Clinical and hemodynamic assessment of the Omniscience prosthetic heart valve

From 1980 to 1985, 154 Omniscience valve prostheses were implanted in 132 patients (mitral in 72, aortic in 33, and both in 27), 81 women and 51 men, aged 22 to 72 years. There were 13 early deaths (30 day mortality of 9.8%) and nine late deaths. The actuarial survival rate was 79.1% after 4 years, and survival rates after aortic, mitral, and multiple valve replacement were 71.8%, 80%, and 85.2%, respectively. After a postoperative follow-up period averaging 27 months, 96% of the survivors were in Class I or II. The linearized incidence of thromboembolism, hemorrhagic episodes, and reoperation was 3.8%, 3.4%, and 2.3% per patient-year, respectively. After 4 years, freedom from valve-related mortality, valve-related mortality and reoperation, thromboembolic episodes, and all valve-related complications was 93%, 89%, 88%, and 70%. Moderate hemolysis with increases of reticulocyte count and serum lactic dehydrogenase above normal values was found in 80% of the patients, but only one had hemolytic anemia. In 22 patients, the maximal opening angle of the prosthetic disc averaged 54 +/- 11 degrees. Postoperative hemodynamic evaluation was obtained in five patients with aortic prostheses and in 13 with mitral prostheses. Mean aortic gradient and effective orifice area averaged 17.6 mm Hg and 1.2 cm2 at rest and increased to 18.8 mm Hg and 1.7 cm2 with exercise. With mitral prostheses, these values averaged 6.5 mm Hg and 1.9 cm2 at rest and 15.4 mm Hg and 2.1 cm2 with exercise. Thus excellent clinical improvement is obtained with the Omniscience prosthesis; however, the hemodynamic performance of the valve and opening of the tilting disc are suboptimal, causing the prosthesis to be moderately obstructive to blood flow.