Long-term clinical and echocardiographic outcome of percutaneous mitral valvuloplasty: Randomized comparison of Inoue and double-balloon techniques

OBJECTIVES The purpose of the present study was to compare the long-term clinical and echocardiographic results of the Inoue and the double-balloon techniques. BACKGROUND The large randomized trial comparing the extent of commissurotomy and the long-term results between the double-balloon and Inoue balloon techniques has not been reported. METHODS We conducted a prospective, randomized trial comparing two procedures in 302 consecutive patients who underwent percutaneous mitral valvuloplasty (PMV) using Inoue (n = 152; group I) or double-balloon technique (n = 150, group D) between 1989 and 1995. The sample size was planned to provide the study with approximately 80% power for the detection of a 10% difference between the two groups. RESULTS There were no significant differences in baseline characteristics between the two groups. Immediately after PMV, mitral valve area (MVA) increased from 0.9 ± 0.2 to 1.8 ± 0.3 cm2 in group I and from 0.9 ± 0.2 to 1.9 ± 0.3 cm2 in group D. No significant differences existed between the two groups in terms of development of commissural splitting, commissural mitral regurgitation (CMR), moderate to severe mitral regurgitation (MR) and MVA after PMV. The successful immediate results (MVA ≥1.5 cm2 and MR ≤2) were achieved in 127 (84%) patients of group I and 122 (81%) patients of group D (p = NS). Annual clinical and echocardiographic evaluation was completed for 290 (96%) patients with mean follow-up of 51 ± 27 months. Adverse events occurred in 19 (13%) patients of group I (3 deaths, 7 mitral valve replacements, 5 repeat PMV, 2 NYHA class ≥3, 2 technical failures) and 16 (11%) patients of group D (2 deaths, 10 mitral valve replacements, 3 repeat PMV, 1 NYHA class ≥3). Estimated actuarial seven-year event-free survival was 75 ± 7% in group I and 82 ± 6% in group D (p = NS). Estimated actuarial seven-year restenosis-free survival was 67 ± 7% in group I and 76 ± 6% in group D (p = NS). On multivariate analysis, unsuccessful immediate result (p < 0.001) and absence of CMR (p < 0.01) were independently related with events. Absence of CMR and smaller mitral valve area after PMV were independently related with restenosis (p < 0.001). CONCLUSIONS The Inoue and double-balloon techniques were equally effective in commissurotomy and produced similar, excellent long-term results. The achievement of complete commissurotomy with development of CMR or larger post-PMV mitral valve area is important to optimize the long-term results of PMV.