Predictors of outcome in severe, asymptomatic aortic stenosis

Background Whether to perform valve ment in patients with asymptomatic but severe aortic stenosis is controversial. Therefore, we studied the natural history of this condition to identify predictors of outcome. Methods During 1994, we identified 128 consecutive patients with asymptomat ic, severe aortic (59 women and 69 men; mean [+/- SD] age, 60 +/- 18 years; aortic-jet velocity, 5.0 +/- 0.6 m per second). The patients were prospect ively followed until 1998. Results Follow-up information was available for 126 patients (98 percent) f or a mean of 22 +/- 18 months. Event-free survival, with the end point defi ned as death (8 patients) or valve replacement necessitated by the developm ent of symptoms ( 59 patients), was 67 +/- 5 percent at one year, 56 +/- 5 percent at two years, and 33 +/- 5 percent at four years. Five of the six d eaths from cardiac disease were preceded by symptoms. According to multivar iate analysis, only the extent of aortic-valve calcification was an indepen dent tor of outcome, whereas age, sex, and the presence or absence of coron ary artery disease, hypertension, diabetes, and hypercholesterolemia were n ot. survival for patients with no or mild valvular calcification was 92 +/- 5 percent at one year, 84 +/- 8 percent at two years, and 75 +/- 9 percent at four years, as compared with 60 +/- 6 percent, 47 +/- 6 percent, and 20 +/- 5 respectively, for those with moderate or severe calcification. The r ate of progression of stenosis, as reflected by the aortic-jet velocity, wa s significantly higher in patients who had cardiac events (0.45 +/- 0.38 m per second per year) than those who did not have cardiac events (0.14 +/- 0 .18 m per second year, P<0.001), and the rate of progression of stenosis pr ovided useful prognostic information. Of the patients with moderately or se verely calcified aortic valves whose aortic-jet velocity increased by 0.3 m per second or more within one year, 79 percent surgery or died within two years of the observed increase. Conclusions In asymptomatic patients with aortic stenosis, it appears to be relatively safe to delay surgery until symptoms develop. However, outcomes vary widely. The presence of moderate or severe valvular calcification, to gether with a raid increase in aortic-jet velocity, identifies patients wit h a ver poor prognosis. These patients should be considered for early valve replacement rather than have surgery delayed until symptoms develop. (N En gl J Med 2000; 343:611-7.) (C) 2000, Massachusetts Medical Society.