The role and outcome of cardiac rehabilitation program in patients with atrial fibrillation

Background: Atrial fibrillation (AF) is associated with diminished cardiac function, and exercise tolerance. Hypothesis: We sought to investigate the role of cardiac rehabilitation program (CR) in patients with AF. Methods: The study included 2165 consecutive patients that participated in our CR program between the years 2009 to 2015. All were evaluated by a standard exercise stress test (EST) at baseline, and upon completion of at least 3 months of training. Participants were dichotomized according to baseline fitness and the degree of functional improvement. The combined primary end point was cardiac related hospitalization or all-cause mortality. Results: A total of 292 patients had history of AF, with a mean age of 68 +/- 9 years old, 76% of which were males. The median predicted baseline fitness of AF patients was significantly lower compared to non-AF patients (103% vs 122%, P < 0.001, respectively). Prominent improvement was achieved in the majority of the patients in both groups (64% among AF patients and 63% among those without AF). Median improvement in fitness between stress tests was significantly higher in patients with AF (124% vs 110%, P < 0.001, respectively). Among AF patients, high baseline fitness was associated with a lower event rates (HR 0.40; 95%CI 0.23-0.70; P = 0.001). Moreover, prominent improvement during CR showed a protective effect (HR 0.83; 95% CI 0.69-0.99; P = 0.04). Conclusion: In patients with AF participating in CR program, low fitness levels at baseline EST are associated with increased risk of total mortality or cardiovascular hospitalization during long-term follow-up. Improvement on follow-up EST diminishes the risk.