Late results of percutaneous balloon mitral commissurotomy in patients with restenosis after surgical commissurotomy compared to patients with 'de-novo' stenosis.

BACKGROUND AND AIMS OF THE STUDY: The outcome of percutaneous balloon mitral commissurotomy (BMC) has been reported as poor in patients with prior surgical commissurotomy. The study aim was to evaluate immediate and long-term follow up results of BMC in patients with restenosis after surgical commissurotomy compared to patients with 'de-novo' mitral stenosis.

METHODS

Between October 1988 and September 1999, a total of 1,027 patients underwent BMC. Of these patients, 169 (16.5%) were examined at 17+/-7 years (range: 2-33 years) after surgical commissurotomy (group 1), and 858 (83.5%) had de-novo mitral stenosis (group 2).

RESULTS

Group 1 patients were older than group 2 patients (49.4+/-9.3 versus 47.3+/-9.6 years; p <0.05), and atrial fibrillation was seen more often in group 1 (53.9% versus 32.4%; p <0.005). Before BMC, mitral valve area (MVA) was similar in both groups (1.18+/-0.27 and 1.15+/-0.26 cm2 in groups 1 and 2 respectively; p = NS); following BMC, MVA was 1.82+/-0.3 and 1.93+/-0.40 cm2 respectively (p <0.05). Four patients (2.4%) from group 1, and 24 (2.8%) from group 2 required mitral valve replacement due to severe regurgitation (p = NS). Annual clinical and echocardiographic evaluation was completed for 950 patients (mean follow up 56.2+/-31.1 months (range: 12-132 months). Cardiac events defined as death, valve surgery or repeat BMC occurred in 16.0% of patients in group 1, and in 9.6% of those in group 2. At follow up of three, five and 10 years, actuarial event-free survival was 85.7+/-2.9%, 79.8+/-3.8% and 65.2+/-7.5% respectively in group 1, and 93.4+/-0.9%, 90.1+/-1.1% and 72.7+/-3.9% respectively in group 2 (log rank test, p = 0.02). Multivariate analysis showed MVA <1.5 cm2 after BMC, mitral regurgitation grade >2/4, Wilkins score >8, and mean transmitral gradient and left atrial mean pressure post BMC to be independent predictors of an adverse event occurring during follow up.

CONCLUSION

BMC in patients with restenosis after surgical commissurotomy is an effective method of treatment, and may help to avoid valve surgery in most patients.