Comparative Effectiveness of CRT-P vs CRT-D in Octogenarians With HFrEF and LBBB: A Real-World, Propensity-Matched Cohort Study

Background: Cardiac resynchronization therapy (CRT) has demonstrated survival and symptom benefits in patients with heart failure with reduced ejection fraction (HFrEF). However, the comparative effectiveness of CRT with a defibrillator (CRT-D) versus pacemaker-only (CRT-P)remains uncertain in octogenarians, who are underrepresented in clinical trials. Objective: To assess long-term mortality and hospitalization outcomes associated with CRT-D versus CRT-P in octogenarians with HFrEF and left bundle branch block (LBBB), using real-world propensity-matched data. Methods: We identified 1,240 patients aged >/=80 years with HFrEF (LVEF </=35%) and LBBB who underwent device implantation. After 1:1 propensity score matching across 65 clinical variables, 772 patients (386 CRT-D, 386 CRT-P) were included in the primary analysis. The primary endpoint was all-cause mortality over 3 years. Secondary endpoints included timepoint-specific mortality and all-cause hospitalization burden. Prespecified subgroup analyses were performed by ejection fraction (EF </=25%, 26-35%) and by sex within each CRT modality. Results: Three-year mortality did not differ significantly between CRT-D and CRT-P (37.2% vs 39.1%; HR 1.026, 95% CI 0.814-1.293; p = 0.829). Mortality at 30 days, 90 days, and 1 year was numerically lower in CRT-D but not statistically significant. CRT-D recipients experienced fewer hospitalizations (mean 4.05 vs 5.36; p = 0.032). In EF-stratified subgroups, mortality was modestly lower with CRT-D (risk difference -3.8% in EF </=25%; -2.1% in EF 26-35%), though not significant. Among CRT-D recipients, females had lower mortality than males (20.0% vs 29.5%; HR 0.637, 95% CI 0.353-1.149). Conclusions: In this real-world cohort of octogenarians with HFrEF, CRT-D did not improve survival over CRT-P but was associated with reduced hospitalization burden. These findings highlight the importance of phenotype-guided device selection, informed by arrhythmic risk, comorbid burden, and patient-centered goals of care.