Treatment of severe mitral stenosis with percutaneous balloon valvotomy in pregnant patients

Background: Pregnancy can cause life-threatening complications in women with mitral stenosis. Frequently, there is an urgent need to increase the mitral valve area mechanically. In selected cases, percutaneous mitral balloon valvotomy (PMBV) has emerged as a safe and effective alternative to surgical commissurotomy. Hypothesis: The study evaluates the effects of PMBV by the Inoue technique in nine pregnant patients with severe symptomatic mitral stenosis. Methods: The patients were in New York Heart Association (NYHA) functional class II to IV and had echocardiographic scores of less than or equal to 8. The mean gestational age was 24.8 +/- 6.1 weeks. The patient's pelvic and abdominal regions were covered with a lead apron to protect the fetus from radiation. A stepwise dilatation technique was used. Fluoroscopy time was kept to 10 to 15 min. Results: One patient developed severe mitral regurgitation requiring emergency valve replacement. The remaining eight patients showed marked immediate symptomatic and hemodynamic improvement. After dilatation, the transmitral pressure gradient decreased from 20.8 +/- 6.5 to 7.3 +/- 1.4 mmHg (p = 0.001) and the calculated mitral valve area increased from 0.9 +/- 0.1 to 1.8 +/- 0.4 (p < 0.001). All patients had uneventful term deliveries of normal babies. On follow-up they were in NYHA functional class I. Conclusions: Percutaneous mitral balloon valvotomy is a safe and effective procedure for selected pregnant patients with severe mitral stenosis. The procedure is well tolerated by the fetus. Severe mitral regurgitation requiring immediate surgery may occur occasionally. The possible harmful effects to the fetus from its exposure to radiation during PMBV are unknown.