Left atrial remodelling in patients with successful percutaneous mitral valvuloplasty: determinants and impact on long-term clinical outcome

BACKGROUND: Left atrial (LA) volume is an independent prognosticator in various cardiac diseases. The authors assessed the changes of LA volume after successful percutaneous mitral valvuloplasty (PMV) and the impact of LA enlargement on long-term clinical outcome after PMV. METHODS AND RESULTS: From a prospective PMV registry started in 1988, 303 patients (242 women, age: 39.3+/-10.8 years) who had undergone successful PMV were followed for 4-20 years (median 11 years). Echocardiographic examination including LA volume measurement was performed before PMV and repeated after PMV. LA volume decreased from 92+/-50 to 69+/-42 ml (p < 0.001) immediately after PMV and remained stationary until 1 year after PMV. Since then, LA volume subsequently increased exceeding the pre-PMV level by 8 years after PMV. Multivariate analysis showed that LA volume increase at 10 years after PMV was independently related to the post-PMV mitral valve area, the echo score, the presence of atrial fibrillation and post-PMV LA volume. On multiple regression analysis, pre-PMV LA volume and percentage change of LA volume immediately after PMV emerged as independent predictors of event-free survival along with age, pre-PMV tricuspid regurgitation and post-PMV mitral valve area. Ten-year survival rate was 93% in patients with smaller LA before PMV (< or =72 ml/m(2)), whereas it was only 60% in those with larger LA (>72 ml/m(2)). CONCLUSIONS: Progressive increase of LA volume was observed even after successful PMV. Larger pre-PMV LA volume was associated with poor prognosis.