More Favorable Response to Cardiac Resynchronization Therapy in Women than in Men
Background—Data on gender difference in response to cardiac resynchronization therapy (CRT) remain controversial. We conducted a meta-analysis to summarize all published studies to determine whether sex-based differences in response to CRT exist.
Methods and Results—We performed a literature search using MEDLINE (source PubMed, Jan., 1966 to Mar., 2014) and EMBASE (Jan., 1980 to Mar., 2014) with no restrictions. Pooled effect estimates were obtained by using random-effects meta-analysis. Seventy-two studies involving 33,434 patients were identified. Overall, female patients had better outcomes from CRT than male patients, with a significant 33% reduction in the risk of death from any cause (hazard ratio [HR]: 0.67, 95% CI, 0.61-0.74, p<0.001), 20% reduction in death or hospitalization for heart failure (HR: 0.80, 95% CI, 0.71-0.90, p<0.001), 41% reduction in cardiac death (HR: 0.59, 95% CI, 0.42-0.84, p<0.001) and 41% reduction in ventricular arrhythmias or sudden cardiac death (HR: 0.59, 95% CI, 0.49-0.70, p<0.001). These more favorable response to CRT in women were consistently associated with greater echocardiographic evidence of reverse cardiac remodeling in women than in men.
Conclusions—Women obtained greater reductions in the risk of death from any cause, cardiac cause, death or hospitalization for heart failure, and ventricular arrhythmias or sudden cardiac death with CRT therapy than men, with consistently greater echocardiographic evidence of reverse cardiac remodeling in women than in men. Further studies are needed to investigate the exact reasons for these results and determine whether indications for CRT in women should be different from men.
- Received December 15, 2013.
- Revision received July 3, 2014.
- Accepted July 22, 2014.