Elevated Exercise Capacity Mitigates Atrial Fibrillation Incidence and Major Cardiovascular Outcomes: A Decade-Long Cohort Study.

Background: Atrial fibrillation (AF) increases cardiovascular risks and reduces quality of life. Although impaired physical activity has correlated with incident AF, the impacts of exercise capacity and blood pressure changes during exercise on AF development remain unclear.

Objectives: The purpose of this study was to evaluate the association between exercise capacity and AF incidence and its effects on major adverse cardiovascular events (MACE).

Methods: We conducted a retrospective analysis using a prospectively maintained administrative database of patients undergoing exercise treadmill testing between 2003 and 2012. Blood pressure measurements at baseline, peak exercise, and recovery were recorded. Participants were followed for new-onset AF and MACE.

Results: Among 15,450 subjects (median follow-up: 9.1 years; IQR: 7.0-11.5 years), 515 (3.3%) developed AF. Peak METS (pMETs) independently predicted a lower risk of incident AF (HR: 0.92; 95% CI: 0.88-0.97), after adjusting for confounders. Cubic spline analysis revealed a continuous inverse association between pMETs and incident AF. This association was stronger in older adults and those without chronotropic incompetence. Although incident AF increased the risks of ischemic stroke and MACE, higher pMETs independently reduced the risks of ischemic stroke (HR: 0.88; 95% CI: 0.83-0.94) and MACE (HR: 0.86; 95% CI: 0.84-0.88), even after adjusting for incident AF as a time-dependent variable. Additionally, diastolic blood pressure during recovery independently also correlated with incident AF and ischemic stroke.

Conclusions: Higher exercise capacity was associated with a lower AF incidence and reduced risks of ischemic stroke and MACE, reinforcing the prognostic value of cardiorespiratory fitness in AF prevention and cardiovascular risk reduction.