Good prognostic value of the intraoperative tissue Doppler-derived index E/e' after non-cardiac surgery

The index E/e' derived from tissue Doppler imaging and pulsed Doppler is the ratio of the early transmitral flow velocity and the early mitral annular velocity and it correlates with left ventricular filling pressure. The purpose of this study was to investigate the relationship between intraoperative E/e' and postoperative cardiovascular complications and length of ICU and hospital stays after a non cardiac surgery.

This observational study investigated a total of 82 patients with cardiac disease undergoing non cardiac surgery. Diastolic function was evaluated by conventional echocardiographic pulsed-wave Doppler and TDI. The early peak (E) as well as the late peak (A) filling velocity of the left ventricle (LV) were measured at the mid-esophageal four-chamber at the mitral leaflet tips. Early Peak diastolic filling velocity (e'), Late peak diastolic filling velocity (a') and systolic velocity (s') were obtained from the mid-esophageal four-chamber view placed in the septal and lateral mitral annular sites.

Patients were divided into three groups: E/e'<8 (normal LV filling pressure= 24 patients), E/e' 8-15 (moderately increased =35 patients) and E/e'>15 (severely increased = 23 patients). An elevated E/e' ratio was significantly associated with increased postoperative cardiovascular events, pulmonary congestion (P<0.05) arrhythmias (P<0.05) and with longer ICU and hospital stays (P<0.05).

This data suggests that the tissue Doppler index E/e' may be a useful indicator for predicting morbid events after non-cardiac surgery. Furthermore, patients with an elevated intraoperative E/e' may need more careful postoperative management.