Autopsy-determined causes of death following heart valve replacement

The pathological findings and the principal cause of death were reviewed in 275 patients with 345 heart valve prostheses. Rheumatic fever necessitated valve replacement in 73% of these patients. Tissue valves bore significantly fewer and scantier thrombi than did the mechanical prostheses. Patients with these two groups of valves showed no significant difference with regard to the incidence of infarction of systemic organs. Patients with prostheses showed infarcts of the spleen, brain, and heart more often than did nonoperated controls with valvular disease. Among the mechanical valves, patients with Starr-Edwards valves showed the highest incidence of fatal thromboembolism. Prosthesis-related problems formed the biggest single cause of death in the 275 patients with valve prostheses. The mechanical valve group, which formed 82% of the total, had prosthesis-related problems as the prime cause of death; in the tissue valve group this complication ranked third in importance after unknown causes and diseases unrelated to valve surgery. Analysis of the valve-related causes of death showed that thrombosis and infection of the prosthesis were more important in the mechanical valves, whereas structural failure was more common with the tissue valves. Prosthesis-related fatal complications were present in 13% of the patients who died within 30 days postoperatively and in 61% of those who died later.