This study sought to investigate the prognostic potential of layer-specific global longitudinal strain (GLS) in predicting cardiac events among non-ST-segment elevated acute coronary syndrome (NSTE-ACS) patients with preserved LVEF. In this prospective study, we enrolled 160 consecutive NSTE-ACS patients with preserved LVEF (≥ 50%) who underwent successful percutaneous coronary intervention (PCI). Transthoracic two-dimensional echocardiography examinations were performed within 48 h of admission (before PCI). Cardiac events were defined as all-cause death, re-infarction, and hospitalization for heart failure. During a median follow-up of 30.2 months, 23 patients (14.4%) developed cardiac events. GLS for all three myocardial layers were reduced in patients with adverse outcome (all P < 0.001). Yet GLSendo (area under curves = 0.85) and GLSmid (area under curves = 0.83) showed relatively higher predictive power than GLSepi when identifying patients with cardiac events. The best cut-off value of GLSendo was - 20.8%, with a diagnostic sensitivity and specificity of 87% and 71% respectively. A significant increase in the risk of cardiac events development was shown among patients with impaired layer GLS (log-rank test, P < 0.001). In conclusion, NSTE-ACS patients with preserved LVEF, layer GLS assessed before PCI all had good abilities to predict cardiac events, which might provide more prognostic information against conventional echocardiographic risk factors.
Keywords: Global longitudinal strain; Layer; Left ventricular function; Non-ST-segment elevated acute coronary syndrome; Prognosis.