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.