Pre-hospital heparin use for ST-elevation myocardial infarction is safe and improves angiographic outcomes

Jason E. Bloom, Emily Andrew, Ziad Nehme, Diem T. Dinh, Himawan Fernando, William Y. Shi, Peter Vriesendorp, Shane Nanayakarra, Luke P. Dawson, Angela Brennan, Samer Noaman, Jamie Layland, Jeremy William, Ali Al-Fiadh, Matthew Brooks, Melanie Freeman, Adam Hutchinson, David McGaw, William Van Gaal, William WillsonA. White, Roshan Prakash, Christopher Reid, Jeffrey Lefkovits, Stephen J. Duffy, William Chan, David M. Kaye, Michael Stephenson, Stephen Bernard, Karen Smith, Dion Stub

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AIMS: This study aims to evaluate if pre-hospital heparin administration by paramedics is safe and improves clinical outcomes. METHODS AND RESULTS: Using the multicentre Victorian Cardiac Outcomes Registry, linked with state-wide ambulance records, we identified consecutive patients undergoing primary percutaneous coronary intervention for STEMI between January 2014 and December 2018. Information on thrombolysis in myocardial infarction (TIMI) flow at angiography was available in a subset of cases. Patients receiving pre-hospital heparin were compared to those who did not receive heparin. Findings at coronary angiography and 30-day clinical outcomes were compared between groups. Propensity-score matching was performed for risk adjustment. We identified a total of 4720 patients. Of these, 1967 patients had TIMI flow data available. Propensity-score matching in the entire cohort yielded 1373 matched pairs. In the matched cohort, there was no observed difference in 30-day mortality (no-heparin 3.5% vs. heparin 3.0%, P = 0.25), MACCE (no-heparin 7% vs. heparin 6.2%, P = 0.44), and major bleeding (no-heparin 1.9% vs. heparin 1.4%, P = 0.64) between groups. Propensity-score analysis amongst those with TIMI data produced 552 matched pairs. The proportion of cases with TIMI 0 or 1 flow in the infarct-related artery (IRA) was lower among those receiving pre-hospital heparin (66% vs. 76%, P <0.001) compared to those who did not. CONCLUSION : In this multicentre, propensity-score matched study, the use of pre-hospital heparin by paramedics was safe and is associated with fewer occluded IRAs in patients presenting with STEMI.
Original languageEnglish
Pages (from-to)1140-1147
Number of pages9
JournalEuropean Heart Journal: Acute Cardiovascular Care
Issue number10
Publication statusPublished - Dec 2021


  • Emergency medical services Heparin Propensity-score matching Stemi Systems of care TIMI flow

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