Effect of early enrollment on outcomes in cardiac rehabilitation

Abstract

Outpatient cardiac rehabilitation (CR) is most beneficial when delivered 1 to 3 weeks after the index cardiac event. The effects of delayed enrollment on subsequent outcomes are unclear. A total of 1,241 patients were enrolled in CR after recent (<1 year) treatment of cardiac events or postcardiac surgery. Risk factors and metabolic equivalent levels (METs) during aerobic exercise were calculated before and after CR. The mean CR delay time was 34 days (maximum of 327). Delay time >30 days was associated with older age, female gender, nonwhite race, being unemployed, and increased length of hospital stay before CR after index cardiac event (p <0.05 vs 0 to 15 and 16 to 30 days for all comparisons). Patients with delay time >30 days had significant improvements in all CR metrics, but peak METs and weight improvements were lesser in magnitude compared with patients with CR delay times 0 to 15 and 16 to 30 days. After multivariate adjustment, delay time >30 days remained an independent predictor of decreased MET improvement compared with delay time 0 to 15 days (β = -0.59, p <0.001). In conclusion, time to enrollment in CR varies substantially and is independently linked to demographics and length of index hospital stay. Delayed enrollment in CR is directly related to patient outcomes. Although all patients showed improvements in key metrics regardless of delay time, CR was of greatest benefit, particularly for weight and exercise capacity, when initiated within 15 days of the index event.