Abstract 4696: Myocardial Velocities and Longitudinal Strain Assessed by Speckle Tracking can Predict Optimal Timing of Surgery in Asymptomatic Patients with Severe Primary Mitral Regurgitation
Optimal timing of mitral valve repair in asymptomatic patients with primary mitral regurgitation (PMR) is still controversial. LV ejection fraction (EF) and end-systolic diameter (ESD) represent the most widely used indices to demonstrate LV dysfunction, however, in many cases, a normal EF can mask significant LV impairment. Therefore, new methods might be better to detect subclinical LV dysfunction, and thereby, to improve timing of mitral valve surgery. To assess accuracy and predictive value of indices of tissue Doppler and speckle tracking to detect subclinical LV dysfunction with further impaired postoperative LV function, in asymptomatic patients with severe PMR. 23 asymptomatic patients (59±13 years, 14 male) with severe PMR (regurgitant volume > 65 ml), and LVEF > 60% and ESD < 45 mm, were evaluated preoperatively and at 14 days after successful MVR. 11 patients had a postoperative EF reduction >10% (group A), and 12 patients an EF reduction <10% (group B). Conventional and tissue Doppler echo were used to assess LV diameters and volumes, LV mass index, EF, and long-axis systolic function (from mean 6 basal segments velocities - STDE, and mean time-to-peak systolic contraction - TTP-S); and 2D speckle tracking was used to assess mean negative longitudinal strain of 6 segments in the apical 4-chamber view (LS). Although both groups had similar preoperative LV mass index, LV diameters and volumes, and EF, group A had significantly lower STDE and LS (7.58±0.9 vs. 10.7±1.3 m/s; and −16.29±4.6% vs. −20.57±2.1%, both p<0.01), and a significant higher TTP-S (207.3±73.6 vs. 147.3 ±24 ms, p=0.01) than group B. Multiple regression analysis showed that STDE, and the combination of STDE and LS, represent the main independent predictors for postoperative EF reduction >10% (R2 = 0.66, p<0.001; and R 2 = 0.80, p<0.05, respectively). A cutoff limit of STDE of 9.2 cm/s had a 100% sensitivity and 100% specificity to predict a postoperative EF reduction >10%. Tissue Doppler systolic indices and longitudinal strain assessed by speckle tracking can detect subclinical LV dysfunction and predict impaired postoperative LV dysfunction, in asymptomatic patients with severe PMR.