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

The present study examined the utility of the stepwise balloon dilatation t echnique in 41 patients with significant calcific mitral stenosis undergoin g percutaneous transvenous mitral commissurotomy (PTMC). Thirty-five patien ts (85.4%) had a successful procedure; one patient developed cardiac tampon ade and underwent mitral valve replacement. The mitral valve area increased from 0.9 +/- 0.2 cm(2) to 1.7 +/- 0.3 cm(2) following PTMC. Increase in mi tral regurgitation (MR) was seen in 11 patients (26.8%). All patients showe d improvement in functional class of greater than or equal to 1 level follo wing PTMC, which was sustained in 34 patients at follow-up. At a mean follo w-up period of 20 +/- 12 months (range 3-51 months) in 35 patients, 26 pati ents (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 HI. The cumulative 4-year cardiac event-free survival rate was 81.8%. However, patients with grade 4+ calcification had only 50% event-free surv ival rate. At follow-up, an increased incidence of cardiac events was seen in female patients as compared,vith male patients (83.3% versus 16.7%). Res tenosis 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 mit ral valve replacement at follow-up. We conclude that the stepwise balloon dilatation technique can be safely an d effectively applied for patients with significant calcific mitral stenosi s 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 im proved functional status and low incidence of repeat procedures (repeat PTM C or mitral valve replacement). The majority of patients (74.3%) were in NY HA functional class I without medication. Patients with grade 4+ calcificat ion show less benefit from PTMC and may be considered for mitral valve repl acement. Cardiac events occur more frequently in female patients than in ma le patients during follow-up.