Reduced Left Ventricular Torsion Early After Myocardial Infarction is Related to Left Ventricular Remodeling Running title : LV torsion in AMI

Background-Left ventricular (LV) torsion is emerging as a sensitive parameter of LV systolic myocardial performance. Aim of the present study was to explore the effects of acute myocardial infarction (AMI) on LV torsion, and to determine the value of LV torsion early after AMI in predicting LV remodeling at 6-month follow-up. Methods and Results-A total of 120 patients with first ST-elevation AMI (59±10 years, 73% male) were included. All patients underwent primary percutaneous coronary intervention. After 48 hours, speckle-tracking echocardiography was performed to assess LV torsion; infarct size was assessed by myocardial contrast echocardiography (MCE). At 6-month follow-up, LV volumes and LV ejection fraction (EF) were reassessed, to identity patients with LV remodeling (defined as 15% increase in LV end-systolic volume). Compared to control subjects, peak LV torsion in AMI patients was significantly impaired (1.54±0.64o/cm vs. 2.07±0.27o/cm; p<0.001). At multivariate analysis, only LVEF ( =0.36, p<0.001) and infarct size ( =-0.47, p<0.001) were independently associated with peak LV torsion. At 6-month follow-up, 19 patients showed LV remodeling. At multivariate analysis, only peak LV torsion (OR=0.77; 95%CI 0.65-0.92; p=0.003) and infarct size (OR=1.04; 95%CI 1.01-1.07; p=0.021) were independently related to LV remodeling. Peak LV torsion provided modest but significant incremental value over clinical, echocardiographic and MCE variables in predicting LV remodeling. At receiver-operating characteristic curve analysis, peak LV torsion 1.44°/cm provided the highest sensitivity (95%) and specificity (77%) to predict LV remodeling. Conclusions-LV torsion is significantly impaired early after AMI. The amount of impairment of LV torsion predicts LV remodeling at 6-month follow-up.