IVUS-Guided Dobutamine Challenge to Guide Anomalous RCA PCI: An Interesting Case Report

Congenital coronary artery anomalies are quite uncommon-they are observed in 1.3% of the coronary angiograms. Although most of them are benign, some coronary anomalies are associated with poor clinical outcomes. The exact mechanism of these outcomes in patients with anomalous RCA from the left aortic cusp with interarterial course is hypothesized to be either compression of the coronary artery during its course between the aorta and the pulmonary artery, or obstruction of the coronary flow during exercise due to the acute angulation of the RCA ostium. We present the case of a 54 y/o patient with NSTEMI, who, after a diagnostic coronary angiogram and coronary CT, was found to have complex coronary artery disease, including an anomalous RCA from the left aortic cusp with "malignant" interarterial course. In order to determine the optimal treatment, we proceeded with IVUS assessment of the ostial and proximal RCA with dobutamine challenge, which showed significant stenosis of both the RCA ostium and the interarterial segment at the peak dose of the dobutamine challenge. As a result a decision was made to treat both the RCA ostium and its interarterial segment with PCI, producing an excellent final result. Our case underscores the importance of the combination of IVUS and dobutamine challenge in order to answer the ever-important pathophysiologic mechanism of a lesion and accordingly provide tailor-made treatment for anomalous coronary arteries.