Coronary artery anomalies (CAA) generally affect nearly 1% of the population; however, the estimates vary from 0.3 to 5.6% in different angiographic studies to nearly 1% in routine autopsy. These anomalies vary in the clinical spectrum from potentially fatal to a largely benign condition [1]. Anomalies in the origin of the coronary artery also known as anomalous origin of the coronary artery (AOCA) constitute a small subset of coronary artery anomalies and are seen in about 0.2–1.2% of patients undergoing coronary angiography. The risk associated with AOCA depends upon the anatomical path taken by the artery to its perfusion territory [2]. The association of coronary artery disease (CAD) in CAA is not clear; AOCA has been shown to be associated with an increase incidence of atherosclerotic CAD [3], while no such association could be established in other abnormalities like coronary artery ectasia [4] although most of the patients presented with symptoms of typical angina.
Anomalous origin of the right coronary artery from the left coronary sinus, first described by Yans et al. [5], has a prevalence of 0.026 to 0.255% in different autopsy and coronary angiographic studies [6]. The origin of anomalous right coronary artery in relation to left coronary artery ostium and sinotubular junction is divided into 4 types: type A, origin from the aorta above the sinotubular plane; type B, origin just below the ostium of the left coronary artery (LCA); type C, origin below the sinotubular plane between the midline and the origin of left coronary artery; and type D, origin along the midline of the ascending aorta. These different origins demand a different type of catheter for easy cannulation [2]. Anomalous RCA from left coronary sinus has been shown by multiple studies to be associated with angina, syncope, ventricular tachycardia, and sudden death even in the absence of atherosclerotic lesions [7,8,9].
Anomalous origin of coronary artery causes significant difficulty in patients requiring PCI. The procedure is usually associated with increased radiation exposure to both the patient and operator, an increase in the amount of dye used, and an increase in the procedure time. There is also an associated increase in the psychological stress to the operator. There have been few reports of primary PCI done in patients with anomalous RCA published so far using guiding catheters. Another study has evaluated the use of diagnostic catheters for PCI in a difficult situation and found it helpful in certain cases [10].
The current case with RCA arising from above the sinotubular junction (type A) has an estimated prevalence of 0.006% [2]. Just more than a dozen cases have been defined in literature so far, and only a few among them with acute coronary syndrome required primary intervention [11,12,13]. The current case in our view is probably the first case of anomalous origin RCA type A in which primary PCI was done using a diagnostic catheter successfully. Pre- and post-dilatations, balloons could be easily passed without much difficulty through the catheter without dampening the pressure tracing. There was also adequate visualization of the coronary artery on dye injection, although in some studies there has been inadequate opacification of the distal vessel in procedure with diagnostic catheters. There were no other difficulties encountered during the procedure. The use of diagnostic catheters for simple percutaneous coronary intervention has been found to be feasible; however, the use of diagnostic catheters for PCI for complex coronary intervention requiring thrombosuction or bifurcation stenting is not possible due to smaller lumen of the diagnostic catheters [10]. This case is aiming to generate awareness about the different anatomical variations of the coronary artery and its management during an emergency procedure.
