Left Main Coronary Artery Atresia Presenting as Heart Failure with Preserved Ejection Fraction in a Septuagenarian

Left main coronary artery (LMCA) atresia is a rare congenital coronary anomaly that is frequently fatal in childhood because the perfusion of the left coronary system depends entirely on collateral circulation. Consequently, adult presentation is uncommon, particularly in advanced age. We report a case of LMCA atresia newly diagnosed in a patient in his late seventies, who presented with heart failure with preserved ejection fraction (HFpEF) in the absence of typical anginal symptoms. Coronary computed tomography revealed a single coronary artery originating from the right sinus of Valsalva, and coronary angiography confirmed retrograde perfusion of the left coronary system via collateral flow from the right coronary artery, establishing the diagnosis of LMCA atresia. This case underscores that congenital LMCA atresia may remain clinically silent for decades before manifesting in very elderly patients without typical ischemic symptoms.