Multimodality Imaging-Guided Diagnosis and Management of a Rare Coronary Artery Fistula with Coexistent Left Ventricular Noncompaction Cardiomyopathy

Coronary artery fistulae (CAF) are rare congenital anomalies involving abnormal communications between coronary arteries and cardiac chambers or vessels, with an estimated prevalence of 0.002% in the general population. Left ventricular noncompaction cardiomyopathy (LVNC) is a rare cardiomyopathy characterized by excessive trabeculations and deep recesses, associated with heart failure, arrhythmias, and thromboembolism. The coexistence of CAF and LVNC is exceptionally rare and poses significant diagnostic and therapeutic challenges. We report a 42year-old male presenting with severe heart failure due to a large CAF from the left anterior descending artery (LAD) to the right ventricle, coexisting with LVNC. Multimodality imaging, including transthoracic echocardiography (TTE), cardiac magnetic resonance imaging (CMR), coronary computed tomography angiography (CCTA), and invasive angiography, was instrumental in diagnosis and treatment planning. Genetic testing revealed a novel sarcomeric mutation, providing insights into the etiology of LVNC. The patient underwent successful transcatheter closure of the CAF using an Amplatzer Vascular Plug II, with significant improvement in symptoms and left ventricular function at 12-month follow-up. This case highlights the critical role of advanced imaging and genetic evaluation in managing complex cardiovascular anomalies and underscores the efficacy of transcatheter interventions in selected patients.