A novel Doppler echocardiographic index integrating left and right ventricular function is superior to conventional indices for predicting adverse outcome of acute myocardial infarction

The ratio of peak diastolic early velocity (E) of left ventricular (LV) inflow to peak diastolic longitudinal velocity (e’) of the mitral annulus (E/e’) is thought to reflect LV filling pressure, and tricuspid annulus velocity at systole (s’-T) is thought to reflect right ventricular function. However, it has not been reported on significance of the combined use of E/e’ and (s’-T) to predict outcome of acute myocardial infarction (AMI). Over 21 months, beginning in January 2007, we enrolled 65 AMI patients who were measured hemodynamic and echocardiographic parameters by Swan-Ganz (SG) catheterization just after reperfusion therapy and echocardiography immediately after reperfusion therapy. Cardiac index (CI) and pulmonary capillary wedge pressure (PCWP) via SG catheter were measured, and routine echocardiographic indices, including E, e’, E/e’, and (s’-T) were determined. In addition, we defined the functional integrated bi-myocardial tissue Doppler (FIT) index as (s’-T)÷E/e’. The relationships between CI, PCWP, and echocardiographic indices were investigated, including FIT index. Moreover, we investigated whether FIT index could predict adverse cardiac events. FIT index was significantly associated with not only CI but also PCWP. In the Cox proportional hazards model, FIT index<1.0 was a significant predictor for adverse outcome of AMI after adjustment for age, Killip class, history of previous coronary revascularization, location of culprit lesion, and LV ejection fraction. The novel index defined as (s’-T)÷E/e’ could be quite useful predictor of prognosis in AMI.