3D echocardiography is a valuable clinical tool to identify global left ventricular remodeling and myocardial dysfunction early after STEMI

Left ventricular (LV) remodeling after acute ST-elevation myocardial infarction (STEMI) can begin very soon despite timely revascularization and portends a poor prognosis. The ability of 3D speckle-tracking echocardiography to characterize LV shape and performance early after reperfused STEMI has not been explored so far. Methods. 18 patients (pts, 45+8 years) with a first STEMI successfully treated by primary PCI, having good image quality and sinus rhythm, were studied by 2DE and 3DE at predischarge (7+2 days after STEMI). Apical 2D LV views (68+6 fps) and 4-beat LV full-volume data sets (32+3 vps) were acquired using a Vivid E9 scanner (GE Healthcare, N). LV sphericity indexes were calculated by biplane (2D SI) and 3D (3D SI) LV end-diastolic volumes divided by the volume of a sphere, the diameter of which were the respective LV long axes. 3D SI, as well as LV volumes, ejection fraction (EF) and strain - longitudinal (LS), circumferential (CS), radial (RS) and area strain (AS) - were measured and compared with LV parameters from 18 healthy controls matched for age, gender and body size. Results. Each 3D LV data set required on average ,1 min for acquisition and ,4 min for analysis. STEMI pts had larger indexed LV volumes (end-diastolic 69+8 vs 54+7 mL/m2; end-systolic 35+8 vs 22+4 mL/m2) and mass (81+10 vs 70+8 g/m2), lower EF (49+8 vs 60+4%) and increased LV sphericity (0.38+0.06 vs 0.32+0.06) than controls (p,0.006 for all). All LV 3D strain components were significantly impaired in pts in comparison with controls: LS -14+3% vs -19+2%; CS -15+4% vs -20+2%; RS 40+12% vs 57+7%; AS -26+6% vs -35+2% (p,0.001 for all). In STEMI pts, 3D SI yielded significantly higher values than 2D SI (0.38+0.06 vs 0.32+0.04), the latter being similar in pts and in controls (0.32+0.04 vs 0.31+0.06, p=0.54). 3D SI showed greater predictive power than 2D SI (AUC 0.74 vs 0.54), a cut-off value of 0.34 having 75% sensitivity and 67% specificity to identify early remodeling in STEMI patients. 3D SI reproducibility expressed as intraclass correlation coefficient (95%CI) was 0.93 (0.83-0.97) for intraobserver and 0.86 (0.64-0.95) for interobserver, respectively. Conclusion. In pts with STEMI, 3D STE was able to detect LV dysfunction and remodeling in a comprehensive, time-saving and reproducible manner. Since early identification of LV remodeling despite successful revascularization may have important prognostic and therapeutic implications, 3D could provide additional benefits soon after STEMI, when the 2D approach may be insensitive to identify early changes in LV geometry.