Ectopic right coronary artery arising from the pulmonary artery: a rare congenital malformation

Abstract

An ectopic origin of the right coronary artery from the pulmonary artery is an extremely rare congenital malformation. This case report aimed to review our experience in the diagnosis and treatment of coronary artery anomalies. We report a case of ectopic origin of the right coronary artery from the pulmonary artery. We analyzed the taxonomy and clinical implications of the ectopic origin of the coronary artery. The findings of this case may increase patients’ and clinicians’ awareness of this anomaly.

Introduction

Coronary artery anomalies (CAAs) are a group of congenital disorders affecting the coronary artery with an incidence of approximately 1%. ¹ CAAs are frequently discovered incidentally during coronary angiography or routine autopsy. ² These abnormalities originate in the pulmonary artery and can occur alone or in combination with other congenital heart defects. At lower pressure during hypoxia, blood flow of the heart muscle is insufficient. Some children die after birth because of heart failure. ³ We report a rare case of ectopic origin of the right coronary artery from the pulmonary artery, and the patient’s symptoms did not appear until old age. We also reviewed previous literature on an ectopic origin of the right coronary artery from the pulmonary artery and discuss our findings.

Case presentation

The reporting of this study conforms to the CARE guidelines. ⁴ A 70-year-old female patient was hospitalized in our department because of chest pain for 20 hours. The patient had a history of hypertension and diabetes mellitus. A physical examination showed no abnormalities, and a full blood count, coagulation function, electrolytes, routine urine tests and abdominal color ultrasound were normal. Her troponin concentration was 0.314 ng/mL, and her brain natriuretic peptide concentration was 261.6 pg/mL. An electrocardiogram showed a normal sinus rhythm and ST-T changes. Echocardiography suggested left atrial enlargement and thickening of the interventricular septum, which may have been caused by myocardial ischemia. However, the location of the coronary opening was not obvious on ultrasound. Computed tomography angiography showed an ectopic origin of the right coronary artery from the pulmonary artery (Figure 1).

Figure 1.

Computed tomography angiography shows an ectopic origin of the right coronary artery from the pulmonary artery.

Following this diagnosis, the patient was referred for surgery for right coronary ostial reimplantation, in which the right coronary artery was reimplanted in the aorta (Figure 2). The patient recovered with no further episodes of chest pain and was discharged on postoperative day 10. One month postoperatively, no further episodes of chest pain were reported by the patient, and coronary computed tomography angiography indicated that the right coronary artery had opened in the aorta (Figure 3).

Figure 2.

An intraoperative exploration shows that the right coronary anomaly originates from the pulmonary artery. The arrow represents the right coronary artery, the circle represents the aorta, and the triangle represents the pulmonary artery.

Figure 3.

Coronary computed tomography angiography indicates that the right coronary artery opens in the aorta (arrows).

Discussion

CAAs occur in approximately 1% of individuals, and are often found in individuals who undergo coronary angiography and are potentially fatal. ¹ Some scholars have proposed that CAAs include single CAAs, coronary artery splitting, loss of the left main artery, coronary artery hypoplasia, abnormal positioning of the coronary artery opening, and abnormal inherent coronary artery anatomy. ³ According to epidemiological data, the most common CAA is a separate origin of the left circumflex artery, followed by a single coronary artery, ectopic left coronary artery, left anterior descending artery, and right coronary artery, accounting for 58.3%, 12.5%, 10.4%, 10.4%, and 8.5%, respectively. ³ The distinction between an abnormal coronary origin and normal variation has not been well described, and the classification is complicated. ³ The most common classification method is based on the ectopic origin. An ectopic origin includes the aorta, pulmonary artery, another coronary artery branch, and other arteries.^5–8 An aortic ectopic origin is the most common type and is dominated by a false abnormal origin of the Valsalva sinus. ³ The origin of an abnormal coronary artery is related to coronary atherosclerotic disease, valvular heart disease, myocardial ischemia, fatal arrhythmia, and sudden cardiac death. As mentioned above, an ectopic origin from the aorta is the most common, ³ and an origin from the pulmonary artery is rare. The origin of the left coronary artery in the pulmonary artery is also known as Bland–White–Garland syndrome, which was first reported by Brooks in 1886, and the clinical manifestations of this congenital heart disease were first described by Bland, White, and Garland in 1933. ⁹ The right coronary artery originating from the pulmonary artery is also rare, and the relationship between its clinical significance and anatomical features remains to be clarified. The diagnosis and treatment of the origin of abnormal coronary arteries need to be understood in detail.

According to angiographic data, the incidence of right CAAs originating from the pulmonary artery is less than <0.002%. ¹⁰ The pathogenesis of this condition is mainly caused by dislocation or improper rotation of the spiral septum during formation of the arterial trunk. ¹¹ These patients are usually asymptomatic and are often identified by a physical examination. Clinical manifestations vary widely from asymptomatic to myocardial ischemia, myocardial infarction, arrhythmia, or sudden cardiac death. ² Clinical manifestations in patients with an abnormal coronary origin from the pulmonary artery include angina pectoris and syncope, and even sudden death and exercise-related death.^12–14 The occurrence of these symptoms may be related to factors, such as coronary artery angle take-off and atypical vessel wall thickening, resulting in insufficient myocardial blood flow, hypoxia, and sudden cardiac death.^15,16 Total CAAs originate in the pulmonary artery and can occur alone or in combination with other congenital heart defects. ³ Bharati et al. ¹⁷ reported the case of an infant with a completely abnormal coronary origin and hypoplastic left heart syndrome who died of congestive heart failure on day 3 of hospitalization, despite treatment with prostaglandins. Diagnosing CAAs is challenging. ³ Transthoracic echocardiography may provide indirect diagnostic signs, such as bipolar flow abnormalities in the left ventricular outflow tract. ¹⁸ A definitive diagnosis of CAAs can be made by multilayer computed tomography and coronary angiography. ¹⁹

The treatment of an abnormal coronary origin is still the subject of debate, and current treatment methods include lifestyle changes, percutaneous coronary intervention, and surgery. ² Surgery is considered the final treatment option. ³ Surgical treatment has two purposes: to eliminate the left-to-right shunt or “coronary steal” and to establish double coronary circulation from the aorta. ²⁰ Surgical options include simple coronary artery ligation, coronary artery bypass grafting, coronary artery opening replantation, and coronary artery stenting. ³ Simple coronary ligation is less invasive, but there is still a risk of a single-pore coronary system. ³ Some authors suggest using the internal mammary artery as the coronary artery for coronary artery bypass grafting. ¹⁸ However, there has been opposition to this suggestion because of the potential dangers of coronary artery steal and poor arterial bypass patency within the mammary gland. ²⁰ In patients with pulmonary arteries of an abnormal origin, replantation is an ideal approach because it can achieve therapeutic objectives at the same time. When the coronary artery originates from the posterior wall of the pulmonary artery and cannot be replanted, coronary artery bypass grafting is selected. When coronary artery bypass and replantation are not possible, ligation is the last option. ²¹

We experienced a rare case in which the right coronary artery originated from the pulmonary artery and was eventually treated with replantation through the coronary artery opening. Patients with chest pain are easily misdiagnosed with myocardial infarction. We emphasize the diagnostic value of coronary computed tomography angiography or coronary angiography. Early intervention is necessary even in asymptomatic patients in whom right coronary artery replantation is feasible and has a good long-term prognosis.

Conclusion

We report a rare case of a heterotopic right coronary artery originating in the pulmonary artery that was treated with coronary artery opening replantation. We believe that patients with an ectopic origin of the coronary artery require a detailed evaluation of symptoms, signs, and imaging and appropriate treatment plans according to different conditions.