Thromboembolism following heart valve replacement by prosthesis: survey among 365 consecutive patients

Of 365 patients operated on, 302 receiving anticoagulant therapy have been followed up from 6 mth to 8 yr. The overall incidence of systemic embolism was 15%. The incidence was higher in patients with mitral valve replacement as compared to those with aortic valve replacement. Atrial fibrillation, preoperative emboli and atrial thrombus have been additional risk factors. The incidence of embolism has been significantly decreased following the third postoperative year, and no emboli were recorded during the sixth and seventh year of follow up. Adequate control of anticoagulation was found effective in reducing the embolic episodes. The completely cloth covered prosthesis appears to have a lower incidence of emboli although the follow up period so far has been too short. Of 302 patients who left the hospital following operation, 46 (13%) developed systemic emboli, six (2%) of them fatal. Only one of the 40 surviving embolism patients remained severely disabled, 3 moderately restricted, 9 retained minor residual symptoms and 27 became asymptomatic.