Primary isolated aortic valve replacement. Early and late results

A total of 1689 consecutive patients underwent isolated aortic valve replacement at the Cleveland Clinic Foundation from 1972 through 1986. There were 57 (3.4%) in-hospital deaths. Multivariate analysis identified advanced age (p = 0.0014), preoperative blood urea nitrogen level greater than 25 mg/100 ml (p = 0.008), New York Heart Association function class (p = 0.015), and preoperative atrial fibrillation (p = 0.04) as independent variables associated with increased in-hospital mortality and the use of cardioplegia for myocardial protection (p = 0.006) as a factor decreasing mortality. Follow-up documented survival rates of 85% and 66% and event-free survival rates of 71% and 43% at 5 and 10 postoperative years, respectively. Advanced age, moderate or severe impairment of left ventricular function, coronary artery disease, and preoperative blood urea nitrogen level greater than 25 mg/100 ml were associated with decreased late survival and event-free survival (all p less than 0.05). Patients with bioprostheses had better survival (p = 0.003) and event-free survival (p = 0.0007) rates than patients with mechanical valves. Patients with bioprostheses had superior results only if not receiving warfarin, and they experienced more reoperations and endocarditis; those with mechanical prostheses had more strokes, myocardial infarctions, bleeding complications, and thromboembolic events. Analysis of patients grouped according to age at operation showed that bioprostheses were associated with improved survival and event-free survival for patients 40 years older or older. Younger patients experienced more reoperations and episodes of endocarditis, and older patients more thromboembolic complications. We conclude that 10-year results after isolated aortic valve replacement are influenced by both patient-related and management-related variables, and the impact of these factors is different for patients of different ages.