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BACKGROUND: With evolving therapy for heart failure with reduced ejection fraction, the benefits of adding a defibrillator in patients undergoing cardiac resynchronization therapy (CRT) remain unclear, particularly for nonischemic cardiomyopathy (NICM). This study evaluates long-term survival among patients with NICM treated with CRT defibrillator (CRT-D) versus CRT pacemaker (CRT-P). METHODS: DECIDE-CRT (Cardiac Resynchronization With or Without Defibrillator in Non-Ischemic Cardiomyopathy) is a multicenter cohort study across 170 US Veterans Affairs hospitals. We identified patients with NICM receiving primary-prevention CRT-P or CRT-D between January 1, 2006, and December 31, 2020. Using a propensity score approach, we applied inverse probability of treatment weighting to balance baseline characteristics between the CRT-P and CRT-D groups. An inverse probability of treatment weighting–weighted Cox model estimated hazards for all-cause mortality. Secondary outcomes included generator replacement, device-related infections, hospitalization for heart failure, and ventricular arrhythmias. RESULTS: Of 16 609 CRT recipients, 3965 met NICM primary-prevention criteria (CRT-D=3158; CRT- P =807). At baseline, patients with NICM receiving CRT-P were much older, with more cardiovascular and noncardiovascular comorbidities compared with the CRT-D group. During the median follow-up of 5.2 years, the mortality rate for CRT-P versus CRT-D was 9.46 versus 9.21 per 100 person-years (RR, 0.97 [95% CI, 0.71–1.13]; P =0.66). The adjusted hazard ratio for all-cause mortality using the inverse probability of treatment weighting-Cox model was 0.90 (95% CI, 0.71–1.13; P =0.34). There was no difference in adjusted hazard for heart failure hospitalization (hazard ratio, 1.27 [95% CI, 0.86–1.87]), while the CRT-D group had higher rates of generator replacement and device-related infections. CONCLUSIONS: This nationwide observational study from the Veterans Affairs Health system did not demonstrate a clear survival advantage with the addition of a defibrillator among patients with NICM receiving CRT although residual confounding cannot be excluded. Given the uncertainty surrounding the incremental benefit of the defibrillator in this setting, a randomized trial is needed to test the incremental value of CRT-D over CRT-P in NICM.

Abstract Aims HELIOS-A was a Phase 3, open-label study of vutrisiran, an RNA interference therapeutic, in patients with hereditary transthyretin (ATTRv) amyloidosis with polyneuropathy. This analysis evaluated vutrisiran's impact on exploratory cardiac endpoints in HELIOS-A patients. Methods and results Patients were randomized 3:1 to subcutaneous vutrisiran 25 mg every 3 months or intravenous patisiran 0.3 mg/kg every 3 weeks (reference group) for 18 months. Exploratory cardiac endpoints included change from baseline in N-terminal prohormone of brain-type natriuretic peptide (NT-proBNP) and echocardiographic parameters versus external placebo (APOLLO study). The modified intent-to-treat (mITT) population comprised randomized patients receiving any study drug (n = 122). A cardiac subpopulation with evidence of cardiac amyloid involvement (n = 40) was prespecified. 99mTc scintigraphy exploratory assessments in a planned vutrisiran-treated cohort at select sites were compared with baseline. At Month 18, vutrisiran demonstrated beneficial effects on NT-proBNP versus external placebo in the mITT and cardiac subpopulations (adjusted geometric mean fold change ratio [95% confidence interval] 0.480 [0.383–0.600], p = 9.606 × 10−10 and 0.491 [0.337–0.716], p = 0.0004, respectively). Benefits or trends towards benefit in echocardiographic parameters versus external placebo were observed for both populations. In 99mTc scintigraphy assessments, 32/47 (68.1%) and 31/48 (64.6%) patients exhibited reduced normalized left ventricular total uptake and heart-to-contralateral lung ratio, respectively. Perugini grade was reduced or unchanged versus baseline in 55/57 (96.5%) evaluable patients. No increase in cardiac adverse events was observed with vutrisiran versus external placebo. Conclusions Vutrisiran demonstrated evidence of potential benefit on cardiac manifestations in patients with ATTRv amyloidosis with polyneuropathy, with an acceptable safety profile.

Abstract Introduction Transthyretin–mediated (ATTR) amyloidosis is a progressive, multisystem, fatal disease. Patisiran, an IV RNAi therapeutic, is approved for the treatment of hereditary ATTR amyloidosis with polyneuropathy. The safety and efficacy of patisiran in patients with wild–type or hereditary ATTR amyloidosis with cardiomyopathy (CM) is being investigated in the ongoing APOLLO–B study. Methods Patients were 18–85 yrs old with evidence of cardiac amyloidosis by echocardiography, and ATTR amyloid by tissue biopsy or fulfilling nonbiopsy diagnostic criteria for ATTR amyloidosis with CM. Medical history of heart failure (HF) due to ATTR amyloidosis with ≥1 prior hospitalization or current clinical evidence of HF was required. Patients were randomized 1:1 to patisiran IV 0.3 mg/kg or placebo Q3W for 12 months. The primary endpoint was change from baseline in 6–MWT at Month 12 (M12) with patisiran vs placebo. Results APOLLO–B enrolled 360 patients (patisiran, n=181; placebo, n=179): median age (range), 76.0 (41, 85) yrs; male, 89%; wtATTR, 80%. Baseline characteristics were consistent between patients on tafamidis at baseline (91/360 [25%]) and those who were not. Patisiran achieved a rapid and sustained reduction in serum TTR, irrespective of baseline tafamidis treatment. At M12, patisiran showed a significant benefit vs placebo in 6–MWT (median [95% CI] change from baseline: patisiran, –8.15 [–16.42, 1.50]; placebo, –21.35 [–34.05, –7.52]; HL estimate of median difference: 14.69 [0.69, 28.69]; p=0.0162) and KCCQ–OS (LS mean [SEM] change from baseline: patisiran, 0.300 [1.263]; placebo, –3.408 [1.277]; LS mean [SEM] difference: 3.709 [1.796]; p=0.0397). Consistent benefits with patisiran in 6–MWT and KCCQ–OS were observed across predefined patient subgroups. Time to first event of all–cause hospitalization, urgent HF visit, or death directionally favored patisiran vs placebo (HR [95% CI], 0.839 [0.557, 1.263]), as did all–cause mortality (HR [95% CI], 0.355 [0.110, 1.138]), but all composite outcomes endpoints did not achieve statistical significance over 12 months. Patisiran was well tolerated; most AEs were mild or moderate in severity, and there were no cardiac safety concerns. Conclusions Benefits at 12 months were observed with patisiran vs placebo in functional capacity, and health status and quality of life, in patients with ATTR amyloidosis with CM. The efficacy and safety of patisiran continues to be studied in the APOLLO–B open–label extension.

Abstract Introduction Transthyretin–mediated (ATTR) amyloidosis is a progressive and fatal disease. Patients with hereditary or wild–type ATTR amyloidosis frequently develop cardiomyopathy (CM). Patisiran, an IV RNAi therapeutic that inhibits synthesis of wt and variant TTR, is approved for the treatment of hATTR amyloidosis with polyneuropathy. Methods In APOLLO–B, patients were 18–85 yrs old with evidence of cardiac amyloidosis by echocardiography, ATTR amyloid deposition on tissue biopsy or fulfilling nonbiopsy diagnostic criteria for ATTR amyloidosis with CM, and had prior hospitalization for heart failure (HF) due to ATTR amyloidosis or clinical evidence of HF. Patients were randomized 1:1 to patisiran IV 0.3 mg/kg or placebo Q3W for 12 months. The primary endpoint was change from baseline in 6–MWT at Month 12 (M12) with patisiran vs placebo. Exploratory parameters at M12 included changes in cardiac biomarkers, echocardiography and Tc scintigraphy. Results APOLLO–B enrolled 360 patients (patisiran, n=181; placebo, n=179): median age, 76.0 yrs; male, 89%; wtATTR, 80%; on tafamidis at baseline, 25%. Patisiran showed a significant benefit compared with placebo in 6–MWT (median [95% CI] change from baseline: patisiran, –8.15 [–16.42, 1.50]; placebo, –21.35 [–34.05, –7.52]; HL estimate of median difference: 14.69 [0.69, 28.69]; p=0.0162). Patisiran demonstrated favorable trends in change from baseline of NT–proBNP (mean fold change ratio [95% CI]: 0.80 [0.73, 0.89]; p=1.825×10–5) and troponin I (mean fold change ratio [95% CI]: 0.87 [0.80, 0.95]; p=0.0011) at M12 vs placebo. Patisiran also demonstrated a trend towards benefit in change from baseline of most evaluated echocardiographic parameters at M12 vs placebo. Patisiran–treated patients evaluable for scintigraphy (n=37) experienced a reduction (37.8%) or no change (62.2%) in Perugini grade at M12 compared with baseline. Among placebo patients (n=28) at M12, none experienced a reduction from baseline in Perugini grade, and 1 (3.6%) increased in grade. Patisiran demonstrated an acceptable safety profile; AEs were mostly mild or moderate in severity, and there were no cardiac safety concerns. Conclusions Exploratory analyses after 12 months provide further evidence for the potential benefit of patisiran treatment on cardiac biomarkers and manifestations of cardiac amyloid involvement in patients with ATTR amyloidosis. The long–term impact of patisiran will be assessed in the ongoing APOLLO–B open–label extension.

Abstract Background Transthyretin-mediated (ATTR) amyloidosis is a rapidly progressive, debilitating, and fatal disease caused by misfolded TTR accumulating in multiple organs and tissues. Patients with hereditary (hATTR) amyloidosis (also known as ATTRv amyloidosis) or wild-type (wtATTR) amyloidosis with cardiomyopathy exhibit decreased survival. Patisiran, an IV RNAi therapeutic that inhibits synthesis of wt and variant TTR, was approved for the treatment of hATTR amyloidosis with polyneuropathy. Exploratory analyses of a predefined cardiac subpopulation in the APOLLO study demonstrated the potential for patisiran to improve the manifestations of cardiomyopathy in patients with hATTR amyloidosis with polyneuropathy. Objective To investigate the safety and efficacy of patisiran in patients with ATTR amyloidosis with cardiomyopathy in the ongoing APOLLO-B study (NCT03997383). Material & Methods Patients were 18–85 years of age with evidence of cardiac amyloidosis by echocardiography (end-diastolic interventricular wall thickness >12 mm), and either ATTR amyloid deposition on tissue biopsy or fulfilling nonbiopsy diagnostic criteria for ATTR amyloidosis with cardiomyopathy. Patients had a medical history of heart failure (HF) due to ATTR amyloidosis with at least 1 prior hospitalization for HF, or current clinical evidence of HF. Patients were randomized (1:1) to receive patisiran IV 0.3 mg/kg or placebo Q3W for 12 months. After the double-blind, placebo-controlled period, all patients may receive patisiran in an open-label extension period for up to 36 months. The primary endpoint was change from baseline in 6-MWT at Month 12 with patisiran treatment, compared with placebo. Secondary endpoints evaluated the effect of patisiran vs placebo at Month 12 on QOL (KCCQ-OS score) as well as two sets of composite endpoints: 1) All-cause mortality, frequency of CV events (CV hospitalizations and urgent HF visits) and change from baseline in 6-MWT; and 2) All-cause mortality and frequency of all-cause hospitalizations and urgent HF visits. The pharmacodynamic effect of patisiran on serum TTR level (change from baseline through Month 12) was also assessed. Results & Discussion Enrollment completed (359 patients) in May 2021. About 80% of patients have wtATTR amyloidosis. Primary and secondary endpoint data will be presented, including change in 6-MWT and KCCQ-OS score at Month 12, in addition to safety data. Summary & Conclusion The primary results of the APOLLO-B study will inform the potential of patisiran as a treatment for the cardiomyopathy of ATTR amyloidosis. APOLLO-B will continue to investigate the efficacy and safety of patisiran on ATTR amyloidosis in an open-label extension period.