OC 51.5 - Outcomes Associated with The Use of Dual Antiplatelet Therapy in Patients Presenting with Out of Hospital Cardiac Arrest supported with Veno arterial Extracorporeal Membrane Oxygenation

Background: Among patients with (ventricular tachycardia/ventricular fibrillation) VT/VF OHCA treated with veno-arterial extracorporeal membrane oxygenation (VA-ECMO), there is a frequent need for angioplasty to treat coronary artery disease and therefore dual antiplatelet therapy (DAPT). However, the hematologic impact of DAPT use in patients on VA-ECMO are uncertain.

Aims: We aimed to assess whether the use of DAPT was associated with all-cause in-hospital mortality in patients with VT/VF OHCA supported with VA-ECMO. Secondary outcomes were major bleeding and thrombosis.

Methods: We performed a secondary analysis of prospectively collected data. Consecutive patients presenting to the Minnesota Resuscitation Consortium with refractory VT/VF OHCA between December 2015 and March 2022 meeting criteria for VA-ECMO initiation were included. Kaplan-Meier and adjusted Cox proportional hazards analyses were performed to determine whether DAPT was associated with the hazard of in-hospital mortality, major bleeding or thrombotic events as defined by ELSO.

Results: Patients receiving DAPT (N=125) were older (58±10y v. 54±14; p=0.02) than those not taking DAPT (N=75). After adjustment for age, sex, down-time, and use of intra-aortic balloon pump (IABP), the use of DAPT was not associated with in hospital death (HR 0.70, 95% CI 0.47,1.05). In adjusted analyses, the use of DAPT was associated with a reduced hazard of thrombosis (HR 0.31, 95% CI: 0.11-0.86) but not bleeding (HR 1.24, 95% CI 0.83,1.86). The rates of in-hospital mortality, bleeding and thrombosis are shown in figure 1A. Patients on DAPT required a higher number of units of red blood cells (7.5±0.7 v 5.2±0.8; p=0.05; Fig 1B).

Conclusion(s): The use of DAPT in addition to unfractionated heparin for patients presenting with VT/VF OHCA treated with VA-ECMO appears to be safe. This combination is associated with decreased thrombotic rates, though we found a higher number of red blood cell transfusions perhaps by increasing minor bleeding.