Predictors of successful percutaneous transvenous mitral commissurotomy using the Bonhoeffer Multi-Track system in patients with moderate to severe mitral stenosis: Can we see beyond the Wilkins score?

Objective: To know the predictors of a successful outcome of percutaneous transvenous mitral commissurotomy (PTMC) other than described in the Wilkins scoring system. Methods: Two hundred fifty-eight consecutive patients were enrolled for this observational study in a tertiary care heart center of Pakistan who had a Wilkins score of <= 8. Patients with more than mild mitral regurgitation (MR) or having a clot in the left atrium were excluded. The Bonhoeffer multi-track system was used as a default technique. Successful PTMC was defined as achieving a mitral valve area (MVA) of >= 1.5 cm(2) with no more than mild MR. Results: Out of 258 PTMC procedures, 197 were successful. The Bonhoeffer multi-track system was used in similar to 94% cases. Among unsuccessful procedures, 41 patients did not achieve the required valve area, and 21 patients developed more than mild MR, including those 8 patients who did not achieve the required valve area and had more than mild MR. Bigger mean annulus size (33.5+/-2.6 versus 32.8+/-2.1 mm; p=0.02) and pre-procedure MVA (0.93+/-0.1 versus 0.87+/-0.1 cm(2); p=0.002) had a significant effect on successful PTMC. Lower mean preprocedure systolic right ventricular pressure on echo (65.4+/-19.4 versus 75.3+/-18 mm Hg; p=0.000) and on cath (74+/-21.5 versus 81.5+/-24.6 mm Hg; p=0.002), lower grade of left ventricular dysfunction (p=0.04), and tricuspid regurgitation on echo (p=0.003) also had positive effects on the outcome. Conclusion: Bigger preprocedure mitral valve annulus size and mitral valve area, and better left and right ventricular hemodynamics are correlated with successful PTMC.