RESUMEN
BACKGROUND: Quadricuspid aortic valve (QAV) is a rare congenital disease. The clinical characteristics of this disease remain unclear except for those in relatively young patients reported from tertiary referral hospitals. The aim of this study was to determine the clinical features of QAV in a regional population. METHODS AND RESULTS: We retrospectively investigated 25 340 consecutive patients over middle age (median age, 73 (IQR 65-80) years; range, 45-102 years) who underwent transthoracic echocardiography (TTE) at our institute during the period from April 2008 to December 2023. Eight (0.032%) of the patients (median age, 65 years; range, 47-91 years) were diagnosed with QAV. Six patients suffered from aortic regurgitation (AR), and one patient had mild aortic stenosis at the time of QAV diagnosis. Two patients who had severe AR at referral underwent aortic valve surgery. The severity of AR in the other patients was moderate or less. During a median follow-up period of 27 months (range, 1-171 months), none of the patients other than above two patients had cardiac events. One patient died from a non-cardiac cause at 94 years of age. CONCLUSIONS: Patients diagnosed with QAV after middle age, who do not exhibit severe valve insufficiency at the time of diagnosis, may not experience worse clinical outcomes. However, further research is required for a better understanding of the long-term outcomes.