Baron T, et al. - The intent of the authors was to identify the changes of global longitudinal strain (GLS) and their predictors related to classical echocardiographic parameters of left ventricular (LV) function, over 1 year, in consecutive patients with myocardial infarction (MI) and initially normal or impaired LV ejection fraction (EF). Although the divergent evolution of GLS compared with EF and ventricular volumes, one year after MI GLS substantially improved in patients with initially both normal and impaired EF. The independent predictors of GLS improvement were determined as the initial impairment of LV function (by EF, wall motion score index (WMSI) or GLS), male gender, non-smoking, and treatment with beta-blockers. The presence of LV remodelling was noted even in patients with normal EF at baseline and during follow-up. This data affirmed the limited functional analysis by EF alone.

Methods

• Patients from the REBUS (RElevance of Biomarkers for future risk of thromb-oembolic events in UnSelected post-myocardial infarction patients) study underwent echocardiography within 72 h from admission and after 1 year.
• The enrollment consisted of 285 patients with MI.

Results

• At baseline, 213 (74.7%) of MI patients presented with a normal EF (≥52% in men or ≥54% in women), but 70.4% of them reported an impaired GLS (≥ -18.0%).
• In patients with normal EF at baseline, an improvement was noted in GLS from -15.8% to -17.4% (10.1% relative change); EF decreased from 62.5% to 59.9% (4.0% relative change); indexed end-diastolic volume, indexed end-systolic volume, and indexed stroke volume increased with 15.6%, 24.8%, and 10.0% of relative change, respectively (P < 0.001 for all the comparisons), during 1-year follow-up.
• Initial impairment of LV function [by EF, wall motion score index (WMSI), or GLS], male gender, non-smoking, and treatment with beta-blockers were discovered to be the independent predictors of GLS improvement, in the whole cohort.
• The group with initially impaired EF displayed an improvement in over 1 year GLS from -11.9% to -14.8% (24.4% relative change) and EF from 44.6% to 52.6% (18.2% relative change) (P < 0.001 for both).
• A notable connection was found between improvement in GLS with EF increase in the group with impaired EF (r = -0.41, P=0.001) but not in the patients with normal EF (r = -0.14, P=ns).