title: Factors influencing postoperative survival in aortic regurgitation. Analysis by Cox regression model.
abstract: From 1965 to 1981, 114 patients underwent aortic valve replacement for severe aortic regurgitation in our institution. Catheterization was performed preoperatively in 103 patients. Follow-up was possible in 98% of the survivors. Long-term survival was significantly different between patients in preoperative Functional Class I-II and those in Class III-IV (p less than 0.03); those with a preoperative cardiothoracic ratio less than 0.64 versus greater than or equal to 0.64 (p less than 0.001); and those with a preoperative ejection fraction greater than 0.50 versus less than or equal to 0.50 (p less than 0.03). A multifactorial analysis was used to identify the dominant preoperative prognostic variables affecting survival. Three of the 13 parameters examined simultaneously were found to independently influence survival rates: cardiothoracic ratio (p = 0.001), strain pattern on the electrocardiogram (p = 0.072), and left ventricular end-systolic pressure (p = 0.127). After stratification of the population into two groups according to preoperative functional class, the predictive variables were cardiothoracic ratio (p = 0.014), strain pattern (p = 0.050), and acute/chronic form of aortic regurgitation (p = 0.034). This statistical analysis enabled us to derive a mathematical equation for predicting an individual patient's probability of survival. We found a close fit between the survival rate predicted by the mathematical model and the observed survival rate.
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001022:Aortic Valve Insufficiency / Q000401:mortality / Q000601:surgery*; D002315:Cardiopulmonary Bypass; D002648:Child; D005260:Female; D005500:Follow-Up Studies; D006350:Heart Valve Prosthesis / Q000401:mortality; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012044:Regression Analysis