Effect of percutaneous balloon valvuloplasty on pulmonary hypertension in mitral stenosis

Percutaneous mitral balloon valvuloplasty (PMBV) has been useful in decreasing mitral valve obstruction in mitral stenosis; however, the long-term effects of valvuloplasty on pulmonary artery pressure have not been extensively studied. Thirty-three patients underwent PMBV in our institution between January 1988 and December 1991. There were significant reductions in peak (19 ± 1 to 12 ± 1 mm Hg) and mean (10 ± 0.7 to 6 ± 0.4 mm Hg) mitral valve gradients estimated by Doppler techniques immediately after PMBV. The mitral valve area, as assessed by the pressure half-time method, increased from 1.06 ± 0.05 to 1.98 ± 0.08 cm 2 ( p < 0.001) after the procedure and remained significantly greater (1.68 ± 0.11 cm 2) at 17 ± 2 months. Right ventricular systolic pressure (RVSP) was estimated in patients with tricuspid regurgitation (TR) using the modified Bernoulli equation. There was a good correlation between Doppler and catheterization for RVSP ( r = 0.83 pre valvuloplasty; r = 0.87 post valvuloplasty). Right ventricular systolic pressure by Doppler was 56 ± 4 mm Hg before valvuloplasty and 48 ± 4 mm Hg immediately afterwards ( p < 0.001). Nine patients had TR on follow-up Doppler studies with an estimated RVSP of 53 ± 9 mm Hg ( p = NS compared with pre- and postvalvuloplasty values). Six of these nine patients had moderate or severe mitral regurgitation (MR), compared with one patient without TR at follow-up ( p < 0.05). There appears to be a good correlation between the RVSP determined by Doppler and measured at catheterization. Despite an initial improvement in RVSP after valvuloplasty, this effect may not persist at 17 months of follow-up. Therefore Doppler echocardiography may be used to assess pulmonary hypertension before and after PMBV in mitral stenosis and to assess possible causes of persistently elevated RVSP after valvuloplasty (such as significant MR).