Association Of Blood Pressure Responses To Submaximal Exercise With Incident Atrial Fibrillation: The Framingham Offspring Study

Introduction: Atrial fibrillation (AF) is the most common arrhythmia and a leading cause of stroke. Blood pressure (BP) responses to submaximal exercise are associated with incident cardiovascular disease and mortality. The association of BP responses to submaximal exercise with incident AF in the community is unknown. Hypothesis: We hypothesized that higher BP during and slower BP recovery after submaximal exercise are associated with a higher risk of incident AF. Methods: We evaluated Framingham Offspring Study participants who attended examination cycle 7, were free of AF, and underwent submaximal treadmill exercise testing. Systolic BP (SBP) and diastolic BP (DBP) were obtained pre-exercise (standing), during exercise (second stage, 2.5 mph at 12% grade), and 3-minutes post-exercise (supine). ΔBP during exercise was defined as exercise BP minus pre-exercise BP. ΔBP during recovery was defined as peak exercise BP minus 3-minutes post-exercise BP. We related exercise BP variables to risk of AF using Cox proportional hazards regression, adjusting for age, sex, height, weight, resting heart rate, resting SBP, resting DBP, use of antihypertensive medication, current smoking status, and diabetes. Results: We studied 2,002 participants (mean age 58 years; 53% women). During a median follow-up of 15 years, 236 participants (39% women) developed AF. We observed a positive association of exercise DBP and ΔDBP during exercise with risk of AF (Hazards Ratio [HR] per standard deviation [SD] increase 1.28, 95% CI 1.12-1.47 and HR 1.22, 95% CI 1.07-1.39, respectively). There was also a positive association between 3 minutes post-exercise SBP and AF risk (HR per SD-increase 1.31, 95% CI 1.07-1.60) and an inverse relation between ΔSBP during recovery and AF risk (HR per SD-increase 0.79, 95% CI 0.66-0.94, Table ) Conclusions: BP responses to submaximal exercise during midlife may serve as a marker for AF risk in later life.