In adults with discrete subaortic stenosis, the peak LVOT gradient progressed slowly at 0.8 ± 0.1 mmHg/year, with faster progression in those with associated congenital heart defects (P=0.005).
Cohort (n=149)
Yes
In adults, discrete subaortic stenosis progresses slowly, but those with associated congenital heart defects have faster progression and require cautious monitoring.
Effect estimate: HR 3.9 (95% CI 2.0-7.6)
AIMS: 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. METHODS AND 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). CONCLUSION: 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.
Linde et al. (Thu,) conducted a cohort in Discrete subaortic stenosis (DSS) (n=149). Conservative management was evaluated on Intervention-free survival (association with baseline LVOT gradient) (HR 3.9, 95% CI 2.0-7.6). In adults with discrete subaortic stenosis, the peak LVOT gradient progressed slowly at 0.8 ± 0.1 mmHg/year, with faster progression in those with associated congenital heart defects (P=0.005).