Comparison of results of percutaneous balloon valvuloplasty in patients with mild and moderate mitral stenosis to those with severe mitral stenosis

Most reported studies of percutaneous balloon valvuloplasty in adults with acquired mitral stenosis have used patients with severely stenosed valves. The risks and benefits of valvuloplasty were examined in a multicenter registry of patients to determine whether balloon valvuloplasty can effectively dilate less severely obstructed valves, and to clarify the rote of this procedure in symptomatic patients with mild and moderate mitral stenosis. The study groups were derived from the North American Inoue Balloon Valvuloplasty Registry. Full hemodynamic data were available in 264 patients; 45 (17%) with mild or moderate mitral stenosis (mitral valve area ≥1.3 cm²) were compared with the remaining 219 with severe mitral stenosis (valve area <1.3 cm²). Percutaneous balloon valvuloplasty was performed using the anterograde transseptal technique with an Inoue balloon. The mean age of patients with mild and moderate mitral stenosis was 53 ± 13 years, and all were symptomatic with a mean New York Heart Association functional class of 2.9 ± 0.7. Balloon valvuloplasty resulted in an increase in calculated mitral valve area from 1.4 ± 0.1 to 2.3 ± 0.7 cm² (p < 0.05), and a final valve area ≥1.9 cm² was achieved in 37 patients (82%). There were no procedural deaths, but complications included right atrial perforation, transient ischemic attack and emergency surgery for severe mitral regurgitation. One-year follow-up evaluation revealed symptomatic improvement in most patients (mean New York Heart Association class 1.4 ± 0.6; p < 0.0001). However, 2 patients needed repeat valvuloplasty for restenosis, and 5 had mitral valve replacements. Patients with less severe stenosis had lower pulmonary artery pressures and transmitral gradients, higher cardiac outputs and lower total echocardiographic scores than did those with severe mitral stenosis. A larger final valve area was achieved in patients with mild and moderate stenosis (2.3 ± 0.7 vs 1.7 ± 0.5 cm²; p < 0.05).