Global longitudinal strain value for predicting left ventricular remodeling after primary percutaneous reperfusion therapy in acute myocardial infarction

Abstract

Background and objectives: After an acute myocardial infarction with ST-segment elevation (STEMI) treated with percutaneous coronary intervention (PCI), the left ventricle (LV) can either recover its function or undergo negative remodeling (R-), with different well-known prognostic implications. In order to identify viable myocardium, different cardiac image techniques have been used, including transthoracic echocardiography with speckle tracking imaging (TTE-STI), that allows assessment of ventricular deformity (strain and strain rate). Material and methods: 83 patients (56.1+/- 11.4 years) admitted to our hospital with the diagnosis of STEMI at any LV localization and subjected to primary PCI (reperfusion time 5.1+/-2.9 hours). TTE-STI was performed two-three days after primary PCI. Strain global longitudinal (SGL) and other usual TTE parameters were analyzed. Left ventricular ejection fraction (LVEF) and ventricular volume were calculated using the modified Simpson's rule. Six months later, a further TTE-STI was performed. LV R- criteria were: LVEF increase = 15%. Results: Patients were classified into two groups according to these criteria: LV R- patients (n=35, 42%) and no LV R- patients (n=48, 58%). Bivariable demographic analysis only showed higher incidence of diabetes mellitus (41% vs 19%; p< 0.001) and higher TnI index (1.2 +/- 2.1 ug/L vs 0.4 +/-0.3 ug/L;p=0.005 ) in LV R- patients with respect to no LV R- patients. TTE-STI analysis revealed that LV R- patients had significativ lower basal LVEF (42.1 +/- 4.0% vs 52.7 +/- 6.6%) and left ventricular segmental movement index (1.90 +/- 0.39 vs 2.6 +/- 0.39) than no LV R- patients. SGL was -12.5 +/- 5.6% in no LV R- patients and -6.5 +/- 3.4 in LV R- patients. The analysis of ROC curves revealed that at the cut level of -11%, SGL identify LV Rwith a sensibility of 70% and a specificity of 80% (AUC=0.82: IC 95% 0.75-0.91; p<0.002). Conclusion: SGL assessment in the first days after primary PCI is useful in the prediction of LV Rindependently of the of the myocardial infarction localization.