Balloon aortic valvuloplasty (BAV) was performed in 219 elderly patients with aortic stenosis between December 1985 and April 1990. Forty-three patients underwent repeat BAV for symptomatic restenosis of the aortic valve 13 +/- 8 mo following initial BAV. To evaluate the outcome following initial and repeat BAV, hemodynamic results were analyzed according to the following subgroups: BAV 1--initial BAV for all patients (n = 219); BAV 1/1--initial BAV in those who had only one BAV (n = 176); BAV 1/2--the initial BAV in those who had repeat BAV (n = 43); and BAV 2--repeat BAV (n = 43). The mean age of patients undergoing BAV 2 was 82 +/- 6 yr compared to 78 +/- 10 yr for all patients undergoing BAV 1 (p = .01). At the time of BAV 1 there was no difference in baseline or post-valvuloplasty aortic valve area (AVA) or peak aortic valve gradient (AVG) for patients having BAV 1/1 compared to those having BAV 1/2. However, for patients having repeat BAV, although the magnitude of the hemodynamic improvement of BAV 1/2 (AVA increased from 0.6 to 0.9 cm2, AVG decreased from 68 to 34 mm Hg, p less than .001) was similar to the magnitude of the hemodynamic improvement of BAV 2 (AVA increased from 0.5 to 0.8 cm2, AVG decreased from 65 to 34 mm Hg, p less than .001), the baseline AVA (0.5 cm2 at BAV 2 vs. 0.6 at BAV 1/2) and the post-valvuloplasty AVA (0.8 cm2 at BAV 2 vs. 0.9 at BAV 1/2) were significantly smaller (p less than .004).(ABSTRACT TRUNCATED AT 250 WORDS)