The Incremental Prognostic Value of E/(e'×s') Ratio in Non-ST-Segment Elevated Acute Coronary Syndrome

It has been shown that the E/(e'×s') index, which associates a marker of diastolic function (E/e', early transmitral/diastolic mitral annulus velocity ratio) and a parameter that explores LV systolic performance (s', systolic mitral annulus velocity), is a good predictor of outcome in acute anterior myocardial infarction. There are no studies that have investigated the prognostic value of E/(e'×s') in a non-ST-segment elevated acute coronary syndrome (NSTE-ACS) population. Echocardiography was performed in 307 consecutive hospitalized patients with NSTE-ACS and succesful percutaneous coronary intervention, before discharge and six weeks after. The primary endpoint consisted of cardiac death or readmission due to re-infarction or heart failure. During the follow-up period (25.4 ± 3 months), cardiac events occurred in 106 patients (34.5%). Receiver operating characteristic (ROC) analysis identified E/(e'×s') at discharge as the best independent predictor of composite outcome. The optimal cut-off value was 1.63 (74% sensitivity, 67% specificity). By multivariate Cox regression analysis, E/(e'×s') was the only independent predictor of cardiac events. Kaplan-Meier analysis identified that patients with an initial E/(e'×s') > 1.63 that worsened after six weeks presented the worst prognosis regarding composite outcome, readmission, and cardiac death (all p < 0.001). In conclusion, in NSTE-ACS, E/(e'×s') is a powerful predictor of clinical outcome, particularly if it is accompanied by worsening after 6-weeks.