Abstract 13273: Left Ventricular Subepicardial Twist Predicts Left Ventricular Remodeling After Acute Myocardial Infarction
Introduction: Left ventricular (LV) remodeling is a well-known prognostic factor after acute myocardial infarction (AMI). Therefore, early identification of patients prone to develop LV remodeling after AMI is crucial for patient management. LV twist assessed by two-dimensional (2D) speckle-tracking echocardiography represents an accurate index of LV systolic function. Furthermore, separate quantification of LV twist in the subendocardial and subepicardial layers may provide additional information for risk stratification after AMI.
Hypothesis: We tested the hypothesis that LV subepicardial twist is a predictor of LV remodeling after AMI, reflecting the extent of infarct transmurality as assessed by magnetic resonance imaging (MRI).
Methods: A total of 213 patients with ST elevation AMI underwent 3D echocardiography for LV volumes and function assessment, and 2D speckle-tracking analysis for evaluation of LV twist (subendocardial versus subepicardial). At 6-month follow-up, significant LV remodeling was defined as ≥15% increase in LV end-systolic volume. A subgroup of 40 patients underwent MRI within 2 months for infarct size quantification.
Results: At 6-month follow-up, 44 patients (21%) developed LV remodeling and showed a significantly more impaired baseline LV subepicardial twist as compared to patients without LV remodeling (4.5±1.3° versus 9.4±3.5°, p<0.001). By univariate analysis, several variables were significantly related to LV remodeling: LV subepicardial and subendocardial twist, LV end-diastolic volume, LV ejection fraction and peak troponin T. By multivariate analysis, only LV subepicardial twist (OR=0.241; 95%CI, 0.134 to 0.431; p<0.001) and peak troponin T (OR=1.152; 95%CI, 1.006 to 1.320; p=0.041) were independent determinants of LV remodeling. A cutoff value of 5.17° for LV subepicardial twist had 95% sensitivity and 86% specificity to predict LV remodeling. Furthermore, LV subepicardial twist demonstrated a strong inverse relation with the number of transmural segments at MRI (r²=0.526, p<0.001), and with the total scar score (r²=0.515, p<0.001).
Conclusions: LV subepicardial twist is an independent determinant of LV remodeling after AMI and strongly reflects infarct transmurality as assessed by MRI.
- © 2011 by American Heart Association, Inc.