Cardiac Resynchronization Therapy in Ischemic Versus Nonischemic Cardiomyopathy: Patient-Level Meta-Analysis of 7 Randomized Clinical Trials.

BACKGROUND: Data on whether cardiac resynchronization therapy (CRT) results in better clinical and echocardiographic outcomes in patients with nonischemic cardiomyopathy (NICM) vs ischemic cardiomyopathy (ICM) are conflicting. OBJECTIVES: The authors conducted this meta-analysis of 7 clinical trials of CRT to determine the association between etiology of cardiomyopathy and clinical and echocardiographic outcomes. METHODS: The authors analyzed patient-level data using Bayesian Hierarchical Weibull survival regression modeling to determine the association between etiology of cardiomyopathy and time to all-cause death or heart failure hospitalization (HFH). Linear regression was used to assess the association between etiology of cardiomyopathy and echocardiographic measurements. RESULTS: Of 6,252 patients included, 4,717 (75%) were men, median age was 66 years (IQR: 58-73 years), 3,704 (59%) had ICM, and 3,778 (60%) received CRT. CRT increased the time to HFH or all-cause death (HR: 0.67; 95% credible interval [CrI]: 0.56-0.82; P < 0.001) with no difference by etiology of cardiomyopathy (HR ratio: 1.06 [95% CrI: 0.87-1.29]; P = 0.57). Likewise, CRT increased the time to all-cause death (HR: 0.71 [95% CrI: 0.55-0.93]; P = 0.019) with no difference by etiology of cardiomyopathy (HR ratio: 1.06 [95% CrI: 0.80-1.43]; P = 0.70). Echocardiographic data that were available for 2,430 (39%) patients showed that CRT improvements in left ventricular ejection fraction, left ventricular end-diastolic diameter, and left ventricular end-systolic diameter were larger for patients with NICM. CONCLUSIONS: Although CRT led to greater increases in left ventricular ejection fraction and reductions in ventricular dimensions for patients with NICM compared with those with ICM, CRT significantly increased the time to HFH or all-cause death independently of the etiology of cardiomyopathy. Further studies on improving patient selection for CRT are needed.

Patiromer for Heart Failure Medication Optimization in Patients With Current or Past Hyperkalemia: DIAMOND Subanalysis.

BACKGROUND: For heart failure with reduced ejection fraction (HFrEF), suboptimal use of renin-angiotensin-aldosterone system inhibitors (RAASis), including mineralocorticoid receptor antagonists (MRAs), due to hyperkalemia, may be improved by potassium binders. OBJECTIVES: This prespecified analysis of the phase 3 DIAMOND (Patiromer for the Management of Hyperkalemia in Subjects Receiving RAASi Medications for the Treatment of Heart Failure) trial assessed the effect of patiromer in patients with HFrEF and either current or past hyperkalemia. METHODS: Patients with HFrEF and current or past (within 1 year before enrollment) hyperkalemia (serum potassium [sK+] >5.0 mmol/L) entered a single-blind, run-in phase to optimize RAASis while receiving patiromer. They were subsequently randomized, double-blind, to continue patiromer or change to placebo. RESULTS: Of the 1,038 patients who completed run-in, 354 (83.9%) of 422 with current hyperkalemia and 524 (85.1%) of 616 with past hyperkalemia achieved RAASi optimization and were randomized to treatment. During the double-blind phase, patiromer lowered sK+ levels compared with placebo in both the current and past hyperkalemia subgroups: difference in adjusted mean change from baseline: -0.12 (95% CI: -0.17 to -0.07) and -0.08 (95% CI: -0.12 to -0.05), respectively; Pinteraction = 0.166. Patiromer was more effective than placebo in maintaining MRA at target dose in patients with current vs past hyperkalemia (HR: 0.45 [95% CI: 0.26-0.76] vs HR: 0.85 [95% CI: 0.54-1.32]; Pinteraction = 0.031). Adverse events were similar between subgroups. CONCLUSIONS: The use of patiromer facilitates achieving target doses of RAASis in patients with HFrEF with either current or past hyperkalemia. For those with current hyperkalemia before RAASi optimization, use of patiromer may be more beneficial in helping to maintain sK+ control and achieve MRA target dose. (Patiromer for the Management of Hyperkalemia in Subjects Receiving RAASi Medications for the Treatment of Heart Failure [DIAMOND]; NCT03888066).

Cardiovascular and Renal Treatment in Heart Failure Patients With Hyperkalemia or High Risk of Hyperkalemia: Rationale and Design of the CARE-HK in HF Registry.

BACKGROUND: Despite guideline recommendations, many patients with heart failure (HF) do not receive target dosages of renin-angiotensin-aldosterone system inhibitors (RAASis) in clinical practice due, in part, to concerns about hyperkalemia (HK). METHODS AND RESULTS: This noninterventional, multinational, multicenter registry (NCT04864795; 111 sites in Europe and the USA) enrolled 2558 eligible adults with chronic HF (mostly with reduced ejection fraction [HFrEF]). Eligibility criteria included use of angiotensin-converting-enzyme inhibitor/angiotensin-II receptor blocker/angiotensin-receptor-neprilysin inhibitor, being a candidate for or treatment with a mineralocorticoid receptor antagonist, and increased risk of HK (eg, current serum potassium > 5.0 mmol/L), history of HK in the previous 24 months, or estimated glomerular filtration rate < 45 mL/min/1.73 m2). Information on RAASi and other guideline-recommended therapies was collected retrospectively and prospectively (≥ 6 months). Patients were followed according to local clinical practice, without study-specific visits or interventions. The main objectives were to characterize RAASi treatment patterns compared with guideline recommendations, describe RAASi modifications following episodes of HK, and describe RAASi treatment in patients treated with patiromer. Baseline characteristics for the first 1000 patients are presented. CONCLUSIONS: CARE-HK is a multinational prospective HF registry designed to report on the management and outcomes of patients with HF at high risk for HK in routine clinical practice.

Long-term follow-up of the TRED-HF trial: Implications for therapy in patients with dilated cardiomyopathy and heart failure remission.

AIMS: In TRED-HF, 40% of patients with recovered dilated cardiomyopathy (DCM) relapsed in the short term after therapy withdrawal. This follow-up investigates the longer-term effects of therapy withdrawal. METHODS AND RESULTS: TRED-HF was a randomized trial investigating heart failure therapy withdrawal in patients with recovered DCM over 6 months. Those randomized to continue therapy subsequently withdrew treatment between 6 and 12 months. Participants were recommended to restart therapy post-trial and were followed until May 2023. Clinical outcomes are reported in a non-randomized fashion from enrolment and from the end of the trial. The primary outcome was relapse defined as ≥10% reduction in left ventricular ejection fraction to <50%, doubling in N-terminal pro-B-type natriuretic peptide to >400 ng/L, or clinical features of heart failure. From enrolment to the last follow-up (median 6 years, interquartile range 6-7), 33 of 51 patients (65%) relapsed. The 5-year relapse rate from enrolment was 61% (95% confidence interval [CI] 45-73) and from the end of the trial was 39% (95% CI 19-54). Of 20 patients who relapsed during the trial, nine had a recurrent relapse during follow-up. Thirteen relapsed for the first time after the trial; seven had restarted low intensity therapy, four had not restarted therapy and two did not have therapy withdrawn. The mean intensity of therapy was lower after the trial compared to enrolment (mean difference -6 [-8 to -4]; p < 0.001). One third of relapses during follow-up had identifiable triggers (arrhythmia [n = 4], pregnancy [n = 1], hypertension [n = 1], infection [n = 1]). Corrected atrial fibrillation was associated with reduced risk of relapse (hazard ratio 0.33, 95% CI 0.12-0.96; p = 0.042). CONCLUSIONS: The risk of relapse in the 5 years following the TRED-HF trial remained high. Restarting lower doses of heart failure medications at the end of the trial, external triggers and disease progression are likely to have contributed to relapse.

Effects of spironolactone on exercise blood pressure in patients at increased risk of developing heart failure: report from the HOMAGE trial.

None of the spironolactone trials in heart failure (HF) assessed the blood pressure (BP) responses to exercise, while conflicting results were reported for exercise capacity. In the HOMAGE trial, 527 patients at increased HF risk were randomized to usual treatment with or without spironolactone (25-50 mg/day). The current substudy included 113 controls and 114 patients assigned spironolactone, who all completed the incremental shuttle walk test at baseline and months 1 and 9. Quality of life (QoL) was assessed by EQ5D questionnaire. Between-group differences (spironolactone minus control [Δs]) were analyzed by repeated measures ANOVA with adjustment for baseline and, if appropriate, additionally for sex, age and body mass index. Δs in the pre-exercise systolic/diastolic BP were -8.00 mm Hg (95% CI, -11.6 to -4.43)/-0.85 mm Hg (-2.96 to 1.26) at month 1 and -9.58 mm Hg (-14.0 to -5.19)/-3.84 mm Hg (-6.22 to -1.47) at month 9. Δs in the post-exercise systolic/diastolic BP were -8.08 mm Hg (-14.2 to -2.01)/-2.07 mm Hg (-5.79 to 1.65) and -13.3 mm Hg (-19.9 to -6.75)/-4.62 mm Hg (-8.07 to -1.17), respectively. For completed shuttles, Δs at months 1 and 9 were 2.15 (-0.10 to 4.40) and 2.49 (-0.79 to 5.67), respectively. Δs in QoL were not significant. The correlations between the exercise-induced BP increases and the number of completed shuttles were similar in both groups. In conclusion, in patients at increased risk of developing HF, spironolactone reduced the pre- and post-exercise BP, but did not improve exercise capacity or QoL.

Hospitalization of Symptomatic Patients With Heart Failure and Moderate to Severe Functional Mitral Regurgitation Treated With MitraClip: Insights From RESHAPE-HF2.

BACKGROUND: For patients with functional mitral regurgitation (FMR) and symptomatic heart failure (HF), randomized trials of mitral transcatheter edge-to-edge repair (M-TEER) have produced conflicting results. OBJECTIVES: This study sought to assess the impact of M-TEER on hospitalization rates, and explore the effects of M-TEER on patients who did or did not have a history of recent HF hospitalizations before undergoing M-TEER. METHODS: RESHAPE-HF2 (Randomized Investigation of the MitraClip Device in Heart Failure: 2nd Trial in Patients with Clinically Significant Functional Mitral Regurgitation) included patients with symptomatic HF and moderate to severe FMR (mean effective regurgitant orifice area 0.25 cm2; 14% >0.40 cm2, 23% <0.20 cm2) and showed that M-TEER reduced recurrent HF hospitalizations with and without the addition of cardiovascular (CV) death and improved quality of life. We now report the results of prespecified analyses on hospitalization rates and for the subgroup of patients (n = 333) with a HF hospitalization in the 12 months before randomization. RESULTS: At 24 months, the time to first event of CV death or HF hospitalization (HR: 0.65; 95% CI: 0.49-0.85; P = 0.002), the rate of recurrent CV hospitalizations (rate ratio [RR]: 0.75; 95% CI: 0.57-0.99; P = 0.046), the composite rate of recurrent CV hospitalizations and all-cause mortality (RR: 0.74; 95% CI: 0.57-0.95; P = 0.017), and of recurrent CV death and CV hospitalizations (RR: 0.76; 95% CI: 0.58-0.99; P = 0.040), were all lower in the M-TEER group. The RR of recurrent hospitalizations for any cause was 0.82 (95% CI: 0.63-1.07; P = 0.15) for patients in the M-TEER group vs control group patients. Patients randomized to M-TEER lost fewer days due to death or HF hospitalization (13.9% [95% CI: 13.0%-14.8%] vs 17.4% [95% CI: 16.4%-18.4%] of follow-up time; P < 0.0001, and 1,067 vs 1,776 total days lost; P < 0.0001). Patients randomized to M-TEER also had better NYHA functional class at 30 days and at 6, 12, and 24 months of follow-up (P < 0.0001). A history of HF hospitalizations before randomization was associated with worse outcomes and greater benefit with M-TEER on the rate of the composite of recurrent HF hospitalizations and CV death (Pinteraction = 0.03) and of recurrent HF hospitalizations within 24 months (Pinteraction = 0.06). CONCLUSIONS: These results indicate that a broader application of M-TEER in addition to optimal guideline-directed medical therapy should be considered among patients with symptomatic HF and moderate to severe FMR, particularly in those with a history of a recent hospitalization for HF.

Implantable Cardioverter Defibrillator and Resynchronization Therapy in Patients With Overt Chronic Kidney Disease: JACC State-of-the-Art Review.

Heart failure and chronic kidney disease are common and clinically important conditions that regularly coexist. Electrophysiologic changes of advanced heart failure often result in abnormal conduction, causing dyssynchronous contraction, and development of ventricular arrhythmias, which can lead to sudden cardiac arrest. In the last 2 decades, implantable cardioverter-defibrillator and cardiac resynchronization therapy devices have been developed to address these complications. However, when the coexisting chronic kidney disease is advanced, the associated pathophysiologic cardiovascular changes can alter the efficacy and safety of those interventions and complicate the management. This review explores the impact of comorbid advanced heart failure and advanced chronic kidney disease on the efficacy and safety of implantable cardioverter-defibrillator and cardiac resynchronization therapy, the currently available evidence, and potential future directions.

Diabetes mellitus is associated with low exercise capacity and impaired peripheral vasodilation in patients with heart failure - a propensity score-matched study.

AIMS: Diabetes mellitus (DM) and heart failure (HF) share vascular, skeletal and metabolic abnormalities that can reduce exercise capacity. We investigated whether exercise capacity differ in patients with type 2 DM compared to those without DM with HF of similar severity. METHODS AND RESULTS: The Studies Investigating Co-morbidities Aggravating HF (SICA-HF) prospectively enrolled 615 patients with chronic HF, 259 (42.1 %) of whom had DM. We assembled a propensity score-matched cohort of 231 pairs of patients with HF with or without DM who were balanced on age, sex and variables reflecting HF severity. Patients with DM had lower median peak VO2 (15.7 [13.0-19.1] vs. 17.3 [14.1-21.0] ml/min/kg; p = 0.005). Forearm blood flow reserve (per 1 ml/min/100 ml increase) was associated with lower exercise capacity (peak VO2 ≤ 16.6 ml/min/kg) in patients with DM (OR, 0.92; 95 % CI, (0.85-0.98; p = 0.014), but not in those without DM (OR, 0.98; 95 % CI, 0.93-1.02). A similar heterogeneity was also observed for HDL cholesterol. CONCLUSIONS: Diabetes is associated with a reduced exercise capacity in patients with HF. Most predictors of lower exercise capacity in HF are similar regardless of DM except impaired vascular function and lower HDL cholesterol which predict lower exercise capacity only in those with DM.

Transcatheter Valve Repair in Heart Failure with Moderate to Severe Mitral Regurgitation.

BACKGROUND: Whether transcatheter mitral-valve repair improves outcomes in patients with heart failure and functional mitral regurgitation is uncertain. METHODS: We conducted a randomized, controlled trial involving patients with heart failure and moderate to severe functional mitral regurgitation from 30 sites in nine countries. The patients were assigned in a 1:1 ratio to either transcatheter mitral-valve repair and guideline-recommended medical therapy (device group) or medical therapy alone (control group). The three primary end points were the rate of the composite of first or recurrent hospitalization for heart failure or cardiovascular death during 24 months; the rate of first or recurrent hospitalization for heart failure during 24 months; and the change from baseline to 12 months in the score on the Kansas City Cardiomyopathy Questionnaire-Overall Summary (KCCQ-OS; scores range from 0 to 100, with higher scores indicating better health status). RESULTS: A total of 505 patients underwent randomization: 250 were assigned to the device group and 255 to the control group. At 24 months, the rate of first or recurrent hospitalization for heart failure or cardiovascular death was 37.0 events per 100 patient-years in the device group and 58.9 events per 100 patient-years in the control group (rate ratio, 0.64; 95% confidence interval [CI], 0.48 to 0.85; P = 0.002). The rate of first or recurrent hospitalization for heart failure was 26.9 events per 100 patient-years in the device group and 46.6 events per 100 patient-years in the control group (rate ratio, 0.59; 95% CI, 0.42 to 0.82; P = 0.002). The KCCQ-OS score increased by a mean (±SD) of 21.6±26.9 points in the device group and 8.0±24.5 points in the control group (mean difference, 10.9 points; 95% CI, 6.8 to 15.0; P<0.001). Device-specific safety events occurred in 4 patients (1.6%). CONCLUSIONS: Among patients with heart failure with moderate to severe functional mitral regurgitation who received medical therapy, the addition of transcatheter mitral-valve repair led to a lower rate of first or recurrent hospitalization for heart failure or cardiovascular death and a lower rate of first or recurrent hospitalization for heart failure at 24 months and better health status at 12 months than medical therapy alone. (Funded by Abbott Laboratories; RESHAPE-HF2 ClinicalTrials.gov number, NCT02444338.).

Heart Failure Specialist Care and Long-Term Outcomes for Patients Admitted With Acute Heart Failure.

BACKGROUND: For patients with acute heart failure (HF), specialist HF care during admission improves diagnosis and treatments. OBJECTIVES: The authors aimed to investigate the association of HF specialist care with in-hospital and longer term prognosis. METHODS: The authors used data from the National Heart Failure Audit from January 1, 2018, to December 31, 2022, linked to electronic records for hospitalization and deaths. All-cause mortality was the primary outcome measure and in-hospital mortality the secondary outcome measure. RESULTS: Data for 227,170 patients admitted to hospital with HF (median age: 81 years; IQR: 72-88 years), were analyzed. Approximately 80% of acute HF admissions received support from HF specialists. Thirty-nine percent of patients (n = 70,720) were seen by a multidisciplinary team (HF physicians and HF specialist nurses [HFSNd]), 22% (n = 40,330) were seen by HFSNs alone, and the remaining 39% (n = 71,700) were seen exclusively by specialist HF physicians. At discharge, more patients who received HF specialist care were prescribed medical therapy for HF and had specialized follow-up. Conversely, diuretic agents were prescribed to fewer patients. HF specialist care was independently associated with a higher rate of prescribing HF therapies at discharge and a lower likelihood of receiving diuretic therapy (OR: 0.90 [95% CI: 0.86-0.95]; P < 0.001). HF specialist care was associated with better long-term survival (HR: 0.89 [95% CI: 0.87-0.90]; P < 0.001) and lower in-hospital mortality (OR: 0.92 [95% CI: 0.0.88-0.97]; P < 0.001). CONCLUSIONS: Receiving HF specialist care during admission for HF is associated with a higher rate of implementation of medical therapy, fewer discharges on diuretic therapy, and lower in-hospital and long-term mortality across the left ventricular ejection fraction spectrum, especially for patients with heart failure with reduced ejection fraction.

Heart failure with improved versus persistently reduced left ventricular ejection fraction: A comparison of the BIOSTAT-CHF (European) study with the ASIAN-HF registry.

AIMS: We investigated the prevalence, clinical characteristics, and prognosis of patients with heart failure (HF) with improved ejection fraction (HFimpEF). METHODS AND RESULTS: We used data from BIOSTAT-CHF including patients with a left ventricular ejection fraction (LVEF) ≤40% at baseline who had LVEF re-assessed at 9 months. HFimpEF was defined as a LVEF >40% and a LVEF ≥10% increase from baseline at 9 months. We validated findings in the ASIAN-HF registry. The primary outcome was a composite of time to HF rehospitalization or all-cause mortality. In BIOSTAT-CHF, about 20% of patients developed HFimpEF, that was associated with a lower primary event rate of all-cause mortality (hazard ratio [HR] 0.52, 95% confidence interval [CI] 0.28-0.97, p = 0.040) and the composite endpoint (HR 0.46, 95% CI 0.30-0.70, p < 0.001) compared with patients who remained in persistent HF with reduced ejection fraction (HFrEF). The findings were similar in the ASIAN-HF (HR 0.40, 95% CI 0.18-0.89, p = 0.024, and HR 0.29, 95% CI 0.17-0.48, p < 0.001). Five independently common predictors for HFimpEF in both BIOSTAT-CHF and ASIAN-HF were female sex, absence of ischaemic heart disease, higher LVEF, smaller left ventricular end-diastolic and end-systolic diameter at baseline. A predictive model combining only five predictors (absence of ischaemic heart disease and left bundle branch block, smaller left ventricular end-systolic and left atrial diameter, and higher platelet count) for HFimpEF in the BIOSTAT-CHF achieved an area under the curve of 0.772 and 0.688 in the ASIAN-HF (due to missing left atrial diameter and platelet count). CONCLUSIONS: Approximately 20-30% of patients with HFrEF improved to HFimpEF within 1 year with better clinical outcomes. In addition, the predictive model with clinical predictors could more accurately predict HFimpEF in patients with HFrEF.

Disease progression in chronic heart failure is linear: Insights from multistate modelling.

AIMS: Understanding the pattern of disease progression in chronic heart failure (HF) may inform patient care and healthcare system design. We used a four-state Markov model to describe the disease trajectory of patients with HF. METHODS AND RESULTS: Consecutive patients (n = 4918) were enrolled (median age 75 [67-81] years, 61.3% men, 44% with HF and reduced ejection fraction). We generated a model by observing events during the first 2 years of follow-up. The model yielded surprisingly accurate predictions of how a population with HF will behave during subsequent years. As examples, the predicted transition probability from hospitalization to death was 0.11; the observed probabilities were 0.13, 0.14, and 0.16 at 3, 4, and 5 years, respectively. Similarly, the predicted transition intensity for rehospitalization was 0.35; the observed probabilities were 0.38, 0.34, and 0.35 at 3, 4, and 5 years, respectively. A multivariable model including covariates thought to influence outcome did not improve accuracy. Predicted average life expectancy was approximately 10 years for the unadjusted model and 13 years for the multivariable model, consistent with the observed mortality of 41% at 5 years. CONCLUSIONS: A multistate Markov chain model for patients with chronic HF suggests that the proportion of patients transitioning each year from a given state to another remains constant. This finding suggests that the course of HF at a population level is more linear than is commonly supposed and predictable based on current patient status.

Heart rate reactivity, recovery, and endurance of the incremental shuttle walk test in patients prone to heart failure.

AIMS: Few randomized trials assessed the changes over time in the chronotropic heart rate (HR) reactivity (CHR), HR recovery (HRR) and exercise endurance (EE) in response to the incremental shuttle walk test (ISWT). We addressed this issue by analysing the open HOMAGE (Heart OMics in Aging) trial. METHODS: In HOMAGE, 527 patients prone to heart failure were randomized to usual treatment with or without spironolactone (25-50 mg/day). The current sub-study included 113 controls and 114 patients assigned spironolactone (~70% on beta-blockers), who all completed the ISWT at baseline and at Months 1 and 9. Within-group changes over time (follow-up minus baseline) and between-group differences at each time point (spironolactone minus control) were analysed by repeated measures ANOVA, unadjusted or adjusted for sex, age and body mass index, and additionally for baseline for testing 1 and 9 month data. RESULTS: Irrespective of randomization, the resting HR and CHR did not change from baseline to follow-up, with the exception of a small decrease in the HR immediately post-exercise (-3.11 b.p.m.) in controls at Month 9. In within-group analyses, HR decline over the 5 min post-exercise followed a slightly lower course at the 1 month visit in controls and at the 9 month visits in both groups, but not at the 1 month visit in the spironolactone group. Compared with baseline, EE increased by two to three shuttles at Months 1 and 9 in the spironolactone group but remained unchanged in the control group. In the between-group analyses, irrespective of adjustment, there were no HR differences at any time point from rest up to 5 min post-exercise or in EE. Subgroup analyses by sex or categorized by the medians of age, left ventricular ejection fraction or glomerular filtration rate were confirmatory. Combining baseline and Months 1 and 9 data in both treatment groups, the resting HR, CHR and HRR at 1 and 5 min averaged 61.5, 20.0, 9.07 and 13.8 b.p.m. and EE 48.3 shuttles. CONCLUSIONS: Spironolactone on top of usual treatment compared with usual treatment alone did not change resting HR, CHR, HRR and EE in response to ISWT. Beta-blockade might have concealed the effects of spironolactone. The current findings demonstrate that the ISWT, already used in a wide variety of pathological conditions, is a practical instrument to measure symptom-limited exercise capacity in patients prone to developing heart failure because of coronary heart disease.

Outcomes of Cardiac Resynchronization Therapy by New York Heart Association Class: A Patient-Level Meta-Analysis.

BACKGROUND: Data on the benefits of cardiac resynchronization therapy (CRT) in patients with severe heart failure symptoms are limited. We investigated the relative effects of CRT in patients with ambulatory New York Heart Association (NYHA) IV versus III functional class at the time of device implantation. METHODS AND RESULTS: In this meta-analysis, we pooled patient-level data from the MIRACLE (Multicenter InSync Randomized Clinical Evaluation), MIRACLE-ICD (Multicenter InSync Implantable Cardioversion Defibrillation Randomized Clinical Evaluation), and COMPANION (Comparison of Medical Therapy, Pacing, and Defibrillation in Heart Failure) trials. Outcomes evaluated were time to the composite end point of the first heart failure hospitalization or all-cause mortality, and time to all-cause mortality alone. The association between CRT and outcomes was evaluated using a Bayesian hierarchical Weibull survival regression model. We assessed if this association differed between NYHA III and IV groups by adding an interaction term between CRT and NYHA class as a random effect. A sensitivity analysis was performed by including data from RAFT (Resynchronization-Defibrillation for Ambulatory Heart Failure). Our pooled analysis included 2309 patients. Overall, CRT was associated with a longer time to heart failure hospitalization or all-cause mortality (adjusted hazard ratio [aHR], 0.79 [95% credible interval [CI], 0.64-0.99]; posterior probability or P=0.044), with a similar association with time to all-cause mortality (aHR, 0.78 [95% CI, 0.59-1.03]; P=0.083). Associations of CRT with outcomes were not significantly different for those in NYHA III and IV classes (ratio of aHR, 0.72 [95% CI, 0.30-1.27]; P=0.23 for heart failure hospitalization/mortality; ratio of aHR, 0.70 [95% CI, 0.35-1.34]; P=0.27 for all-cause mortality alone). The sensitivity analysis, including RAFT data, did not show a significant relative CRT benefit between NYHA III and IV classes. CONCLUSIONS: Overall, there was no significant difference in the association of CRT with either outcome for patients in NYHA functional class III compared with functional class IV.

High variability in assays of blood markers of collagen turnover in cardiovascular disease: Implications for research and clinical practice.

AIMS: Fibrosis is a common feature of many chronic diseases, including heart failure, which can have deleterious effects on cardiac structure and function that are associated with adverse outcomes. By-products of collagen synthesis and degradation, such as carboxy- and amino-terminal pro- or telo-peptides of collagen type I and III (PICP, PINP, PIIINP, and CITP) have been extensively investigated as markers of fibrosis. Although the majority of studies report on the reproducibility of their assay results, there is no a comparison of biomarker assays across studies. Therefore, we conducted a systematic review adhering to PRISMA guidelines. METHODS AND RESULTS: The search terms employed in Medline were: 'collagen AND cardiac' or 'collagen AND heart'. This query yielded a total of 1049 articles. Thereafter, specific search criteria were applied: (i) original English-language papers; (ii) human studies; (iii) in-vivo investigations; and (iv) blood/serum/plasma samples. Overall, 89 studies were identified (42 on PIIINP, 32 on PICP, 29 on CITP, and 17 on PINP). The range of reported values for PIIINP was between 0.06 to 11 800 µg/l; for PICP 0.006 to 1265 µg/l; for CITP 0.3 to 5450 µg/l; for PINP 0.15 to 80 µg/l. Extreme variations in values for fibrosis biomarkers were observed across studies, especially when different assays were used, but also with the same assays. CONCLUSIONS: Our findings show that it is challenging to ascertain normal ranges or compare studies for the measurement of fibrosis biomarkers. Given the potential implications for clinical practice and current lack of awareness of these issues, this subject warrants comprehensive acknowledgement and understanding.