Heparin administration at first medical contact vs immediately before primary percutaneous coronary intervention: the HELP-PCI trial

Background and Aims The beneficial effect of pre-treatment with unfractionated heparin (UFH) at first medical contact (FMC) before primary percutaneous coronary intervention (PPCI) in all-comers with ST-elevation myocardial infarction (STEMI) remains uncertain. Methods HELP-PCI was an investigator-initiated, randomized controlled trial conducted at 36 clinical centres in China. Patients with STEMI presenting ≤12 h after symptom onset undergoing PPCI were randomly assigned (1:1) to intravenous administration with UFH (100 U/kg) at FMC or in the Cath Lab through a catheter sheath. The primary endpoint was Thrombolysis in Myocardial Infarction flow grade (TFG)-3 of infarct-related artery (IRA) at diagnostic angiography before PPCI. The secondary outcome was complete epicardial and myocardial reperfusion after PPCI and major adverse cardiac and cerebrovascular events (MACCE; defined as the composite of all-cause death, cardiac death, heart failure hospitalizations, re-infarction, stent thrombosis, unplanned revascularization, and stroke) at 12 months. Safety outcome was 30-day Bleeding Academic Research Consortium (BARC) type ≥2 bleeding. Results A total of 999 patients with STEMI undergoing PPCI were randomly assigned to receive either UFH administration at FMC (n = 505) or in the Cath Lab (n = 494). Pre-treated population at FMC showed a higher frequency of TFG-3 of IRA compared with the Cath Lab group (23.6% vs 17.6%; odds ratio, 1.44; 95% confidence interval, 1.06–1.97; P = .02). There were no significant differences in secondary endpoints or in the safety endpoint, including 12-month MACCE, complete epicardial and myocardial reperfusion, and major bleeding. Conclusions Pre-treatment with loading-dose UFH at FMC was associated with an improvement of spontaneous reperfusion of IRA without increasing the risk of major bleeding.