PB1222 - ROTEM-Identified Hyperfibrinolysis does not Correlate with Poor Outcomes in Large Vessel Occlusion Stroke

Tuesday, June 27, 2023

18:30 – 19:30 ET

Room: Exhibition

Presenting Author(s)

Susan M. Shea, MSME, PhD (she/her/hers)

Assistant Professor
Trauma and Transfusion Medicine Research Center, Department of Surgery and Department of Bioengineering, University of Pittsburgh
Pittsburgh, Pennsylvania, United States

Co-Author(s)

AZ

Amanda Zakeri

Resident
OSUMC
Columbus, Ohio, United States
JZ

Jessica Zakeri

Researcher
OSUMC
Columbus, Ohio, United States
PY

Patrick Youssef

Researcher
OSUMC
Columbus, Ohio, United States
CP

Ciaran Powers

Researcher
OSUMC
Columbus, Ohio, United States
RR

Rassam M.G. Rassam

Senior Research Laboratory Specialist
Trauma and Transfusion Medicine Research Center, Department of Surgery, University of Pittsburgh
Pittsburgh, Pennsylvania, United States
Emily P. Mihalko, PhD

Research Scientist
Trauma and Transfusion Medicine Research Center, Department of Surgery, University of Pittsburgh
Pittsburgh, Pennsylvania, United States
SN

Shahid Nimjee

Associate Professor of Neurological Surgery
Department of Neurological Surgery, The Ohio State University Medical Center, Columbus, OH, USA
Columbus, Ohio, United States

Background: Rotational thromboelastometry (ROTEM) is one of few assays to rapidly measure whole blood coagulation and lysis. However, utility in the large vessel occlusion (LVO) stroke population remains unclear.

Aims: The study objective was to assess utility of ROTEM via outcome stratification in LVO patients.

Methods: Blood samples were prospectively collected from LVO patients (N=167) at time of thrombectomy, and assayed on ROTEM. Clinical data including administration of intravenous thrombolytic (IVT; alteplase), labs, anticoagulant and antiplatelet use, and outcome measures were collected. Ex vivo samples (N=7) mixed with therapeutic and supertherapeutic levels of alteplase were also run to assess lysis induction. Data are presented as N(%) or median(interquartile range). Comparisons were determined using Wilcoxon rank-sum test.

Results: A subset [59(45%)] of patients received IVT. Patients that received IVT were less likely to have an on-board anticoagulant (8% vs. 31%, p< 0.001), most likely due to contraindication. However, coagulation measures including INR and PTT, as well as VWF levels and platelet counts, were not different between those that received IVT and those that did not. Patients that received IVT had greater EXTEM, INTEM, and FIBTEM maximum lysis (ML) levels (p < 0.001); reduced platelet function as measured by EXTEM maximum clot firmness [63(53-66) vs. 67(65-71) mm, p< 0.001], and reduced fibrinogen [299(195-344) vs. 343(291-427) mg/dL, p< 0.001]. In ex vivo experiments, therapeutic levels of alteplase did not induce hyperfibrinolysis, which was only achieved in some samples with supertherapeutic doses. However, a subset of LVO patients were hyperfibrinolytic [14 (8%)]. Interestingly, those patients did not have worse outcomes.

Conclusion(s): While a subset of ischemic stroke patients undergoing thrombectomy that received IVT converted to a hyperfibrinolytic state, this did not impact cognitive outcomes. The conversion to hyperfibrinolysis may involve patient-specific mechanisms that cannot be explained by IVT administration alone, as this does not occur with therapeutic doses ex vivo.