Anomalous left coronary artery origin unmasked by non-ST-elevation myocardial infarction

Anomalous coronary arteries originating from the opposite sinus of Valsalva (ACAOS) encompass a spectrum of congenital coronary abnormalities, with reported prevalence estimates of approximately 0.44% in large screening cohorts [1]. Although many ACAOS variants are incidental findings with a benign clinical course, the anomalous origin of the left coronary artery (LCA) from the right sinus of Valsalva (L-ACAOS) is associated with substantial risk of myocardial ischemia, ventricular arrhythmias, and even sudden cardiac death [2, 3]. Particular hemodynamic significance is attributed to the interarterial course between the aorta and pulmonary trunk, an intramural segment within the aortic wall, and high-risk ostial features such as an acute-angle take-off or slit-like/fish-mouth-shaped orifice of the anomalous coronary artery [2, 3].

A 47-year-old male patient with a history of dyslipidemia and active smoking was transferred to the Cardiology Department due to a non-ST-elevation myocardial infarction (NSTEMI). Upon admission, he reported retrosternal chest pain and dyspnea. He denied previous angina-like symptoms, and no triggering factor was identified. Physical examination was unremarkable. Serum troponin I was elevated and increased from 96 to 127 ng/l over 24 h, with an upper reference limit of 34.20 ng/l. Echocardiography revealed mild segmental left ventricular wall hypokinesia, with a left ventricular ejection fraction of 55%. The ECG showed sinus rhythm, a normal electrical axis, and a heart rate of 68 beats per minute (Figure 1 F).

Figure 1.

Anomalous origin of the left coronary artery from the right sinus of Valsalva (yellow arrows) visualized on coronary computed tomography angiography: A, B – Three-dimensional volume-rendered reconstructions. C – Multiplanar reconstruction: an acute take-off angle with proximal luminal narrowing, consistent with an interarterial and likely intramural course. D – Axial view, E – Oblique multiplanar reconstruction showing the proximal course of the left anterior descending artery between the aortic root and the pulmonary trunk. Panels C–E correspond to the diastolic phase. F – Admission ECG showing sinus rhythm, a normal electrical axis, a heart rate of 68 beats per minute, and no signs of acute ischemia

Coronary angiography excluded significant stenosis in the right coronary artery; however, the left coronary ostium was not identified in its expected anatomical position during diagnostic catheter engagement. Subsequent exploration revealed an anomalous origin of the LCA arising from the right sinus of Valsalva. Because invasive angiography could not delineate the proximal course, the patient underwent coronary computed tomography angiography (CCTA), which demonstrated an acute take-off angle (< 45°) of the LCA arising from the right coronary sinus (Figure 1). The vessel coursed leftward between the proximal ascending aorta (29 mm in diameter) and the pulmonary trunk (27 mm in diameter, measured 1 cm above the pulmonary valve) (Figure 1). Along this segment, luminal narrowing was observed, suggesting an intramural trajectory. No atherosclerotic lesions were identified, which excluded the diagnosis of obstructive coronary artery disease. During hospitalization, conservative pharmacological treatment was administered. Clinical improvement was achieved, with symptom resolution and normalization of troponin levels.

Given the malignant LCA course, the Heart Team scheduled him for surgical leftward pulmonary trunk translocation with concomitant left internal mammary artery-to-left anterior descending artery bypass grafting. The perioperative course was uneventful, and the patient was discharged home in good general condition on the eighth day after the procedure.

Accurate assessment of coronary artery anomalies during invasive coronary angiography may be particularly difficult, especially in patients presenting with acute coronary syndrome, due to challenges in selective cannulation and limited visualization of the anomalous vessel course [4]. Consequently, CCTA is an essential modality for detailed anatomical evaluation, risk stratification, and treatment guidance [2, 3, 5]. In ambiguous cases, intravascular ultrasound, when technically feasible, may complement CCTA by enabling direct assessment of the intramural segment and dynamic changes in coronary cross-sectional area [1]. Rather than resulting from “scissor-like” compression between the great arteries, ischemia is now thought to arise primarily from dynamic unilateral compression of the intramural coronary segment within the aortic wall, especially during systole, tachycardia, and increased arterial pressure [1]. Current evidence regarding optimal management of L-ACAOS remains limited to small registries, case series, and observational studies [3, 5]. Percutaneous coronary intervention is often technically complex and should not be considered a standard approach for revascularization. Surgical intervention is indicated for symptomatic patients or those with documented myocardial ischemia, and is generally considered reasonable in asymptomatic individuals with high-risk anatomical features [2].

Funding Statement

Funding Poznan University of Medical Sciences.

Ethical approval

Not applicable.

Conflict of interest

The authors declare no conflict of interest.