Combination of Static Echocardiographic Indices for the Prediction of Fluid Responsiveness in Patients Undergoing Coronary Surgery: A Pilot Study

Abstract

We investigated the role of echocardiographic indices consisting of left ventricular end-diastolic area (LVEDA) in combination with Doppler-derived surrogates of diastolic compliance and filling (E/E', E'/S', E'/A'; early transmitral flow velocity (E), tissue Doppler-derived early (E') diastolic, late (A') diastolic, or peak systolic (S') velocity of the mitral annulus) in predicting fluid responsiveness in off-pump coronary surgery. Hemodynamic and echocardiographic variables were prospectively assessed under general anesthesia before and after a fluid challenge of 6 mL/kg during apnea at atmospheric pressure in 64 patients with LV ejection fraction ≥40%. Forty patients (63%) were fluid responders (≥15% increase in stroke volume index). E/E' and E'/S' could predict fluid responsiveness with area under the receiver operating characteristic curve (AUROC) of 0.71 (95% confidence interval [CI], 0.56-0.85; p = 0.006) and 0.68 (95% CI, 0.54-0.82; p = 0.017), respectively. The combination of LVEDA and E/E' showed incremental predictive ability for fluid responsiveness compared with LVEDA (AUROC, 0.60; p = 0.170) or pulse pressure variation (AUROC, 0.70; p = 0.002), yielding the highest AUROC of 0.78 (95% CI, 0.66-0.90; p < 0.001). The combined index of echocardiographic variables reflecting LV dimension (LVEDA) and diastolic compliance and filling (E/E') is a potentially useful predictor of fluid responsiveness.