Temporal Trends on Percutaneous Mitral Commissurotomy: 30 Years of Experience

Background Percutaneous mitral commissurotomy ( PMC ) was the first available transcatheter technique for treatment of mitral valve diseases. Experience has led to extending the indications to patients with less favorable characteristics. We aimed to analyze (1) the temporal trends in characteristic and outcomes of patients undergoing PMC in a single center over 30 years and (2) the predictive factors of poor immediate results of PMC . Methods and Results From 1987 to 2016, 1 full year for each decade was analyzed: 1987, 1996, 2006, and 2016. Poor immediate results of PMC were defined as a mitral valve area <1.5 cm² or MR (mitral regurgitation) grade >2. Mitral anatomy was assessed using the Cormier classification and the fluoroscopic extent of calcification. Six hundred three patients were included: 111, 202, 205, and 85, respectively. Mean age increased >10 years over time ( P<0.0001). Mitral anatomy was less favorable over the years: the presence of calcification increased from 25% of patients at the beginning of PMC to >40% during the past decade ( P<0.0001) with a 3-fold increase in severe mitral calcification. Consistently, the proportion of good immediate results decreased over time ( P<0.05) but remained at 76% in 2016. Multivariate analysis showed 3 predictive factors of poor immediate results: smaller baseline mitral valve area ( P<0.0001), pre- PMC MR grade 2 ( P<0.01), and the presence or amount of calcification ( P<0.001). Conclusions This clinic's patients became significantly older with more frequent and severe calcification in the past decade. Predictive factors of poor immediate results were related to valve anatomy, including calcification. Despite challenges raised by severe calcification, PMC was still successful in >3 out of 4 patients in recent years.