Effectiveness and Safety of Early Administration of Heparin at First Medical Contact for STEMI Patients Undergoing Primary Percutaneous Coronary Intervention - HELP PCI

Oct 28, 2024
Font Size
A
A
A
Author/Summarized by Author:
Amit Saha, MD
Summary Reviewer:
Dharam J. Kumbhani, MD, SM, FACC
Trial Sponsor:
Renmin Hospital of Wuhan University
Date Presented:
10/28/2024
Date Published:
10/28/2024
Original Posted Date:
10/28/2024
References

Contribution To Literature:

The HELP-PCI trial showed that in patients with STEMI, early administration of unfractionated heparin at first medical contact led to improved culprit artery TIMI flow before PCI but did not reduce 1-year MACCE compared with standard of care.

Description:

The goal of the trial was to determine the efficacy and safety of administering unfractionated heparin at first medical contact versus during cardiac catheterization only in patients with ST-segment elevation myocardial infarction (STEMI).

Study Design

  • Multicenter
  • Randomized
  • Open-label

Patients with symptoms and electrocardiogram findings concerning for STEMI were randomized in a 1:1 fashion to receive 100 U/kg unfractionated heparin at first medical contact (i.e., ambulance or emergency department, n = 494) or in the catheterization laboratory after insertion of arterial sheath (n = 505).

  • Total number of enrollees: 999
  • Duration of follow-up: 1 year
  • Mean patient age: 60 years
  • Percentage female: 82%

Inclusion criteria:

  • Age 18-80 years
  • STEMI with intention to perform primary percutaneous coronary intervention (PCI)
  • Symptom onset ≤12 hours

Exclusion criteria:

  • Active bleeding or on therapeutic anticoagulation
  • History of heparin-induced thrombocytopenia
  • Mechanical complication of MI (e.g., ventricular septal rupture)
  • Prior coronary artery bypass grafting
  • Cardiopulmonary resuscitation before randomization

Other salient features/characteristics:

  • Killip class I: 79%
  • P2Y12 inhibitor loading dose given at first medical contact: 89%; P2Y12 inhibitor used: ticagrelor 85%, clopidogrel 4%
  • PCI performed: 93%
  • Thrombectomy performed: 13%
  • GPI use: during (6.4%), after (40%)

Principal Findings:

The primary outcome, Thrombolysis in MI (TIMI) 3 flow in the infarct-related artery on diagnostic angiography prior to PCI, first medical contact vs. control, was: 23.6% vs. 17.6%, relative risk (RR) 1.34 (95% confidence interval [CI] 1.04-1.71), p = 0.02.

Secondary outcomes for first medical contact vs. control:

  • Post-PCI TIMI grade 3: 94.9% vs. 93.9%, p = 0.52
  • Major adverse cardiac or cerebrovascular events (MACCE), a composite of death, heart failure (HF), MI, stent thrombosis, unplanned revascularization, and stroke at 30 days: 2.2% vs. 4.7%, HR 0.47 (95% CI 0.24-0.91), p = 0.032
  • HF hospitalization at 30 days: 0% vs. 1.0%, p = 0.023
  • MACCE at 1 year: 5.5% vs. 6.7%, HR 0.82 (95% CI 0.50-1.35), p = 0.435
  • HF at 1 year: 0.8% vs. 2.0%, HR 0.38 (95% CI 0.13-1.09), p = 0.092

Safety outcome for first medical contact vs. control:

  • Bleeding Academic Research Consortium (BARC) ≥2 bleeding at 30 days: 0.4% vs. 1.2%, HR 0.33 (95% CI 0.08-1.30), p = 0.148
  • Access site-related BARC ≥2 bleeding: 0% vs. 0%

Time intervals for first medical contact vs. control:

  • Symptom onset to heparin: 2.85 vs. 3.10 hours, p = 0.002
  • First medical contact to heparin: 35 vs. 71 minutes, p < 0.001
  • Heparin to wire crossing: 37 vs. 12 minutes, p < 0.001

Interpretation:

Multiple observational and registry cohorts have suggested increased rates of culprit artery reperfusion in STEMI with early administration of unfractionated heparin at first medical contact, although the consequent effects on outcomes such as death or HF have been mixed. Interpretation of these nonrandomized data is further limited by differences in the timing of P2Y12 administration between treatment arms. The HEAP trial demonstrated no benefit to early high-dose heparin in STEMI but was conducted before the contemporary era of dual antiplatelet therapy (DAPT) and drug-eluting stents.

In HELP-PCI, early heparin administration resulted in higher rates of TIMI 3 flow on initial angiography (pre-PCI) against a background of routine pre-catheterization DAPT loading with no significant difference in bleeding. MACCE did not differ at 1 year despite a reduction in HF readmissions and MACCE at 30 days with early heparin administration. Given its apparent safety, heparin administration at first medical contact could be considered in STEMI patients, especially in the setting of potential delays to primary PCI. Future studies outside Chinese cohorts would enhance the generalizability of these findings.

References:

Presented by Dr. Jing Chen at the Transcatheter Cardiovascular Therapeutics meeting (TCT 2024), Washington, DC, October 28, 2024.

Clinical Topics: Anticoagulation Management, Invasive Cardiovascular Angiography and Intervention, Stable Ischemic Heart Disease, Vascular Medicine, Interventions and Vascular Medicine, Chronic Angina

Keywords: Heparin, Percutaneous Coronary Intervention, ST Elevation Myocardial Infarction, Transcatheter Cardiovascular Therapeutics, TCT24


< Back to Listings