# Contemporary Clinical Practices in Anticoagulation Management During Cardiopulmonary Bypass: A Europe-Wide Survey

## TL;DR

This study surveyed European cardiac surgery centers to understand variations in anticoagulation practices during heart surgery, finding both consensus and significant differences in protocols.

## Contribution

The study provides a comprehensive Europe-wide analysis of anticoagulation practices during cardiopulmonary bypass, highlighting areas needing standardization.

## Key findings

- Most centers use written heparinization protocols, with a common initial dose of 300 IU/kg.
- There is significant variability in heparin:protamine ratios and post-reversal ACT targets.
- Only 83.3% of centers have explicit protocols for managing high-bleeding-risk patients.

## Abstract

Clinical practice in anticoagulation management, particularly in heparin administration, monitoring, reversal and haemostasis, is known to differ significantly. To better characterize this variability, we conducted a Europe-wide survey aimed at mapping current practices, identifying areas of consensus and divergence and guiding future research and standardization efforts.

A 27-question electronic questionnaire was designed by an expert panel and distributed across European cardiac surgery centres with a snowball sampling method. Results were examined via descriptive statistics, with categorical variables shown as percentages and 95% CIs.

A total of 114 centres from 29 countries completed the questionnaire between February and April 2025. Most centres were high-volume institutions (>500 cases/year, 59.6%) and reported the use of written heparinization protocols (78.1%)—initial heparin dose of 300 IU/kg in 61.4%. Many used normothermic perfusion (52.6%). Pre-cardiopulmonary bypass activated clotting time (ACT) targets varied from 400 s (41.2%) to 480 s (38.6%). There was significant heterogeneity in reversal practices: heparin: protamine ratios were 1:1 in 57.0%, <1:1 in 36.8%, and >1:1 in 6.1%. Universal post-reversal ACT target was absent in 70.2%, with 78.1% using an ACT value close to baseline. Although almost all centres (90.4%) had viscoelastic testing, clinical criteria alone were used in 48.2% to guide transfusion decisions. Only 83.3% of centres had any explicit protocol for managing high-bleeding-risk patients.

While essential heparinization practices demonstrate consensus across Europe, heterogeneity exists in anticoagulation reversal strategies and haemostasis monitoring. However, significant variability remains in protamine dosing, post-reversal monitoring, and the use of viscoelastic assays, representing an opportunity to optimize patient care.

Systemic heparin anticoagulation is a cornerstone of safe adult cardiac surgery with cardiopulmonary bypass (CPB), playing an essential role in preventing potentially devastating thrombosis within the extracorporeal circuit.