Factors influencing thromboembolic complications in Omniscience cardiac valve patients

Clinical data were gathered over five years (650 patient-years) for all 155 aortic valve replacement, 125 mitral valve replacement and 46 double valve replacement patients implanted with the Omniscience cardiac valve prosthesis at three North American medical cent es. Mean age was 56 +/- 12 years, 80% were preoperatively in NYHA class III or IV, and 57% had previous or concomitant cardiac surgery. Data were evaluated for the incidence of thromboembolic complications. During the late postoperative period, transient ischaemic episodes occurred in six patients (0.92% per patient-year). The five-year actuarial thrombus-free rate for serious thromboembolic complications (valve thrombosis or thromboembolism with residual effects) for aortic valve replacement patients is 96% and 95% for mitral valve replacement patients. For patients experiencing any transient or serious thromboembolic complication, 35% had a compromise of coumadin anticoagulation shortly before the thromboembolic event, 60% had a history of atrial fibrillation, and 76% a history of rheumatic heart disease. Statistically, these rates are significantly higher compared with the original valve population. The low incidence of thromboembolic complications over this five-year clinical study demonstrates a commendable degree of safety and performance for the Omniscience valve.