Percutaneous transvenous mitral commissurotomy during pregnancy: a contemporary Southeast Asian experience

Background Severe rheumatic mitral stenosis during pregnancy is associated with substantial maternal and fetal morbidity because physiological hemodynamic changes may precipitate heart failure and pulmonary hypertension. Percutaneous transvenous mitral commissurotomy (PTMC) is the recommended intervention for carefully selected symptomatic patients who remain refractory to medical therapy. Although PTMC during pregnancy has been widely reported, contemporary data describing procedural characteristics, radiation exposure, and maternal–fetal outcomes from Southeast Asia remain limited. This study aimed to evaluate the procedural, hemodynamic, radiation, maternal, and neonatal outcomes of PTMC performed during pregnancy. Methods We conducted a retrospective observational study of consecutive pregnant women with rheumatic mitral stenosis who underwent PTMC at a tertiary referral center in Thailand between 2002 and 2022 according to the institutional eligibility criteria used during the study period. Given the limited sample size, all analyses were considered exploratory. Hemodynamic, echocardiographic, procedural, radiation, maternal, and neonatal outcomes were evaluated. Results Eighteen pregnant women underwent PTMC at a mean gestational age of 24.6 ± 5.7 weeks. Procedural success was achieved in 94% of patients. Mitral valve area significantly increased from 0.98 ± 0.23 cm² to 1.50 ± 0.34 cm² ( p < 0.001), while mean transmitral gradient decreased from 15.98 ± 5.97 mmHg to 7.26 ± 3.92 mmHg ( p = 0.001). Mean left atrial pressure also significantly decreased from 31.94 ± 5.95 mmHg to 17.41 ± 4.29 mmHg ( p < 0.001), and most patients improved from New York Heart Association functional class III–IV to class I–II ( p < 0.001). Among the 12 patients with available radiation data, the median fluoroscopy time was 3.76 min and the median cumulative air Kerma was 21 mGy. Among patients with available obstetric follow-up ( n = 12), no maternal deaths, neonatal deaths, or congenital anomalies were observed. Conclusions In this small retrospective single-center study, PTMC was associated with significant immediate hemodynamic and symptomatic improvement in carefully selected pregnant women with rheumatic mitral stenosis. Among patients with available follow-up, maternal and neonatal outcomes were generally favorable; however, these findings should be interpreted cautiously because of the limited sample size, prolonged recruitment period, retrospective design, and incomplete follow-up. Larger prospective multicenter studies are required to confirm these findings.