Defibrillator capability and all-cause mortality in patients receiving cardiac resynchronization therapy for non-ischemic cardiomyopathy: a Korean nationwide cohort study

Abstract

Abstract Funding Acknowledgements Type of funding sources: None. Background Concerns exist about the benefit of cardiac resynchronization therapy with a defibrillator (CRT-D) compared to those without a defibrillator (CRT-P), especially in patients with non-ischemic cardiomyopathy. We evaluated the association between defibrillator capability and all-cause mortality in patients receiving cardiac resynchronization therapy (CRT) for non-ischemic cardiomyopathy. Methods From patients with nationally registered cardiomyopathy in the Korea National Health Insurance Service (KNHIS) database, after the exclusion of those with ischemic heart disease, 1,478 patients with newly-implanted CRT-P (n=258) or CRT-D (n=1220) were identified from 2008 to 2020. The association between defibrillator capability and all-cause mortality was assessed with propensity score (PS) weighting to correct for differences between the groups. Results Compared with patients receiving CRT-D, those receiving CRT-P included more subjects older than 75. After PS weighting, over a mean follow-up period of 52.9 months (interquartile interval: 23.5-75.8), CRT-D was associated with a lower rate of mortality (6.5 vs 9.2 per 100 person-years) compared with CRT-P. The weighted risk of all-cause death in patients with CRT-D was lower than those with CRT-P within 1 year (hazard ratio [HR]: 0.70 [95% CI, 0.53–0.91]; p = 0.009) and 5 years (HR: 0.71 [95% CI, 0.61–0.83]; p < 0.001). Results were consistent regardless of subgroups, such as age, sex, year of registration, and comorbidities. Conclusions In Korean patients with non-ischemic cardiomyopathy, the defibrillator capability of CRT was associated with reduced 1-year and 5-year all-cause mortality. This association was consistent across all the investigated subgroups.