Short- and long-term follow-up of left ventricular function after surgical treatment of chronic mitral valve regurgitation

Abstract

There are conflicting data concerning late LV remodeling following mitral valve surgery due to chronic MR. We performed serial echocardiographic evaluation of 35 consecutive patients prior and following surgical treatment of mitral valve for chronic regurgitation. Studies were performed 1 week before operation (exam I), then at 1 week (exam II) and 9-13 months (exam III) (mean 11 months) after surgery. LVEDD and LVESD and LA size were recorded from parasternal long-axis view, and EF was calculated by Teichholtz formula. Statistical significance of achieved values was assessed. The study group consisted of 35 patients (25 males, 10 females, age 63 +/- 9 yrs). All pts were symptomatic due to the significant MR: NYHA II (n = 8), III (n = 25), IV (n = 2). All subjects had excluded coronary artery disease by coronary angiogram. 30 patients underwent successful mitral valve replacement without preservation of subvalvular apparatus and 5 mitral valve repair. Echo-Doppler examination before procedure discovered isolated significant MR (4+) with left ventricular dilatation (LVEDD 6.6 +/- 0.3 cm, LVESD 4.3 cm +/- 0.8), LA enlargement (6.0 +/- 1.1 cm), and pulmonary hypertension (systolic PAP 46 +/- 16 mmHg). After operation, marked decrease of LVEDD was observed (5.7 +/- 0.7 cm, p<0.0001 vs exam I) with only slight decrease of LVESD (4.0 +/- 0.6 cm, p<0.05 vs exam I) resulting in a significant decrease in EF (61 +/- 15.3% vs 57 +/- 4.8%, p<0.01). Significant reduction of LA size and PAP was noticed between exam I and III (6.0 +/- 1.1 cm vs 5.22 +/- 0.94 cm, p<0.0001, 46 +/- 16 mmHg vs 38 +/- 15 mmHg, p<0.01, respectively). Conclusions: After successful surgical treatment of mild-to-moderate symptomatic chronic MR there is a gradual fall of LVEDD implying continued ventricular remodeling over several months. However, we observed only a slight decrease of LVEDS with subsequent decrease of EF that may support the opinion of the crucial role of mitral valve apparatus in overall LV performance. EF fall did not preclude, however, reduction of pulmonary hypertension and LA diameter in long-term follow up.