title: Natural history of discrete subaortic stenosisin adults: a multicentre study.
abstract: OBJECTIVE
  Discrete subaortic stenosis (DSS) is often diagnosed early in life and known for its sometimes rapid haemodynamic progression in childhood and strong association with aortic regurgitation (AR). However, data about the evolution of DSS in adulthood are scarce. Therefore, we aimed to evaluate the natural history of DSS, and identify risk factors for the progression of DSS, AR, and intervention-free survival.
  
  
  RESULTS
  Conservatively managed adult DSS patients were included in this retrospective multicentre cohort study. Mixed-effects and joint models were used to assess the progression of DSS and AR, and intervention-free survival. Longitudinal natural history data were available for 149 patients [age 20 (IQR: 18-34) years, 48% male]. Sixty patients (40.3%) had associated congenital heart defects (CHDs). The median follow-up duration was 6.3 (IQR: 3.0-12.4) years. The baseline peak left ventricular outflow tract (LVOT) gradient was 32.3 ± 17.0 mmHg and increased by 0.8 ± 0.1 mmHg/year. While the baseline LVOT gradient (P = 0.891) or age (P = 0.421) did not influence the progression rate, the presence of associated CHD was associated with faster progression (P = 0.005). Mild AR was common (58%), but did not significantly progress over time (P = 0.701). The median intervention-free survival was 16 years and associated with the baseline LVOT gradient [hazard ratio (HR) = 3.9 (95% CI: 2.0-7.6)], DSS progression [HR = 2.6 (95% CI: 2.0-3.5)], and AR [HR = 6.4 (95% CI 2.6-15.6)].
  
  
  CONCLUSIONS
  In contrast to children, DSS progresses slowly in adulthood. In particular, patients with associated CHD are at risk for faster progression and should be monitored cautiously. Discrete subaortic stenosis progression is not influenced by the baseline LVOT gradient or age. Mild AR is common, but non-progressive over time.
authors.affiliation: Department of Cardiology, Ba-583a, Erasmus University Medical Centre, Rotterdam, The Netherlands.
authors.forename: Denise
authors.initials: D
authors.lastname: van der Linde
authors.forename: Johanna J M
authors.initials: JJ
authors.lastname: Takkenberg
authors.forename: Dimitris
authors.initials: D
authors.lastname: Rizopoulos
authors.forename: Helena J
authors.initials: HJ
authors.lastname: Heuvelman
authors.forename: Werner
authors.initials: W
authors.lastname: Budts
authors.forename: Arie P J
authors.initials: AP
authors.lastname: van Dijk
authors.forename: Maarten
authors.initials: M
authors.lastname: Witsenburg
authors.forename: Sing C
authors.initials: SC
authors.lastname: Yap
authors.forename: Ad J J C
authors.initials: AJ
authors.lastname: Bogers
authors.forename: Candice K
authors.initials: CK
authors.lastname: Silversides
authors.forename: Erwin N
authors.initials: EN
authors.lastname: Oechslin
authors.forename: Jolien W
authors.initials: JW
authors.lastname: Roos-Hesselink
mesh_terms: D000293:Adolescent; D000328:Adult; D001022:Aortic Valve Insufficiency / Q000209:etiology / Q000401:mortality; D058385:Cardiac Valve Annuloplasty / Q000401:mortality / Q000706:statistics & numerical data; D021922:Discrete Subaortic Stenosis / Q000209:etiology* / Q000401:mortality / Q000601:surgery; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006330:Heart Defects, Congenital / Q000150:complications / Q000401:mortality; D019918:Heart Valve Prosthesis Implantation / Q000401:mortality / Q000706:statistics & numerical data; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors; D055815:Young Adult