25 YEARS OF AORTIC-VALVE REPLACEMENT USING MECHANICAL VALVES - RISK-FACTORS FOR EARLY AND LATE MORTALITY

This study describes the changes that have taken place in patient char acteristics in 25 years of aortic valve replacement using mechanical v alves, and looks for risk factors for early and late mortality. During this period, 1449 mechanical valves were implanted. Overall early mor tality (<30 days) was 5.3% and for aortic valve replacement without co ncomitant procedures 3.9%. Overall survival rates at 5, 10 and 15 year s were 80%, 63% and 49%, respectively. Despite an increased proportion of higher risk patients (older age, more reoperations, more concomita nt coronary bypass surgery) survival rates improved throughout the stu dy period. Early mortality was related to an early year of operation, urgency, reoperation and concomitant surgery to the tricuspid valve or ascending aorta. Late mortality was higher for patients of older age, with an early year of operation, male gender, concomitant coronary by pass surgery, mitral valve surgery or replacement of the ascending aor ta. Aortic regurgitation did not have a major influence on early nor l ate mortality. The improvement in early and late mortality in more rec ent years was largely the result of the introduction of cardioplegia. A changing, nonproportional effect was observed For several risk facto rs during the follow-up period. This study illustrates the changes and improvements in medical care that have taken place in patients requir ing aortic valve replacement.