Rest and exercise evaluation of St. Jude Medical and Medtronic Hall prostheses. Influence of primary lesion, valvular type, valvular size, and left ventricular function.

To compare St. Jude Medical and Medtronic Hall mechanical prosthetic heart valves, we prospectively randomized 90 consecutive patients requiring mechanical valve replacement and studied their rest and exercise hemodynamics by Doppler echocardiography. Fifty-six aortic and 42 mitral valves were implanted. All patients were examined preoperatively and postoperatively, and follow-up studies were obtained at rest and immediately after upright, treadmill exercise at 6 months (n = 68). Clinical parameters (mortality, morbidity, and congestive heart failure classification), as well as rest and exercise hemodynamics (valvular area, gradients, and left ventricular ejection fraction), were examined, and their relation to exercise duration was defined. Mortality (perioperative, 8.8% and late, 2.4%) was similar between patients in the two valve groups (five in each group). There was one late thromboembolic episode with each valve. Improvement in New York Heart Association congestive heart failure class was seen in 85% of patients at 6 months. There were no significant differences in calculated aortic valve areas (2.2 vs. 2.0 cm2), resting (24 vs. 21 mm Hg) and exercise (41 vs. 35 mm Hg) peak aortic gradients, and exercise duration between patients with the St. Jude Medical and Medtronic Hall aortic prostheses. In patients with aortic prostheses, valvular size was correlated with exercise duration (r = 0.41, p less than 0.05). In patients with mitral prostheses, we observed no significant differences between St. Jude Medical and Medtronic Hall prostheses in calculated mitral valve areas (3.4 cm2 vs. 3.4 cm2) and rest (2.5 vs. 3.0 mm Hg) and exercise (5.1 vs. 7.0 mm Hg) mean gradients.(ABSTRACT TRUNCATED AT 250 WORDS)