Left ventricular mass regression after aortic valve replacement with 17-mm St Jude Medical mechanical prostheses in isolated aortic stenosis

Objective: The present study investigated the outcomes of aortic valve replacement with 17-mm mechanical prostheses in patients with isolated aortic stenosis. Methods: Between January 1997 and January 2003, 35 patients (mean age, 63.4 +/- 17 years; median age, 70 years; age range, 16-84 years) underwent isolated aortic valve replacement with a 17-mm St Jude Medical Hemodynamic Plus (16 [45.7%] patients) or a St Jude Medical Regent prosthesis (19 [54.3%] patients). The paired Student t test or the paired Wilcoxon rank sum test were used to compare preoperative with follow-up echocardiographic measurements. Results: Thirty-two (91.4%) patients were female, mean height was 154.4 +/- 8.3 cm, mean weight was 62.2 +/- 9.2 kg, and mean body surface area was 1.59 +/- 0.13 m2. The preoperative average New York Heart Association class was 2.8 * 0.8. The mean preoperative left ventricular mass index was 135.2 +/- 31 g/m2. Preoperative echocardiography showed an average gradient of 65.7 +/- 19.2 mm Hg (mean) and 103.6 +/- 30.7 mm Hg (peak) and a mean indexed effective orifice area of 0.40 +/- 0.1 cm2/m2. Echocardiographic follow-up time averaged 28.2 +/- 22.7 months (range, 13-72 months). Follow-up was 100% complete (1131.7 patient-months). Hospital mortality was 8.6% (3 patients). Actuarial 5-year survival was 94.7%. The mean postoperative New York Heart Association class was 1.13 +/- 0.34 (P < .001), with 27 (87.1%) patients in class I and 4 patients in class II. A significant regression of the indexed left ventricular mass was found (postoperative mean value, 107.8 +/- 22.8 g/m2; P < .0001), despite a mean indexed effective orifice area of 0.67 +/- 0.14 cm2/m2 (median, 0.66 cm2/m2). Conclusions: Selected patients with aortic stenosis can experience satisfactory clinical improvement and significant indexed left ventricular mass regression after aortic valve replacement with modern small-diameter bileaflet prostheses.