Abstract 13284: Cardiac Rehabilitation, Cardiorespiratory Fitness, and Risk of Incident Atrial Fibrillation in Patients With Coronary Artery Disease

Abstract

Introduction: Cardiorespiratory fitness (CRF) is an independent risk factor for cardiovascular morbidity and mortality. Cardiac rehabilitation (CR) can reduce cardiovascular risk factors and improve CRF. However, the relationship between CR, CRF, and risk of incident atrial fibrillation (AF) in patients with cardiovascular disease is less clear. Objectives: To examine the association of CR completion and associated CRF changes with the incidence of new-onset AF in patients referred to a CR program after coronary revascularization. Methods and Results: We included 11,662 patients without a history of AF, referred to CR after coronary revascularization between January 1996 to March 2016. The mean age was 60.9 ± 10.9 years and 80.6% were males. Incident AF was ascertained by linkage with provincial administrative data sources and the local ECG repository. Competing-risks regression was used to estimate the association of CR completion and CRF with incident AF, with death as a competing event. During a median follow-up of 4.8 years, 618 patients developed AF, and 638 died. In adjusted models, CR completion was not associated with the risk of incident AF [Hazard ratio (HR): 0.97; 95% confidence interval (CI): 0.83-1.15]. However, both baseline CRF [HR: 0.83; 95% CI: 0.76-0.90 per metabolic equivalent (MET)] and CRF gain (HR: 0.82; 95% CI: 0.72-0.94 per MET increase) for those who completed the CR program were associated with a lower risk of incident AF (Table 1). Conclusions: In patients referred to CR, CR completion was not associated with a reduced risk of incident AF. However, both higher baseline CRF and CR-associated CRF gains had a dose-dependent protective association with incident AF. Therefore, it is important to maximize CRF gains during the CR program. Further attention to AF-specific risk factor modification (i.e., obesity, sleep apnea, and alcohol) may be required to enhance CR program efficacy for this outcome, especially in patients with lower baseline CRF.