A Case of the Uncommon Cause of Chronic Coronary Syndrome: Coronary Fistula and Coronary Stenosis, Which One to Intervene?

We report a case of chronic coronary syndrome (CCS) that had two completely distinct mechanisms in one patient. We applied comprehensive diagnostic tools using noninvasive and invasive physiology and imaging tests before, during, and after the intervention procedure to evaluate the outcome. The patient had previously visited many physicians and was diagnosed with noncardiac chest pain. He was referred to our department due to the increased frequency and intensity of angina pectoris. After a careful diagnosis, we found a nonsignificant stenosis (50%) in the mid-left anterior descending (mid-LAD) artery and an unexpectedly high-flow coronary artery fistula from the LAD to the main pulmonary artery (MPA). We tried a combination therapy with escalation of the anti-ischemic therapy but failed. He was rehospitalized with unstable angina pectoris. After a comprehensive physiology and imaging test, our team decided to perform fistula embolization with detachable coils and defer stenting in the mid-LAD artery. After the intervention procedure, his angina subsided, and his exercise capacity was remarkably improved. Cardiac computed tomography angiography (CCTA) and cardiac magnetic resonance (CMR) evaluation in 3 months revealed all coils in situ and improved cardiac function. We postulate that comprehensive diagnostic tools are required to select appropriate management and prevent unnecessary procedures.