Comparative effectiveness of cardiac resynchronization therapy in older patients with heart failure: Systematic review and meta-analysis.

BACKGROUND: Pivotal CRT trials enrolled patients with HFrEF significantly younger than the typical contemporary patient with HFrEF. Thus, the risks and benefits in this older population with HFrEF are largely unknown. We sought to perform meta-analyses comparing safety and effectiveness of cardiac resynchronization therapy (CRT) in older vs younger patients with heart failure with reduced ejection fraction (HFrEF). METHODS AND RESULTS: PubMed, The Cochrane Library, Scopus, and Web of Science were queried for comparative effectiveness studies of CRT in older patients with HFrEF. Title, abstract, and full-text screening was performed to identify studies comparing at least 1 prespecified end point between older and younger adult patients with at least 50 participants. Random effects meta-analysis in the left ventricular ejection fraction (LVEF) mean difference (older minus younger) and the relative risk (RR) of death, improvement in New York Heart Association (NYHA) functional class, and complications are reported along with estimates of heterogeneity. In 7 studies, there was similar LVEF improvement between groups (mean difference 1.14, 95% confidence interval [CI] -0.04 to 2.32, P = .06, I2 = 53%). Older patients were equally likely as younger patients to see an improvement in NYHA functional class of at least 1 in 6 studies (RR 0.99, 95% CI 0.93-1.06, P = .76, I2 = 25%). No significant differences in the incidence of hematoma, pneumothorax, lead dislodgment, cardiac perforation, or infection requiring explant was observed. The RR of mortality in 11 studies demonstrated higher risk of all-cause mortality in older patients (RR 1.05, 95% CI 1.03-1.08, P < .01, I2 = 0%). CONCLUSIONS: Compared with younger patients, older patients receiving CRT were equally likely to experience improvement in LVEF, left ventricular end-diastolic diameter, and NYHA functional class. There was no difference in procedural complications. The higher rate of all-cause mortality in older patients likely reflects a greater underlying risk of death from competing causes.