Abstract Funding Acknowledgements Type of funding sources: None. Background Limited data are available on predictors for weaning from veno-arterial extracorporeal membrane oxygenation (VA-ECMO) in acute myocardial infarction (AMI) complicated by cardiogenic shock (CS). Thus, we aimed to identify predictive ability for VA-ECMO weaning success and prognostic implications of serial pulse pressure (PP) and adjusted PP by vasoactive inotropic score (VIS) in AMI patients with CS who underwent VA-ECMO. Method A total of 213 patients with AMI complicated by CS who received VA-ECMO were enrolled between January 2010 and August 2021 from AMI-ECMO registry. Serial PP and VIS were measured at immediate, 12 hours, 24 hours, and 48 hours after VA-ECMO insertion. Adjusted PP by VIS was defined as PP/√VIS. The primary outcome was successful VA-ECMO weaning. The probability for VA-ECMO weaning success was assessed using the receiver-operating-characteristic (ROC) curve analysis. Results Successful weaning from VA-ECMO were observed in 151 patients (70.9%). PP and adjusted PP by VIS immediate after VA-ECMO insertion did not differ between successful and failed weaning groups. However, patients with successful weaning of VA-ECMO had a significantly higher serial PP and adjusted PP by VIS at 12, 24, and 48 hours after VA-ECMO insertion than those with failed weaning. In ROC analysis, 12 hours’ after adjusted PP by VIS showed significantly better discriminative function for VA-ECMO weaning success compared with PP alone (Area under the curve, adjusted PP by VIS vs. PP, 0.800 vs. 0.670, p=0.001). Patients with low adjusted PP by VIS at 12 hours (≤7) was associated with a higher in-hospital mortality (80.2% vs. 55.6%, p<0.001) and 6-month follow-up mortality (hazard ratio 2.41, 95% confidence interval 1.49-3.90, p<0.001) than those with high adjusted PP by VIS at 12 hours (>7). Conclusion Adjusted PP by VIS at 12 hours can predict successful weaning from VA-ECMO better than PP alone in CS patients complicating AMI who underwent VA-ECMO. These findings suggest that early PP after ECMO initiation can mean cardiac recovery, and its clinical significance may be enhanced when the effects of vasoactive drugs are adjusted.