Long-Term Follow Up After Successful Percutaneous Balloon Mitral Valvuloplasty

Percutaneous balloon mitral valvuloplasty (PMV) is the cornerstone of rheumatic mitral stenosis treatment in suitable patients. Previous studies have reported low rates of technical failure and few major complications, with good long-term results after successful PMV. The study aim was to assess the very long-term outcome in patients after PMV performed at a single tertiary center.

Between 1991 and 2010, a total of 213 consecutive patients underwent PMV at the authors' center. The criteria used to define successful procedure were post-procedural mitral valve area ≥1.5 cm2 and mitral regurgitation less than grade III, without in-hospital major cardiac or cerebrovascular events. The primary endpoint evaluated during the follow up period was the occurrence of cardiovascular death and need for mitral reintervention (percutaneous or surgical). Kaplan-Meier curves were generated to determine event rates, and predictors of major cardiac events in patients with successful PMV were determined using Cox regression analysis.

A total of 190 patients (89%) underwent a successful PMV; 88% of these are currently being followed up at the authors' center. During a mean follow up of 11.2 ± 7.3 years, at least one major adverse cardiac event occurred in 25.1% of patients (6.6% all-cause death, 6.6% repeated PMV, 21% required mitral valve surgery). Cumulative event-free survival at 20 years was 54.7 ± 6.3%. On univariate analysis, the echocardiographic score [hazard ratio (HR) = 1.25 (1.00-1.70), p <0.05], left atrial diameter [HR = 1.06 (1.01-1.11), p <0.05] and mean mitral valve gradient soon after the procedure [HR = 1.25 (1.02-1.55), p <0.05] were predictors of events. On multivariate analysis, the echocardiographic mitral valve score before PMV was the only independent predictor of primary outcome [HR=1.75 (1.16-2.64), p<0.01].

Up to 20 years after successful PMV, a sizeable proportion of patients remained event-free, which confirmed the late efficacy of PMV. Among the present patient cohort, echocardiographic score before PMV was the only independent predictor of long term events.