Abstract 11831: Late Outcome of Percutaneous Mitral Commissurotomy: Randomized Comparison of Inoue versus Double-Balloon Technique

Introduction: Percutaneous mitral commissurotomy (PMC) using either the Inoue or the double balloon technique showed similar, excellent 7-year outcomes, but very late results after successful PMC have been unknown. Hypothesis: We assessed late results of PMC up to 20 years in a randomized trial comparing Inoue versus double-balloon technique. Methods: Between 1989 and 1995, a total of 302 patients (77 men, 41±11 years) with severe mitral stenosis were randomly assigned to undergo PMC using Inoue (n=152; group I) or double-balloon technique (n=150; group D). The end points were the composite clinical events of death, mitral surgery, repeat PMC, or deterioration of NYHA class ≥3 that occurred after enrollment. Results: The successful immediate results [post-PMC mitral valve area (MVA) ≥1.5 cm 2 and mitral regurgitation (MR) grade ≤2] were achieved in 127 (84%) patients of group I and 122 (81%) patients of group D (p= NS). During median follow-up of 20.7 years (IQR, 18.9 to 22.9), clinical events occurred in 82 (53.9%) patients of group I (37 deaths, 44 mitral surgeries, 9 repeat PMCs and 3 NYHA class ≥3) and 79 (52.7%) patients of group I (34 deaths, 51 mitral surgeries, 5 repeat PMCs and 4 NYHA class ≥3). The event-free survival rates were not significantly different between group I and group D (49.3% and 55.3% at 20 years, respectively; HR, 1.22; 95% CI, 0.88-1.70; p=0.23) (Figure). On multivariate Cox analysis, absence of commissural MR (HR, 1.75; 95% CI, 1.22-2.51; p=0.002), immediate post-PMC MVA 2 (HR, 1.54; 95% CI, 1.04-2.27; p=0.03), and atrial fibrillation (HR, 1.53; 95% CI, 1.04-2.23; p=0.03) were independently related with clinical events after successful PMC. Conclusions: In this randomized trial, the Inoue and double-balloon methods showed similar, good outcomes up to 20 years, and the achievement of effective commissurotomy with development of commissural MR or immediate post-PMC MVA ≥1.8cm 2 is important in optimizing the late results of PMC.