Effect of mitral valve replacement on reduction of left atrial size.

INTRODUCTION

asymptomatic left atrial enlargement is not uncommon in rheumatic mitral valve disease. We studied the change in size of the left atrium after mitral valve replacement.

PATIENTS AND METHODS

between January and December 2005, 116 patients underwent isolated mitral valve replacement. Two groups were identified based on left atrial size: group 1 < 60 mm (n = 79) and group 2 > 60 mm (n = 37). The patients were followed up for 40.4 ± 19.3 months Clinical assessment, preoperative and last postoperative echocardiograms were considered for analysis.

RESULTS

the left atrium decreased by 5.84 mm ± 10.5 in group 1 compared to 20.9 mm ± 10.64 in group 2 (p = 0.0001). This correlated with preoperative mitral valve area (p = 0.009), preoperative mitral regurgitation (p = 0.000), and preoperative atrial fibrillation (p = 0.022). Linear regression analysis revealed atrial fibrillation (p = 0.001, b1 = 6.006), a high grade of mitral regurgitation (p = 0.001, b1 = -3.812), and larger size of the left atrium (p = 0.000, b1 = -0.701) predicted a greater reduction of left atrial size during follow-up. Left atrial size decreased by 28 mm in patients with a preoperative left atrium >60 mm (75% sensitivity and 100% specificity).

CONCLUSION

the asymptomatic left atrium reduces in size considerably after mitral valve replacement, and the decrease is greater in patients with a left atrium >60 mm in size.