Abstract
PURPOSE: To evaluate the functional capacity following mitral valve replacement in the early postoperative period and to determine the correlation of biventricular function and residual pulmonary artery hypertension (PAH) to the functional capacity.
METHODS: On the seventh postoperative day, 53 patients who underwent mitral valve replacement with preoperative diagnosis of PAH underwent a 2-dimensional echocardiographic and Doppler examination for the assessment of right ventricular systolic pressure, along with right ventricular (RV) and left ventricular (LV) myocardial performance indices (MPIs). These assessments were followed by a 6-Minute Walk Test. Five patients were eventually withdrawn from the study.
RESULTS: The diminished functional capacity (51.6% +/- 4.1% of predicted 6-Minute Walk Test distance for age, gender, weight, and height) significantly correlated with biventricular dysfunction evident from elevated RVMPI (0.35 +/- 0.09) and LVMPI (0.52 +/- 0.11) (for both Ps <= .001). Furthermore, the residual PAH, with mean right ventricular systolic pressure of 37 +/- 11 mm Hg, showed negative correlation with the functional capacity (P <= .001). In addition, LVMPI had strong association with RVMPI (P <= .001). Linear regression analysis demonstrated that LVMPI and right ventricular systolic pressure were independent predictors of functional capacity.
CONCLUSIONS: The RV and LV function, as quantified by MPI, and the degree of residual PAH are associated with functional capacity impairment after mitral valve replacement, with LVMPI and residual PAH as the independent predictorsqbetween RV and LV performance indices indicate that ventricular interactions contribute to the functional capacity impairment in these patients.