European practices on antithrombotic management during percutaneous mechanical circulatory support in adults: insights from an international survey
Authors: Van Edom C , Castelein T , Gramegna M , Huber K , Leonardi S , Mueller T , Pappalardo F , Price S , Schaubroeck H , Schrage B , Swol J , Tavazzi G , Vercaemst L , Vranckx P , Vandenbriele C 
Published: October 2024

Abstract

Background
Bleeding and thrombotic complications remain a major concern in cardiogenic shock (CS) patients undergoing percutaneous mechanical circulatory support (pMCS) with veno-arterial extracorporeal membrane oxygenation (V-A ECMO) and/or microaxial flow pumps like the Impella. Antithrombotic practices strongly determine the coagulopathic risk, but standardized protocols are lacking in this context.

Purpose
This survey outlines European practices on antithrombotic management in adults on pMCS for CS, making an initial effort to standardize practices, inform future trials, and enhance outcomes.

Methods
This online cross-sectional survey was distributed through digital newsletters and social media platforms by the Association of Acute Cardiovascular Care (ACVC) of the ESC and the European branch of the Extracorporeal Life Support Organization (EuroELSO). The survey was accessible from April 17th to May 23rd, 2023. The target population were European clinicians involved in care for adults on pMCS.

Results
We included 105 responses from 26 European countries. In 72.4% of the European respondents’ institutions, a standardized local anticoagulation protocol is present, with unfractionated heparin (UFH) being the predominantly used anticoagulant (Impella: 97.0%; V-A ECMO: 96.1%). Similarly, the purge solution during Impella support is most frequently UFH-based (84.1%). A bicarbonate-based purge solution (BBPS) as standard purge is reported by only 1.6%. UFH titration based on the activated partial thromboplastin time (APTT) alone is the most common practice either for Impella (43.1%) and for V-A ECMO (32.9%). A minority of 16.9% and 13.2% indicate relying on activated clotting time (ACT) for UFH-titration during Impella and V-A ECMO support, respectively. UFH-titration protocols are anti-Xa based for 12.3% (Impella) and 10.5% (V-A ECMO) of the respondents. An UFH anticoagulant protocol based on APTT and anti-Xa in parallel is the preferred option for 10.8% (Impella) and 14.5% (V-A ECMO) of the respondents. Anticoagulant targets for APTT, ACT and anti-Xa varied across institutions. The majority (83.8%) does not alter their anticoagulation management in case of combined Impella plus V-A ECMO-approach (ECMELLA). Typical thresholds for transfusion or administration of blood products without acute bleeding as indication vary substantially and are frequently not predefined. Following acute coronary syndrome without percutaneous coronary intervention (PCI), 54.0% and 42.7% administered dual antiplatelet therapy during Impella and V-A ECMO support, increasing to 93.7% and 84.0% after PCI.

Conclusions
Our survey validated the considerable variation in antithrombotic management in adults in CS on pMCS across European centres. There is a pressing demand for a standardized approach to antithrombotic management in this context to mitigate the impact of coagulopathic complications and, consequently, enhance outcomes.Figure 1.Figure 2.