Sex‐Specific Differences in Survival and Heart Failure Hospitalization After Cardiac Resynchronization Therapy With or Without Defibrillation

Background Women are underrepresented in cardiac resynchronization therapy ( CRT ) trials. Some studies suggest that women fare better than men after CRT . We sought to explore clinical outcomes in women and men undergoing CRT ‐defibrillation or CRT‐pacing in real‐world clinical practice. Methods and Results A national database (Hospital Episode Statistics for England) was used to quantify clinical outcomes in 43 730 patients (women: 10 890 [24.9%]; men: 32 840 [75.1%]) undergoing CRT over 7.6 years, (median follow‐up 2.2 years, interquartile range, 1–4 years). In analysis of the total population, the primary end point of total mortality (adjusted hazard ratio [ aHR ], 0.73; 95% CI, 0.69–0.76) and the secondary end point of total mortality or heart failure hospitalization ( aHR , 0.79, 95% CI 0.75–0.82) were lower in women, independent of known confounders. Total mortality ( aHR , 0.73; 95% CI, 0.70–0.76) and total mortality or heart failure hospitalization ( aHR , 0.79; 95% CI, 0.75–0.82) were lower for CRT ‐defibrillation than for CRT ‐pacing. In analyses of patients with ( aHR , 0.89; 95% CI, 0.80–0.98) or without ( aHR , 0.70; 95% CI, 0.66–0.73) a myocardial infarction, women had a lower total mortality. In sex‐specific analyses, total mortality was lower after CRT ‐defibrillation in women ( aHR , 0.83; P =0.013) and men ( aHR , 0.69; P <0.001). Conclusions Compared with men, women lived longer and were less likely to be hospitalized for heart failure after CRT . In both sexes, CRT ‐defibrillation was superior to CRT ‐pacing with respect to survival and heart failure hospitalization. The longest survival after CRT was observed in women without a history of myocardial infarction.