- This cross-sectional study investigated the prevalence of aortic dilatation (≥40 mm) among 442 competitive rowers and runners who were age 50 to 75 and had participated in at least 10 years of endurance training after age 40
- Aortic dilatation was noted in 21% of participants (31% of men and 6% of women)
- 24% of participants had an aortic size two standard deviations above the population mean
- Long-term participation in competitive endurance sports may represent a novel, clinically relevant risk factor for acquired ascending aorta dilatation
High levels of exercise training stimulate cardiac remodeling that often results in myocardial wall thickening and chamber dilatation pronounced enough to meet definitions of cardiomyopathy. Prior research suggests routine vigorous exercise can also cause aortic dilatation, but below common thresholds for pathology.
However, that research largely involved athletes in the first two to three decades of life. In the first study of its kind, Timothy W. Churchill, MD, clinical fellow in medicine, and Aaron L. Baggish, MD, director of the Cardiovascular Performance Program at Massachusetts General Hospital, and colleagues recently observed substantial aortic dilatation among aging endurance athletes. Their report appears in JAMA Cardiology.
Inclusion criteria for the study were age 50 to 75 and at least 10 years of endurance training after age 40. From February to October 2018, participants were recruited based on participation in the Boston Marathon (n=153 men, 61 women) or competitive rowing clubs/national rowing competitions (n=114 men, 114 women).
The average age was 61. Seven women and 28 men were elite competitors (marathon time under 2 hours 45 minutes or rowing participation in world championships or the Olympics). The cohort had a low burden of cardiovascular disease and traditional CVD risk factors.
Participants underwent transthoracic echocardiography designed to optimize measurements of the ascending aorta.
Clinically relevant aortic dilatation, defined as diameter at sinuses of Valsalva or ascending aorta ≥40 mm, was found in:
- 21% of all participants
- 40% of elite athletes
- 31% of men
- 6% of women
Differences between men and women were less pronounced after adjustment for body surface area (BSA) or height.
Comparison with Population Data
Aortic sizes of the endurance athletes were compared with population-level data, taking into account age, sex and BSA/height. 105 individuals (24%) had a measurement of more than two standard deviations above the population mean.
Factors significantly associated with aortic size at the sinuses of Valsalva were:
- Sport type (rowing)
- Elite status
Correlates of aortic size in the ascending aorta were:
Increased Risk of Aortic Events
Mild to moderate dilatation of the ascending aorta may be a previously unrecognized benign adaptation to long-term exercise. Alternatively, it may represent acquired overuse pathology that increases the risk of morbidity and mortality.
Aortic rupture is a rare cause of sudden death among young competitive athletes, but the prevalence of acute aortic syndromes and elective aortic surgical intervention among aging endurance athletes is unknown. Until those risks are researched, the clinical implications of this study are uncertain and patients require individualized assessment.
Learn more about the Cardiovascular Performance Program at Mass General
Refer a patient to the Corrigan Minehan Heart Center at Mass General