Left ventricular global function index as a predictor of adverse cardiovascular events in patients with acute coronary syndrome

Abstract

Aim      To evaluate the prognostic significance of the left ventricular global function index (LV GFI) in patients with acute coronary syndrome (ACS) using echocardiography (EchoCG).Material and methods             The LV GFI is an index that integrates LV cavity volumes, stroke volume, and myocardial volume. This study included 2169 patients with ACS (1340 (61.8%) men) aged 64.1±12.6 years from two observational multicenter studies, ORACLE I and ORACLE II. 1800 (83 %) cases were associated with increased concentrations of myocardial injury markers, including 826 (38.1 %) cases of ST segment elevation myocardial infarction (MI). The observation was started on the 10th day of clinical condition stabilization and lasted for one year. EchoCG was performed with evaluation of LV GFI, which was calculated as a ratio of LV stroke volume to LV global volume. The LV global volume was calculated as a sum of mean LV cavity volume (LV end-diastolic volume + LV end-systolic volume / 2) and LV myocardial volume.Results The main outcome of the study was all-cause death (n=193); recurrent coronary complications (n=253) were analyzed separately. The only EchoCG parameter indicating an adverse outcome during the one-year follow-up was a LV GFI decrease to below 22.6 % with a sensitivity of 72 % and a specificity of 60% (area under the curve, AUC=0.63). A LV GFI <22.6 % was an independent predictor of all-cause death (p=0.019) along with age (p=0.0001), history of MI (p=0.034), and presence of heart failure (HF) (p=0.044), diabetes mellitus (p=0.012), and peripheral atherosclerosis (p=0.001). The LV GFI <22.6 %, (p=0.044), heart rate upon discharge from the hospital (p=0.050), history of MI (p=0.006), presence of HF (p=0.014), and peripheral atherosclerosis (p=0.001) were also independent predictors for recurrent coronary complications. Decreased LV GFI was associated with the risk of fatal outcomes independent of the LV ejection fraction at baseline.Conclusion      In patients with ACS, the left ventricular global function index is an independent predictor for all-cause death and recurrent coronary complications and may be used for risk stratification.