Years of endurance competition may result in aortic dilatation
The aorta may be an exercise-responsive plastic organ that remodels in aging competitive endurance athletes, researchers reported in JAMA Cardiology.
In a cohort of endurance athletes (mean age, 61 years; 60% men; 52% rowers; 48% runners) with at least 20 years of experience, clinically relevant aortic dilation was found in 21% of participants (31% of men; 6% of women). Dilation was defined as an aortic diameter at sinuses of Valsalva or ascending aorta of at least 40 mm.
Researchers found that approximately 24% of participants had at least one z score of 2 or more, indicating an aortic diameter greater than 2 standard deviations (SDs) above the cohort mean.
Moreover, among elite competitors, defined as rowing participation in world championships or Olympics or marathon time less than 2:45, 40% had at least one aortic measurement of 40 mm or larger.
“To our knowledge, this study presents the first detailed characterization of the prevalence of clinically relevant ascending aortic dilatation among aging competitive endurance athletes,” Timothy W. Churchill, MD, clinical fellow in medicine at Massachusetts General Hospital, and colleagues wrote. “Among a group of experienced competitive male and female rowers and runners with a low burden of both cardiovascular disease and traditional risk factors, we observed a prevalence of aortic dilatation, as defined by an aortic dimension of 40 mm or larger, of 21% (31% among men and 6% among women). These findings appeared particularly pronounced among rowers and elite competitors from both sports.”
In male rowers, aortic size was greater at both the sinuses of Valsalva (mean, 39.2 mm; 95% CI, 38.5-39.9 vs. 36.7 mm; 95% CI, 36.1-37.2) and ascending aorta (mean, 37.6 mm; 95% CI, 36.9-38.4; vs. 35.6 mm; 95% CI, 35.1-36.2) compared with male runners.
In addition, male rowers represented the majority of participants with aortic dimensions of more than 40 mm, with 45% having at least one aortic measurement exceeding 40 mm.
“Notably, when compared with guideline-endorsed z scores, almost 25% of study individuals had a z score of 2 or above, indicating an aortic size 2 SDs above the population mean,” the researchers wrote. “In aggregate, these findings suggest that long-term participation in competitive endurance sport may represent a novel, clinically relevant risk factor for acquired ascending aorta dilatation.”
From February to October 2018, researchers recruited volunteer rowers at competitive rowing clubs and national competitions and runners at the Boston Marathon. Aortic measurements were taken at the aortic annulus, sinuses of Valsalva, sinotubular junction and ascending aorta using transthoracic echocardiographic protocol and standard imaging techniques. Dimensions were compared by age, sex, body size and z scores that were calculated where applicable.
“While aortic rupture is a rare cause of sudden death among young competitive athletes, the prevalence of aortic events among long-term aging endurance athletes remains unknown,” researchers wrote. “Future studies aimed at defining the natural history of aortic dilatation in this population with an emphasis on clinical outcomes, including the incidence of acute aortic syndromes and elective aortic surgical intervention, will be required to resolve this fundamental uncertainty. In the absence of such data, clinical implications of our findings remain uncertain and will require individualized assessment.” – by Scott Buzby
Disclosures: One author reports he received funding from the NIH/NHLBI and the National Football League Players Association; the American Heart Association to study the impact of exercise on CV health; and compensation for his role as team cardiologist from U.S. Soccer, U.S. Rowing, the New England Patriots, the Boston Bruins, the New England Revolution and Harvard University. The other authors report no relevant financial disclosures.