Anomalous Coronary Artery Origin and Sudden Cardiac Death: Clinical and Pathological Insights From a National Pathology Registry

Objectives: This study sought to describe the clinical and pathological features of anomalous origin of a coronary artery (AOCA) in sudden cardiac death (SCD) victims. Background: AOCA from the inappropriate sinus of Valsalva or from the pulmonary artery is increasingly diagnosed with current imaging techniques. AOCA is a possible cause of SCD. Methods: We reviewed a database of 5,100 consecutive cases of SCD referred to our specialist cardiac pathology center between January 1994 and March 2017 and identified a subgroup of 30 cases (0.6%) with AOCA. All cases underwent detailed post-mortem evaluation including histological analysis by an expert cardiac pathologist. Clinical information was obtained from referring coroners. Results: The mean age was 28 ± 16 years and 23 individuals were male (77%). In 8 cases (27%), SCD occurred before 18 years of age. Cardiac symptoms were present in 11 individuals (37%), and syncope was the most common (n = 6, 20%). Anomalous left coronary artery arising from the right sinus of Valsalva (ALCA) with interarterial course (n = 11) and anomalous right coronary artery arising from the left sinus of Valsalva (ARCA) with interarterial course (n = 11) were the most common found. ALCA arising from pulmonary artery was present in 7 cases, whereas in 1 case, the left coronary artery arose from the noncoronary cusp. Left ventricular fibrosis was reported in 11 cases (37%) and was mainly subendocardial. There was evidence of acute infarction in 2 cases. Death occurred during exercise or emotional stress in 15 (50%) cases. The AOCA variant where death occurred more frequently during physical activity was ALCA (8 of 11, 73%), followed by ALCA arising from pulmonary artery (4 of 7, 57%) and ARCA (2 of 11, 18%). Conclusions: AOCA is a rare cause of SCD. ALCA and ARCA with interarterial course are the most common anatomical variants recognized at the postmortem of SCD victims. ALCA is more commonly associated with death during exercise. Cardiac arrhythmias causing sudden death seem most likely in the cases without overt myocardial damage.