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 characteristics in 25 years of aortic valve replacement using mechanical valves, and looks for risk factors for early and late mortality. During this period, 1449 mechanical valves were implanted. Overall early mortality (< 30 days) was 5.3% and for aortic valve replacement without concomitant procedures 3.9%. Overall survival rates at 5, 10 and 15 years were 80%, 63% and 49%, respectively. Despite an increased proportion of higher risk patients (older age, more reoperations, more concomitant coronary bypass surgery) survival rates improved throughout the study 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 bypass surgery, mitral valve surgery or replacement of the ascending aorta. Aortic regurgitation did not have a major influence on early nor late mortality. The improvement in early and late mortality in more recent years was largely the result of the introduction of cardioplegia. A changing, non-proportional effect was observed for several risk factors during the follow-up period. This study illustrates the changes and improvements in medical care that have taken place in patients requiring aortic valve replacement.