Congenital Absence of the Left Coronary Artery in a 64 Year Old Asymptomatic Man: A Rare Coronary Anomaly Uncovered Through Cardiac CT

Congenital coronary artery anomalies are rare, and complete congenital absence of the left coronary artery (LCA) is among the rarest subtypes. Most are diagnosed incidentally, though they may have significant implications for myocardial perfusion. We present the case of a 64-year-old asymptomatic man referred for routine coronary calcium scoring due to a strong family history of coronary artery disease. A coronary calcium score of 77 was noted (Agatston method) and revealed a unique right coronary artery. Subsequent coronary computed tomography angiography (CCTA) confirmed the complete congenital absence of the LCA. The right coronary artery (RCA) was dominant and supplied the entire myocardium, including the left anterior descending (LAD) and circumflex (LCx) territories, via prominent collateral vessels. No stenotic lesions were identified. This case highlights a rare Lipton R-I type coronary anomaly with a benign course. The absence of ischemia and presence of an RCA with extensive collateral supply are in line with recent literature on similar cases. Multimodal imaging plays a key role in diagnosis and management, supporting non-invasive monitoring for asymptomatic individuals.