Relationship between hypoplastic right coronary artery and coronary artery anomalies

OBJECTIVES: The frequency of hypoplastic right coronary artery (HRCA) and its contribution to coronary artery anomalies (CAAs) has not been thoroughly studied. Here we aimed to investigate whether a casual relationship exists between the presence of HRCA and CAAs. MATERIALS AND METHODS: We retrospectively reviewed coronary angiography records of 7500 patients. The images were carefully assessed for coronary artery (CA) anatomy and CAAs. Overall, we compared CAAs at the presence and absence of HRCA and evaluated potential association between HRCA and CAAs. Besides, we grouped HRCA patients according to the presence of CA disease (CAD) into two groups and compared their CAAs. RESULTS: While the percentage of HRCA was 6.2%, it was 3.34% for CAAs. The percentage of CA with anomalous origin (CAAO) at the presence of HRCA was significantly higher than the presence of normal right coronary artery (NRCA) (p < 0.01). Similarly, the percentage of absent left main coronary artery (ALMCA) was also considerable increased in HRCA patients with respect to the patients with NRCA (p < 0.01). The percentage of CAAO was notably higher in the CAD (-) than CAD (+) patients with HRCA (p < 0.01). Likewise, the prevalence of ALMCA was also noticeably higher in the CAD (-) than CAD (+) patients with HRCA (p < 0.01). CONCLUSIONS: HRCA is a clinically significant and frequently encountered congenital variation. The present observations indicate that the presence of HRCA is closely associated with a high prevalence of CAAO, particularly with increased rate of ALMCA.