Natural History of Asymptomatic Patients With Normally Functioning or Minimally Dysfunctional Bicuspid Aortic Valve in the Community

BACKGROUND: Bicuspid aortic valve is frequent and is reported to cause numerous complications, but the clinical outcome of patients diagnosed with normal or mildly dysfunctional valve is undefined. METHODS AND RESULTS: In 212 asymptomatic community residents from Olmsted County, Minn (age, 32+/-20 years; 65% male), bicuspid aortic valve was diagnosed between 1980 and 1999 with ejection fraction > or =50% and aortic regurgitation or stenosis, absent or mild. Aortic valve degeneration at diagnosis was scored echocardiographically for calcification, thickening, and mobility reduction (0 to 3 each), with scores ranging from 0 to 9. At diagnosis, ejection fraction was 63+/-5% and left ventricular diameter was 48+/-9 mm. Survival 20 years after diagnosis was 90+/-3%, identical to the general population (P=0.72). Twenty years after diagnosis, heart failure, new cardiac symptoms, and cardiovascular medical events occurred in 7+/-2%, 26+/-4%, and 33+/-5%, respectively. Twenty years after diagnosis, aortic valve surgery, ascending aortic surgery, or any cardiovascular surgery was required in 24+/-4%, 5+/-2%, and 27+/-4% at a younger age than the general population (P or =50 years (risk ratio, 3.0; 95% confidence interval, 1.5 to 5.7; P70% events at 20 years). Baseline ascending aorta > or =40 mm independently predicted surgery for aorta dilatation (risk ratio, 10.8; 95% confidence interval, 1.8 to 77.3; P<0.01). CONCLUSIONS: In the community, asymptomatic patients with bicuspid aortic valve and no or minimal hemodynamic abnormality enjoy excellent long-term survival but incur frequent cardiovascular events, particularly with progressive valve dysfunction. Echocardiographic valve degeneration at diagnosis separates higher-risk patients who require regular assessment from lower-risk patients who require only episodic follow-up.