The long-term effect of successful mitral balloon valvotomy on left atrial size.

BACKGROUND AND AIM OF THE STUDY

The study aim was to determine the extent of regression of left atrial (LA) enlargement following mitral balloon valvotomy (MBV) for mitral stenosis.

METHODS

Data obtained from 205 patients before, and at a mean of 31.0 +/- 21.1 months (range: 6 to 86.3 months) after successful MBV were analyzed retrospectively.

RESULTS

The invasively determined mitral valve area increased from 0.81 +/- 0.27 cm2 at baseline to 1.73 +/- 0.54 cm2 immediately after valvotomy (p <0.0001), and the mean mitral gradient fell from 15.6 +/- 5.3 to 5.4 +/- 2.5 mmHg (p <0.0001). Similar changes were noted in Doppler-determined mitral valve area (0.89 +/- 0.16 to 1.97 +/- 0.29 cm2; p <0.0001) and gradient (12.6 +/- 5.3 to 4.9 +/- 1.7 mmHg; p <0.0001). In comparison with baseline, significant (p <0.0001) reductions were noted at follow up in the echocardiographic anteroposterior (48.7 +/- 6.9 to 42.4 +/- 6.6 mm), superior-inferior (68.5 +/-8.1 to 59.6 +/- 8.2 mm) and medial-lateral LA dimension (51.2 +/- 6.7 to 44.1 +/- 7.7 mm) and calculated LA volume (91.6 +/- 29.1 to 60.7 +/- 23.8 cm3) Patients in atrial fibrillation had larger LA dimensions, but substantially smaller absolute and relative reduction in LA size at follow up than patients in sinus rhythm. Among patients with prevalvotomy LA enlargement, normalization of LA dimension at follow up was seen in 29.2% of patients in sinus rhythm, but in none of the 32 with atrial fibrillation.

CONCLUSIONS

Successful MBV results in significant long-term reduction in LA size in most patients, but normalization of LA size is unusual.