Atrial Fibrillation in 63-Year-Old Former Elite Endurance Athletes: A 38-Year Follow-Up Study.

Introduction: There are many reports on atrial fibrillation/flutter (AF) in previous elite endurance athletes (ExA) and veteran athletes (VA), but no prospective studies on AF in elite endurance athletes (EA) have been published. Most studies are on males and increased risk in males has been found, but the explanation of this has been controversial. Methods: We present a study where 15 male and 15 female EA and matched groups of sports students and non-athletes were studied with clinical examination, a questionnaire, standard ECG, echocardiography, and 24-h ECG (Holter) monitoring in 1985. Twenty-nine EA were re-examined with the same examinations in 2000, and in 2023, a follow-up of 24 of them was done with a questionnaire and ambulatory ECG recording, aiming at the effect of risk factors, training parameters and sex on the occurrence of AF in ExA. The ambulatory ECG recording was done with smartphone (ECG 247) for 72 h or more. Results: The mean age was 62.6 years. All had ended their competition career before the age of 39. Three had known AF, all males, with the sex difference being significant. Another two males and one female had a history of tachycardia, and the sex difference in total tachycardias was also significant. None of the ExA had asymptomatic AF. A paternal history of AF was significantly more frequent in males with AF than in males without AF. There were no significant sex differences in training parameters. Conclusions: We think our study does not support doing ambulatory ECG recording of all ExA at age 65, but one should be aware of increased risk in males with a paternal history of AF. Both AF and symptomatic tachycardias were significantly increased in males. However, the low number of AF is a limitation of these conclusions and does not permit concluding on whether training during middle age confers a higher risk of AF than training at a younger age. No sex differences in training in ExA indicate that biological factors (like hormones) contribute considerably to the sex difference in the risk of AF in ExA. Despite the low number of AF cases, we believe our study provides new knowledge as it is prospective, free of baseline selection bias, includes detailed investigations both at baseline and at follow-up, and addresses a gap in prospective studies on AF in EA.