Even Low Physical Activity May Lower Stroke Risk in AF

Even low levels of physical activity were associated with a lower risk for stroke and all-cause mortality among adults with atrial fibrillation (AF), with greater activity generally associated with larger benefits.Results of a prospective cohort study of more than 87,000 adults showed that compared with inactivity, physical activity was associated with up to a 19% lower risk for stroke and a 22% lower risk for all-cause mortality. Similar associations were observed in participants with and without AF.Among adults with AF, physical activity was also tied to an estimated 0.50-1.15 additional years of life expectancy compared with inactivity.“Regular physical activity is important for all and could be an important preventive strategy for people with AFib [atrial fibrillation],” lead investigator Kristoffer Robin Johansen, PhD, researcher at the School of Sport Sciences, Faculty of Health Sciences at UiT The Arctic University of Norway in Tromsø, Norway, said in a statement.The study was published online August 5 in the Journal of the American Heart Association.AF and Physical ActivityAF is the most common arrhythmia worldwide and is associated with an increased risk for stroke and reduced life expectancy. Depending on concomitant risk factors, stroke rates may be more than five times higher in those with AF.Physical activity is recommended for cardiovascular disease prevention and risk-factor management and may also lower stroke and mortality risk in AF. However, evidence on the association between physical activity and these outcomes in AF remains limited and inconsistent.To address these gaps, the investigators examined the association of physical activity with stroke and mortality and whether these associations varied by AF status. They hypothesized that physical activity could complement conventional medical management by improving cardiovascular risk factors and potentially reducing adverse outcomes.The prospective analysis included 87,340 adults (mean age, 50.9 years; 47.4% men; 6539 had AF) enrolled in the HUNT and Tromsø population-based studies in Norway.Participants were categorized as inactive or as having low, moderate, or high physical activity based on a self-reported index incorporating exercise frequency, duration, and intensity. Low, moderate, and high activity were defined as 1-449, 450-899, and ≥ 900 metabolic equivalent of task minutes per week (MET-min/wk), respectively; inactivity was defined as 0 MET-min/wk. Over a median follow-up of 13.5 years, 3415 strokes and 7833 deaths occurred.AF diagnoses were obtained from hospital and national health registries, with physician or cardiologist review and ECG confirmation used where available. Participants who developed AF during follow-up were reclassified from the time of diagnosis.Analyses were adjusted for age, sex, education, BMI, smoking, alcohol consumption, coronary heart disease, and study cohort. Additional analyses examined potential confounding from stroke risk and anticoagulant treatment.Stroke, Mortality Risks ReducedCompared with physically inactive adults, those with low, moderate, and high levels of activity had a 9%, 19%, and 18% lower stroke risk, respectively. All-cause mortality was 11%, 18%, and 22% lower among those who reported low, moderate, and high activity.Similar associations were observed among participants with and without AF. Among participants with AF, adjusted risk ratios (aRRs) for 15-year stroke risk were 0.80, 0.88, and 0.80 for low, moderate, and high activity, respectively, compared with inactivity.The association with lower mortality was strongest among participants with AF who reported the highest activity levels. The aRRs for mortality were 0.91, 0.88, and 0.79 for low, moderate, and high activity, respectively, compared with inactivity.Physical activity was also associated with longer survival among those with AF. Compared with inactivity, low, moderate, and high activity were associated with gains in life expectancy of 0.50, 0.66, and 1.15 years, respectively.Of the 3415 strokes that occurred during follow-up, 87% were ischemic and 13% were intracerebral hemorrhages (ICHs). The association between physical activity and stroke was similar when the analysis was limited to ischemic stroke, whereas physical activity was not significantly associated with ICH.The study had several limitations, including its observational design, which means residual or unmeasured confounding cannot be ruled out. Physical activity was self-reported and only modestly correlated with device-measured moderate-to-vigorous activity. Anticoagulant use was not available for the entire cohort, although adjusting for anticoagulation use in a subgroup led to similar results.Complementary Option to Conventional CarePhysical activity may complement current treatment strategies for stroke prevention in AF, the investigators concluded.“The results of our study provide an argument to add PA [physical activity] as a complementary option to conventional AF treatment strategies to prevent stroke,” they wrote.The researchers called for large, randomized trials to better define the optimal type and amount of physical activity for individuals with AF.The study “adds important evidence linking physical activity with lower risks of stroke and death in people with and without AFib,” Mina Chung, MD, co-chair of a 2023 joint guideline for the diagnosis and management of AF from the American Heart Association and other organizations, who was not involved in the study, said in a statement.However, physical activity may also reflect overall health, making it difficult to determine whether the observed associations are attributable specifically to exercise, Chung cautioned. Nonetheless, she said the results support encouraging patients to be as active as they can.The study was funded by the Northern Norway Regional Health Authority (Grant No. HNF1568-21). Disclosure information for study authors is available in the original study publication. Chung reported having no relevant financial disclosures.