Supravalvular and Valvular Pulmonary Stenosis: Predictive Features and Responsiveness to Percutaneous Dilation.
Poupart S, Navarro-Castellanos I, Raboisson MJ, Lapierre C, Dery J, Miró J, Dahdah N.
Pediatr Cardiol. 2021 Jan 19. doi: 10.1007/s00246-021-02545-w. Online ahead of print.
Take Home Points:
- Echocardiogram has a 56% sensitivity and 82.5% specificity (using angiogram as gold standard) to accurately identify valvular pulmonary stenosis from supra-valvular pulmonary stenosis.
- Post balloon dilation, patients with supra-valvular pulmonary stenosis had a higher RV-PA gradient as compared to patients with valvular PS.
- Patients with supra-valvular pulmonary stenosis, balloon-annulus ratio <1.2 or an immediate post intervention gradient 30mmHg had a higher rate of reintervention in the follow up.
Commentary from Dr. Varun Aggarwal (Minneapolis, MN, USA), section editor of Congenital
Heart Disease Interventions Journal Watch: Valvar pulmonary stenosis is a common congenital cardiac lesion. Classic valvular pulmonary stenosis with thin doming pulmonary valve leaflets responds very well to balloon pulmonary valvuloplasty. However, patients with coexistent supra-valvular pulmonary stenosis may not respond as well to balloon dilation.
Poupart S et al (1) aimed to evaluate the diagnostic accuracy of echocardiography to differentiate valvular from supravalvular pulmonary stenosis and evaluate the outcomes of percutaneous balloon dilation in supravalvular pulmonary stenosis compared to valvular pulmonary stenosis. They conducted a retrospective analysis of 106 patients from 2006-2017 at a single center in Montreal, Quebec. Both groups had comparable RV-PA gradients prior to intervention (SVPS: 68.04 ± 21.65 vs. VPS: 64.10 ± 14.37; p = 0.312). Using angiogram as a gold standard, the echocardiogram had a low sensitivity of 56% and specificity of 82.5%. A smaller pulmonary artery to pulmonary valve diameter ratio was noted in SVPS as compared to VPS. A pulmonary artery to pulmonary valve annulus ratio (as measured on echocardiogram) of 1.16 had a 64.7% sensitivity and 80.3% specificity to accurately diagnose SVPS.
Post balloon dilation (with similar balloon-annulus ratio in the two groups), the RV-PA gradients were higher in SVPS group as compared to VPS (26.8 ± 12.6 mmHg vs. 11.5 ± 8.5 mmHg; p ≤ 0.001). 71.4% patients with SVPS were deemed resistant to balloon dilation as compared to only 25.9% patients with VPS, p=0.001. Receiver operator curve analysis yielded a cut-off value of 1.20, below which the pulmonary stenosis would likely be resistant to percutaneous angioplasty (AUC = 0.730, p = 0.002).
Figure 1 is a figure from the article (1) demonstrating the follow up echocardiographic gradients in the two groups. The rate of future reinterventions was also higher in the SVPS group (32%) as compared to VPS (6.2%), p<0.05. Despite similar balloon annulus ratios in the two groups, VPS had a higher prevalence of high-grade pulmonary valve insufficiency as compared to SVPS.
This study highlights some of the challenges and lower success rate of balloon dilation for SVPS as compared to pure valvular PS. The echocardiographic evaluation prior to the procedure and paying attention to main pulmonary artery diameter to pulmonary valve annulus ratio can help identify these patients more accurately. This information can be helpful in counseling families prior to intervention.
Echocardiographic follow-up of RV-PA gradients. Follow-up excludes all data measured after a second intervention, of any kind, on the PV or PA. There was significant decrease in RV-PA gradients in both groups; however, gradients in patients with SVPS were significantly higher than patients with VPS (1).
1. Poupart S, Navarro-Castellanos I, Raboisson MJ, Lapierre C, Dery J, Miró J, et al. Supravalvular and Valvular Pulmonary Stenosis: Predictive Features and Responsiveness to Percutaneous Dilation. Pediatr Cardiol. 2021.