Prehospital Heparin Administration in STEMI Patients Undergoing Primary PCI: A Randomized Trial

30 Mar 20264 min read0 viewsJournal Feed

GIST

Circulation, Ahead of Print. Background: Primary PCI is the preferred reperfusion strategy in patients with ST-elevation myocardial infarction (STEMI).

We investigated benefits and safety of pretreatment with unfractioned heparin (UFH) in STEMI referred to primary PCI.Methods: Our single-center, open-label, randomized controlled trial assigned STEMI with ≤6 hours of symptom duration either to 70-100 IE/kg bolus of UFH at first prehospital medical contact (FMC) plus supplemental dose before PCI adjusted to activated clothing time ≥250 seconds or to control group undergoing standard UFH at the time of PCI. Primary efficacy endpoint was TIMI 2-3 flow in infarct related artery (IRA) at initial coronary angiography.

Primary safety endpoint was BARC 3-5 bleeding during the index hospital stay.Results: From March 2022 to February 2025, 298 patients were randomized to UFH pretreatment and 295 to the control group. Both groups were comparable in age, gender, risk factors, previous cardiovascular events and median delay from symptoms to coronary angiography (145 min vs 150 min; p=0.814).

Median time from UFH pretreatment to coronary angiography was 60 min (25thand 75thIQR 47 - 55 min).

Clinical Editorial

Strategic Design and Population Context

Participants were randomized to receive UFH bolus at 70–100 IE/kg with a supplemental dose before PCI, aiming for an activated clotting time ≥250 seconds, versus a control arm receiving UFH only at the time of PCI.

Study design and scope: A single-center, open-label randomized controlled trial evaluated whether early unfractionated heparin (UFH) pretreatment at first prehospital contact benefits STEMI patients destined for primary PCI.
Population and timing: Enrolled adults with ST-elevation myocardial infarction within six hours of symptom onset.
Setting and workflow: The trial operates within a mature STEMI network, and results hinge on prehospital-to-PCI timelines and pre-angiography anticoagulation strategy.

Intervention Details and Comparisons

Prehospital strategy: UFH pretreatment administered at first prehospital medical contact, followed by an additional dose before proceeding to PCI.
Control strategy: Standard UFH administration timed at coronary angiography during PCI.
Timing metrics: Median interval from UFH pretreatment to coronary angiography was 60 minutes, with interquartile range 47–55 minutes.

Key Efficacy Signal

Primary angiographic outcome: Proportion achieving TIMI flow grade 2–3 in the infarct-related artery (IRA) at initial coronary angiography.
Findings: TIMI 2–3 flow occurred in 43% of the UFH pretreatment group versus 27% in controls, indicating a relative increase (risk ratio 1.59; 95% CI 1.27–1.98; p<0.001).

Safety Profile

Bleeding risk: Major bleeding (BARC 3–5) did not differ meaningfully between groups, with 2.4% in the pretreatment group versus 2.0% in controls (risk ratio 1.16; 95% CI 0.39–3.45; p=0.789).