Echocardiographic parameters for weaning from extracorporeal membrane oxygenation-the role of longitudinal function and cardiac time intervals

Abstract

Aims: Limited data exist on echocardiographic predictors of weaning from veno-arterial extracorporeal membrane oxygenation (V-A ECMO). We aimed to test the performance of different echocardiographic indices to predict weaning from V-A ECMO and free survival after weaning.

Methods and results: Observational study including patients with cardiogenic shock submitted to V-AECMO. Echocardiography was performed after V-AECMO placement and daily during the weaning trial to assess cardiac recovery. Echocardiography data after V-A ECMO implantation and during the last weaning trial before V-A ECMO removal were analysed. Besides traditional parameters, total isovolumic time (t-IVT, a left ventricular performance index) and mitral annular plane systolic excursion (MAPSE) were also tested. Seventy-six patients were included. A greater ventricular velocity time integral (LVOT VTI) at baseline was associated with a five-fold increase in weaning success (P < 0.001) as MAPSE lateral >6.15 mm (P = 0.001) did. TAPSE and S' at tricuspid annulus showed an analogous association. During the weaning trial t-IVT, LVEF, MAPSE, LVOT VTI, and TAPSE all improved significantly (P < 0.001 for all). At regression analysis t-IVT <14.4 s/min (<0.001), LVOT VTI >12.3 cm (P < 0.001), MAPSE > 8.9 mm (P < 0.001), TAPSE > 16 mm (<0.001), and E/e' < 15.5 (P = 0.001) were associated with weaning success and free survival after weaning. LVEF did not predict the weaning success and survival at any time-point (P = 0.230).

Conclusion: Longitudinal function, t-IVT and native ejection, measured with LVOT VTI, are reliable parameters to predict weaning success in V-A ECMO whereas the LVEF, although dynamically changing during weaning trial, it is not.

Keywords: echocardiography; longitudinal function; stroke volume; total isovolumic time; veno-arterial extracorporeal circulatory membrane oxygenation; weaning.