Association of Ascending Aortic Dilatation and Long-term Endurance Exercise Among Older Masters-Level Athletes

Question What is the prevalence of aortic dilatation among long-term endurance athletes? Findings In this cross-sectional study of 442 masters-level athletes, 94 individuals (21%) were found to have an ascending aortic size of 40 mm or larger, representing a marked increase in the prevalence of aortic dilatation compared with that predicted by established age- and sex-specific population nomograms. Meaning This study identified an elevated prevalence of aortic dilatation among aging endurance athletes without clear explanatory risk factors, suggesting that long-term endurance exercise is associated with aortic enlargement. Importance Aortic dilatation is frequently encountered in clinical practice among aging endurance athletes, but the distribution of aortic sizes in this population is unknown. It is additionally uncertain whether this may represent aortic adaptation to long-term exercise, similar to the well-established process of ventricular remodeling. Objective To assess the prevalence of aortic dilatation among long-term masters-level male and female athletes with about 2 decades of exercise exposure. Design, Setting, and Participants This cross-sectional study evaluated aortic size in veteran endurance athletes. Masters-level rowers and runners aged 50 to 75 years were enrolled from competitive athletic events across the United States from February to October 2018. Analysis began January 2019. Exposures Long-term endurance exercise. Main Outcomes and Measures The primary outcome was aortic size at the sinuses of Valsalva and the ascending aorta, measured using transthoracic echocardiography in accordance with contemporary guidelines. Aortic dimensions were compared with age, sex, and body size-adjusted predictions from published nomograms, and z scores were calculated where applicable. Results Among 442 athletes (mean [SD] age, 61 [6] years; 267 men [60%]; 228 rowers [52%]; 214 runners [48%]), clinically relevant aortic dilatation, defined by a diameter at sinuses of Valsalva or ascending aorta of 40 mm or larger, was found in 21% (n = 94) of all participants (83 men [31%] and 11 women [6%]). When compared with published nomograms, the distribution of measured aortic size displayed a rightward shift with a rightward tail (all P < .001). Overall, 105 individuals (24%) had at least 1 z score of 2 or more, indicating an aortic measurement greater than 2 SDs above the population mean. In multivariate models adjusting for age, sex, body size, hypertension, and statin use, both elite competitor status (rowing participation in world championships or Olympics or marathon time under 2 hours and 45 minutes) and sport type (rowing) were independently associated with aortic size. Conclusions and Relevance Clinically relevant aortic dilatation is common among aging endurance athletes, raising the possibility of vascular remodeling in response to long-term exercise. Longitudinal follow-up is warranted to establish corollary clinical outcomes in this population. This cross-sectional study assesses the prevalence of aortic dilation among older masters-level athletes with decades of exercise exposure.