Sex-Specific Differences in Ventricular Remodeling and Response After Cardiac Resynchronization Therapy

In this study, we investigated the baseline characteristics and "trajectories" of clinical response in men and women after cardiac resynchronization therapy (CRT) implantation. Although women enjoy improved echocardiographic response after CRT compared with men, the kinetics of this response and its relation to functional performance and outcomes are less clear. We identified 592 patients who underwent CRT implantation at our center between 2004 and 2017 and were serially followed in a multidisciplinary clinic. Longitudinal linear mixed effects regression for cardiac response was specified, including interaction terms between time after CRT and sex , and Cox regression models were used to assess differences in all-cause mortality by gender after CRT. Women in our cohort were younger than men, had less frequent ischemic etiology of heart failure (24% vs 60% in men), a shorter QRS (151 vs 161 ms) and more frequent left bundle branch block (77% vs 52%) at baseline. Women had a greater improvement in left ventricular ejection fraction that was evident starting at approximately 1-month after CRT. We did not observe effect modification by gender in New York Heart Association class or 6-minute walk distance after CRT. Although women had improved mortality after CRT, after adjustment for potential confounders, gender was not associated with mortality after CRT. In conclusion, women were more likely to have CRT implantation for left bundle branch block and exhibited improved echocardiographic but not functional response within the first year after CRT. Clinical outcomes after CRT were not associated with gender in adjusted analysis.