Natural history of adults with congenitally malformed aortic valves (unicuspid or bicuspid).

Appreciation of the frequency of the congenitally malformed aortic valve has come about during the last 50 years, a period during which aortic valve replacement became a predictably successful operation. Study of patients at necropsy with either a congenitally unicuspid (1 true commissure) or bicuspid (2 true commissures) valve in whom no aortic valve operation has been performed has not been conducted during these 50 years, to our knowledge. We studied 218 patients at necropsy with congenitally malformed aortic valves: 28 (13%) had a unicuspid valve and 190 (87%), a bicuspid valve. Their ages at death ranged from 21 to 89 years (mean, 55 yr), and 80% were men. Of the 218 adults, the aortic valve functioned normally during life in 54 (25%) and abnormally in 164 (75%): aortic stenosis in 142 (65%), pure aortic regurgitation without superimposed infective endocarditis (IE) in 2 (1%), and IE superimposed on a previously normally functioning aortic valve in 20 (9%). IE occurred in a total of 31 (14%) of the 218 patients: involving a previously normally functioning valve in 20 (65%) and a previously stenotic valve in 11 (35%). Of the 218 patients, at least 141 (65%) died as a consequence of aortic valve disease (124 patients) or ascending aortic tears with or without dissection (17 patients). An estimated 1% of the population, maybe higher in men, has a congenitally malformed aortic valve. Data from this study suggest that about 75% of them will develop a major complication. Conversely, and encouragingly, about 25% will go through life without a complication.