Myocardial infarct size is a major determinant of left ventricular (LV) remodeling after ST-segment–elevation myocardial infarction. We evaluated whether LV global longitudinal strain (GLS), proposed as a novel marker of infarct size, is associated with 3- and 6-month LV dilatation after ST-segment–elevation myocardial infarction.
Methods and Results—
In the first ST-segment–elevation myocardial infarction patients treated with primary percutaneous coronary intervention, baseline LVGLS was measured with 2-dimensional speckle-tracking echocardiography. Patients were dichotomized according to median value. The independent relationship between GLS groups and LV end-diastolic volume at 3 and 6 months (adjusted for clinical and echocardiographic variables) was assessed. The final study population comprised 1041 patients (60±12 years; 76% men). Median LVGLS was −15.0%. Patients with baseline LVGLS >−15.0% exhibited greater LV dilatation at 3 and 6 months compared with patients with GLS ≤−15.0% (LV end-diastolic volume 123±44 versus 106±36 mL and 121±43 versus 102±34 mL, respectively; global group–time interaction
P<0.001). This association retained the same statistical significance after adjustment for various relevant demographic, clinical, and echocardiographic characteristics. Further, net reclassification improvement index demonstrated significant incremental value of LVGLS for prediction of LV end-diastolic volume increase (0.14 [95% confidence interval, 0.00034–0.29]; P=0.04). Conclusions—
LVGLS before discharge after ST-segment–elevation myocardial infarction is independently associated with LV dilatation at follow-up.