Comparison of the effects of phosphorylcholin versus heparin-based surface coating on clinical and histologic outcomes during veno-arterial extracorporeal membrane oxygenation support: a propensity score weighted analysis

Abstract

Background: Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) is associated with a high rate of thrombotic complications, which are prevented using systemic anticoagulation and surface coating technologies. Heparin and phosphorylcholin (PPC) coatings are widely used in clinical practice, but little is known about their effectiveness in VA-ECMO setting.

Objectives: To compare the effects of heparin and PPC coatings on thrombotic complications, bleeding, blood trauma, inflammation, thrombi composition, and mortality.

Methods: A retrospective multicenter clinical cohort was studied for clinical endpoints, and a prospective histologic cohort was investigated for thrombi composition. The clinical cohort included adult patients supported by VA-ECMO for cardiogenic shock, without any constitutive or acquired hemostasis disease disorder, from January 2013 to December 2020. Thrombi retrieved from circuit junctions underwent histochemical and immunochemical analysis for erythrocytes, von Willebrand factor (VWF), platelets, fibrinogen, and neutrophil extracellular traps content. The clinical cohort was compared using a propensity score overlap weighting. A P value <.05 was significant.

Results: Compared with PPC coating, heparin coating was associated with a lower incidence of thrombotic complications before and after propensity score overlap weighting (hazard ratio [HR]: 0.67; 95% CI: 0.48-0.93; P = .015), a lower decrease in hemoglobin, but a greater decrease in platelet count. In the histologic analysis, PPC coating resulted in a greater content of VWF. The other endpoints were similar among groups.

Conclusion: Compared with PPC coating, heparin coating is associated with fewer thrombotic complications during VA-ECMO support. Kinetics of platelet count and hemoglobin, thrombi contents differed according to coating types.

Trial registration: The prospective substudy is ancillary to the WITECMO-H multicenter study registered at ClinicalTrial.gouv (NCT03070912).

Keywords: ECMO; bleeding; heparin; histology; mortality; phosphorylcholin; surface coatings; thrombosis.