Long term clinical results with 19 mm or 21 mm standard aortic St. Jude Medical prosthesis.

Comparison of long term clinical results after aortic valve replacement with 19 mm or 21 mm vs. 23 mm or larger bileaflet prostheses has not yet been reported. Between December 1979 and September 1993, 80 consecutive patients who underwent isolated aortic valve replacement at Niigata University using a standard St. Jude Medical valve were assigned to small size group (19 mm and 21 mm, n = 34) or to large size group (23 mm or larger, n = 46). In the small size group, patient's age was older, body surface area smaller, female patients and calcified aortic stenosis were dominant (all p < 0.01). The left ventricular systolic dimension was shorter (p < 0.001), while the cardiothoracic ratio was similar to that of the large size group. All patients received warfarin treatment, and target thrombotest level was 15 to 25% (equivalent to INR 1.6 to 2.1). Actuarial survival rates including hospital death in the small size group (94% at fifth postoperative year) were comparable to those in the large size group. Cerebrovascular event occurred in two patients with the small size prosthesis (1.3%/pty) and three with larger prosthesis (0.9%/pty). Major hemorrhagic complication was not observed in either group. No significant difference was noticed in the proportion free from valve-related morbidity. In the patients with aortic stenosis (n = 41), the left ventricular posterior wall thickness decreased from 15 mm preoperatively to 11 mm late post surgery in both groups.(ABSTRACT TRUNCATED AT 250 WORDS)