Percutaneous mitral commissurotomy (PMC) was the first available percutaneous treatment of valvular diseases and experience has led to extend its indications to patients with less favourable anatomy.

The aims of this study were to analyze:

– the temporal trends of PMC in a single center with a large experience of this technique;

– the predictive factors of poor immediate results (PIR) of PMC.

From mid-1986 to 2016, 1 year for each decade was chosen to analyze the temporal trends over 30 years: 1987, 1996, 2006 and 2016. All patients who underwent a PMC in our center during these 4 years were included in the study. PIR of PMC were defined as a final mitral valve area (MVA)<1.5 cm² or the presence of mitral regurgitation (MR) grade>2.

603 patients were included: 111, 202, 205 and 85 for the 4 years, respectively. Mean patient age increased>10 years between 1987 and 2016 (P<0.0001). Consistently, the presence of calcification increased from 25% of patients at the beginning of PMC to>40% during the last decade (P<0.0001) (Figure 1). The severity of mitral stenosis did not significantly differ during the 30 years. Over the 3 decades, 84 patients experienced PIR of PMC (13.9%) and the percentage of PIR increased significantly in 2016 (24% versus 11 to 14% in previous decades, P<0.05). We found in multivariate analysis 3 factors to be independently associated with PIR: a smaller baseline MVA (P<0.0001), a higher pre-PMC grade of MR (P<0.01) and the presence of calcification as assessed by a Cormier score of 3 (P<0.001).

Changes in patient presentation, with an older age and an increased occurrence of calcification, over the years are consistent with the epidemiology of rheumatic fever and account for the increase in the rate of PIR. Despite more patients with severe mitral calcification, good immediate results of PMC were still achieved in>3/4 patients in recent years, thus allowing to postpone surgery.