The clinical and hemodynamic results of mitral balloon valvuloplasty for patients with mitral stenosis complicated by severe pulmonary hypertension.

BACKGROUND: Percutaneous balloon mitral valvuloplasty (PBMV) has become the procedure of choice for isolated, uncomplicated mitral stenosis (MS) with favorable morphology and may be a useful method for surgical high-risk conditions such as advanced age, the presence of severe tricuspid regurgitation, New York Heart Association (NYHA) class IV at presentation, and severe pulmonary hypertension (PH). The development of PH is a common and important sequela in patients with advanced mitral stenosis and is associated with hemodynamic and clinical decompensation. However, the influence of PBMV on patients with severe PH has seldom been evaluated. Our objective was to probe into the immediate and long-term effects of PBMV on patients with MS complicated by severe PH and to predict the factors that determine the prognosis of patients with severe PH.
METHODS: We included 44 patients with MS complicated by severe PH (systolic pulmonary pressure >80 mm Hg, group S) and 67 patients with MS complicated by mild PH (systolic pulmonary pressure <50 mm Hg, group M) in this study and we compared their immediate and late results after a follow-up period of 24 months after PBMV.
RESULTS: Compared with group M, patients in group S were older, presented more frequently with NYHA III-IV class, valvular echo score >or=8, and more severe tricuspid regurgitation, and had a bigger left atrial diameter before PBMV. The successful rate and the incidence of severe complications from the PBMV procedure were similar in both groups. There were more cases of post-PBMV mitral valve area >or=1.5 cm(2) in group M than in group S, and the average mitral valve area in group M was somewhat larger than that of group S. After PBMV, NYHA class obviously improved in both groups, but there were more patients with NYHA<or=class II in group M than in group S at discharge. During the 24-month follow-up, 7 patients (10.5%) in group M and 11 (25.0%) in group S developed cardiac events (p<0.1). Cumulative event-free survival was 89.6% in group M and 75.0% in group S (p>0.05). NYHA class I or II was present for 80.6% in group M and 59.1% in group S (p<0.10).
RESULTS: PBMV is a safe and effective procedure for patients with severe PH. It can remarkably improve clinical outcomes, although hemodynamic effects of PBMV on this subgroup are not complete. Pre-existing older age, more severe valvular lesion and tricuspid regurgitation, worse cardiac function, and bigger left atrial size in patients with severe PH may be important risk factors for the poor hemodynamic outcomes of PBMV.