Whether percutaneous mitral commissurotomy (PMC) should be attempted in patients with severe mitral stenosis and commissural calcifications remains debated, since commissural splitting is the mechanism by which mitral valve stenosis is relieved.

To determine whether the presence of calcium in the mitral valve commissures influence the immediate result of PMC.

PMC by the Inoue balloon was attempted in 247 patients (mean age: 35 years) with severe mitral valve stenosis. All the patients had undergone echocardiographic examination before PMC to assess mitral anatomy, commissural calcification (CC) and to determine the Wilkins score. According to the absence or presence of CC, patients were divided into 2 groups: 216 patients in group CC− (no commissural calcification) and 31 patients in group CC+ (presence of calcification in 1 or 2 commissures). Baseline mitral valve area (MVA) was 1 ± 0.19 cm² (range 0.5–1.4 cm²), the mean value of Wilkins score was 7.98 ± 1.61 (range 5–13) and 29 patients had unilateral commissural calcification. Post-PMC success was defined as final MVA ≥ 1.5 cm² and no mitral regurgitation ≥ grade3.

After PMC, the mean MVA increased to 1.79 ± 0.34 cm² (P < 0.001) resulting in a success rate of 83%. Severe mitral regurgitation (MR) occured in 5 patients (2%). Final MVA (1.83 ± 0.32 cm² versus 1.50 ± 0.36 cm²), success rate (87% versus 55%) and the rate of opening of at least one commissure (97% versus 77%) were significantly different between groups CC− and CC+ (P < 0.001). The rate of post-PMC MR of grade ≥ 3 was not different between the two groups (2% in group CC− and 0% in group CC+; P = 0.6).

Our results showed that the presence of commissural calcification was associated with a lower procedural success rate but a good immediate result could be achieved in half of cases. Then, unilateral commissural calcification should not be considered as a contra-indication to PMC.