHypertension is the leading risk factor for cardiovascular disease and death. Appropriate treatment of hypertension is necessary to reduce mortality. A prescription-based study is one of the most influential and helpful methods to examine physicians’ irrational prescribing practices. This study was designed to investigate the antihypertensive prescription of physicians and their adherence to the treatment guidelines, as well as the blood pressure (BP) control rate in a general hospital in the Kingdom of Saudi Arabia.MethodologyA retrospective, cross-sectional study was conducted between February 2020 and June 2021 in an outpatient department. Patients diagnosed with hypertension as per the 2020 International Society of Hypertension guidelines and those who received antihypertensive drugs were included. Study data included prescriptions, patient’s age, duration of hypertension, comorbidities, BP, drug therapy type, and antihypertensive class.Results2 = 71.316; p < 0.001).Overall, angiotensin-converting enzyme inhibitors/angiotensin II receptor blockers (67.1%) were the most prescribed agents, followed by dihydropyridine-calcium channel blockers (62.6%), diuretics (26.1%), and β-blockers (10.1%). Comorbid and stage 2 hypertensive patients mainly received combination therapy (51.6%) rather than monotherapy (48.4%). The study revealed an 83.5% prescription adherence to the treatment guidelines. However, non-adherence was encountered in monotherapy, polytherapy, and elderly-treated patient groups. A 66.4%  and 39.3% (at target BP in comorbid patients <130/80 mmHg) rate of BP control was observed. Furthermore, the rate of BP control was significantly associated with prescription adherence (χConclusionsThe degree of prescription adherence and rate of BP control were found to be compatible with other published hypertension studies. However, considerable scope exists for improvement in rational drug utilization and rate of BP control, particularly in high-risk patients. Therefore, treatment guidelines must be followed by clinicians to achieve BP goals and reduce cardiovascular events among the Saudi population. Hypertension is one of the major preventable risk factors for heart disease and stroke . HyperteThe rational use of antihypertensive drugs is one of the leading global challenges. Studies have revealed that irrational prescribing practices are associated with increased morbidity and mortality -7. ThereThe prescribing patterns of antihypertensive medication studies are beneficial in monitoring and evaluating prescribing habits to achieve better outcomes and patient safety -13. StudStudy design and participantsWe conducted a retrospective, cross-sectional study among established hypertensive patients. The study was conducted between February 2020 and June 2021 in the medicine outpatient department (OPD) at Dawadmi General Hospital, Riyadh, Saudi Arabia. The inclusion criteria required that the patient had a clinic systolic/diastolic BP (SBP/DBP) ≥140/90 mmHg at the time of diagnosis, had received at least one antihypertensive medication, had Saudi citizenship, and was aged ≥18 years. The study excluded pregnant women.Sample size2 pq/I2, where n is the minimum sample size; z is 1.96, which corresponds to 95% confidence interval; p is the proportion of the study population estimated to have hypertension (15.2%) (p = 0.152); q is 1.0 - p = 1.0 - 0.152 = 0.848; I is the allowable error (5%) = 0.05. Hence, the sample size was calculated as n = (1.96)2 × 0.152 × 0.848/(0.05)2 = 199. This formula gave the most diminutive sample size of 199, which was exceeded by enrolling 417 participants.The sample size was calculated using the following formula described by Alruways et al.  based onBlood pressure measurementThe office BP method was used to diagnose hypertension. Two readings  of BP levels were taken and averaged on at least two occasions .Criteria of non-adherence to antihypertensive therapyHealthcare practitioners define irrational therapy as not following the treatment guidelines. The established criteria in defining irrational therapy are (a) monotherapy prescribed to grade 2 hypertensive patients; (b) monotherapy prescribed to high-risk grade 1 hypertensive patients aged less than 80 years; (c) β-blockers used without complaints of IHD, HF, AF, or pregnancy; (d) triple therapy prescribed without TZD/TZD-like diuretics; (e) ACEI and ARB concurrently used; (f) ACEI/ARB monotherapy prescribed to elderly patients (age ≥75 years) and grade 1 hypertensive patients; (g) polytherapy prescribed to elderly patients (age ≥80 years) and low-risk grade 1 hypertensive patient; and (h) short-acting DHP-CCB (nifedipine) prescribed for IHD .Data collectionWe reviewed 417 outpatient prescriptions from patients diagnosed with hypertension and prescribed at least one antihypertensive drug. Data collected from physicians’ prescribing records of medicine OPD of Dawadmi General Hospital included the duration of hypertension, SBP, DBP, and comorbidities such as diabetes mellitus (DM), dyslipidemia (DLP), IHD, chronic kidney disease (CKD), congestive heart failure (CHF), and stroke. Before data collection, we obtained consent from the Dawadmi General Hospital Authority and the Ministry of Health, Saudi Arabia. All data were kept confidential during and after the study.Statistical analysis2) test was applied to examine the statistical significance. Continuous variables were presented as the mean ± standard deviation (SD), and categorical variables were presented as frequencies and percentages. All comparisons were considered significant at p-values <0.05.Data were analyzed using SPSS version 25 . A one-sample binomial or chi-square  and Medical Research Ethics Committee, College of Medicine, Dawadmi, Shaqra University, Saudi Arabia (project number: CMD/DWD/SU/2019/11/004).Ethics guideline statementThe 2020 ISH Global Hypertension Practice Guidelines  and the Characteristics of the study populationIn total, 417 prescriptions fulfilled the inclusion criteria. Of the total, 78.2% of the patients were under 65 years of age. The average age of the study population was 56.58 ± 11.11 years. Our study found that more than half (64.7%) of the participants had at least one comorbidity. Regarding comorbidities, most hypertensive patients had DM (48.2%), followed by DLP (16.3%), IHD (5.3%), stroke (3.1%), CKD (2.9%), and CHF (1.9%), as summarized in Table Table Utilization of different classes of antihypertensive drugsFigure Utilization of antihypertensive drugs as monotherapy or polytherapy in different age groupsMost younger age groups received monotherapy which is significantly higher compared to the older group of hypertensive patients . However, polytherapy was more commonly used in the elderly group of hypertensive patients , as summarized in Figure Utilization of antihypertensive drugs as monotherapy or polytherapy in comorbidityFigure Types of antihypertensive therapy and duration of hypertensionUtilization of polytherapy was found to be significantly higher among patients who had hypertension for the last five years or more than five years, as summarized in Figure Prescription pattern of antihypertensive drugs in hypertensive patients with or without comorbidityThe study results revealed that most hypertensive patients received combination therapy (51.6%) rather than monotherapy (48.4%). Overall, renin-angiotensin system (RAS) blockers  were the most prescribed antihypertensive agents, followed by DHP-CCBs (62.6%), diuretics (26.1%), and β-blockers (10.1%). Hypertensive patients who had no comorbidity received mostly DHP-CCBs (71.4%), followed by RAS blockers 48.3%), diuretics (24.5%), and β-blockers (2.7%). The hypertensive patients who had DM mostly received RAS blockers (75.5%), followed by DHP-CCBs (59.2%), diuretics (21.4%), and β-blockers (6.5%). However, RAS blockers (83.3%) and diuretics (58.4%) were the most preferred choice among CKD patients. Polytherapy was mainly prescribed to DM (53.2%), DLP (58.8%), and CKD (91.7%) hypertensive patients, as summarized in Table %, diuretUse of antihypertensive drugs in hypertensive patients with ischemic heart disease, stroke, or congestive heart failure or in the elderlyHypertensive patients who had IHD mostly received RAS blockers (86.3%), followed by β-blockers (72.7%), DHP-CCBs 40.9%), and diuretics (40.9%). However, RAS blockers (92.3%) and DHP-CCBs (69.2%) were the most preferred choice among stroke patients, followed by β-blockers (68.2%) and diuretics (38.4%). CHF patients received mainly diuretics (75%) and RAS blockers (75%), followed by DHP-CCBs (37.5%) and β-blockers (37.5%). However, elderly patients primarily received RAS blockers (73.6%), DHP-CCBs (69.2%), diuretics (31.9%), and β-blockers (24.2%). Regarding types of antihypertensive therapy, polytherapy was mainly used among the elderly (70.3%), IHD (81.8%), stroke (84.6%), and CHF (87.5%) hypertensive patients, as summarized in Table 0.9%, andNon-adherence to antihypertensive treatmentThe results indicated 17.7%, 10.7%, and 11% non-adherence prescriptions with monotherapy, polytherapy, and elderly treated patients, respectively. The non-adherence prescription finding was (a) 4.9% monotherapy prescribed to grade 2 hypertensive patients; (b) 12.2% monotherapy prescribed to high-risk grade 1 hypertensive patients aged less than 80 years; (c) 3.7% and 0.5% β-blockers used in dual and triple therapy, respectively, as first-line antihypertensive without IHD, HF, AF, or pregnancy; (d) 4.6% triple therapy prescribed without TZD/TZD-like diuretics; (e) ACEI plus ARB concurrently used (1.4%); (f) ACEI/ARB monotherapy (8.8%) prescribed to elderly patients (age ≥75 years) and grade 1 hypertensive patients; (g) 2.2% polytherapy prescribed to elderly patients (age ≥80 years) and low-risk grade 1 hypertensive patients; and (h) 0.5% monotherapy of short-acting DHP-CCB prescribed to IHD, as summarized in Tables Association of blood pressure control with prescription adherence according to cut-off points2 = 71.316; p < 0.001). In hypertension with comorbidity groups, our study revealed a 78.5% degree of prescription adherence. However, the rate of BP control dropped to 39.3% at a lower cut-off point (target BP <130/80 mmHg) and exhibited a significant association with prescription adherence , as summarized in Table Among the total patients, the result demonstrated an 83.5% degree of prescription adherence and a 66.4% rate of BP control (at BP target ≤140/90 mmHg). Moreover, BP control was significantly associated with prescription adherence  the type of antihypertensive therapy and intensity of BP control depended on the patient’s age; young patients were less aggressively treated (mostly with monotherapy) compared to the older age group. (2) Treatment intensity increased for patients with comorbidity and treatment duration of hypertension. (3) Rate of BP control was linked to a percentage of adherence to the treatment guidelines; non-adherence to treatment showed poor BP control. Treatment intensity (as indicated by polytherapy) increased with age, comorbidities, and duration of hypertension. The broad armamentarium of drug treatment options was applied preferably at a later age and in patients with comorbidities. Our study supports a previous study conducted in Germany .Regarding overall drug utilization, our study revealed that RAS blockers (ACEIs/ARBs) and DHP-CCBs were the most preferred antihypertensive classes, supporting previous hypertension studies conducted in South Korea , India , and SauAccording to the 2020 ISH Global Hypertension Practice Guidelines, monotherapy should be considered in low-risk grade 1 hypertension, elderly ≥80 years), or frail patients 0 years,  and hypeComorbidities such as DM, IHD, HF, CKD, stroke, and metabolic syndrome may affect therapeutic choices of antihypertensive drugs ,9. Our sRegarding drug utilization in DLP patients, our study revealed that the most preferred antihypertensive drugs in dyslipidemia are RAS blockers 79.4%) and DHP-CCBs 58.8%), aligning with the hypertension guidelines and consistent with a previous study in Germany reported by Pittrow et al. [9.4% and .8%, aligAccording to the hypertension guidelines, using RAS blockers is recommended as the first line in CKD patients because they reduce albuminuria in addition to BP control. In this study, physicians mainly used RAS blockers, revealing adherence to the hypertension guidelines ,9 and coAs first-line therapy, hypertensive patients with IHD should be treated with RAS blockers and β-blockers for compelling indications  . Our resTreatment of elevated BP in advanced age (≥65 years) is challenging due to a high degree of heterogeneity in comorbidity, polypharmacy, and frailty . Our stuWe highlighted non-adherence to monotherapy, combination therapy, and elderly patient treatment. According to the treatment guidelines, a combination of ACEIs, ARBs, and direct renin inhibitors is not recommended due to the greater risk of hyperkalemia and hypotension and the lack of demonstrated benefit in cardiology trials  and diabStudy limitationsOur study result has certain limitations. First, because of the retrospective, cross-sectional design, there was no assessment of whether the current therapy was the initial one or whether it replaced or amended the original therapy. Second, the study was conducted in a single general hospital, and thus the results cannot be generalized to the whole population. Third, only outpatients were included in the study. Further, some information regarding side effects, contraindications, and other comorbidities such as electrolyte abnormalities, gout, bronchial asthma, chronic obstructive pulmonary disease, and secondary hypertension-endocrine causes were not evaluated and might have played a role in drug choice.Our study evaluates the prescription pattern in an OPD of a general hospital in Saudi Arabia and its alignment with the 2020 ISH Global Hypertension Practice Guidelines. The current findings indicate that the pattern of prescription is in line with hypertension guidelines and other published hypertension studies. However, considerable scope exists for improvement in rational drug utilization and rate of BP control, particularly in high-risk patients, such as those with DM, DLP, IHD, HF, and CKD, and the elderly. Therefore, treatment guidelines should be followed by clinicians to meet blood pressure goals and reduce cardiovascular events among the Saudi population.


To evaluate whether symptomatic recurrent nephrolithiasis leads to loss of kidney function.Adults who presented to the Emergency Department at least twice with symptomatic and radiologically confirmed nephrolithiasis were retrospectively recruited. Primary endpoint was the change in glomerular filtration rate (GFR) between baseline and at the time of data collection. Secondary endpoints include GFR slope defined as the mean rate of change in GFR from baseline to the end of the study period.n = 42) had worsening GFR, with the average change in GFR of − 8.64 ml/min/1.73 m2 per year. Four patients progressed to ESKD requiring haemodialysis. 14.5% (n = 35) had calcium oxalate stones. Univariate analysis showed older patients (p < 0.001), more symptomatic stone episodes (p < 0.001) and non-calcium-containing stones (p < 0.001) were strongly associated with deteriorating kidney function. Age (p = 0.002) and number of acute stone episodes (p = 0.011) were significant predictive factors when unadjusted to co-morbidities. Age (p = 0.018) was the only predictive factor of worsening GFR when adjusted for co-morbidities. Average mean GFR slope was − 2.83/min/1.73 m2 per year.240 patients had recurrent symptomatic nephrolithiasis. Median follow-up was 5.4 years. The median age of first acute presentation was 51.6 years and the median baseline serum creatinine (bsCr) was 85.5 umol/l. 17.5% (Recurrent symptomatic nephrolithiasis is associated with loss of kidney function, in older patients, increased episodes of symptomatic nephrolithiasis and non-calcium-containing stones. Age is the only predictive factor for progression to chronic kidney disease in this subgroup.The online version contains supplementary material available at 10.1007/s11255-023-03463-x. In the U.S., almost 2 million outpatient visits were recorded with urolithiasis as the primary diagnosis in 2000 . CollateAccording to Vaughan et al., the risk of stone recurrence in 5 years ranged from 0.9 to 94% depending on risk factors, number of previous episodes, and years since the last episode . A recenThis is the first study looking at the Australian cohort to determine the impact of recurrent symptomatic nephrolithiasis on kidney function.Initial data were extracted using International Classification of Diseases, 10th revision (ICD-10) codes  to identify Emergency Department (ED) presentations of nephrolithiasis between 1st January 2005 and 31st December 2017 at Flinders Medical Centre in South Australia. An interval of at least 1 month between codes represented a separate stone episode. De-identified data were collected between November and December 2019.This study was approved by the Office for Research, Southern Adelaide Local Health Network, South Australia Health . Informed consent was not required.This was a retrospective cohort study to evaluate recurrent nephrolithiasis and loss of kidney function in the Australian cohort. Patients 18 years or older with at least two documented ED presentations with acute symptomatic nephrolithiasis, and stone visualised on imaging (computed tomography or ultrasound) or which required intervention during that 12-year study period were enrolled. We excluded pregnant patients and those on maintenance dialysis at baseline.Radiology images and reports were reviewed to confirm nephrolithiasis and to classify the degree of obstruction if present. Where severity of obstruction was not reported, the grading system of hydronephrosis from Society of Foetal Urology was utilised. Where radiology imaging was not available, the operation report for any intervention of nephrolithiasis was reviewed to confirm obstruction.Baseline demographics at initial ED presentation were recorded. This consisted of age, gender, co-morbidities including diabetes, hypertension, obesity, ischaemic heart disease, inflammatory bowel disease, gout and previous gastrointestinal surgery. Gastrectomy, partial or total colectomy and appendicectomy were considered as previous gastrointestinal surgery. Underlying kidney conditions identified on imaging such as medullary sponge kidney, polycystic kidney disease, single functioning kidney or congenital abnormalities of the urinary system were documented.All laboratory results were acquired from the same pathology service in South Australia. Modification of Diet in Renal Disease (MDRD) equation was used to calculate the estimated glomerular filtration rate (eGFR) until 2013. This was subsequently changed to Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formula as it was validated in Aboriginals and Torres Strait Islanders population. Baseline serum creatinine (bsCr) and eGFR were defined as levels measured at least 1 month prior to initial ED presentation. However, the bsCr and eGFR from the first acute ED presentation were taken if there was no previous documentation of renal function. For missing eGFR values, MDRD equation was used to obtain an eGFR based on the serum creatinine and patient’s age at the time of the blood test.2 for at least 3 months. All eGFR values then were recalculated using CKD-EPI formula [The most recent sCr and eGFR were obtained at the end of data collection (December 2019). Patients who died or became dialysis dependent were recorded. Chronic kidney disease (CKD) was defined as eGFR < 60 ml/min/1.73 m formula  as indicThe total number of acute ED presentations for recurrent nephrolithiasis for each patient was documented. Of those, the initial four ED presentations were assessed. For each presentation, two sCr measurements were obtained—the peak sCr during admission and last documented sCr on discharge. If there is no discharge sCr available for that stone episode, the same peak sCr value during admission is used as the discharge sCr measurement. Stone characteristics were also collected, including stone size based on diameter reported on imaging (in millimetres) with four subgroup ranges , location , and presence and severity of obstruction. All stone chemistries at any point during the study period were recorded. In patients where two stone compositions were detected, they were regarded as mixed stone formers. Metabolic workup at any point during the study period were also identified, including serum electrolytes, parathyroid hormone, vitamin D levels and 24-h urinary electrolytes.t test to analyse eGFR change. Variables that were evaluated included age, number of nephrolithiasis episodes, cumulative stone diameter, degree of obstruction categorised between no obstruction and mild obstruction against moderate to severe obstruction, and stone composition categorised as those with or without calcium. Associations were summarised with corresponding 95% confidence intervals (CI). A multivariate linear regression model was developed, and this included the variables with significant associations from univariate analysis. The model was adjusted for co-morbidities including diabetes, hypertension, ischaemic heart disease, obesity, inflammatory bowel disease, gout, and previous bowel surgery. Associations were summarised with corresponding 95% confidence intervals (CI). All analyses with p value < 0.05 were considered statistically significant.Statistical analyses were performed using Stata version 15 . Continuous variables are expressed as mean ± standard deviation or median with interquartile ranges as appropriate. Categorical variables are expressed as counts with percentage. The primary outcome measured was the change between eGFR at baseline and at the end of data collection. Univariate analysis was performed using Pearson correlation test or two-sample 2 per year [Mean decline in eGFR over time, also known as eGFR slope was measured. Slope was calculated as the coefficient of the best-fitted line estimated for the relationship between all eGFR values recalculated using CKD-EPI formula and time using simple linear least-squares regression analysis. A reduction in eGFR slope of at least 1.07 ± 0.42 ml/min/1.73 mper year  was cons334 patients had at least 2 coded ED presentations. After chart review, 240 patients had confirmed recurrent symptomatic nephrolithiasis with a total 554 episodes incorporated in the final analysis Fig. . Nine pa2. 44.2% had CKD Stage 1. The percentage of patients with the same sCr on admission and discharge for each stone episode are 70%, 64.2%, 62.1% and 81.3% respectively , followed by distal ureter (17.7%) and proximal ureter (17.3%). 45.1% of all episodes had mild hydronephrosis. Only 24 episodes (4.3%) had severe hydronephrosis. Of the 118 patients where stone composition was available, 14.6% had calcium oxalate stones, followed by mixed calcium oxalate and calcium phosphate stones (12.5%) and pure uric acid stones (9.6%)  and 64 (26.7%) patients, respectively. 34 (14.2%) patients had 24-h urinary electrolytes performed. Supplementary Table S1 provides the number of patients whose 24-h urine electrolyte collection was available with and without their stone chemistries.Median follow-up was 5.4 years. Four patients progressed to end-stage kidney failure requiring haemodialysis. During the study period, 11 patients died—5 due to malignancy, 1 due to hospital acquired pneumonia, and 5 where the cause was unknown (died as outpatient).2 per year. In patients with a reduction of eGFR, the average change in eGFR was − 8.64 ml/min/1.73 m2 per year. 14 had an improvement in eGFR (5.8%) but 8 of these 14 patients had unknown baseline renal function prior to their first ED presentation.42 of the 184 patients had a worsening eGFR (17.5%). When adjusting the change in eGFR in relation to time between baseline eGFR and at the end of data collection, the average change in eGFR was − 1.32 ml/min/1.73 mp < 0.001), number of symptomatic episodes of nephrolithiasis (p < 0.001) and cumulative stone size diameter (p = 0.004). There was no significant association of reduction of eGFR with degree of obstruction (p = 0.089). Univariate analysis for 118 patients where stone composition was available demonstrated that non-calcium-containing nephrolithiasis was significantly associated with a reduction in eGFR (p < 0.001). A multivariate linear regression model demonstrated older patients (p < 0.001) and increased episodes of symptomatic nephrolithiasis (p = 0.011) were significant predictors for a reduction in eGFR unadjusted for co-morbidities. Cumulative stone size was not a significant predictive factor for reduced eGFR (p = 0.894). Only age was a significant predictor for reduction in eGFR when adjusted for all co-morbidities (p = 0.018). The average eGFR slope is ‒ 2.83 ± 14.5 ml/min/1.73 m2 per year .Our results were also consistent with previous study findings despite different definitions for a recurrent nephrolithiasis episode. A cohort study by Alexander et al. compared 23,706 stone formers with 3,065,488 non-stone formers using ICD-9 and ICD-10 derived from registry data from the Alberta Kidney Disease Network database and the Northern and Southern Alberta Renal Programs . Their dAnother cross-sectional, case–control study of 195 adult patients conducted in Iceland  defined We also found that age was a significant predictor for reduction in eGFR when adjusted for co-morbidities. This is supported by a study conducted by Haley et al. which compared kidney function of incident symptomatic patients with their first episode of nephrolithiasis and age- and sex-matched controls . They foFurthermore, we observed that a higher number of symptomatic episodes of nephrolithiasis were significantly associated with a greater likelihood in the loss of kidney function, but it was not a predictive indicator when adjusted for hypertension, diabetes, ischaemic heart disease, obesity, inflammatory bowel disease and gout.The pathophysiology behind recurrent nephrolithiasis and CKD is likely multi-faceted. Despite patients with nephrolithiasis having co-morbidities associated with CKD, such as diabetes, hypertension and gout , there iSimilarly, stone-specific factors such as stone composition  and stonWe also found a significant association between cumulative stone size and deterioration of kidney function, but it was not considered a predictive factor for CKD. This is in contrast to a prospective study of 97 external shockwave lithotripsy patients in Iran. They found in individuals with cumulative stone size of less than 20 mm, it was an independent predictor for CKD; each 1 mm increase in cumulative stone size was associated with a 20% increased risk of CKD .Another important consideration of CKD progression includes medications such as nonsteroidal anti-inflammatory drugs (NSAIDs) for pain relief which was not collected in our study. Whilst there is well-reported evidence of NSAIDs-related acute kidney injury, a recent review showed the risk of CKD progression from NSAIDs to be small and relative to cumulative dosing. They have recommended that there is no increased risk of progression of CKD in patients with CKD stage 1–3 in the absence of risk factors such as being more than 65 years old, having coronary artery disease and concomitant analgesic use . This coWe take note of the 14 patients who had an improvement of their renal function, for which over half did not have a baseline eGFR. As a result, their baseline eGFR was considered as their eGFR at the time of their first ED presentation. This may reflect a false improvement of their renal function due to the lack of previous eGFR readings. We also observed the lack of 24-h urinary electrolytes within our cohort. This could be due to two main factors: data collection was confined to one pathology service which was approved by our ethics committee, or it was not ordered by the treating physician.This study has several strengths. To date, this is the first known study which examines recurrent nephrolithiasis in an Australian population. It also has a reasonably long follow-up period to evaluate for CKD. Second, we only selected patients who had both clinical symptoms and radiological diagnosis or at least requiring intervention, which minimised the risk of including asymptomatic and incidental stone formers. Finally, we evaluated composition of nephrolithiasis associated with CKD which have not been previously reported.Conversely, this study has several limitations that should be addressed. First, due to the retrospective nature of our study, there is a paucity of unmeasured confounding factors such as collection of baseline medications like NSAIDS contributing to a reduction in kidney function, and lifestyle factors which can increase risk of nephrolithiasis. We also found the lack of key variables like 24-h urinary electrolytes being performed which may further assist in patient’s care. Second, we had 50 patients who did not have a baseline eGFR prior to their first ED presentation with symptomatic nephrolithiasis. This may underestimate the change of our primary outcome. Finally, we could not consider medications and lifestyle factors which may increase the risk of nephrolithiasis due to the retrospective nature of our study. Thus, we cannot exclude the possibility of some unmeasured confounding factors in the association between recurrent symptomatic nephrolithiasis and the risk of loss of kidney function in the long term.In this cohort with recurrent symptomatic and radiologically confirmed nephrolithiasis, the risk of CKD is positively associated with the increased number of ED presentations for nephrolithiasis. The risk of CKD is also impacted by being older, having non-calcium-containing stones and cumulatively larger stones with age being a predictive factor for CKD progression. Our study highlights the importance for physicians to advocate for stone prevention strategies to reduce nephrolithiasis and consequently preserve kidney function, especially in those patients with a first episode of nephrolithiasis.Supplementary file1 (DOCX 30 KB)Below is the link to the electronic supplementary material.


This study investigated the functional outcomes of patients with chronic heart failure (CHF) after physiological ischemic training (PIT), identified the optimal PIT protocol, evaluated its cardioprotective effects and explored the underlying neural mechanisms.n = 25, PIT intervention + regular treatment) and control group . The outcomes included the left ventricular ejection fraction (LVEF), brain natriuretic peptide (BNP) and cardiopulmonary parameters. LVEF and cardiac biomarkers in CHF rats after various PIT treatments  were measured to identify the optimal PIT protocol. The effect of PIT on cardiomyocyte programmed cell death was investigated by western blot, flow cytometry and fluorescent staining. The neural mechanism involved in PIT-induced cardioprotective effect was assessed by stimulation of the vagus nerve and muscarinic M2 receptor in CHF rats.Patients with CHF were randomly divided into experimental group (2max increased while BNP decreased in patients subjected to PIT. The optimal PIT protocol in CHF rats was composed of five cycles of 5 min ischemia followed by 5 min reperfusion on remote limbs for 8 weeks. LVEF and cardiac biomarker levels were significantly improved, and cardiomyocyte apoptosis was inhibited. However, these cardioprotective effects disappeared after subjecting CHF rats to vagotomy or muscarinic M2 receptor inhibition.LVEF and VOPIT improved functional outcomes in CHF patients. The optimal PIT protocol required appropriate intensity, reasonable frequency, and adequate treatment course. Under these conditions, improvement of cardiac function in CHF was confirmed through cardiomyocyte apoptosis reduction and vagus nerve activation. It is oPhysiological ischemic training (PIT) has recently emerged as a novel therapeutic method to achieve protection in the target organ  by brief repetitive cycles of ischemic training on remote limbs . PreviouApart from that, the understanding of the cardioprotective mechanisms regulating PIT is also important for a further customization of the training protocol. According to a literature review, programmed cell death (PCD) has been reported in the context of PIT. One recent study showed that PIT attenuates acute myocardial injury through the inhibition of apoptosis and the promotion of autophagy . The carTherefore, in this work PIT was performed in patients with CHF, and the changes in functional outcomes after PIT were evaluated. Various PIT cycles at different intensity, frequency, and course were performed in CHF rats to discover the optimal PIT protocol. Once the optimal PIT protocol was determined, the effects on various types of PCD were investigated. Last, we constructed several experiments to explore underlying neural mechanisms of PIT-induced cardioprotective effects in CHF.2.2.1.2.1.1.n = 25) who underwent supplementary PIT and control group (n = 25) without supplementary PIT.A total of 167 CHF patients were recruited from 2020 to 2022 at the First Affiliated Hospital of Nanjing Medical University to investigate the clinical effects exerted by PIT in patients with CHF. The inclusion criteria were the following: (1) patients aged 18–80 years; (2) patients diagnosed with CHF resulting from coronary artery disease (CAD), confirmed by imaging examination; (3) patients belonging to the functional class II-III according to the New York Heart Association (NYHA); (4) patients eligible for cardiopulmonary exercise test (CPET). The exclusion criteria were the following: (1) acute coronary syndrome; (2) hemodynamically significant valve disease; (3) second- or third-degree atrioventricular block; (4) atrial fibrillation or flutter in the previous 3 months; (5) severe renal or hepatic failure; (6) uncontrolled diabetes and hypertension; (7) acute stroke; (8) peripheral artery disease or deep vein thrombosis; (9) other diseases impeding the participation of patients. Fifty eligible CHF patients were enrolled and provided the written informed consent. All the enrolled patients received a standard pharmaceutical treatment , as well as adequate health education . One self-checklist was developed to ensure all patients follow the standard pharmaceutical treatment, routine physical activity and dietary habits, without great modification during the study. The general conditions of the patients are listed in 2.1.2.Standard instructions regarding PIT were provided to patients in the experimental group. Three cycles of 5 min of ischemia were applied to the upper left arm, which was achieved by the inflation of the blood-pressure cuff to 200 mmHg, followed by 5 min of reperfusion when the cuff was deflated, according to a previous study . During 2.1.3.2max) and anaerobic threshold (AT) measured using CPET; (3) 6-min walk test (6MWT), (4) quality of life assessed by the Minnesota Living with Heart Failure Questionnaire (MLHFQ) (Primary outcomes included left ventricular ejection fraction (LVEF), left ventricular end-systolic diameter (LVESD), and left ventricular end-diastole diameter (LVEDD), using echocardiography, measured as indicators of cardiac function. The secondary outcomes were the following: (1) BNP level in peripheral blood; (2) maximal oxygen uptake (VO (MLHFQ) .2.2.2.2.1.via Wheat germ agglutinin (WGA) staining and Masson trichrome staining in the exploratory preliminary experiment , or CHF group. According to previous studies , CHF was2.2.2.2 environment. H9c2 cells were cultured in serum-free DMEM for 24 h and treated with angiotensin II  for 24 h to induce cell hypertrophy and fibrotic response. Phosphate buffer saline was used as a negative control. After 24 h, the control cells were treated with phosphate buffer saline.H9c2 myoblasts, a cell model used as an alternative for cardiomyocytes, were purchased from Shanghai FuHeng Cell Center . They were cultured in Dulbecco’s modified eagle medium  supplemented with 10% fetal bovine serum, 100 U/mL penicillin and 100 U/mL streptomycin and incubated at 37°C under a humidified 5% CO2.2.3.Transthoracic echocardiography was performed on all rats using Vevo3100 with a MX250S linear array transducer . Rats were anesthetized using 2–3% isoflurane and they were kept warm on a heated platform (37°C). The chest fur was removed, and a layer of acoustic coupling gel was applied to the thorax. The cardiac function was measured on M-mode images after the alignment in transverse B-mode with papillary muscles. Echocardiography data were collected using VisualSonics Vevo 3,100 and analyzed using Vevo LAB 3.1.0.2.2.4.Three biomarkers were selected, such as NT-proBNP, tumor necrosis factor-α (TNF-α) and interleukin 6 (IL-6), which were measured by enzyme-linked immunosorbent assay (ELISA), as previously described . ELISA k2.2.5.Plasma NE concentration was determined as an indirect index of sympathetic activity  using a 2.2.6.The activity of AChE, an enzyme involved in parasympathetic neurotransmission, is often used as a potential marker of the parasympathetic activity . AChE ac2.2.7.Western blot was performed according to a standard protocol . The pri2.2.8.The histochemical staining of cholinergic neurons was performed using the Karnovsky–Roots method , as prev2.2.9.Annexin V-Fluorescein isothiocyanate (FITC) and propidium iodide (PI) staining kit  were used to identify apoptotic H9c2 cells. Flow cytometry analysis was performed using Cytoflex  and data were analyzed using the FlowJo software . The second quadrant (FITC+/PI+) showed the late apoptotic cells and the fourth quadrant (FITC+/PI−) showed the early apoptotic cells.2.2.10.Double staining using YO-PRO-1/PI kit  was used to detect necrotic H9c2 cells and distinguish apoptosis from necrosis. In brief, the dye mix solution (YO-PRO-1 dye and PI) was prepared following the manufacturer’s instructions. Cells were fixed with the above mixed dye solution, wrapped into a tin foil to avoid light and incubated at 37°C for 30 min. A fluorescence inverted microscope was used to visualize apoptotic cells by a green fluorescence, whereas necrotic cells exhibited both red fluorescence and green fluorescence. The fluorescence images were analyzed by a THUNDER Imaging System .2.2.11.Lipid ROS assay was performed using C11-BODIPY581/591-Lipid Peroxidation Sensor  to quantify ferroptosis in H9c2 cells. Briefly, cells were treated with 1 ml C11-BODIPY581/591 dye 10 μM for 30 min at 37°C. Oxidation of C11-BODIPY581/591 was revealed by the change in BODIPY fluorescence from red to green, and fluorescence imaging were acquired using the THUNDER Imaging System .2.2.12.MDC autophagy staining assay kit  was used to measure autophagy in H9c2 cells. Briefly, cells were treated with 50 μM MDC and incubated at 37°C for 15 min in the dark. Cells were washed with phosphate buffer saline and visualized using the THUNDER Imaging System , and MDC activity was evaluated by the quantification of green fluorescence.2.3.t-test or Mann–Whitney U-test. The comparisons among multiple groups (≥3) were performed by one-way analysis of variance (ANOVA) with Tukey’s post hoc test. Continuous variables were presented as mean ± standard deviation or median (25th–75th percentile). Categorical variables were presented as proportions (percentages) and analyzed by chi-square test or Fisher exact test. Spearman’s correlation test was used for correlation analysis. A p-value < 0.05 was considered statistically significant.Statistical analysis was performed using GraphPad Prism 9 , and SPSS 21.0 . The comparisons between two groups were performed by Student’s 3.3.1.vs 3.28% for LVEF, p < 0.001; −3.08 vs −2.86% for LVEDD, p < 0.05; −2.00 vs −1.89% for LVESD, vs −11.46% for BNP, p < 0.05, vs 5.24% for VO2max, p < 0.001; 13.60 vs 6.20% for AT, p < 0.01; 17.22 vs 8.99% regarding the distance under the 6MWT, p < 0.05, vs −21.21% for the MLHFQ score, p < 0.001, All patients completed the 12-week treatment and the outcomes were measured before and after the intervention. In total, 50 patients were included in the final analysis with 25 patients in the experimental group and 25 patients in the control group . The raw3.2.LVEF in CHF rats treated with 5 min-, 5 cycles-, 7 cycles-, 8 weeks-, and 12 weeks-PIT was significantly improved compared to no-treatment group . NT-proB3.3.in vitro and in vivo. Apoptotic index of H9c2 cells were significantly increased after the treatment with Ang II compared with the index in the control group  group, while decreased in the vagus nerve cut (VNC) group compared to the PIT group . The den3.4.3.2 receptor is the typical functional subtype, we observed that intravenous injection of nonselective muscarinic acetylcholine receptor agonist  via the tail vein in CHF rats exerted protective effects in the heart, however, application of selective muscarinic M2 receptor antagonist  via tail intravenous injection in CHF rats had no significant effects on cardiac performance  and antagonist (M2R−). LVEF improvement was observed in the PIT group, while the improvement was increased in the M2R+ group and decreased in the M2R− group compared to that in the PIT group  levels were evaluated. The combined results showed that the PIT protocol with five cycles of 5 min ischemia with 5 min reperfusion on remote limbs for 8 weeks was the optimal protocol, since it resulted in a significant improvement of LVEF, and reduction of adverse cardiac biomarkers in CHF rats. Thus, the improvement of cardiac function in CHF was established based on this optimal protocol. However, the changes at a cellular level responsible for these functional improvements were unclear.PCD is an important adaptive mechanism in response to various physiological or pathological conditions. The aberrant activation of PCD is associated with the progressive loss of cardiomyocytes during the progression of heart failure, leading to a deterioration of the cardiac function and adverse cardiac remodeling . PCD inc1 to M5  are the main functional subtypes distributed within the heart (2 receptor antagonist) abrogated the protective effects. However, a previous study suggested that the activation of the muscarinic M3 receptor was crucially important for PIT-induced cardioprotection, based on the abolishment of the cardioprotection after M3 receptor inhibition .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.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.