Coronary artery anomalies (CAAs) include congenital or acquired anomalies that may affect young athletes. Examples of congenital anomalies include anomalous aortic origin of a coronary artery (AAOCA) and anomalous origin of a coronary artery from the pulmonary artery. The main example of acquired CAAs affecting young athletes today is Kawasaki disease, an acquired inflammatory process that targets small vessels, particularly the coronary circulation. For the purpose of this discussion, the focus will be on AAOCA, reportedly the second most common cause of sudden cardiac death (SCD) in young athletes.

The occurrence of SCD generates extreme anxiety in schools, sports organizations, and communities at large, causing it to become a greater societal burden.¹ Several factors of AAOCA are unknown, including the exact prevalence, the pathophysiological mechanisms leading to SCD, the actual risk of death for the different types of anatomy, the optimal way to evaluate these patients, and whether or not any treatment strategies decrease the risk of SCD in such patients are unknown. Most of the deaths associated with AAOCA occur unexpectedly in healthy children or young athletes, and may occur immediately after exercise^2,3,4 or at rest. An increasing number of children and young adults have been found to have AAOCA on imaging studies performed as part of pre-participation screening or for other incidental reasons, such as the presence of a murmur or an "abnormal" electrocardiogram. The estimated prevalence of AAOCA varies according to the source of data, ranging from 0.06%-0.9% for anomalous right coronary artery (ARCA), to 0.025%-0.15% for anomalous left coronary artery (ALCA).^6,9 Despite the available evidence suggesting that ARCA is approximately six times more prevalent than ALCA, the latter seems to be responsible for up to 85% of SCDs related to AAOCA^3,4,10 and is thus considered a more lethal anomaly.

The precise mechanism leading to SCD in this condition is yet to be defined, although it is postulated that occlusion or compression of the anomalous vessel during exercise leads to myocardial ischemia and subsequent lethal ventricular arrhythmia (ventricular tachycardia and fibrillation). Morphologic factors that are believed to account for this include abnormal ostium (stenotic, slit-like) of the anomalous coronary artery, a vessel course between the aorta and the pulmonary artery (interarterial), and a vessel course inside the aortic wall (intramural). Clinical presentations are variable, but the first manifestation of AAOCA is often a sudden cardiac event. Why an athlete can exercise intensely for several years without symptoms until the sentinel event occurs remains unknown. Other clinical manifestations that are present in approximately half of patients include the occurrence of chest pain, syncope or near syncope, dizziness, and/or palpitations during exertion.^3,4,11 Current reports indicate that the risk of SCD is higher during childhood and early adulthood, with most reported events occurring in patients between 10 and 30 years of age,^10,12 abating significantly thereafter. Anecdotal factors have been postulated for such phenomena, pathophysiologic mechanisms, and thus risk stratification,are still lacking in patients diagnosed with AAOCA.

Optimal evaluation of patients with AAOCA is not established but typically includes assessment of exercise performance (stress test), often with myocardial perfusion and tomographic imaging with computerized tomography (CT) or magnetic resonance imaging (MRI). Except in some select cases, cardiac catheterization is rarely utilized when additional information is needed, such as when determining coronary flow reserve and assessing vessel compression throughout the cardiac cycle with intravascular ultrasound.

Stress testing, including myocardial perfusion imaging, has limitations because current published data indicate studies are rarely positive for ischemia, even in those who suffered SCD.^3,13 Evaluation using stress testing can often lead to both false positive and false negative results, which limits the utility in AAOCA assessment. Tomographic imaging is not only now considered to be the imaging modality of choice to evaluate AAOCA, but also crucial in determining details of ostial anatomy and the course of the anomalous vessel. Cardiac MRI and CT are the preferred modes of imaging, and the choice between the two varies among institutions.

The management of patients with AAOCA is also challenging given the paucity of data in risk stratification and longitudinal follow-up data. Existing research varies significantly among different centers as recently described by the Congenital Heart Surgeons Society (CHSS).¹⁴ Management strategies span from surgery for all, to exercise restriction, to observation without restriction, depending on the institution, vessel anatomy, and vessel course.

Recommending exercise restriction, either comprehensive or selective, for competitive sports is not without controversy. First, exercise restriction would not necessarily prevent the possibility of SCD occurring at rest or with minimal activity. In addition, health care providers should consider the psychological and emotional consequences of restricting exercise in a child or adolescent and the known health consequences of not exercising. Moreover, although most reported series of patients operated on do not have abnormalities identified with stress testing – with and without myocardial perfusion tests postoperatively – a recent series from the Children's Hospital of Philadelphia reported that five out of 24 patients operated on had abnormal stress findings postoperatively,13 suggesting that the value of an operation may be limited. Reports of SCD following successful surgical repair of AAOCA have also been described.¹⁵

Figure 1

In light of so many unknowns and a hunger for meaningful data, a multi-institutional AAOCA registry was recently developed by the Congenital Heart Surgeons' Society (CHSS)^16,17, and in December of 2012, the first dedicated Coronary Anomalies Program was created at Texas Children's Hospital. The program aims at a standardized approach to the diagnosis, management, and follow-up of these patients. A multidisciplinary team including dedicated cardiologists, surgeons, cardiovascular radiologists, nurses, and research and outcomes program staff developed an algorithm (Figure 1) that has been followed consistently.¹⁸ Initial data in 90 patients evaluated and followed thus far show that approximately 45% of patients are symptomatic upon presentation, 4% present with either sudden cardiac arrest or shock, and 43% are asymptomatic. Of these patients, 35% underwent surgical intervention, and all have returned to physical activity with no restrictions postoperatively.¹⁹

This remains an obscure area in which many questions are yet to be answered. However, nationwide efforts for collaboration continue to gather meaningful data, with longitudinal follow-up of patients with AAOCA in order to allow better risk stratification and hopefully decrease the occurrence of SCD and unnecessary exercise restriction in these patients.

References

1. Stecker EC, Reinier K, Marijon E, et al. Public health burden of sudden cardiac death in the United States. Circ Arrhythm Electrophysiol 2014;7:212-17.
2. Maron BJ, Doerer JJ, Haas TS, Tierney DM, Mueller FO. Sudden deaths in young competitive athletes: analysis of 1866 deaths in the United States, 1980-2006. Circulation 2009;119:1085-92.
3. Basso C, Maron BJ, Corrado D, Thiene G. Clinical profile of congenital coronary artery anomalies with origin from the wrong aortic sinus leading to sudden death in young competitive athletes. J Am Coll Cardiol 2000;35:1493-1501.
4. Taylor AJ, Rogan KM, Virmani R. Sudden cardiac death associated with isolated congenital coronary artery anomalies. J Am Coll Cardiol 1992;20:640-47.
5. Angelini P, Shah NR, Uribe CE, et al. Novel MRI-based screening protocol to identify adolescents at high risk of sudden cardiac death. J Am Coll Cardiol 2013;61:E1621.
6. Drory Y, Turetz Y, Hiss Y, et al. Sudden unexpected death in persons less than 40 years of age. Am J Cardiol 1991;68:1388-92.
7. Davis JA, Cecchin F, Jones TK, Portman MA. Major coronary artery anomalies in a pediatric population: incidence and clinical importance. J Am Coll Cardiol 2001;37:593-7.
8. Angelini P, Villason S, Chan AV, Diez JG. Normal and Anomalous Coronary Arteries in Humans. In: Angelini P, ed. Coronary Artery Anomalies: A Comprehensive Approach. Philadelphia: Lippincott Williams & Wilkins. 1999;27-150.
9. Prakken NH, Cramer MJ, Olimulder MA, Agostoni P, Mali WP, Velthuis BK. Screening for proximal coronary artery anomalies with 3-dimensional MR coronary angiography. Int J Cardiovasc Imaging 2010;26:701-10.
10. Kragel AH, Roberts WC. Anomalous origin of either the right or left main coronary artery from the aorta with subsequent coursing between aorta and pulmonary trunk: analysis of 32 necropsy cases. Am J Cardiol 1988;62:771-7.
11. Eckart RE, Scoville SL, Campbell CL, et al. Sudden death in young adults: a 25-year review of autopsies in military recruits. Ann Intern Med 2004;141:829-34.
12. Taylor AJ, Byers JP, Cheitlin MD, Virmani R. Anomalous right or left coronary artery from the contralateral coronary sinus: "high-risk" abnormalities in the initial coronary artery course and heterogeneous clinical outcomes. Am Heart J 1997;133:428-35.
13. Brothers JA, McBride MG, Seliem MA, et al. Evaluation of myocardial ischemia after surgical repair of anomalous aortic origin of a coronary artery in a series of pediatric patients. J Am Coll Cardiol 2007;50:2078-82.
14. Brothers J, Gaynor JW, Paridon S, Lorber R, Jacobs M. Anomalous aortic origin of a coronary artery with an interarterial course: understanding current management strategies in children and young adults. Pediatr Cardiol 2009;30:911-21.
15. Nguyen AL, Haas F, Evens J, Breur JM. Sudden cardiac death after repair of anomalous origin of left coronary artery from right sinus of Valsalva with an interarterial course : Case report and review of the literature. Neth Heart J 2012;20:463-71.
16. Brothers JA, Gaynor JW, Jacobs JP, et al. The registry of anomalous aortic origin of the coronary artery of the Congenital Heart Surgeons' Society. Cardiol Young 2010;20 Suppl 3:50-8.
17. Poynter JA, Williams WG, McIntyre S, et al. Anomalous aortic origin of a coronary artery: a report from the Congenital Heart Surgeons Society Registry. World J Pediatr Congenit Heart Surg 2014;5:22-30.
18. Mery CM, Lawrence SM, Krishnamurthy R, et al. Anomalous aortic origin of a coronary artery: toward a standardized approach. Semin Thorac Cardiovasc Surg 2014;26:110-22.
19. Molossi S, Mery CM, Krishnamurthy R, et al. Stantardized approach to patients with anomalous aortic origin of a coronary artery: results from the coronary anomalies program at Texas Children's Hospital. J Am Coll Cardiol 2015;65:A501.

Keywords: Adolescent, Anxiety, Aorta, Arrhythmias, Cardiac, Athletes, Cardiac Catheterization, Chest Pain, Cooperative Behavior, Coronary Circulation, Coronary Vessels, Cost of Illness, Death, Sudden, Cardiac, Dizziness, Electrocardiography, Exercise Test, Heart Defects, Congenital, Hunger, Magnetic Resonance Imaging, Motor Activity, Mucocutaneous Lymph Node Syndrome, Myocardial Ischemia, Myocardial Perfusion Imaging, Physical Exertion, Prevalence, Pulmonary Artery, Sports, Surgeons, Syncope, Tachycardia, Ventricular, Tomography, Young Adult

< Back to Listings