Pre-hospital heparin improves coronary flow in STEMI: insights and implications from the HELP-PCI trial

This commentary refers to ‘Heparin administration at first medical contact vs immediately before primary percutaneous coronary intervention: the HELP-PCI trial’, by J. Chen et al., https://doi.org/10.1093/eurheartj/ehaf481 and the discussion piece ‘Pre-hospital vs Cath-Lab heparin in STEMI: a reappraisal based on the HELP-PCI trial findings’, by B. Zhang, https://doi.org/10.1093/eurheartj/ehaf849. We thank Dr Zhang for their interest in our trial and their thoughtful comments regarding the HELP-PCI study.1 We appreciate the opportunity to address these points and clarify our methodology and interpretations. Firstly, we acknowledge that our trial was open-label, which may introduce potential performance bias. However, the primary endpoint [TIMI flow grade 3 (TFG-3) in the infarct-related artery (IRA)] was assessed by an independent core laboratory blinded to treatment allocation, thereby minimizing assessment bias. More importantly, key procedural strategies, including thrombus aspiration, stent implantation, and the use of glycoprotein IIb/IIIa inhibitors, were comparable between the two groups. This indicates that interventional cardiologists did not adopt a more aggressive thrombus management approach in the pre-treatment group, mitigating concerns about performance bias.