Defining three coagulation-based phenotypes for OHCA patients undergoing ECPR: an unsupervised cluster analysis
Tommaso Scquizzato, Evgeny Fominskiy, Maria Grazia Calabrò, Annalisa Franco, Savino Altizio, Pasquale Nardelli, Alessandro Ortalda, Claudia Francescon, Giovanna Basile, Mario Gramegna, Silvia Delrio, Christophe Vandenbriele, Marina Pieri, Anna Mara ScandroglioAbstract
Introduction
Coagulopathy is frequent in refractory out-of-hospital cardiac arrest (OHCA) patients treated with extracorporeal cardiopulmonary resuscitation (ECPR), yet its prognostic significance and heterogeneity remain poorly characterised.
Objectives
To characterize coagulopathy at ECPR initiation, identify coagulation phenotypes, evaluate their association with outcomes, and describe their temporal evolution.
Methods
All consecutive refractory OHCAs treated with ECPR (2013–2024) were included. Phenotypes were identified by unsupervised K-means clustering on PT-INR, aPTT, platelets, antithrombin, fibrinogen, and D-dimer measured at ECPR initiation. Associations with survival, neurological outcomes, and complications were assessed by multivariable logistic regression.
Results
Of 406 ECPR patients, 360 had coagulation data for analysis (initial shockable rhythm 67%, low-flow 70 min [IQR 58–81]). Three phenotypes were identified: severe consumptive coagulopathy (phenotype 1, n=49, 13.6%), mild consumptive coagulopathy (phenotype 2, n=175, 48.6%), and preserved coagulation (phenotype 3, n=136, 37.8%). Phenotype 1 had no survivors, compared with survival of 8.6% and 33.1% in phenotypes 2 and 3, respectively; favourable neurological outcome was achieved in 0%, 5.1%, and 17.6%. Phenotype severity correlated with ischaemic burden (lactate, arterial pH, end-tidal CO2, and low-flow duration). On multivariable analysis, phenotype 2 was associated with lower survival (OR 0.25, 95% CI 0.12–0.55) and favourable neurological outcome (OR 0.31, 95% CI 0.12–0.81) versus phenotype 3. Bleeding incidence rates were 38, 12, and 2.5 events per 100 patient-days in phenotype 1, 2, and 3, respectively (all p < 0.001).
Conclusions
Three distinct coagulation phenotypes at ECPR initiation were independently associated with survival and neurological outcome and appear to reflect ischaemic injury severity. These findings require validation in independent cohorts before clinical application.