"CV Sports Chat" is an interview series including expert discussions relative to sports and exercise cardiology and the health care management of athletes.*

Dr. Alan Braverman is the alumni endowed professor in cardiovascular diseases and professor of medicine in the Cardiovascular Division of the Department of Medicine at Washington University School of Medicine. He is also the director of the Marfan Syndrome and Aortopathy Center at Washington University School of Medicine and Barnes-Jewish Hospital. Dr. Sean Meagher is a cardiology fellow at Beth Israel Deaconess Medical Center.

The following is an edited summary of an interview conducted by Dr. Meagher, with Dr. Braverman on his approach to treating an athlete with aortic dilation.

What is the relationship between exercise/sports and aortic dilation? Is this a physiological response or predictor of future risk?

The so-called normal aortic diameter depends upon one's age, sex, and body size (especially height). The normal aorta is larger in males, in big and tall people, and in older individuals.

The aortic root and ascending aorta respond to high levels of physical exercise, with an enlargement of their diameters. A meta-analysis of 5,580 young elite athletes reported a small (~3.2 mm) but significantly larger aortic root diameter compared with nonathletic control patients.¹ Longitudinal studies of strength-trained athletes observed an increase in aortic diameter over time, with the largest increase in those with the longest duration of training.^2,3

What is our current understanding of potential mechanisms behind this association?

Vigorous endurance exercise leads to an increase in stroke volume and cardiac output and may increase aortic wall stress. Depending upon the degree of resistance components, elevated blood pressure may associate with increases in aortic diameters.

How prevalent is aortic dilation among athletes? Do we know if certain exercises or sports make athletes more prone to aortic dilation?

The prevalence of aortic dilation among athletes depends on the definition of dilated and the study population. Athletes performing endurance-trained and strength-trained sports tend to have slightly larger aortas compared with skilled-based sports. Endurance athletes, particularly endurance rowing/canoeing, have greater aortic diameters than those who engage in predominantly isometric exercise such as strength-trained athletes.^4,5 However, it is rare for an athlete <35 years of age to have aortic diameter >40 mm in men or >36 mm in women. Even among the extremes of body size, aortic dilation >42 mm is rare in a young male athlete.

In contrast, masters and older athletes (defined as ≥35 of age for masters athletes or ≥50 years of age for older athletes) are much more likely to have a dilated aortic root. Compared with control patients, a significantly higher proportion of former National Football League (NFL) athletes had an aortic diameter of >40 mm (29.6% vs. 8.6%).⁶ Among endurance masters athletes (rowers/marathoners, mean age 61 years), almost 20% of the male athletes had aortic diameters >40 mm and 6% had aortic diameters of 45-49 mm.⁷

When evaluating an athlete with aortic dilation, what is your approach in the evaluation of heritable thoracic aortic disease (HTAD)?

A careful multigenerational family history is taken regarding aortic aneurysm (especially thoracic aortic aneurysm [TAA]/dissection), cerebral or peripheral artery aneurysm, or unexplained sudden death at an early age. Examine carefully (or refer to a medical geneticist) for clinical features involving the skeletal, eyes, face, oropharynx, and skin suggesting a syndromic HTAD. In athletes with unexplained aortic dilation, I typically perform genetic testing. Aortic imaging in the patient's parents may be helpful.

When an athlete appears to have nonsyndromic aortic dilatation, when do you consider pursuing further aortic imaging (computed tomography/magnetic resonance imaging)?

Patients with syndromic HTAD need imaging from head to pelvis to assess for other aneurysm disease. When isolated aortic root and/or ascending aortic dilation is completely visualized by echocardiography, I may do one computed tomography angiography or magnetic resonance angiography and, if congruent with echo, typically will follow up with echo.

If an athlete has a known aortopathy or HTAD, what are your recommendations regarding physical activity, exercise, and competitive sports?

Shared decision-making (SDM) is necessary in approaching the athlete with aortic dilation, and especially those with HTAD. For individuals with HTAD, one assesses specific concerns relative to the condition and creates a plan for regular recreational exercise and physical activity considered safe and low risk. For too long, sedentary lifestyle and avoidance of exercise was considered the standard of care. Now, everyone who is able to is encouraged to live an active lifestyle that encompasses exercise.

If a diagnosis of a genetic aortopathy is made, recommendations are based upon the specific gene variant, aortic diameter, risk factors for aortic dissection (family history, aortic growth rate, phenotype), and specific sport, exercise, and level of competition.

In syndromic and nonsyndromic HTAD, I am restrictive about high-level, intense competitive sports that involve significant isometric components, intense/sustained high-level endurance exercise, and significant bodily contact. There are no outcomes data regarding competitive sports for those with HTAD. Suitability to play in some competitive sports is considered depending upon the nature of the sport, the aortic condition, and SDM.

In athletes with a bicuspid aortic valve (BAV), recommendations are less restrictive. Athletes with aortic dilation <4.5 cm are generally allowed to participate in all types of exercise and physical activity, but this involves SDM incorporating individual characteristics and aortic dissection risk.

What is your approach for follow-up and serial imaging in athletes with an aortopathy (genetic or spontaneous)?

This requires short-term follow-up during athletic participation and long-term follow-up for any progressive aortic dilation. There are studies that have followed athletes with mild aortic dilation that have gone on to form aneurysms later in life.

If an athlete with an aortopathy undergoes aortic surgery, how do you counsel their physical activity/exercise after surgery?

The 2022 American College of Cardiology/American Heart Association (ACC/AHA) guideline recommends cardiac rehabilitation after TAA surgery.⁸ After recovery from surgery, routine aerobic exercise is recommended. Regarding participation in exercise/competitive athletics, a few elite athletes have returned to professional sports (like the National Basketball Association [NBA]) after BAV-TAA resection. We performed a study on athletes with BAV aortopathy who underwent TAA resection and returned to endurance exercise (including triathlons, marathons, etc.). Over an 8-year follow-up period, no athlete experienced an untoward aortic complication.⁹ Thus, it is reasonable to return to this type of exercise after BAV-TAA resection.

For individuals with HTAD, the distal aorta remains at risk of TAA and type B aortic dissection. Continued caution regarding competitive exercise after TAA resection is recommended with the guidance that it is low risk to perform low-intensity and moderate-intensity recreational exercise.

*The interviews are edited for grammar and clarity.

References

1. Iskandar A, Thompson PD. A meta-analysis of aortic root size in elite athletes. Circulation 2013;127:791-98.
2. Tso JV, Turner CG, Liu C, et al. Longitudinal aortic root dilatation in collegiate American‐style football athletes. J Am Heart Assoc 2023;12:[ePub ahead of print].
3. Babaee Bigi MA, Aslani A. Aortic root size and prevalence of aortic regurgitation in elite strength trained athletes. Am J Cardiol 2007;100:528-30.
4. Gati S, Malhotra A, Sedgwick C, et al. Prevalence and progression of aortic root dilatation in highly trained young athletes. Heart 2019;105:920-25.
5. Limongelli G, Monda E, Lioncino M, et al. Aortic root diameter in highly-trained competitive athletes: reference values according to sport and prevalence of aortic enlargement. Can J Cardiol 2023;39:889-97.
6. Gentry JL, Carruthers D, Joshi PH, et al. Ascending aortic dimensions in former National Football League athletes. Circ Cardiovasc Imaging 2017;10:[ePub ahead of print].
7. Churchill TW, Groezinger E, Kim JH, et al. Association of ascending aortic dilatation and long-term endurance exercise among older masters-level athletes. JAMA Cardiol 2020;5:522-31.
8. Isselbacher EM, Preventza O, Hamilton Black J III, et al.; Writing Committee Members. 2022 ACC/AHA guideline for the diagnosis and management of aortic disease: a report of the American Heart Association/American College of Cardiology Joint Committee on Clinical Practice Guidelines. J Am Coll Cardiol 2022;80:e223-e393.
9. Lai AF, Braverman AC. Endurance exercise following ascending thoracic aortic aneurysm resection in bicuspid aortic valve aortopathy. JAMA Cardiol 2022;7:772-73.