Percutaneous transvenous mitral commissurotomy for juvenile mitral stenosis at a cardiac center in Ethiopia: a 12-year retrospective follow-up study

Background and purpose: Percutaneous transvenous mitral commissurotomy (PTMC) is the preferred treatment for juvenile patients with rheumatic mitral stenosis and favorable valve anatomy, as it improves survival and quality of life. However, data regarding PTMC outcomes, complications, and predictors of restenosis in pediatric populations from Ethiopia and across Africa are limited. This study aimed to investigate the outcomes and complications of PTMC in children and to identify predictors of restenosis. Methods: This retrospective study was conducted at the Cardiac Center of Ethiopia and included 121 patients younger than 20 years who underwent PTMC for rheumatic mitral stenosis between October 2010 and January 2022. The primary objectives were to evaluate the immediate procedural success, complications, and predictors of restenosis. Kaplan–Meier analysis was utilized to assess overall survival, freedom from re-intervention, and restenosis. The Cox proportional hazard regression model was employed to determine predictors of restenosis. Results: The immediate procedural success rate of PTMC was 97.5%, with an overall long-term survival rate of 95% at 12 years of follow-up. Following the procedure, the median mitral valve area increased significantly from 0.60 cm 2 (interquartile range [IQR]: 0.50–0.70 cm 2 ) to 1.60 cm 2 (IQR: 1.40–1.90 cm 2 ) (P < 0.001). The median mean mitral valve inflow gradient decreased from 21 mmHg (IQR: 16–26 mmHg) to 6 mmHg (IQR: 5–8 mmHg) (P < 0.001), left atrial pressure decreased from 42 mmHg (IQR: 40–48 mmHg) to 14 mmHg (IQR: 10–20 mmHg) (P < 0.001), and pulmonary artery peak systolic pressure decreased from 70 mmHg (IQR: 55–93 mmHg) to 40 mmHg (IQR: 35–52 mmHg) (P < 0.001). Among the 118 patients with successful immediate PTMC, restenosis occurred in 32 patients (27.1%) during a median follow-up period of 50 months (IQR: 36–72 months). Lower immediate post-PTMC valve area (P = 0.030), higher pre-procedural mean mitral inflow gradients (P = 0.040), and New York Heart Association (NYHA) functional classes III–IV (P = 0.001) were significant predictors of restenosis. Conclusions: PTMC is a safe and effective treatment for juvenile mitral stenosis and has favorable long-term survival. However, a considerable proportion of patients experienced restenosis over time, underscoring the importance of regular follow-up for early detection of complications and timely re-intervention.