Balloon mitral valvuloplasty during pregnancy--our experience

Mitral stenosis is the most common valvular heart lesion found in pregnancy. When severe, it leads to significant maternal and fetal morbidity and mortality, since the hemodynamic adaptations to pregnancy are badly tolerated. Pregnancy can lead to development of heart failure in patients with asymptomatic or even unknown mitral stenosis, as a result of the increased mitral valve pressure gradient caused by the physiologic increase in heart rate and blood volume in pregnancy. When symptoms persist despite optimal medical therapy, the poor prognosis justifies the correction of mitral stenosis during pregnancy.

To present our experience in treating severe mitral stenosis in women who develop severe heart failure during pregnancy, using percutaneous balloon mitral valvuloplasty.

From 1996 to March 2002, in our department, 47 balloon mitral valvuloplasties were successfully performed in women, three of them pregnant. These were patients with congestive heart failure, New York Heart Association (NYHA) functional class III or IV, at the end of the second trimester of pregnancy, who did not respond positively to drug treatment with diuretics and digitalis.

We performed percutaneous balloon mitral valvuloplasty using the Inoue technique in the three pregnant patients, with success, at around 25 weeks of gestation.

After the procedure, the patients showed clinical improvement, returning to the NYHA functional class that they were in before becoming pregnant (I-II). The previous mitral valve area was 0.9-1.2 cm2, nearly doubling after valvuloplasty. Mean left atrial pressure decreased on average by 42%, and the maximum pressure (V wave) decreased on average by 40%. The mitral valve pressure gradient decreased from 15, 10 and 28 mmHg to 7, 5 and 5 mmHg after valvuloplasty. During the procedure there were no maternal or fetal complications. All patients were discharged 24 to 48 h after valvuloplasty, continuing their pregnancies without complications. One woman had vaginal delivery, and the other two had cesarean sections at 35 weeks of gestation, all without complications with healthy newborns that developed normally. In follow-up, one patient who had moderate mitral regurgitation after valvuloplasty developed severe mitral regurgitation, requiring surgical correction after two years.

In pregnant patients who have severe mitral stenosis and persistent congestive heart failure symptoms despite conventional medical treatment, when feasible, percutaneous balloon mitral valvuloplasty is the best treatment.