Extrinsic compression of an anomalous right coronary artery causing cardiac arrest

Anomalous Aortic Origin of the Right Coronary Artery: Invasive Haemodynamic Assessment in Adult Patients With High-Risk Anatomic Features

Background

Anomalous aortic origin of a right coronary artery (AAORCA) with an interarterial course merits further evaluation; however, robust risk assessment strategies for myocardial ischemia and sudden cardiac death are currently lacking. The aim of this study is to explore the potential role of fractional flow reserve (FFR), instantaneous wave-free ratio (iFR), and intravascular ultrasound (IVUS) in patients with AAORCA.

Methods

Consecutive adult patients with AAORCA with an interarterial course were included. Computed tomography angiography, noninvasive ischemia detection, and FFR, iFR, and IVUS were performed at baseline and during adrenaline-induced stress. External compression was evaluated with IVUS.

Results

Eight patients (63% female, mean age: 53 ± 9.5 years) were included. Five patients (63%) were symptomatic, and computed tomography angiography revealed high-risk anatomy of the AAORCA in all patients. Only in 1 (12.5%) patient FFR and iFR were positive; however, this was attributed at large to concomitant diffuse atherosclerosis. In 2 of 8 (25%), IVUS revealed external compression; however, the ostial coronary surface area remained unchanged. In all patients, a conservative treatment strategy was pursued. During a mean follow-up of 29.3 months (standard deviation ±2.6 months), symptoms spontaneously disappeared in 4 of 5 (80%) and no adverse cardiac events occurred in any of the patients.

Conclusions

Despite the presence of high-risk anatomy in all patients, none had proven ischemia prompting a conservative treatment strategy. No adverse cardiac events occurred during follow-up, and in the majority of patients, symptoms spontaneously disappeared. Therefore, FFR, iFR, and IVUS with pharmacologic stress merit further investigation and might contribute to ischemia-based risk stratification and management strategies in adult patients with AAORCA.

Malignant Course of the Right Coronary Artery Originating from the Left Main Coronary Artery: An Odd Exit

INTRODUCTION

Congenital coronary artery anomalies are quite uncommon with estimates ranging from 0.2% to 1.3% on coronary angiography. The rarity of these anomalies makes their diagnosis a formidable challenge. Variable arterial courses have been described. In this report, we present a case with unique arterial course, which starts as a hyperacute take-off of the right coronary artery (RCA) from the left main coronary artery (LMCA), with subsequent coursing, without external compression, between the right ventricular outflow tract and aorta. Our case is relevant to the concept of whether we should keep a reasonable index of suspicion for coronary artery anomalies during cardiac evaluations of patients undergoing non-cardiac surgeries.

CLINICAL CASE

This is an asymptomatic 47-year-old African American female who presented for cardiac clearance for renal transplantation. She had a past medical history of hypertension, bronchial asthma, and former smoking of 10 years (quitting 15 years prior to presentation). She also has end-stage renal disease on hemodialysis. Cardiac workup revealed left ventricular hypertrophy on EKG, multi-chamber dilation seen on echo, and anomalous RCA course seen on CT coronary angiography. Cardiac catheterization revealed non-obstructive coronary artery disease of the LCX and RCA. After consulting with cardiothoracic surgery, conservative medical management was decided based on the patient's risk stratification. She was advised to have close monitoring of her condition.

DISCUSSION

Coronary artery anomalies represent the second most common cause of sudden cardiac death in young athletes. At this time, the prevalence of right coronary artery (RCA) take off from the left coronary sinus occurs at a percentage of 0.019% to 0.49%. The RCA origination from the left main coronary artery (LMCA) accounts for only 0.65% of these anomalies. Our patient had high-risk anatomy consisting of a hyper-angulated take-off of the RCA from the LMCA as well as course between the pulmonary artery and right ventricular outflow tract (RVOT). CT coronary angiography is the most useful imaging modality that characterizes coronary artery anomalies. Although this patient exhibited no signs or symptoms of cardiorespiratory compromise, she warranted a full cardiac workup preoperatively that incidentally revealed a coronary anomaly. Recognition of this disease is critical for timely prevention of potential complications as well as discussion of goals of care. Guidelines for medical versus surgical management are available, but the management strategy should be individualized, with the highest consideration given to risk-benefit analysis.

Abnormal origins of the coronary arteries from the aortic root

Anomalous origin of a coronary artery from the aorta is a potentially serious anomaly that occurs in about 0.1-0.2% of the population. This percentage is small; however, it translates into about 4000 annual births with these anomalies. The clinical presentation of these anomalies is rare, and hence most are and will remain asymptomatic. The various anatomic anomalies are described, with anomalous origin of the left coronary artery that then passes between the aorta and pulmonary artery being the most serious of these anomalies. The pathophysiology resulting from these anomalies is described, as are methods for identifying those who require treatment; however, we still do not know the best methods of determining which patients need treatment.