Strain Echocardiography and Wall Motion Score Index Predicts Final Infarct Size in Patients with Non ST Segment Elevation Myocardial Infarction
Background—Infarct size is a strong predictor of mortality and major adverse cardiovascular events after myocardial infarction (MI). Acute reperfusion therapy limits infarct size and improves survival, but its use has been confined to patients with ST-segment elevation MI. The purpose of this study was to assess the relationship between echocardiographic parameters of left ventricular (LV) systolic function obtained prior to revascularization and final infarct size in patients with non ST-segment myocardial infarction (NSTEMI), as well as these parameters' ability to identify patients with substantial infarction.
Methods and Results—61 patients with NSTEMI were examined by echocardiography immediately prior to revascularization, 2.1±0.6 days after hospitalization. LV systolic function was assessed by ejection fraction (LVEF), wall motion score index (WMSI), circumferential, longitudinal and radial strain in a 16 segments LV model. Global strain represents average segmental strain values. Infarct size was assessed after 9±3 months by late enhancement magnetic resonance imaging, as percentage of total LV myocardial volume. A good correlation was found between infarct size and WMSI (r=0.74, p<0.001) and global longitudinal strain (r=0.68, p<0.001). Global longitudinal strain > -13.8% and WMSI > 1.30 accurately identified patients with substantial infarction (≥12% of myocardium, n=13), area under the receiver operator curve 0.95 and 0.92 respectively.
Conclusions—Echocardiographic parameters of LV systolic function correlate to infarct size in NSTEMI patients. GLS and WMSI are both excellent parameters to identify patients with substantial MI, who may benefit from urgent reperfusion therapy.
- Received September 18, 2009.
- Accepted January 4, 2010.
- Copyright © 2010, American Heart Association, Inc. All rights reserved. Unauthorized use prohibited