BENEFITS OF EARLY SURGICAL REPAIR IN FIXED SUBAORTIC STENOSIS

Objectives. We sought to determine whether early resection can improve outcome in fixed subaortic stenosis. Background The diagnosis of suba ortic stenosis (SAS) is often made before significant gradients occur. Whereas resection is the accepted treatment, it remains uncertain whe ther surgical intervention at this early stage can reduce the incidenc e of recurrence or influence the progression of aortic valve damage. M ethods. Follow-up was available for 75 of 83 consecutive patients oper ated on for fixed SAS; the average duration of follow-up was 6.7 years . The lesion was discrete in 68 patients (91%) and of a tunnel type in 7, with associated ventricular septal defect in 28 (37%). All underwe nt transaortic resection. Results. There were no deaths. There were 18 recurrences of SAS in 15 patients (20%). Thirteen patients (17%) unde rwent 17 reoperations for recurrence or aortic valve disease. The cumu lative hazard of recurrence was 8.9%, 16.1% and 29.4% +/- 2.3% (mean a SEM), and the hazard of events, including recurrence and reoperation, was 9.2%, 18.4% and 35.1% +/- 3.5% at 2, 5 and 10 years, respectively . Residual end-operative left ventricular outflow tract (LVOT) gradien ts (>10 mm Hg, n = 8) and tunnel lesions were univariate predictors of recurrence (p = 0.0006 and p = 0.003, respectively). Multivariate pre dictors included higher preoperative LVOT gradient (p < 10(-4)) and yo unger patient age (p = 0.002). Only two recurrences (0.87 per 100 pati ent-years of follow-up) were noted in patients with a preoperative pea k LVOT gradient less than or equal to 40 mm Hg (n = 40), whereas highe r gradients (n = 35) were associated with a greater than sevenfold rec urrence rate (6.45 events per 100 patient-years, p = 0.002). The aorti c valve required concomitant repair in 17 cases in the high gradient g roup (48.6%) but in only 8 in the low gradient group (20%, p = 0.018). Despite relief of the obstruction, progressive aortic regurgitation w as noted at follow-up after 14 procedures in the high gradient group ( 40%) but after only 5 procedures in the low gradient group (12.5%, p = 0.014). Conclusions. The data suggest that surgical resection of fixe d subaortic stenosis before the development of a significant (>40 mm H g) outflow tract gradient may prevent recurrence, reoperation and seco ndary progressive aortic valve disease. (C) 1997 by the American Colle ge of Cardiology.