Evaluation of Gender Differences in Response to Cardiac Resynchronization Therapy in a Single Heart Center

Background: Cardiac resynchronization therapy (CRT) has a beneficial effect on clinical symptoms, exercise capacity, and systolic left ventricular (LV) performance in patients with heart failure. The objective of the current study was to evaluate whether a gender difference exists in response to CRT according to clinical indices. Methods: Totally, 229 consecutive patients with end-stage heart failure (LV ejection fraction ≤35%), QRS duration >120 ms, and left bundle branch block configuration underwent CRT. At baseline and 6 months post-CRT, clinical and echocardiographic parameters were evaluated and followed-up was obtained for up to 6 months. The clinical alterations after CRT implantation were compared between the men and the women. Results: The study population consisted of 229 patients [129 (56.3%) male and 100 (43.7%) female; mean age=62.90±12.97 y, and age range=9–24]. No significant difference between the men and the women regarding age was found [men=62.13±14.26 y and women=63.89±11.12 y (P=0.3)]. The mean of the QRS width after CRT implantation in the men and the women was 147.50±23.09 and 145±18.45 ms, respectively, and the difference between the 2 groups was significant (P=0.001). There was no significant relationship between sex and hospitalization (P=0.09). At 6 months’ follow-up, LV ejection fraction in the men and the women was 18.56±6.18 and 20.78±8.96, respectively (P=0.1). Conclusions: At 6 months’ follow-up, most of the patients had a normal sinus rhythm. Most of the deaths were seen in the males. The men had a slightly greater QRS width after CRT implantation in than the women. The chief reasons for hospitalization and mortality were shock and heart failure decompensation. LV ejection fraction before and after CRT was significantly greater in the female patients than in their male counterparts; however, the difference was significant before the implantation.