Sex Differences in Changes in Cardiorespiratory Fitness and Additional Health Outcomes Following Exercise Training in Adults with Atrial Fibrillation: A Systematic Review and Meta-Analysis

Purpose: Improving cardiorespiratory fitness (CRF) through exercise training is associated with lower morbidity and mortality in patients with atrial fibrillation (AF). Smaller CRF improvements have been suggested in females than males with cardiovascular disease following exercise training. This systematic review compared changes in CRF (primary) and additional physical and mental health outcomes following exercise training between females and males with AF. Review Methods: Five bibliographic databases were searched to identify prospective studies implementing exercise training in patients with AF. The mean difference (MD) in the change following exercise training was compared between sexes using random-effects meta-analyses. Summary: Sex-specific data were obtained from 19 of 63 eligible studies, with 886 participants enrolled in exercise training (n = 259 [29%] females; female: 68 ± 7 years, male: 66 ± 8 years). Exercise training was 6 weeks to 1 year in duration and mostly combined moderate- to vigorous-intensity aerobic and resistance training, 2 to 6 d/wk. Changes in CRF did not differ between sexes (MD = 0.15: 95% CI, -1.08 to 1.38 mL O₂/kg/min; P =.81; I² = 27%). Severity of AF (MD = 1.00: 95% CI, 0.13-1.87 points; I² = 0%), general health perceptions (MD = -3.71: 95% CI, -6.88 to -0.55 points; I² = 22%), and systolic blood pressure (MD = 3.11: 95% CI, 0.14-6.09 mmHg; I² = 42%) improved less in females than in males. Females may benefit from more targeted exercise training programs given their smaller improvement in several health outcomes than males. However, our findings are largely hypothesis-generating, considering the limited sample size and underrepresentation of females (29% females in our review vs 47% females with AF globally).