Objectives: This study sought to test the hypothesis that semiautomated calculation of left ventricular global longitudinal strain (GLS) can identify high-risk subjects among patients with myocardial infarctions (MIs) with left ventricular ejection fractions (LVEFs) >40%.
Background: LVEF is a key determinant in decision making after acute MI, yet it is relatively indiscriminant within the normal range. Novel echocardiographic deformation parameters may be of particular clinical relevance in patients with relatively preserved LVEFs.
Methods: Patients with MIs and LVEFs >40% within 48 h of admission for coronary angiography were prospectively included. All patients underwent echocardiography with semiautomated measurement of GLS. The primary composite endpoint (all-cause mortality and hospitalization for heart failure) was analyzed using Cox regression analyses. The secondary endpoints were cardiac death and heart failure hospitalization.
Results: A total of 849 patients (mean age 61.9 ± 12.0 years, 73% men) were included, and 57 (6.7%) reached the primary endpoint (median follow-up 30 months). Significant prognostic value was found for GLS (hazard ratio [HR]: 1.20; 95% confidence interval [CI]: 1.10 to 1.32; p < 0.001). GLS > -14% was associated with a 3-fold increase in risk for the combined endpoint (HR: 3.21; 95% CI: 1.82 to 5.67; p < 0.001). After adjustment for other variables, GLS remained independently related to the combined endpoint (HR: 1.14; 95% CI: 1.04 to 1.26; p = 0.007). For the secondary endpoints, GLS > -14% was significantly associated with cardiovascular death (HR: 12.7; 95% CI: 3.0 to 54.6; p < 0.001) and heart failure hospitalization (HR: 5.31; 95% CI: 1.50 to 18.82; p < 0.001).
Conclusions: Assessment of GLS using a semiautomated algorithm provides important prognostic information in patients with LVEFs >40% above and beyond traditional indexes of high-risk MI.
Copyright © 2013 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.