DISCRETE SUBAORTIC STENOSIS - OPERATIVE AGE AND GRADIENT AS PREDICTORS OF LATE AORTIC-VALVE INCOMPETENCE

Between January 1969 and May 1990, 100 patients were operated on for d iscrete subaortic stenosis. Three patients died in the perioperative p eriod. Patients with intrinsic lesions, prosthetic replacement, or ext ensive operative remodeling of the aortic valve were excluded from the analysis. The 67 remaining patients had a median follow-up of 62 mont hs. Preoperatively, 8 patients had aortic valve competence, 51 had mil d incompetence, and 8 patients moderate aortic valve incompetence. At follow-up mild incompetence persisted in 27 and moderate incompetence in 6 patients. In 1 patient it worsened from no incompetence to mild a nd in another patient from mild to moderate. The probability of aortic incompetence at follow-up was significantly and simultaneously relate d (multivariate ordinal logistic model) to (1) older age at operation (logarithm of months, p = 0.007), (2) higher preoperative gradient (th ird power of milligrams of mercury, p = 0.0004), (3) preoperative card iomegaly (p = 0.04), and (4) surgical myectomy (p = 0.002). There was an interaction between age and gradient (p = 0.03). Two nomograms are proposed as a generalizable aid to decision making. The data support t he policy of early repair of subaortic stenosis.