Predictors of gain in exercise capacity through cardiac rehabilitation: Sex and age matter.

Background: Cardiac rehabilitation (CR) is a cornerstone of secondary prevention that improves cardiovascular outcomes. However, the determinants of treatment success are poorly understood.

Objectives: We investigated the associations of health-related quality of life (HRQoL), sex, age, employment status and housing situation with improvement in exercise capacity throughout CR.

Methods: We analyzed data from 392 CR outpatients (81% men and 19% women). Exercise capacity at baseline and upon completion of the program was measured with the 6-minute walk distance (6MWD). HRQoL at CR entry was assessed with the Short Form 36 Health Survey (SF-36).

Results: A multivariable regression analysis revealed that both men and women showed significant improvement in exercise capacity (p < .001). Female sex (B = 18.118, 95% CI 0.341 - 36.035, p = .046) and younger age (B = -0.887, 95% CI -1.463 - -0.312, p = .003) emerged as predictors of greater improvement, while HRQoL, employment status, and housing situation were not associated with significant change in exercise capacity. The final model explained 25% of the variance in exercise capacity change (adjusted R2 = 0.25, p < .001).

Conclusions: Our results indicate that women and younger participants benefit from CR by improving their exercise capacity. Employment status, housing situation and HRQoL showed no effects on CR outcome.