title: Surgical outcome of discrete subaortic stenosis in adults: a multicenter study.
abstract: BACKGROUND
  Discrete subaortic stenosis is notable for its unpredictable hemodynamic progression in childhood and high reoperation rate; however, data about adulthood are scarce.
  
  
  RESULTS
  Adult patients who previously underwent surgery for discrete subaortic stenosis were included in this retrospective multicenter cohort study. Mixed-effects and joint models were used to assess the postoperative progression of discrete subaortic stenosis and aortic regurgitation, as well as reoperation. A total of 313 patients at 4 centers were included (age at baseline, 20.2 years [25th-75th percentile, 18.4-31.0 years]; 52% male). Median follow-up duration was 12.9 years (25th-75th percentile, 6.2-20.1 years), yielding 5617 patient-years. The peak instantaneous left ventricular outflow tract gradient decreased from 75.7±28.0 mm Hg preoperatively to 15.1±14.1 mm Hg postoperatively (P<0.001) and thereafter increased over time at a rate of 1.31±0.16 mm Hg/y (P=0.001). Mild aortic regurgitation was present in 68% but generally did not progress over time (P=0.76). A preoperative left ventricular outflow tract gradient ≥80 mm Hg was a predictor for progression to moderate aortic regurgitation postoperatively. Eighty patients required at least 1 reoperation (1.8% per patient-year). Predictors for reoperation included female sex (hazard ratio, 1.53; 95% confidence interval, 1.02-2.30) and left ventricular outflow tract gradient progression (hazard ratio, 1.45; 95% confidence interval, 1.31-1.62). Additional myectomy did not reduce the risk for reoperation (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 discrete subaortic stenosis; however, reoperation for recurrent discrete subaortic stenosis is not uncommon. Over time, the left ventricular outflow tract gradient slowly increases and mild aortic regurgitation is common, although generally nonprogressive over time. Myectomy does not show additional advantages, and because it is associated with an increased risk of complete heart block, it should not be performed routinely.
authors: Department of Cardiothoracic Surgery, Erasmus University Medical Center, Rotterdam, Netherlands.
authors: Denise
authors: D
authors: van der Linde
authors: Jolien W
authors: JW
authors: Roos-Hesselink
authors: Dimitris
authors: D
authors: Rizopoulos
authors: Helena J
authors: HJ
authors: Heuvelman
authors: Werner
authors: W
authors: Budts
authors: Arie P J
authors: AP
authors: van Dijk
authors: Maarten
authors: M
authors: Witsenburg
authors: Sing C
authors: SC
authors: Yap
authors: Angela
authors: A
authors: Oxenius
authors: Candice K
authors: CK
authors: Silversides
authors: Erwin N
authors: EN
authors: Oechslin
authors: Ad J J C
authors: AJ
authors: Bogers
authors: Johanna J M
authors: JJ
authors: Takkenberg
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D001022:Aortic Valve Insufficiency / Q000453:epidemiology; D015331:Cohort Studies; D021922:Discrete Subaortic Stenosis / Q000401:mortality* / Q000601:surgery*; D018450:Disease Progression; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D012086:Reoperation / Q000706:statistics & numerical data; D012189:Retrospective Studies; D015996:Survival Rate; D016896:Treatment Outcome; D055815:Young Adult