Multicenter experience with balloon mitral commissurotomy. NHLBI Balloon Valvuloplasty Registry Report on immediate and 30-day follow-up results. The National Heart, Lung, and Blood Institute Balloon Valvuloplasty Registry Participants.

BACKGROUND: Balloon mitral commissurotomy can increase mitral valve areas and reduce symptoms in selected patients with mitral stenosis. The National Heart, Lung, and Blood Institute Balloon Valvuloplasty Registry was organized to address concerns regarding differences in patient selection and technique and to report the current clinical outcome. METHODS AND RESULTS: In 24 cooperating centers, 738 patients had balloon mitral commissurotomy. Baseline clinical, echo Doppler, and cardiac catheterization data, procedure details, and hemodynamic and 30-day clinical outcome were reported. Overall, 81% of the patients were women (mean age, 54 +/- 15 years), and 24% had moderate or severe other valvular lesions. When single- and double-balloon procedures were compared, the final mitral valve area was larger (1.7 +/- 0.7 versus 2.0 +/- 0.8 cm2, p = 0.0009), increase in mitral regurgitation was similar (4% versus 12%, p = 0.08), and interatrial shunts occurred more frequently (2% versus 12%, p = 0.04) after double-balloon procedures. Increase in mitral valve area was weakly related to mitral valve morphology as assessed by an echo score (r = -0.15). Multivariate predictors of improved clinical status at 30 days were cases performed in larger-volume centers, baseline mitral valve area greater than 0.5 cm2, and age less than 70 years. At 30-day follow-up, 4% of the patients with completed procedures had mitral valve surgery, 3% had died, and 83% had their overall condition improved. Patients with mixed mitral stenosis or regurgitation and isolated mitral stenosis had a similar course, but fewer patients with multivalve disease became asymptomatic. CONCLUSIONS: Balloon mitral commissurotomy, as practiced in a broad range of experienced centers, produced significant short-term hemodynamic and clinical improvements. Balloon mitral commissurotomy can be considered an effective treatment option in patients with symptomatic mitral stenosis.