Quadricuspid Aortic Valve: Characteristics, Associated Structural Cardiovascular Abnormalities, and Clinical Outcomes.

BACKGROUND Quadricuspid aortic valve (QAV) is a rare congenital cardiac defect. This study sought to determine QAV frequency in a large echocardiography database, to characterize associated cardiovascular abnormalities, and to describe long-term outcomes. METHODS AND RESULTS Fifty patients (mean ± SD age, 43.5 ± 21.8 years at the time of the index diagnosis; female sex, 52%) received a diagnosis of QAV between January 1, 1975, and March 14, 2014 (frequency, 0.006%). The QAV was type A in 32% and type B in 32% (Hurwitz and Roberts classification). Aortic dilatation was present in 29% of the patients, and 26% had moderate or severe aortic valve regurgitation at the index diagnosis. Stenosis affected only 8% of the valves and was mild. Other findings, including abnormalities of other cardiac valves, septal defects, persistent left superior vena cava, and patent ductus arteriosus, were present in 32% of patients. During a mean ± SD follow-up of 4.8 ± 5.6 years, 8 patients underwent aortic valve surgery, with severe aortic valve regurgitation being the surgical indication in 7 patients. One patient with mild to moderate aortic valve regurgitation underwent aortic valve repair for obstruction of the left coronary ostium by the accessory cusp of QAV. No infective endocarditis or aortic dissection was found. Overall survival was 91.5% and 87.7% at 5 and 10 years. CONCLUSIONS Aortic dilatation and other structural cardiac abnormalities were relatively common among patients with QAV. Aortic valve regurgitation was the predominant hemodynamic abnormality and the indication for aortic valve surgery in most patients who received surgery. Long-term survival was excellent.