Pathological considerations in replacement cardiac valves.

The long-term outcome following cardiac valve replacement is primarily determined by three factors: irreversible cardiac and pulmonary pathology secondary to the valvular disease (especially left ventricular myocardial hypertrophy and degeneration, and pulmonary vascular disease), pre-existing cardiac disease, including congenital lesions and coronary arterial atherosclerotic occlusions, and prosthesis-host interactions. For most of the approximately 40,000 patients who undergo valve replacement each year in the United States, prosthesis-associated pathology is a a major determinant of prognosis. In this article, the significance, morphology, and pathogenesis of the major complications and other alterations during function of mechanical, bioprosthetic, and allograft valves are reviewed. Other reviews of pathologic considerations in cardiac valve replacement are available (l-7).