American Society of Hirudotherapy

Direct thrombin inhibitors in acute coronary syndromes: principal results of a meta-analysis based on individual patients' data

Research article published in Lancet (London, England) (2002)

Last Updated: June 18, 2026Reviewed by: ASH Editorial Board
Research article — evidence reviewArticle reference
Evidence: Meta-analysisDrug DevelopmentDirect et al. · Lancet (London, England), 2002

Abstract

BACKGROUND: To obtain more reliable and precise estimates of the effect of direct thrombin inhibitors in the management of acute coronary syndromes, including patients undergoing percutaneous coronary intervention, we undertook a meta-analysis based on individual patients' data from randomised trials comparing a direct thrombin inhibitor (hirudin, bivalirudin, argatroban, efegatran, or inogatran) with heparin. METHODS: We included trials that involved at least 200 patients. The primary efficacy outcome was death or myocardial infarction, and the primary safety outcome was major bleeding. Data from individual trials were combined by use of a modified Mantel-Haenszel method. FINDINGS: In 11 randomised trials, 35,970 patients were assigned up to 7 days' treatment with a direct thrombin inhibitor or heparin and followed up for at least 30 days. Compared with heparin, direct thrombin inhibitors were associated with a lower risk of death or myocardial infarction at the end of treatment (4.3% vs 5.1%; odds ratio 0.85 [95% CI 0.77-0.94]; p=0.001) and at 30 days (7.4% vs 8.2%; 0.91 [0.84-0.99]; p=0.02). This was due primarily to a reduction in myocardial infarctions (2.8% vs 3.5%; 0.80 [0.71-0.90]; p<0.001) with no apparent effect on deaths (1.9% vs 2.0%; 0.97 [0.83-1.13]; p=0.69). Subgroup analyses suggested a benefit of direct thrombin inhibitors on death or myocardial infarction in trials of both acute coronary syndromes and percutaneous coronary interventions. A reduction in death or myocardial infarction was seen with hirudin and bivalirudin but not with univalent agents. Compared with heparin, there was an increased risk of major bleeding with hirudin, but a reduction with bivalirudin. There was no excess in intracranial haemorrhage with direct thrombin inhibitors. INTERPRETATION: Direct thrombin inhibitors are superior to heparin for the prevention of death or myocardial infarction in patients with acute coronary syndromes. This information should prompt further clinical development of direct thrombin inhibitors for the management of arterial thrombosis.

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

Publication typeComparative StudyJournal ArticleMeta-AnalysisResearch Support, Non-U.S. Gov't
Indexed MeSH termsAngina, UnstableAntithrombinsArginineGlycineHeparinHirudin TherapyHirudinsHumansMyocardial InfarctionOligopeptidesPeptide FragmentsPipecolic Acids

Summary

Peer-reviewed research on anticoagulant and antithrombotic drug development relevant to thrombin and factor inhibition. Indexed in PubMed and verified against the NCBI record.

Why This Matters for Hirudotherapy

This meta-analysis pooled individual-patient data from 11 randomised trials (35,970 patients) comparing direct thrombin inhibitors (hirudin, bivalirudin, argatroban, efegatran, or inogatran) with heparin in acute coronary syndromes and percutaneous coronary intervention. The abstract reports that direct thrombin inhibitors lowered the risk of death or myocardial infarction at end of treatment (4.3% vs 5.1%; OR 0.85, 95% CI 0.77-0.94) and at 30 days (OR 0.91, 0.84-0.99), driven mainly by fewer myocardial infarctions with no apparent effect on death, with a benefit seen for hirudin and bivalirudin but not the univalent agents and differing bleeding profiles. This is the most directly hirudotherapy-relevant item of the set: hirudin is the medicinal leech's signature anticoagulant, and this large pooled analysis shows that leech-derived and leech-inspired direct thrombin inhibitors carried measurable clinical anticoagulant activity in a major cardiovascular setting, anchoring the leech-secretome drug-discovery story in human outcome data. Honest caveat: the trials evaluated purified or recombinant systemic anticoagulant DRUGS in cardiology, not leech application or topical hirudotherapy, and bleeding risk varied by agent, so these results speak to hirudin pharmacology rather than to clinical leech treatment itself.

Citation

Direct thrombin inhibitors in acute coronary syndromes: principal results of a meta-analysis based on individual patients' data.

Direct et al. · Lancet (London, England), 2002

Added to ASH library: May 28, 2026 · Site last updated: June 18, 2026

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