Optimal Timing of Microaxial Flow Pump(Impella CP) in AMI-related Cardiogenic Shock (PRIME-SHOCK)

September 10, 2026 updated by: Min Chul Kim, Chonnam National University Hospital

Routine PRe-PCI Versus Selective Post-PCI Impella CP Management and Evaluation in Acute Myocardial Infarction-Related Cardiogenic SHOCK

PRIME-SHOCK is a prospective, single-center, open-label, randomized, superiority trial. Eligible participants with AMICS and a clinical decision to use Impella CP will be randomized in a 1:1 ratio before culprit-lesion PCI. The routine pre-PCI group will undergo Impella CP insertion immediately after allocation and before culprit-lesion PCI. The selective post-PCI group will undergo culprit-lesion PCI first; Impella CP will be inserted only if prespecified intra-procedural rescue criteria are met or shock persists or worsens after successful PCI. If all post-PCI recovery criteria are met, PCI will be concluded without Impella CP.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

  • Study Objectives: To determine whether routine pre-percutaneous coronary intervention (PCI) Impella CP reduces the composite of all-cause death within 30 days after randomization or refractory shock within 48 hours after index PCI compared with revascularization first and selective post-PCI Impella CP in patients with acute myocardial infarction-related cardiogenic shock (AMICS) for whom Impella CP support is planned.
  • Study Background: AMICS is among the most lethal complications of acute myocardial infarction (AMI). It occurs in approximately 5-10% of patients with AMI, and short-term mortality remains approximately 40-50% despite rapid reperfusion and advances in critical care. Early culprit-vessel revascularization has been central to AMICS care, yet shock and multiorgan failure frequently persist after technically successful PCI.

Vasopressors and inotropes are often required to maintain blood pressure and organ perfusion, but high doses or prolonged use can increase myocardial oxygen demand, provoke arrhythmia, and worsen peripheral vasoconstriction. Routine mechanical circulatory support for unselected AMICS populations has not consistently improved outcomes.

Impella CP is a percutaneous transvalvular microaxial flow pump inserted through the femoral artery. It transfers blood from the left ventricle to the ascending aorta, supporting systemic circulation while unloading the left ventricle and potentially reducing filling pressure, wall stress, and myocardial oxygen demand. The randomized DanGer-Shock (Danish Cardiogenic Shock) trial established a potential survival benefit in selected AMICS patients while reinforcing the need to optimize use and limit device-related harm.

The 2025 American guideline for the management of acute coronary syndromes states that, in selected patients with ST-segment elevation myocardial infarction (STEMI) and severe or refractory cardiogenic shock, the use of a microaxial flow pump may be reasonable to reduce the risk of death. However, in the DanGer-Shock trial, randomization concerned the use of the Impella CP, whereas the timing of device insertion, before or after PCI, was neither randomized nor specified by the study protocol. Accordingly, the guideline also acknowledges that the preferred timing of Impella insertion remains unclear. Therefore, the results of DanGer-Shock alone do not establish the superiority of pre-PCI over post-PCI insertion, and a randomized trial directly comparing these two strategies is warranted.

This study will randomly compare the clinical efficacy and safety of a routine pre-PCI Impella CP insertion strategy with a PCI-first strategy involving selective Impella CP insertion. It will determine whether the potential benefits of early left ventricular unloading and hemodynamic stabiliation outweigh the risks associated with pre-emptive device insertion in all patients, or whether restricting Impella CP use to patients with persistent shock after initial coronary revascularization can reduce unnecessary device use and related complications while providing comparable or superior clinical outcomes. This study has important clinical significance because it will address a key unresolved question following the DanGer-Shock trial, moving beyond "whether to use the Impella CP" to "in whom and when it should be used". By incorporating the potential benefit of avoiding device use in patients whose shock resolves with PCI alone, while simultaneously evaluating the risks of delaying circulatory support in those who require early mechanical support, this study is expected to provide a more individualized, evidence-based strategy for Impella CP use in patients with AMICS.

- Study Hypothesis: Routine pre-PCI Impella CP will reduce the composite of all-cause death within 30 days after randomization or refractory shock within 48 hours after index PCI compared with revascularization first and selective post-PCI Impella CP.

Study Type

Interventional

Enrollment (Estimated)

126

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

  • South Korea
      • Gwangju, South Korea
        • Chonnam National University Hospital

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Age ≥19 years old
  • Acute myocardial infarction with culprit lesion requiring urgent percutaneous coronary intervention
  • Cardiogenic shock before culprit lesion percutaneous coronary intervention
  • Left ventricular ejection fraction ≤40%
  • Patients with persistent signs of shock despite medical therapy who are scheduled to undergo Impella CP insertion
  • Shock onset to randomization ≤12 hours

Exclusion Criteria:

  • Non-acute myocardial infarction-related shock
  • No clear culprit lesion
  • Mechanical complication of myocardial infarction
  • Predominant right ventricular or biventricular shock
  • Ongoing cardiopulmonary resuscitation at the time of screening
  • Refractory ventricular arrhythmia
  • Unwitnessed cardiac arrest without bystander cardiopulmonary resuscitation
  • Cardiopulmonary resuscitation duration >45 minutes
  • Glasgow Coma Scale <8 after return of spontaneous circulation
  • Contraindication to Impella CP use
  • Prior mechanical circulatory support before randomization
  • Active major bleeding or inability to receive anticoagulation or antiplatelet therapy required for percutaneous coronary intervention and Impella CP support
  • Life expectancy <1 year

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Routine pre-percutaneous coronary intervention (PCI) Impella CP
In the pre-percutaneous coronary intervention (PCI) Impella CP group, Impella CP will be routinely inserted before culprit lesion PCI in patients with acute myocardial infarction-related cardiogenic shock.
Procedure: Routine pre-PCI Impella CP
In the PCI Impella CP group, Impella CP will be routinely inserted before culprit lesion PCI in patients with acute myocardial infarction-related cardiogenic shock.
Active Comparator: Selective post-percutaneous coronary intervention (PCI) Impella CP
The selective post-percutaneous coronary intervention (PCI) Impella CP group will undergo culprit-lesion PCI first; Impella CP will be inserted only if prespecified intra-procedural rescue criteria are met or shock persists or worsens after successful PCI for culprit lesion.
Procedure: Selective post-PCI Impella CP

The selective post-PCI Impella CP group will undergo culprit-lesion PCI first; Impella CP will be inserted only if prespecified intra-procedural rescue criteria are met or shock persists or worsens after successful PCI for culprit lesion.

In the selective post-PCI group, immediate mechanical circulatory support will be instituted during PCI if any of the criteria are met. Impella CP is preferred when feasible. VA-ECMO may be initiated during resuscitation when Impella CP cannot be placed promptly or is insufficient.

In the selective post-PCI group, successful culprit-lesion revascularization is done without shock progession, PCI will be concluded without Impella CP only when all of the criteria are met.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Composite of all-cause death or refractory shock within 48 hours after index percutaneous coronary intervention
Time Frame: At 30 days after randomization
At 30 days after randomization

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Composite of all-cause death or refractory shock within 48 hours after index percutaneous coronary intervention
Time Frame: At 12 months after randomization
At 12 months after randomization
All-cause death
Time Frame: At 30 days and 12 months after randomization
At 30 days and 12 months after randomization
Number of participants with refractory shock within 48 hours after index percutaneous coronary intervention (PCI), assessed using prespecified clinical, hemodynamic, and arterial lactate criteria
Time Frame: Within 48 hours after index percutaneous coronary intervention

Refractory shock is defined as any of: (1) rescue escalation to mechanical circulatory support beyond the randomized strategy, (2) acute cardiac arrest, or (3) persistent or worsening tissue hypoperfusion requiring at least one arterial lactate criterion AND at least one concurrent hemodynamic/organ-perfusion criterion.

Lactate criteria: two consecutive increases at approximately 2-hour intervals, 24-hour lactate clearance <40 percent with lactate ≥4 mmol/L at 24 hours, or persistent lactate ≥5 mmol/L during hours 24-48.

Concurrent criteria: increasing vasopressor requirement, use of ≥2 vasoactive agents; persistent mean arterial pressure <65 mm Hg, urine output <0.5 mL/kg/h for ≥6 hours; cardiac power output <0.6 W, or cardiac index <2.2 L/min/m^2.

Protocol-concordant post-PCI Impella CP insertion in the selective group is not, by itself, rescue escalation.
Within 48 hours after index percutaneous coronary intervention
Time from randomization to arterial lactate <2.0 mmol/L
Time Frame: At 30 days after randomization
At 30 days after randomization
24-hour arterial lactate clearance
Time Frame: At 24 hours after randomization
At 24 hours after randomization
Cardiac death
Time Frame: At 30 days and 12 months after randomization
At 30 days and 12 months after randomization
Rate of ischemic or hemorrhagic stroke
Time Frame: At 30 days and 12 months after randomization
At 30 days and 12 months after randomization
Rate of renal replacement therapy
Time Frame: At 30 days and 12 months after randomization
At 30 days and 12 months after randomization
Rate of limb ischemia
Time Frame: At 30 days and 12 months after randomization
At 30 days and 12 months after randomization
Rate of clinically significant Impella CP-related hemolysis
Time Frame: At hospital discharge (up to 30 days)
At hospital discharge (up to 30 days)
Major bleeding (Bleeding Academic Research Consortium [BARC] type 3 or 5 bleeding)
Time Frame: At 30 days and 12 months after randomization
At 30 days and 12 months after randomization
Major vascular complications
Time Frame: At 30 days and 12 months after randomization
At 30 days and 12 months after randomization
Sepsis or bloodstream infection
Time Frame: At 30 days and 12 months after randomization
At 30 days and 12 months after randomization
Impella CP malfunction, malposition, or device-related cardiac or vascular injury
Time Frame: At hospital discharge (up to 30 days)
At hospital discharge (up to 30 days)
Rate of hospitalization for heart failure
Time Frame: At 12 months after randomization
At 12 months after randomization
Rate of stent thrombosis
Time Frame: At 30 days and 12 months after randomization
At 30 days and 12 months after randomization

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Chonnam National University Hospital

Investigators

  • Principal Investigator: Youngkeun Ahn, Chonnam National University Hospital

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

October 1, 2026

Primary Completion (Estimated)

August 31, 2029

Study Completion (Estimated)

July 31, 2030

Study Registration Dates

First Submitted

September 6, 2026

First Submitted That Met QC Criteria

September 10, 2026

First Posted (Actual)

September 14, 2026

Study Record Updates

Last Update Posted (Actual)

September 14, 2026

Last Update Submitted That Met QC Criteria

September 10, 2026

Last Verified

September 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • CNUH-2026-348

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

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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