Identification of high risk patients with severe but asymptomatic aortic stenosis

Whether asymptomatic patients with severe aortic stenosis benefit from surgery remains unclear. We report our data recently published in the New England Journal of Medicine on the natural history of this disease and predictors of outcome. 128 consecutive, asymptomatic patients with severe aortic stenosis (age 60+/-18 years, peak aortic jet velocity 5.0+/- 0.6 m/s), were prospectively followed from 1994 until 1998. During a mean follow-up duration of 22+/-18 months, event-free survival, with end points defined as death or valve replacement necessitated by the development of symptoms was 67+/-5 % at one year, 56+/-5 % at two years, and 33+/-5 % at 4 years. There were 8 deaths (6 cardiac) and 59 underwent valve replacement. By multivariate analysis, only the extent of aortic-valve calcification was an independent predictor of outcome, but not age, sex, and the presence of coronary artery disease, hypertension, diabetes, and hypercholesterolemia. Event-free survival for patients with no or mild calcification of the aortic valve was 92+/-5 % at one year, 84+/-8 % at two years, and 75+/-9 % at 4 years. In contrast, patients with moderate or severe calcification had an event-free survival of only 60+/-6 %, 47+/-6 %, and 20+/-5 % at 1, 2, and 4 years, respectively. Patients with moderate or severe valve calcification and an increase in aortic jet velocity > 0.3 m/s within one year represented a high-risk group: 79 % of these patients underwent surgery or died within two years of the observed increase. In conclusion, moderate to severe aortic valve calcification and the observation of rapid hemodynamic progression identifies a high risk group of patients with asymptomatic severe aortic stenosis in which early elective surgery should be considered rather than have surgery delayed until symptoms develop.