Coronary artery anomalies are a heterogeneous group of congenital disorders presenting with a wide spectrum of symptoms, ranging from vague chest pain to sudden cardiac death. Despite available data, there is no consensus about the classification, nomenclature, and outcomes of coronary anomalies in the normally connected heart. In this study, we aimed to investigate clinical and angiographic characteristics of coronary arterial anomalies, as well as the frequency of atherosclerotic involvement in anomalous coronaries, diagnosed at a tertiary referral centre.

We retrospectively reviewed coronary angiograms performed between 2011 and 2015 for the presence of a coronary anomaly. A total of 111 patients with a final diagnosis of coronary anomaly were included in the study group. We also recruited 110 age- and sex-matched patients who underwent coronary angiography because of symptomatic coronary artery disease as controls.

Among 36,893 coronary angiograms, 111 (0.30%) major coronary anomalies were found. Compared with controls, the prevalence of significant atherosclerotic coronary disease was lower in patients with coronary anomalies and stable symptoms (p=0.02); however, the prevalence of significant coronary atherosclerosis was similar among patients admitted with unstable angina or myocardial infarction (p>0.05). Compared with controls, patients with an anomalous left anterior descending coronary artery had significantly less atherosclerotic involvement than those in whom the left anterior descending artery was not anomalous (p=0.005).

Although coronary artery anomalies are cited as a cause for myocardial ischaemia, atherosclerotic coronary artery disease is also frequent and may offer an alternative explanation to ischaemic symptoms. No predisposition to accelerated atherosclerosis was found, however, and atherosclerotic involvement was less frequent in some anomalous vessels.