Impact of Pre-Hospital Heparin Loading in STEMI Patients for Primary PCI: The HELP-PCI 2 Trial (HELP-PCI 2)

The Impact of Injection of a Loading Dose of Unfractionated Heparin on Patients With Acute ST-segment Elevation Myocardial Infarction Scheduled for Primary PCI at Initial Medical Contact: A Multicenter, Prospective, Randomized Controlled Study（HELP-PCI 2）

This randomized, multicenter, prospective trial will enroll 6,294 participants in approximately 80 centers. STEMI patients with onset time within 12 hours and scheduled for primary PCI will be randomly assigned to two groups in a 1:1 ratio. Patients meeting the criteria were randomly assigned. It is recommended that loading doses of dual antiplatelet therapy be administered immediately after electrocardiogram diagnosis. The experimental group was required to be given an intravenous injection of 100 U/kg of UFH within 10 minutes after randomization, and this should be completed at least before delivery to the catheter lab. The control group was recommended to be given 100 U/kg of UFH through the arterial sheath, but the actual intraoperative dosage was determined by the interventional cardiologist. No patient is allowed to use low-molecular-weight heparin, bivalirudin, glycoprotein IIb/IIIa inhibitors or other antithrombotic drugs before coronary angiography. The planned enrollment period for this study is 24 months. The scheduled follow-up visits will occur at 30 days (±7 days), 3 months (±14 days), and if conditions permit, at 6 months (±30 days) and 1 year (±30 days) after randomization. The purpose of this study is to evaluate the composite endpoint of all-cause death, recurrent myocardial infarction, urgent coronary revascularization, stent thrombosis, or stroke within 30 days after randomization.

Study Overview

• Status: Recruiting
• Conditions: ST-elevation Myocardial Infarction (STEMI); Primary PCI
• Intervention / Treatment: Drug: Unfractionated heparin

• Study Type: Interventional
• Enrollment (Estimated): 6294
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Liwei Chen; Phone Number: 86346 （86）027-88041911; Email: renminkjc@163.com

Study Locations

• China
  • Hubei
    • Wuhan, Hubei, China, 430000
      • Recruiting
      • Renmin Hospital of Wuhan University
      • Contact: Jing Chen, PhD; Phone Number: 13659840327; Email: chenjing1982@whu.edu.cn

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Age ≥18 years old;

2. STEMI within 12 hours of onset Newly developed adjacent two or more leads with ST segment elevation of ≥1mm (lead V2-V3 elevation of ≥2mm).

   Newly developed left bundle branch block (LBBB). In the right bundle-branch block (RBBB), the ST segment of leads V1-V3 is elevated or Q waves occur.

3. Primary PCI was planned if the time from first medical contact to balloon dilatation was expected to be less than 120 minutes.

Exclusion Criteria:

1. Thrombolytic therapy recipients;
2. Currently taking oral anticoagulant drugs or having been treated with heparin, low molecular weight heparin, suldaparinol sodium, bivalirudin or IIb/IIIa receptor antagonists within 48 hours before randomization;
3. Patients undergoing cardiopulmonary resuscitation;
4. Patients with cardiogenic shock;
5. Combined mechanical complications (rupture of the free wall of the heart, perforation of the ventricular septum, insufficiency or rupture of the papillary muscle leading to severe mitral regurgitation);
6. History of intracranial parenchymal aneurysm, intracranial arteriovenous malformation, intracranial hemorrhage, ischemic stroke or transient ischemic attack within the last 6 months, and active hemorrhage within the last 2 weeks;
7. Major surgery within one month;
8. Previous history of CABG;
9. Patients with a history of heparin-induced thrombocytopenia or those known to be allergic to anticoagulant or antiplatelet drugs;
10. Combined with other serious diseases and life expectancy less than 12 months;
11. Pregnant or lactating women;
12. Currently participating in clinical research on other drugs or devices;
13. Refuse to sign the informed consent form;
14. The researcher judged that it was not suitable to participate in this study.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Administration of Heparin at the first medical contact; The experimental group was treated with a loading dose of 100U/kg of unfractionated heparin at the first medical contact	Drug: Unfractionated heparin; An intravenous injection of 100 U/kg of UFH will be given at first medical contact before primary PCI (if assigned to experimental group) or in the catheter lab through the arterial sheath when starting primary PCI (if assigned to control group)
Active Comparator: Administration of Heparin in the catheterization laboratory; the control group was treated with a loading dose of 100U/kg of unfractionated heparin in the catheterization laboratory.	Drug: Unfractionated heparin; An intravenous injection of 100 U/kg of UFH will be given at first medical contact before primary PCI (if assigned to experimental group) or in the catheter lab through the arterial sheath when starting primary PCI (if assigned to control group)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The composite endpoint of all-cause death, recurrent myocardial infarction, urgent coronary revascularization, stent thrombosis, or stroke within 30 days after randomization	The composite endpoint of all-cause death, recurrent myocardial infarction, urgent coronary revascularization, stent thrombosis, or stroke within 30 days after randomization	Within 30 days after randomization.
Primary safety endpoint: Major bleeding (BARC type 3~5) within 30 days	Major bleeding (BARC type 3~5)	within 30 days after randomization

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Net Clinical Adverse Event	Composite of all-cause death, recurrent myocardial infarction, urgent coronary revascularization, stent thrombosis, stroke, and BARC type 3-5 bleeding	With 30 days and 90 days after randomization
Individual Clinical Adverse Event	all-cause death, cardiovascular death, recurrent myocardial infarction, urgent coronary revascularization, stent thrombosis, or stroke	Within 30 days and 90 days after randomization

Collaborators and Investigators

• Sponsor: Chen Jing
• Collaborators: Hanyang University; Renmin Hospital of Wuhan University; The Second Affiliated Hospital of Harbin Medical University; Second Xiangya Hospital of Central South University; Yichang Central People's Hospital; Wuhan Central Hospital; Wuhan No.1 Hospital; The Third People's Hospital of Hubei Province; The Fifth Hospital of Wuhan; Xiangyang Central Hospital; Wuhan Hospital of Traditional Chinese Medicine; Jingzhou Central Hospital; Wuhan Puren Hospital; The Central Hospital of Enshi Tujia And Miao Autonomous Prefecture; Xianning Central Hospital; Ezhou Central Hospital; People's Hospital of Jingshan; Sinopharm Dongfeng General Hospital; Changjiang Shipping General Hospital; Xiangyang Hospital of Traditional Chinese Medicine; The Central Hospital of Huanggang; The First People's Hospital of Tianmen; Xiantao First People's Hospital; Songzi People's Hospital; Jiangxia First People's Hospital; Shiyan People's Hospital; Jiangling People's Hospital; Laohekou First Hospital; Wuxue First People's Hospital; Xianning First People's Hospital; Wuhan No.6 Hospital; Tongcheng People's Hospital of Anhui province; China Resources Wugang General Hospital; Hubei University of Medicine; Caidian District People's Hospital; Chibi People's Hospital; Anlu Pu'ai Hospital; Wuhan No.3 Hospital; Xishui County People's Hospital
• Investigators: Principal Investigator: Jing Chen, PhD, Renmin Hospital of Wuhan University

Study record dates

Study Major Dates

• Study Start (Actual): August 13, 2025
• Primary Completion (Estimated): December 31, 2029
• Study Completion (Estimated): April 1, 2030

Study Registration Dates

• First Submitted: January 15, 2026
• First Submitted That Met QC Criteria: January 15, 2026
• First Posted (Actual): January 23, 2026

Study Record Updates

• Last Update Posted (Actual): January 23, 2026
• Last Update Submitted That Met QC Criteria: January 15, 2026
• Last Verified: January 1, 2026

More Information

Terms related to this study

• Keywords: Heparin; ST-Elevation Myocardial Infarction; Primary Percutaneous Coronary Intervation
• Additional Relevant MeSH Terms: Vascular Diseases; Cardiovascular Diseases; Pathologic Processes; Heart Diseases; Infarction; Necrosis; Myocardial Ischemia; Myocardial Infarction; Ischemia; Pathological Conditions, Signs and Symptoms; ST Elevation Myocardial Infarction; Carbohydrates; Glycosaminoglycans; Polysaccharides; Heparin
• Other Study ID Numbers: WDRM2025-K023

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No