Percutaneous transvenous mitral commissurotomy for significant calcific mitral stenosis: utility of the stepwise balloon dilatation technique and follow-up results

Abstract

The present study examined the utility of the stepwise balloon dilatation technique in 41 patients with significant calcific mitral stenosis undergoing percutaneous transvenous mitral commissurotomy (PTMC). Thirty-five patients (85.4%) had a successful procedure; one patient developed cardiac tamponade and underwent mitral valve replacement. The mitral valve area increased from 0.9 +/- 0.2 cm2 to 1.7 +/- 0.3 cm2 following PTMC. Increase in mitral regurgitation (MR) was seen in 11 patients (26.8%). All patients showed improvement in functional class of > or =1 level following PTMC, which was sustained in 34 patients at follow-up. At a mean follow-up period of 20 +/- 12 months (range 3-51 months) in 35 patients, 26 patients (74.3%) were in New York Heart Association (NYHA) functional Class I, 8 patients (22.9%) were in NYHA Class II, and 1 patient (2.8%) was in NYHA Class III. The cumulative 4-year cardiac event-free survival rate was 81.8%. However, patients with grade 4+ calcification had only 50% event-free survival rate. At follow-up, an increased incidence of cardiac events was seen in female patients as compared with male patients (83.3% versus 16.7%). Restenosis was seen in 3 patients (8.6%). One patient underwent repeat PTMC 37 months after the initial procedure. There was no incidence of death or mitral valve replacement at follow-up. We conclude that the stepwise balloon dilatation technique can be safely and effectively applied for patients with significant calcific mitral stenosis to achieve an optimal mitral valve area with low incidence of significant increase in MR. Favorable long-term benefits also accrue in the form of improved functional status and low incidence of repeat procedures (repeat PTMC or mitral valve replacement). The majority of patients (74.3%) were in NYHA functional class I without medication. Patients with grade 4+ calcification show less benefit from PTMC and may be considered for mitral valve replacement. Cardiac events occur more frequently in female patients than in male patients during follow-up.