Previous Exercise Levels and Outcome in Patients with New Atrial Fibrillation: 'Past Achievements Do Not Predict the Future'

INTRODUCTION: Long-term endurance exercise is suspect to elevate the risk of atrial fibrillation (AF),but little is known about cardiovascular outcome and disease progression in this subgroup of AF patients. We investigated whether previous exercise level determines cardiovascular outcome.

METHODS: In this post hoc analysis of the RACE 4 randomized trial, we analyzed all patients with a completed questionnaire on sports participation. Three subgroups were made based on lifetime sports hours up to randomization and previous compliance to the international physical activity guidelines. High lifetime hours of high dynamic activity patients were defined as more than 150 min/week of high intense physical exercise. The primary endpoint was a composite of cardiovascular death and hospital admissions.

RESULTS: A total of 879 patients were analyzed, divided in 203 high lifetime hours of high dynamic activity -, 192 high lifetime hours of activity- and 484 low lifetime hours of activity patients. Over a mean follow up of 36 months (±14), the primary endpoint occurred in 61 out of 203 (30%) high lifetime hours of high dynamic activity -, 53 out of 192 (27%) high lifetime hours of activity- and 135 out of 484 low lifetime hours of activity patients (28%) (p = 0.74). During follow up 42 high lifetime hours of high dynamic activity- (35%), 43 high lifetime hours of activity- (32%) and 104 low lifetime hours of activity patients (34%) with paroxysmal AF received electrical or chemical cardioversion or atrial ablation (p = 0.90).

CONCLUSIONS: In patients included in the RACE 4, there appears to be no relation between previous activity levels and cardiovascular outcome and the need for electrical or chemical cardioversion or atrial ablation. Cardiovascular outcome was driven by AF related arrhythmic events.