Myocardial infarction in a patient with single coronary artery - rare but real

Abstract

A 53-year-old woman was referred to our hospital with acute coronary syndrome. The coronary angiography demonstrated a single coronary artery. Culprit lesion was a subtotal occlusion of the proximal left anterior descending coronary artery, which was recanalized and treated with drug-coated balloon angioplasty. The patient recovered quickly after the procedure. A coronary computed tomography angiography visualized the left main coronary artery, which was passing between the ascending aorta and the pulmonary trunk and categorized this anomaly as R-II-B according to Lipton's classification, representing an extremely rare coronary anomaly.

<Learning objective: ST-segment elevation myocardial infarction can present with atypical electrocardiographic manifestations. Percutaneous coronary intervention with drug-coated balloon may be considered in patients with relevant coronary stenosis in an anomalous coronary artery.>

Introduction

Single coronary artery is an unusual condition, which cardiologists rarely encounter. We present a case of a middle-aged patient who presented with myocardial infarction and atypical electrocardiographic findings. Coronary angiography and cardiac computed tomography revealed a rare finding of the left main coronary artery passing between the ascending aorta and pulmonary trunk. The patient was successfully treated using a drug-coated balloon to avoid permanent metallic implant.

Case report

A 53-year-old postmenopausal woman with medical history of hypertension, obesity, and cigarette smoking was referred to our hospital by ambulance. On the day of admission, she woke up with de-novo angina pectoris. The electrocardiogram (ECG), which was performed in the ambulance showed sinus rhythm with ST-elevation in aVR and ST-depression (>1 mm) in leads II, III, aVF, V2, V3, V4, V5, and V6 (Fig. 1). According to the ECG finding, nitroglycerin, aspirin, heparin, and morphine were administrated by the emergency physician. Coronary angiography was performed immediately and indicated a single coronary artery (SCA) arising from right sinus of Valsalva. The culprit lesion was a subtotal occlusion of the proximal left anterior descending coronary artery (LAD) (Fig. 2A). Percutaneous coronary intervention (PCI) was performed using two semi-compliant balloons (Sequent Neo 2.0 × 15 mm and Sequent Neo 3.0 × 15 mm, B. Braun Melsungen, Berlin, Germany) for lesion preparation. The result after balloon-dilatation was acceptable, hence, following the recommendation of the German consensus criteria [1], a paclitaxel-coated balloon (SeQuent Please NEO 3.0 × 15 mm, B. Braun Melsungen) was inflated for 30 s. After balloon-dilatation, we had an almost total resolution of the plaque with prompt flow and no sign of vessel dissection, i.e. thrombolysis in myocardial infarction flow Grade 3 (Fig. 2B). Intravascular imaging was not deemed necessary. There was no sign of vasospasm after administration of the intraarterial nitroglycerin during the coronarography.

Fig. 1.

Electrocardiogram recorded in the ambulance with ST-depression in II, III, aVF, V2, V3, V4, V5, V6, and ST elevation in aVR.

Fig. 2.

Coronary angiography in 30° right anterior oblique view. (a) Before PCI. Arrow indicates subtotal occlusion of the proximal LAD. (b) After PCI. Arrow indicates successful recanalization of the proximal LAD.

LAD, left anterior descending artery; PCI, percutaneous coronary intervention.

Post-procedurally, the patient was admitted to the intensive care unit and was referred to a normal care unit the following day. The ECG changes seen initially receded. Transthoracic echocardiography showed a normal left ventricular ejection fraction without wall motion abnormalities. In order to further categorize the present coronary anomaly, a coronary computed tomography angiography (CCTA) was performed, which confirmed the take-off of the SCA from the right sinus of Valsalva. The right coronary artery arose from the SCA shortly after leaving the right sinus with a typical course in the right atrioventricular sulcus. An elongated left main coronary artery (LMCA) showed an atypical course between the ascending aorta and the pulmonary trunk before dividing into the LAD and circumflex, each of which followed a typical course (Fig. 3). Furthermore, the CCTA revealed a transeptal course of LMCA corresponding to a typical hammock-like downward slope (Fig. 3).

Fig. 3.

Coronary computed tomography angiography with axial oblique maximum intensity projection reconstruction. (A) Depicts the LMCA (arrow) passing between the ascending aorta and the pulmonary trunk, (B) demonstrates the transeptal course of LMCA, (C+D) showing the LMCA passing between the ascending aorta and the pulmonary trunk corresponding to a typical hammock-like downward slope.

LMCA, left main coronary artery.

The patient was free of angina and arrhythmias and was discharged home at day 5. We recommended a secondary prevention i.e. lifestyle modification, dual antiplatelet therapy with aspirin and clopidogrel for 12 months, followed by lifelong aspirin and low-density lipoprotein cholesterol reduction <55 mg/dl using a statin. We recommended a rapid indication for non-invasive tests in case of suspension on progress of the chronic coronary syndrome. We performed an elective exercise stress ECG test with temporal distance to the index event, which was negative for myocardial ischemia.

Discussion

SCA is a congenital anomaly, which is often detected incidentally. Its prevalence among patients undergoing routine coronary angiography ranges between 0.024% and 0.066%. Most patients are asymptomatic until an index event occurs, e.g. unstable angina pectoris, myocardial ischemia, myocardial infarction, heart failure, or sudden cardiac death [2].

Coronary angiography and CCTA are important for the classification of coronary anomalies. The patient described herein was diagnosed with an R-II-B coronary anomaly according to Lipton's classification [3], which was further modified in 1990 by Yamanaka and Hobbs (see online material) [4]. Lipton's classification was proposed in 1979 based on angiographic analyses according to the site of origin and anatomical distribution of the branches. SCA can be associated with other congenital anomalies such as transposition of great vessels, coronary arteriovenous fistula, tetralogy of Fallot, truncus arteriosus, interventricular septal defect, patent ductus arteriosus, bicuspid aortic valve, and patent foramen ovale [2]. Our patient had no additional findings in CCTA or echocardiography. Symptoms associated with coronary artery anomalies are chest pain, dyspnea, palpitations, syncope, myocardial ischemia, and sudden cardiac death (SCD), particularly following exercise. Suggested mechanisms include external compression, acute angulation, kinking, torsion, spasm, and atherosclerotic obstruction [5].

An interesting finding herein was the atypical electrocardiographic presentation of ST-segment elevation myocardial infarction (STEMI) with ST-depression in 8 leads and ST-elevation in aVR [6] (Fig. 1), which triggered the primary PCI. This atypical electrocardiographic presentation suggests left main- or left main equivalent- coronary obstructive or severe three-vessel disease. The coronary angiography, however, identified a subtotal occlusion of the LAD. According to the ECG finding the patient was referred for acute coronary angiography from the emergency physician.

There are case reports indicating that the incidence of stent restenosis may be higher in patients with SCA when compared with patients without this anomaly [7]. Keeping this in mind and given the satisfactory result after lesion preparation (stent-like), the relatively young age of the patient, and the possibility for stent-related events after stent implantation at a rate of ~2%/year, we decided to perform drug-coated balloon (DCB)-PCI instead of implanting a drug-eluting stent.

The use of DCB is associated with a trend toward lower mortality when compared with stent implantation. Furthermore, there is emerging evidence that DCB-treatment in de-novo vessel disease is safe and feasible [8].

Patients with SCA have a higher risk for SCD especially in young adults [9,10]. Our patient was asymptomatic during exercise, had no relevant arrhythmias in 24-hour Holter ECG recordings, normal echocardiography, and no family history of SCD. Hence, the patient was evaluated as low risk for SCD.

Conclusion

The present case shows SCA arising from right sinus of Valsalva, that is a rare coronary anomaly. The LMCA passed between the ascending aorta and pulmonary trunk but was not impaired, the culprit lesion resulting in STEMI was in the proximal LAD. DCB-PCI may be considered in patients with relevant coronary stenosis in an anomalous coronary artery in order to avoid implantation of a metallic stent. In patients with chronic coronary syndrome however, visualization of the coronary anomaly via CCTA may be considered before PCI is performed.

Declaration of Competing Interest

All authors have no relationships relevant to the contents of this paper to disclose. Bruno Scheller is shareholder of InnoRa GmbH, Berlin, and was named as coinventor on patent applications submitted by Charité University Hospital, Berlin, Germany. Felix Mahfoud is supported by Deutsche Gesellschaft für Kardiologie (DGK), and Deutsche Forschungsgemeinschaft (SFB TRR219) and has received scientific support and speaker honoraria from Bayer, Boehringer Ingelheim, Medtronic, and ReCor Medical. The other authors have no conflict of interest.