Surgical Outcome of Discrete Subaortic Stenosis in Adults: A Multicenter Study
Background—Discrete subaortic stenosis (DSS) is notable for its unpredictable hemodynamic progression in childhood and high re-operation rate, however data about adulthood are scarce.
Methods and Results—Adult patients who previously underwent surgery for DSS were included in this retrospective multicenter cohort study. Mixed-effects and joint models were used to assess postoperative progression of DSS and aortic regurgitation (AR), and re-operation. A total of 313 patients at 4 centers were included (age at baseline 20.2 years (Q1 to Q3, 18.4-31.0), 52% male). Median follow-up duration was 12.9 years (Q1 to Q3, 6.2-20.1), yielding 5617 patient-years. The peak instantaneous left ventricular outflow tract (LVOT) gradient decreased from 75.7±28.0 mmHg pre-operatively to 15.1±14.1 mmHg postoperatively (p<0.001), and thereafter increased over time at a rate of 1.31±0.16 mmHg per year (p=0.001). Mild AR was present in 68%, but generally did not progress over time (p=0.76). A pre-operative LVOT gradient ≥80 mmHg was a predictor for progression to moderate AR postoperatively. Eighty patients required at least one re-operation (1.8% per patient-year). Predictors for re-operation included female gender (HR=1.53, 95%CI 1.02-2.30) and LVOT gradient progression (HR=1.45, 95%CI 1.31-1.62). Additional myectomy did not reduce the risk for re-operation (p=0.92), but significantly increased the risk of a complete heart block requiring pacemaker implantation (8.1% versus 1.7%; p=0.005).
Conclusions—Survival is excellent after surgery for DSS, however reoperation for recurrent DSS is not uncommon. Over time the LVOT gradient slowly increases and mild AR is common, though generally nonprogressive over time. Myectomy does not show additional advantages and as it is associated with an increased risk of complete heart block, it should not be performed routinely.
- Received December 28, 2012.
- Accepted January 28, 2013.
- Copyright © 2013, Circulation