(O-A3) Retrospective Analysis of the Use of Viscoelastic Hemostatic Assay (ClotPro) in an Academic Emergency Department

Objectives: We aimed to comprehensively analyse retrospective data of the viscoelastic haemostatic assays (VHA) used at the emergency department (ED). Specific goal was to analyse associations between the patient population, VHA indications, ordered test types, and therapeutic haemostatic interventions.

Background: In the ED, healthcare providers frequently encounter hemostatic disorders of a variety of etiologies like hemorrhages or hematological diseases. Precise diagnostic tools with quick turnaround time are necessary to help decision-making regarding emergency management and therapy of bleeding patients. The use of VHA in the diagnosis of hemostatic disorders and during hemostatic resuscitation has been increasing worldwide. However, their use in the ED is not well-documented yet.

Methods: In our retrospective analysis, we processed data of patients for whom a ClotPro test was ordered between 07/15/2019 – 31/12/2021 at the ED of Semmelweis University. Exclusion criteria was missing patient identifier. We collected demographic, laboratory, and clinical data, as well as ClotPro results. We analysed the correlation between laboratory and ClotPro test results, compared different patient groups based on ClotPro findings, and assessed the relationship between therapeutic interventions and ClotPro results.

Results: After exclusion, we processed the data of 381 patients (178 (43.7%) female). There were 7 major indication categories identified based on the discharge reports. We found significant correlation between EX test clotting time (CT) and INR values, EX MCF (maximal clot firmness) and fibrinogen levels, EX MCF and platelet count, FIB MCF and fibrinogen levels, and IN CT and activated partial thromboplastin time (all p-values < 0.05). There was no EX and FIB test profile difference between different subgroups of bleeding patients. Of the 63 patients who presented with a hemorrhagic event and were on novel oral anticoagulant (NOAC) therapy, only 26 (41.3%) had NOAC-specific RVV or ECA test. Patients with prolonged EX CT had higher likelihood of receiving prothrombin complex concentrate (PCC) or fresh frozen plasma (FFP) (OR=3.12; 95% CI=1.99-4.88). However, during the detailed analysis of patients with a prolonged EX CT, we found that patients with prolonged INR value were more likely to receive PCC/FFP therapy than patients with normal or unknown INR (79.1% vs. 36.5% and 36.3%) [figure1].

Conclusions: VHA is increasingly used in the ED and may be useful in the workup of patients with haemostatic pathologies. ClotPro results correlate well with conventional laboratory tests, making it a reliable diagnostic tool. Data suggests positive correlation with optimal therapeutic decisions. However, our further analysis shows that the haemostatic therapeutic approaches are driven mainly by the standard laboratory results. Further detailed analysis is necessary to establish the patient-oriented outcomes of ClotPro use.

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Funding (Optional): No funding