American Society of Hirudotherapy

Outcomes of patients with suspected heparin-induced thrombocytopenia in a contemporary multicenter cohort

Multicenter cohort published in Blood Adv (2025)

Last Updated: June 18, 2026Reviewed by: ASH Editorial Board
Research article — evidence reviewArticle reference
Evidence: Observational studyDrug DevelopmentSafety & Infection ControlNilius H et al. · Blood advances, 2025

Abstract

Managing patients with suspected heparin-induced thrombocytopenia (HIT) poses significant clinical challenges. Limited evidence exists on how management decisions impact clinical outcomes, leading to treatment recommendations based on low-certainty evidence. This study aimed to evaluate the treatment strategies and clinical outcomes of patients with suspected HIT in a contemporary multicenter cohort. We conducted a prospective, multicenter cohort study including consecutive patients with suspected HIT from 11 centers. Patients were stratified into 3 groups: (1) HIT confirmed, (2) HIT-negative but heparin/platelet factor 4 (PF4) antibody-positive, and (3) HIT-negative without antibodies. Clinical and laboratory data were systematically collected. HIT was diagnosed using the washed-platelet heparin-induced platelet activation test as the reference standard. Among 1393 patients (46% female, median age 67 years), HIT was confirmed in 119 (8.5%). Most patients were in intensive care (37%), or had undergone cardiac surgery (32%). Argatroban was the predominant treatment (70%), and platelet recovery occurred in 77% of patients with HIT. Among patients with HIT, subsequent venous thromboembolism occurred in 23%, arterial thromboembolism in 9%, major bleeding in 12.6%, and mortality in 18%, with no significant differences between anticoagulants. Treatment with argatroban, bivalirudin, or direct oral anticoagulants (DOACs) significantly reduced arterial thromboembolism risk. Outcomes did not differ between patients who were HIT-negative with or without heparin/PF4 antibodies. HIT, as well as the mere suspicion of HIT, remains a serious condition with a high risk of adverse outcomes, including death. Our findings provide further evidence supporting the effectiveness of DOACs, argatroban, and bivalirudin in reducing arterial thromboembolism risk.

Abstract sourced from PubMed (NCBI) for the cited record. See the original publication for the authoritative version.

Publication typeJournal ArticleMulticenter Study
Indexed MeSH termsAgedAged, 80 and overFemaleHumansMaleMiddle AgedAnticoagulantsArginineHeparinHirudinsPipecolic AcidsPlatelet Factor 4Prospective StudiesThrombocytopeniaTreatment OutcomePeptide FragmentsRecombinant ProteinsSulfonamides

Summary

In this prospective multicenter cohort of 1393 patients with suspected HIT, HIT was confirmed in 119 (8.5%); among these, argatroban was the predominant treatment (70%), and argatroban, bivalirudin, or direct oral anticoagulants significantly reduced arterial thromboembolism risk, with mortality of 18%.

Why This Matters for Hirudotherapy

This prospective multicenter cohort study across 11 centers enrolled 1,393 consecutive patients with suspected heparin-induced thrombocytopenia (HIT), using washed-platelet heparin-induced platelet activation as the reference standard, with HIT confirmed in 119 (8.5%). Argatroban was the predominant treatment (70%); argatroban, bivalirudin, and DOACs each significantly reduced arterial thromboembolism risk, with no significant differences between anticoagulants in subsequent VTE, major bleeding, or mortality. The study provides comparative effectiveness data on pharmaceutical anticoagulant strategies for HIT. Bivalirudin (formerly Hirulog) is a synthetic peptide anticoagulant designed partly on the C-terminal sequence of hirudin, the anticoagulant of the medicinal leech (Maraganore et al., 1990); this paper studies the drug, not leech therapy.

Citation

Reference (Vancouver style)

Nilius H, Sinitsa E, Studt JD, Tsakiris DA, Greinacher A, Mendez A, et al. Outcomes of patients with suspected heparin-induced thrombocytopenia in a contemporary multicenter cohort. Blood Adv. 2025;9(21):5546-5555. doi:10.1182/bloodadvances.2025016639. PMID: 40758946

Bibliographic details (authors, volume, pages, DOI) are taken from the PubMed record.

Added to ASH library: May 27, 2026 · Site last updated: June 18, 2026

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