Anomalous origin of the right coronary artery arising from the left coronary sinus of valsalva in a Nigerian adult: a case report

¹Department of Interventional Cardiology, Iwosan Lagoon Hospitals, Victoria Island, Lagos, Nigeria, ²Department of Cardiology, Lagos University Teaching Hospital, Idi Araba, Lagos, Nigeria

^&Corresponding author
Olurotimi John Badero, Department of Interventional Cardiology, Iwosan Lagoon Hospitals, Victoria Island, Lagos, Nigeria

Introduction    

Coronary artery anomalies (CAA) are amongst the most common of the congenital cardiovascular disorders, but infrequently seen in about 1% of the general population [1,2]. They can be found in about 0.3% - 5.6% of subjects undergoing coronary angiographies and 1% of routine autopsies [2]. No CAA documented by angiography has been reported in our country to date, even though coronary imaging has been available in Nigeria for more than a decade now. The anomalous origin of the right coronary artery was first reported by White et al. in 1948 [3]. The clinical presentation is variable and is rarely associated with syncope, myocardial ischemia, and sudden cardiac death [4]. It is categorized into; inter-arterial, pre-pulmonic, sub-pulmonic, and retro-cardiac [5]. The anomalous inter-arterial cause is the commonest subtype, found in 99% of cases [6]. To the best of our knowledge, we report the first case of an anomalous coronary artery discovered by angiography in Nigeria.

Patient and observation     

Patient information: a 71-year-old man with a past medical history of long-standing hypertension, hyperlipidemia, colon, and breast malignancy presented to the clinic with exertional dyspnea and chest pain of two years duration. His symptoms had gradually worsened in the preceding six months. He denied nausea, cough, fever, or weight loss. He was not a tobacco or alcohol user, and his family history was non-contributory. His medications included atorvastatin 20 mg, atenolol 25 mg, hydrochlorothiazide 12.5 mg and aspirin 81 mg daily.

Clinical findings: physical examination revealed a well-nourished male in no painful or respiratory distress. His vitals were all within normal limits. His cardiovascular exam revealed a normal jugular venous pulse and normal first and second heart sounds with no murmurs, rubs, or gallops.

Diagnostic and assessment: given his co-morbidities and symptoms, an echocardiogram was obtained revealing moderate LV systolic dysfunction, ejection fraction (EF) of 43%, grade 1 diastolic dysfunction with impaired LV relaxation and normal valvular function. Coronary angiography was scheduled to rule out ischemic etiology given persistent symptoms and cardiomyopathy. Coronary angiography was performed under moderate conscious sedation via right common femoral access. The left main coronary artery (LMCA) ostium was engaged with a 5F Judkins Left (JL) 4 diagnostic catheter and selective left coronary angiography was performed in multiple orthogonal views. This revealed angiographically normal LMCA, left anterior descending (LAD), and left circumflex (LCX) arteries. Several attempts to cannulate the right coronary artery with a 5F Judkins Right (JR) 4 diagnostic catheter were unsuccessful. An Amplatz left catheter (AL-1) was used to successfully cannulate the right coronary artery and contrast injection showed an angiographically normal right coronary artery originating from the left aortic sinus (Figure 1). The procedure was concluded successfully without any complications.

Diagnosis: a diagnosis of anomalous right coronary artery (RCA) originating from the left aortic cusp was made, and the patient was discharged home. He was scheduled for a coronary CT angiogram to determine the course of the anomalous RCA.

Therapeutic interventions: he was placed on medical therapy with isosorbide dinitrate, atenolol, lisinopril, and hydrochlorothiazide and scheduled for outpatient follow-up.

Follow-up and outcome of interventions: coronary CT angiogram obtained revealed an RCA arising from the left side of the ascending aorta 1cm above the Sino-tubular junction running an inter-arterial course for up to 1.5cm before traversing to the right atrioventricular groove (Figure 2, Figure 3). The patient was appropriately counseled about these findings. Following a heart team discussion, a conservative approach was mutually agreed given his co-morbidities and high surgical risk. His medications were continued.

Patient perspective: this case underscores the importance and utility of angiography in the diagnosis and management of cardiac ischemia. Without angiographic imaging, this rare cardiac condition would not have been picked up, and the patient would not have been aware of this potential congenital life-threatening condition and management options. The patient sent a follow-up e-mail stating that his medications have been helpful, and he does not engage in vigorous exercise. He is very happy the cause of his symptoms has been identified. “A recent procedure I did is called coronary angiogram. I was told my heart ejection fraction was lower than normal 2 years ago. The doctor said I needed coronary angiography to make sure I did not have a blockage in my arteries. The procedure lasted 40 minutes. My heart arteries were checked, and I did not have any blockages. They found that one of my arteries was coming from an unusual location. They recommended further tests to confirm. It was an excellent procedure with no pain. Everything went well. I had no major issues. The treatment I got was my medications were changed. I am glad I had the procedure done. I thank the doctors”.

Informed consent: written consent for publication of this article and related images has been obtained from the patient. A copy of the written consent is available for review by the Editor of this journal.

Discussion     

Anomalous aortic origin of a coronary artery (AAOCA) of clinical concern involves the coronary arteries arising from the opposite sinus of Valsalva. These include in descending order of occurrence, the RCA arising from the left sinus, left main coronary artery arising from the right sinus, left anterior descending (LAD) artery arising from the right sinus and lastly the left circumflex artery (LCX) arising from the right sinus [7]. In the index patient, we incidentally discovered an anomalous RCA arising from the left aortic sinus. To the best of our knowledge, an AAOCA and the variant in this case from our geographical location has not yet been described in the literature. We found a reported case of ACAPA in a two-year-old in Northern Nigeria but was only detected by echocardiography [8] with no angiographic documentation. Although an anomalous RCA from the right sinus is rare in the general population, a significant risk of sudden cardiac death likely due to ischemia and arrhythmia is present even in the absence of atherosclerosis [9]. Suggested mechanisms of ischemia in this rare condition include exercise induced compression of the RCA by the great vessels and a slit like orifice created by the angle between the RCA and left sinus [7-9]. The chest pain and exercise intolerance observed in this patient are more likely related to his dilated cardiomyopathy and LV dysfunction. However, the incidental finding of an AAOCA further increases his risk of sudden death.

It is recommended to perform CT coronary angiography in patients with AAOCA to characterize the course of the anomalous artery and assess for high-risk anatomical features at the ostium [1]. The anomalous coronary artery arising from an opposite sinus can have various courses which are retro-aortic, pre-pulmonic, inter-arterial and septal. This index patient was found to have an inter-arterial course on CT imaging, which has been associated with the highest risk of sudden death [9]. Patients with an anomalous RCA from the left aortic sinus also have a higher occurrence of malignant inter-arterial course, thus making CT imaging evaluation important in this sub-population. Other high-risk features seen on CT imaging associated with myocardial ischemia include slit-like/fish-mouth-shaped orifice, acute angle takeoff, high orifice take off >1cm above the Sino-tubular junction and an intramural course [1]. This index patient had a borderline high orifice take-off, 1cm from the Sino-tubular junction.

Management of patients with AAOCA depends on the clinical scenario such as the presence of ischemic symptoms and/or induced ischemia, occurrence of high risk anatomic features and age [1]. The management strategy can be surgical or conservative. Surgery is recommended for patients with angina or inducible myocardial ischemia [1]. Surgery may also be considered for asymptomatic patients with high-risk anatomical features, ventricular arrhythmias or a younger age less than 35 [1]. Despite the presence of the two high risk anatomical features (inter-arterial course and high orifice take-off) in this index patient, we opted for a conservative approach in view of his advanced age and co-morbidities. Most sudden deaths amongst AAOCA subjects occur below the age of 35. His multiple co-morbidities (cardiomyopathy, LV dysfunction, hypertension) place him at high surgical risk. A conservative approach by long term observation is supported by cohort studies, which have found either similar survival rates compared with surgery [10] or no occurrence of death.

Conclusion     

Anomalous coronary arteries may be found rarely and unexpectedly during coronary angiography for ischemic cardiac work up. With increased number of diagnostic procedures in Nigeria, these conditions may be encountered and the ability to diagnose and manage them appropriately is crucial to patient care. Our patient was diagnosed at an older age due to locally available expertise and technology. A conservative management approach in this patient subset seems reasonable pending the availability of more data from large prospective studies to suggest otherwise.

Competing interests     

The authors declare no competing interests.

Authors' contributions     

Patient management: Olurotimi Badero, Oyewole Kushimo and Bamikole Osibowale. Data collection: Olurotimi Badero, Bamikole Osibowale. Manuscript drafting: Oyewole Kushimo, Olurotimi Badero and Bamikole Osibowale. Manuscript revision: Olurotimi Badero. All the authors have read and agreed to the final manuscript.

Figures     

Figure 1: coronary angiogram image showing the right coronary artery originating from the left aortic sinus in the left anterior oblique view

Figure 2: coronary computed tomography angiographic image showing the right coronary artery arising originating from just above the left aortic cusp (blue arrow)

Figure 3: coronary computed tomography angiographic image showing the right coronary artery origin exiting the left aortic cusp (black arrow) between the aorta (AO) and the pulmonary artery (PA)

References