Abstract 15136: Global Strain by Echocardiography Is Superior to Ejection Fraction to Predict Ventricular Arrhythmias After Myocardial Infarction
Introduction LV function measured as ejection fraction (EF) is currently the main selection parameter when identifying ICD-candidates. Global strain by echocardiography is a more sensitive measure of myocardial function than EF. We recently reported that reduced global strain by echocardiography predicted arrhythmic events in patients after myocardial infarction (MI) with ICD. We hypothesize that strain echocardiography may improve arrhythmic risk stratification in prospectively included post MI patients.
Methods In this prospective multi center study 177 post MI patients were included (114 ST elevation and 63 non-ST elevation). Echocardiography was performed minimum 40 days post MI. From speckle tracking strain we assessed global strain as average peak systolic longitudinal strain from 16 LV segments.
Results Of 177 post MI patients, 8 (4.5%) experienced ventricular arrhythmias defined as sustained VT, VF or sudden cardiac death during 33(14-76) months of follow up. EF was reduced in patients with arrhythmic events (47±15% vs. 55±9%, p=0.03). Global strain was markedly lower in those with arrhythmic events ( 14.4±4.8% vs. -18.9±3.3%, p<0.001). By ROC analyses, global strain was superior to EF in prediction of arrhythmic events (AUC 0.79(95%CI(0.64-0.94) vs. 0.63(95%CI(0.39-0.88), p=0.05), with sensitivity = 74% and specificity = 75%. Optimal cut off for global strain was -17.5%. Survival analyses showed better arrhythmia free survival in those with global strain better than -17.5% (p=0.01) (Figure).
Conclusions Global strain by echocardiography was superior to EF to predict arrhythmic events in this prospective study of post MI patients. Strain echocardiography may refine selection of patients for ICD therapy after MI.
- © 2011 by American Heart Association, Inc.