Abstract

Background: Over the last few decades, cardiac resynchronization therapy (CRT) has become the standard of treatment for heart failure and arrhythmic events. Large randomized trials demonstrating the survival benefits of CRT have been limited to populations of older white males. Our objective was to investigate the effectiveness of CRT across populations differing in sex, age, and race.

Methods: A systematic search was conducted on CINAHL, Embase, Emcare, Medline, and PubMed from inception until July 2020. Studies were included if they were randomized controlled trials (or secondary analyses of) that had CRT as an intervention. Data were analyzed according to sex, race, and age for 3-point major adverse cardiovascular events (MACE) and related adverse clinical events.

Results: 6 studies describing a total of 6580 patients were included. In total, 3580 (54%) patients were implanted with a CRT device. The rate of all-cause death was not significantly decreased for female CRT patients (OR, 0.51 [95% CI, 0.26-1.01]; P= 0.053) nor was it increased for CRT patients >65 years of age (OR, 1.85 [95% CI, 0.84-4.07]; P= 0.129). HFH was not significantly different between male and female CRT patients (OR, 1.23 [95% CI, 0.73-2.09]; P=0.443) nor for CRT patients >65 and <65 years of age (OR, 1.19 [95% CI, 0.66-2.15]; P= 0.559). Cardiovascular death (CVD) was not significantly different between males and females (OR, 0.67 [95% CI, 0.28-1.60]; P= 0.363).

Conclusions: Considerable gaps in research exist pertaining to the effects of age and race on cardiovascular outcomes among CRT recipients. Further research is warranted to better describe the association between sex, age, and race and the long-term clinical outcomes among CRT patients.