Prediction of symptom status following mitral valve replacement for mitral regurgitation by preoperative echocardiographic measurement of the end-systolic stress to end-systolic volume ratio
When determined invasively, the preoperative ratio of left ventricular (LV) end-systolic stress to end-systolic volume index (ESS/ESVi) has correlated well with postmitral valve replacement (MVR) course and LV function, but the predictive power of more practically applicable noninvasive ESS/ESVi measurement has not been assessed. Therefore, we obtained preoperative echocardiographic LV dimensions and simultaneous sphygmomanometric blood pressure for ESS/ESVi determination in 18 patients undergoing MVR for isolated severe chronic mitral regurgitation (MR), and compared results to symptoms and LV function determined by radionuclide cineangiography ejection fraction a mean of 11.8 months postoperatively. Ten of 11 patients with ESS/ESVi > 1.9 had no or mild symptoms (NYHA functional classes 1 and 2 = group I) after operation, while 4/5 patients with preoperative ESS/ESVi < 1.9 had severe symptoms (functional class 3 or 4 = group II) postoperatively (p < 0.002); ESS/ESVi tended to be the best predictor of postoperative symptoms in our patients, though other preoperative noninvasive variables also significantly separated group I and 2 patients, including echocardiographic LV fractional shortening < 31%, radionuclide cineangiographic RVEF ≤30%, end-systolic dimension > 2.6 cm/m2, and the product of ESS/ESVi and LVEF. In addition, preoperative fractional shortening < 31% was the best predictor of postoperative dysfunction of either the left ventricle (resting LVEF < 45 in 4/4 vs. 3/9 without, p < 0.07) or right ventricle (resting RVEF < 35% in 4/4 with vs. 2/9 without, p < 0.025). We conclude that noninvasive measurement of the ESS/ESVi ratio may be useful in predicting the effects of valve replacement in patients with severe chronic MR.