Coronary anomalies in tetralogy of Fallot – A meta-analysis

Background An anomalous coronary artery is reported in 2% to 23% of patients with tetralogy of Fallot (TOF). Knowledge of coronary anatomy prior to corrective surgery is vital to avoid damage to vessels crossing the right ventricular outflow tract (RVOT). A meta-analysis on the prevalence of anomalous coronary arteries in TOF is lacking to date. Here, an overview of coronary anomalies in TOF is provided and implications for patient management are discussed. Methods PubMed, Embase and Web of Science were searched. Analysis was done using Revman 5.3 (Cochrane Community, London). The primary analysis focused on the origin and proximal course of the right and left coronary arteries. In addition, the prevalence of large conus arteries and coronary arteriovenous fistulas (CAVF) was calculated. Results Twenty-eight studies, encompassing 6956 patients, were included; 6% of TOF patients have an anomalous coronary artery. Hereof, 72% cross the RVOT; the majority of the remaining 28% courses behind the aorta. Six percent of patients have a large conus artery and 4% a CAVF. Other coronary anomalies include a left or right coronary artery from the pulmonary trunk or left or right pulmonary artery, coronary tree hypoplasia and anastomoses between coronary and bronchial arteries. Conclusions The prevalence of coronary anomalies in TOF is 4–6%. In patients with an anomalous coronary artery, 72% cross the RVOT. The combined risk of encountering an anomalous coronary artery or a large conus artery crossing the RVOT is 10.3%. Coronary anatomy should be defined before surgery and the surgical approach adapted accordingly.