Long-term Clinical Outcome and Echocardiographic Restenosis after Successful Percutaneous Transmitral Commissurotomy

Abstract

Background:The purpose of this study was to assess the clinical outcome and echocardiographic incidence of restenosis after successful percutaneous transmitral commissurotomy(PTMC) and to identify predictable causes of restenosis. Methods:Between 1989 and 1992, Inoue PTMC(n=73) and double balloon technique(n=85) were used in 158 consecutive patients(male 52, age;41±11 year) with mitral stenosis. Clinical and echocardiographic examinations were performed annually in 137 patients who exhibited good initial results with PTMC(mitral valve area 1.5cm and mitral regurgitation[MR] 2+). Restenosis was defined as a mitral valve area(MVA) <1.5cm or more than 50% loss of the initial gain in MVA. Commissural mitral regurgitation(CMR) was defined as MR originating from medical or lateral commissure on color flow imaging and regarded as an index of complete commissural splitting. Results:Immediately after PTMC, MVA increased from 0.9±0.2cm to 1.8±0.3cm and functional class improved up to NYHA class 1 or 2 in all patients. Annual echocardiographic followups were completed in 129(94%) patients and mean follow-up duration was 54±21 months. Adverse events occurred in 16(13%) patients(1 death, 3 mitral valve replacements, 3 re-PTMCs, 9 deteriorations of the NYHA class), and restenosis occurred in 41(32%) patients. Event-free and restenosis-free survival rates at 7 years were 776% and 586%, respectively. According to multivariate Cox analysis, restenosis(p=0.0017, relative risk[r.r]=2.8) was the only predictor of adverse events;smaller increases(1.0cm) of MVA(p=0.0001, r.r=4.8) and the absence of CMR(p=0.0000, r.r=4.8) were independent predictors of restenosis.