Multivessel percutaneous coronary intervention with bifurcation stenting in a quadfurcated single coronary artery from the right aortic sinus: a case report

Abstract Background Quadfurcation of single coronary artery (SCA) from the right is an extremely rare anomaly and acute coronary syndrome in such patients is catastrophic. Case summary We report a 56-year-old Bangladeshi male who presented with an acute inferior wall ST-elevation myocardial infarction. He was taken to the Cath lab for primary percutaneous coronary intervention which showed the presence of SCA arising from the right aortic sinus with multiple lesions including a bifurcation lesion. Percutaneous coronary intervention was done successfully in two sessions. Discussion Tackling multiple lesions in a case of SCA with quadfurcation was challenging especially in the setting of SCA and bifurcation lesions. This is first reported case of this kind.


Introduction
Single coronary artery (SCA) is a condition in which the entire left coronary arterial system arises from right coronary sinus. 1 Among the congenital coronary anomalies, SCA arising from the right aortic cusp is rare with a prevalence during coronary angiogram between 0.02% and 0.05%. 2 Learning points • Quadfurcation of single coronary artery from the right is extremely rare anomaly. • Always activate heart team while managing such patients for a better outcome and treatment strategy. • During coronary angiogram always look for associated congenital anomalies.

Case presentation
A 56-year-old Bangladeshi male with no prior medical history presented with an inferior wall ST-elevation myocardial infarction with Killip Class II ( Figure 1). The cardiopulmonary examination was normal and the total ischaemic time was 90 min.
Baseline laboratory investigations showed h s -Troponin-i > _100 ng/ mL (Ref. range: 0.01-0.04 ng/mL). Urgent cardiac catheterization was performed which revealed the presence of an SCA arising from the right aortic sinus which quadfurcated into left anterior descending (LAD) coronary artery, first diagonal (D1), left circumflex coronary artery (LCx), and right coronary artery (RCA).
Multiple atherosclerotic lesions were present with 70-90% stenosis in the distal LAD and a severely calcified 70-90% stenosis in the D1 with reference diameter of the vessel at this level less than 1.5 mm. About 70-90% stenosis was present in the proximal circumflex (LCx) and had a 90-99% stenosis in the first obtuse marginal (OM1). Proximal RCA had an acute occlusion ( Figure 2). The crux of the RCA had a bifurcation lesion with MEDINA (0,1,1) of 90-99% (Supplementary material online, Video S1). Percutaneous coronary intervention (PCI) was performed on the RCA with the deployment of three stents. First, one stent was implanted into the proximal RCA and two stents were implanted at the level of crux of RCA with inverted TAP stenting strategy. Full anti-ischaemic treatment including dual antiplatelet therapy was initiated.
After 48 h, repeated PCI of the first obtuse marginal (OM1) and proximal LCx were performed (Supplementary material online, Video S2 and Figure 3).
Post-PCI transthoracic echocardiography revealed preserved left ventricle systolic function with an ejection fraction of 55-60%. Mild hypokinesia of the entire inferior wall, inferior septum, and inferolateral wall detected. We did coronary computed tomography to study the anatomy. Single coronary ostium arising from the right was confirmed. It was found to have three abnormal courses of coronary arteries. Only RCA had a normal course. LCx was found to have retro-aortic course, LAD coronary artery had pre-pulmonic course, and D1 had a sub-pulmonic (septal) course. There was no interarterial course found in this case ( Figure 4).  The patient was discharged on the fourth day from admission. The post-PCI period was uneventful.

Discussion
Anomalous origin of the coronary arteries, and, in particular, SCA arising from the right aortic cusp is rare. 3 In our case, an SCA, with the entire right and left coronaries originating from right sinus of Valsalva was an incidental finding at the time of cardiac catheterization for acute coronary syndrome. There was no history of any congenital or valvular heart disease. However, SCA is associated with congenital anomalies such as bicuspid aortic valve, coronary arteriovenous fistula, and transposition of the great vessels. 4 Our case of an SCA originating from right sinus of Valsalva, with a single ostium that quadrifurcated into LAD, D1, LCx, and a dominant RCA highlights some of the challenges encountered during a PCI in these patients. Associated coarctation has to be ruled out and aortogram is vital in such cases. A DOT sign on left ventricular angiography may be a clue to the presence of an anomalous coronary artery. 5 In our case, we did not perform left ventricular angiography due to the need for emergency PCI.
An SCA originating from the right sinus has the following distribution: (i) anterior to aorta and pulmonary artery, (ii) interarterial, (iii) interseptal, and (iv) retroaortic. 6 In our case, we had all three abnormal courses except interarterial.
Volume rending three-dimensional computed tomography coronary angiogram of our case confirmed an SCA arising from the right coronary sinus giving rise to right coronary artery (RCA) normal course, LCX with retro-aortic course, the diagonal artery (D1) with subpulmonic (septal) course, and LAD with pre-pulmonic course.
Our patient does not fall in any of the types described in Lipton's classification. 7 Figure 3 The final angiographic results with TIMI III flow and trident appearance. Figure 4 Volume rending three-dimensional computed tomography coronary angiogram shows single coronary ostium arising from the right with three abnormal courses of coronary arteries and only right coronary artery was found to have a normal course. Left circumflex coronary artery was found to have retro-aortic course, left anterior descending artery had pre-pulmonic course, and first diagonal had a sub-pulmonic (septal) course. Hence, we propose a modified version of this classification of SCA-Type IV (Rajan's and Vladimir's) an extremely rare presentation SCA which quadfurcated into RCA, LAD, D1, and LCx.
Abnormal coronary anatomy in SCA accounts for 15% ischaemic events. The risk of having ischaemic heart diseases in SCA is high due to 8 : • Acute-angle take-off • Atherosclerosis • Coronary spasm • Interarterial course with associated hypoplasia • Intramural course (at the aortic wall) with lateral compression or exercise-related narrowing • Ostial ridge • Slit-like ostium.

Conclusion
Single coronary artery arising from the right aortic cusp with quadfurcation into RCA, LAD, D1, and LCx is rare. In view of the absence of inter-arterial course in our case, the need for surgical correction was not required. For such rare type of SCA, it is always wise to activate the heart team for proper assessment and better outcome.

Supplementary material
Supplementary material is available at European Heart Journal -Case Reports online.