Young group

Early Heparin Administration in STEMI: Revisiting an Old Question in the Modern PCI Era
The optimal timing of anticoagulation in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI) has remained a matter of debate for decades. The HELP-PCI trial, recently published in the European Heart Journal, provides the largest randomized evidence to date on whether administering unfractionated heparin (UFH) at the time of first medical contact (FMC) improves outcomes compared with standard administration immediately before PCI.

In this multicentre study, 999 patients with STEMI were randomized to receive a full UFH dose (100 U/kg) either at FMC or in the catheterization laboratory. Early administration led to a 34 % relative improvement in infarct-related artery patency before PCI (23.6 % vs 17.6 %; OR 1.44; P = 0.02), reflecting enhanced spontaneous reperfusion, without an increase in bleeding. Rates of 1-year major adverse cardiac and cerebrovascular events (MACCE) were comparable between groups (5.5 % vs 6.7 %), as were indices of epicardial and myocardial reperfusion after PCI.

These results indicate that early heparin pretreatment may optimize pre-procedural coronary flow within modern STEMI networks characterized by rapid transfer times and widespread radial access. The biological rationale is that thrombus organization and fibrin cross-linking progress rapidly after symptom onset, and early anticoagulation may limit propagation and favour spontaneous reperfusion. The short half-life of UFH, however, and the absence of long-term differences suggest that this benefit is transient and largely confined to the pre-PCI phase.

From a clinical perspective, HELP-PCI confirms the safety of pre-hospital heparin, with very low major bleeding rates, likely attributable to radial access, fixed dosing, and prohibition of glycoprotein IIb/IIIa inhibitors before PCI. Nonetheless, the trial population represented low-to-medium risk, prasugrel was not used, and post-discharge management was not standardized, limiting generalizability. Importantly, the early improvement in IRA patency did not translate into better survival or fewer ischemic events at one year.

In conclusion, the HELP-PCI trial reopens the discussion on pre-hospital anticoagulation in STEMI. Early UFH at first medical contact enhances pre-procedural coronary patency and appears safe, but whether this approach can yield meaningful clinical benefit in combination with modern P2Y₁₂ inhibitors and rapid transport systems remains to be shown.

Senior group

HELP-PCI: does a prehospital heparin bolus open the artery before we do?
When every minute is muscle, HELP-PCI asks a  simple question: if we give full-dose UFH in the ambulance, do we arrive to a more patent culprit? In this multicentre RCT (n=999), STEMI patients randomized to UFH 100 U/kg at first medical contact (FMC) had higher pre-PCI IRA patency (TFG-3 23.6% vs 17.6%; OR 1.44, 95% CI 1.06–1.97; P=.02).  

Hard outcomes didn’t separate: 12-month MACCE was similar (5.5% vs 6.7%; HR 0.82, 95% CI 0.50–1.35; P=.44). Major bleeding remained low and comparable (BARC 2–5 at 30 days 0.4% vs 1.2%; at 1 year 1.4% vs 2.0%; both NS). In other words, earlier heparin nudged open the artery without an apparent safety trade-off, but it didn’t (yet) translate into fewer events.  

Biology makes sense: UFH acts within minutes and washes out quickly—perfect for bridging the “no-therapy” transfer gap. Unlike historical prehospital strategies (e.g., GP IIb/IIIa or facilitated lytics) that raised bleeding without durable benefit, this simple anticoagulant move improved spontaneous flow in a modern, radial-first, potent-DAPT era. Notably, a time-to-wire analysis suggested more minutes of pre-lab heparin exposure correlated with higher odds of pre-PCI TFG-3 (adj OR 1.05 per 5-min; P=.003).  

Clinical take: For mature STEMI networks with predictable transport times and low bleeding risk, protocolizing UFH 100 U/kg at FMC is a low-cost, low-friction tweak that may ease wiring, reduce thrombus burden, and potentially lower no-reflow—without adding bleeding. Still, the trial was open-label, conducted in Chinese centres with high radial use, and not powered for MACCE; generalizability and clinical impact remain to be proven.  

Open questions for thrombosis teams: Does earlier UFH shrink infarct size or microvascular obstruction? Are late presenters, anterior MI, or high-thrombus phenotypes the big winners? A pragmatic, outcomes-powered trial is the logical next step.

Early UFH in the ambulance improves pre-PCI patency without extra bleeding; whether that translates into fewer hard events is the question we still need to answer.