Aortic insufficiency. A multivariate analysis of incremental risk factors for operative mortality and functional results.

The object of this study was to establish which of four chosen preoperative parameters, namely NYHA functional Class, cardio-thoracic ratio (CTR), left ventricular end-diastolic pressure (LVEDP) and ejection fraction (EF), might affect, singly or in combination, the operative risk in isolated, chronic aortic insufficiency (AI). To this purpose we reviewed the records of all adult patients consecutively operated upon in our Department for isolated chronic AI, from 1979 to 1985. Patients with associated cardiac disease, transvalvular aortic gradient, recent endocarditis of a malfunctioning bioprosthesis were excluded from the study, leaving 89 consecutive patients (mean age 47.2 years) for evaluation. St. Jude or Duromedics mechanical prostheses were exclusively used for aortic valve replacement (AVR). Post-operatively all patients received long term anticoagulation. Follow up period ranged from 24 to 109 months (mean 61.8 months). The method of analysis was designed as follows: a) each patient was allocated a positive (+) or a negative (-) variable for the value of each parameter, b) five patient groups were formed on the basis of the free association of parameter variables, c) single variables and their association with early and late mortality, functional results as NYHA Class were compared by statistical methods (chi 2, Student's Test, Wilcoxon Test). The results of the study show: a) only EF significantly influenced early mortality (P less than 0.05), b) late mortality was significantly influenced (P less than 0.001) by NYHA Class and CTR, c) single parameter variables (+ or -) and or their association significantly conditioned functional results.