Surgical Management of Acute Myocardial Infarction Caused by Intramural Anomalous Left Coronary Artery in a Young Female Athlete

We report the case of a 24-year-old female athlete presenting with abrupt dyspnea associated with presyncope and typical angina during the eighth kilometer of a running race. This level of exercise was not unusual for the patient, and she had annually acquired regular agnostic certification according to the CONI (Italian Olympic Games Commmittee) protocol (by means of medical examination; stress electrocardiography [ECG]; and spirometry, visual, and urine tests). In her clinical history, there were only some sporadic episodes of dyspnea during severe physical exertion, which had been related to a history of bronchial asthma, but she never felt dizzy or syncopal.

At hospital admission, clinical examination showed basal crackling gasps, severe hypoxia, lactic acidosis, and persistent angina. Her high-sensitivity troponin I level was 7,987 pg/mL and reached 33,431 pg/mL at peak the day after (normal range, 0.0–34.2 pg/mL). Her ECG showed some ventricular ectopic beats, a depressed ST interval from leads V₄ to V₆, and nonspecific intraventricular delay. Transthoracic echocardiography showed apical akinesia with a depressed left ventricle ejection fraction (40%). A computed tomography (CT) scan ruled out pulmonary embolism. A cycle of noninvasive ventilation and intravenous diuretic therapy allowed for clinical stabilization.

The patient had a rapid clinical recovery, with complete regression of the ECG (except persisting inversion of the T wave in lead aVL) and of the echocardiographic abnormalities (left ventricular ejection fraction, 60%).

After clinical stabilization, coronary angiography was performed, which showed hyperdominance of the right coronary artery with collateral circulation to the distal left circumflex coronary artery. By this angiographic evidence, a critical stenosis of the left main coronary artery (LMCA) was highly suspected because of an anomaly in its origin (Fig. 1). No signs of atherosclerotic disease were noticed.

Preoperative ECG-gated coronary CT scan (Fig. 2) showed evidence of the origin of the LMCA from the right sinus and its intramural course. After 1 week, cardiac magnetic resonance imaging showed subendocardial ischemic damage of the anterior and lateral walls of the left ventricle by late gadolinium enhancement (Fig. 3).

Surgery was performed through a full median sternotomy and standard cardiopulmonary bypass (central cannulation). Myocardial protection was obtained with retrograde intermittent blood cardioplegia. After transverse aortotomy, the native coronary ostia were identified. The left native ostium was initially difficult to localize, and we used retrograde cardioplegia to identify it through the backflow. The left coronary ostium originated from the right sinus, in a juxta-commissural position, with the proximal segment of the LCA passing to the left side in an intramural course. As surgical findings, there was no evidence of ostial thrombosis, suggesting that the intramural course of the LCA was the only mechanism responsible for myocardial ischemia. A probe was passed from the native ostium toward the left sinus, and the neo-ostium was then created in the left sinus at the point where the artery left the aortic wall without taking down the intercoronary commissure to prevent aortic regurgitation. At the site of the neo-ostium, the aortic and coronary artery walls were fixed together using multiple 7-0 polypropylene (Prolene) single stitches. Aortic cross-clamp and cardiopulmonary bypass were 65 and 91 minutes, respectively. The postoperative course was uneventful, and the patient was discharged on postoperative day 8.

The CT scan performed 2 weeks later showed an excellent surgical result, with a widely patent neo-ostium (Fig. 4).

Anomalous LCA arising from the opposite sinus of Valsalva with an intramural course is a rare congenital cardiac anomaly and may present at a young age with catastrophic life-threatening myocardial infarction and sudden cardiac death.²  The high complexity of the coronary artery anomaly spectrum remains a difficult clinical challenge for proper diagnosis and treatment, especially those affecting the LMCA. Indeed, in the latter, sudden cardiac death remains the most dangerous clinical feature,³  mostly in young adults during or immediately after intense exertion on the athletic field.^4,5 

This report emphasizes how diagnosis could be misleading and, therefore, how important it is to have the correct interpretation of symptoms. Postexertion symptomatic events, such as dyspnea, syncope, or chest pain, may be a critical warning in most patients. Surgery for coronary artery anomalies, especially when the LCA is involved, is indicated in symptomatic patients with episodes of syncope, angina, arrhythmias, or resuscitation after cardiac arrest and could be considered mandatory when an intramural course is present.^6,7  More controversial is a surgical indication in asymptomatic patients and for the right coronary artery, where usually a functional test can guide the clinicians to the right treatment.² 

The preferred surgical approach is unroofing the intramural segment of the LCA or creating a neo-ostium in the appropriate aortic sinus⁸ ; otherwise, coronary artery bypass grafting needs to be performed.

In our patient, the intramural segment of the coronary artery crossed the intercoronary commissure, and even if coronary artery bypass grafting was supposedly a valid surgical option at the beginning—considering the young age and the favorable coronary anatomy of our patient—the decision was made to create a neo-ostium for the LCA to maintain a physiologic coronary flow; this would preserve the entirety of the aortic root and valve structure.

The authors thank Paolo Angelini, MD, from the Texas Heart Institute (Houston, TX) for his support and help in this case.