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 ~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.