Echocardiographic parameters for weaning from Extracorporeal Membrane Oxygenation - the role of longitudinal function and cardiac time intervals

Aim: 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 analyzed. Besides traditional parameters, total isovolumic time (t-IVT, a left ventricular performance index) and mitral annular plane systolic excursion (MAPSE) were also tested.76 patients were included. A greater ventricular velocity-time integral (LVOT VTI) at baseline was associated with a 5-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 <14.4second/minute (<0.001), LVOT VTI >12.3cm (p <0.001), MAPSE >8.9mm (p < 0.001), TAPSE> 16mm (<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).

Conclusions: 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.