Clinical Research & Data, Safety & Efficacy, Unloading

What is the purpose of the STEMI DTU™ RCT?

On April 26, 2019, Abiomed received FDA approval to initiate the study Primary Unloading and Delayed Reperfusion in ST-Elevation Myocardial Infarction: The STEMI-DTU Trial. The pivotal trial will build on the promising results of the successful STEMI DTU safety and feasibility trial, or STEMI DTU pilot trial, which met its goal by demonstrating it is safe and feasible to conduct a study of 30 minutes of unloading prior to reperfusion.

What is the design of the STEMI DTU pivotal RCT?

The prospective, multicenter, two-arm trial plans to enroll 668 patients undergoing treatment for an ST-segment myocardial infarction (STEMI). Patients will be randomized 1:1 to either 30 minutes of unloading with the Impella CP® heart pump prior to reperfusion, or the standard of care – immediate reperfusion.

What is the hypothesis that the STEMI DTU pivotal RCT will test?

The trial will test the hypothesis that unloading the left ventricle for 30 minutes prior to reperfusion will reduce myocardial damage from a heart attack and improve clinical cardiovascular outcomes. Myocardial damage can lead to an infarct, and every 5% increase in infarct size is associated with a 20% increase in relative hazard for all-cause mortality or hospitalization for heart failure within one year after a primary PCI.1

What is the planned enrollment?

The STEMI DTU RCT will enroll 668 patients at up to 60 sites. Additionally, the protocol requires each site to “roll-in” two patients (one in each arm) to practice adherence to the study protocol before beginning enrollment. The trial allows for an adaptive design, which permits an increase to the study sample size after an interim analysis.

What is the expected timeline?

STEMI DTU RCT enrollment began in December 2019. Projected total enrollment is 3-4 years but depends on COVID-19 impact.

What is the primary endpoint of the pivotal RCT?

The primary endpoint of the STEMI DTU RCT is infarct size (IS) as a percent of left ventricular (LV) mass, measured at 3-5 days following the index procedure using cardiac magnetic resonance (CMR) imaging.

What are the secondary endpoints of the STEMI DTU RCT?

Key Secondary Efficacy Endpoints:

  • Composite clinical secondary endpoint (compared between groups using the Finkelstein-Schoenfeld statistic)
  • Cardiovascular (CV) mortality [time frame: minimum follow-up of at least 12 months]
  • Cardiogenic shock at ≥24h from enrollment [time frame: minimum follow-up of at least 12 months]
  • LVAD or heart transplant [time frame: minimum follow-up of at least 12 months]
  • Heart failure [time frame: minimum follow-up of at least 12 months]
  • ICD or CRT placement [time frame: minimum follow-up of at least 12 months]
  • Infarct size as percent of left ventricular mass [time frame: 3-5 days]

Key Secondary Safety Endpoint:

  • Impella CP® related major bleeding or major vascular complications with pre-specified performance goals [time frame: 30 days]

Who are the co-principal investigators and who is on the STEMI DTU RCT steering committee?

The co-principal investigators (co-PIs) are Navin Kapur, MD, executive director of the CardioVascular Center for Research and Innovation (CVCRI) at Tufts Medical Center and William O’Neill, MD, medical director of the Center for Structural Heart Disease at Henry Ford Hospital. The pivotal trial will be overseen by a steering committee of the co-PIs and expert cardiologists and clinical trialists including:

  • Jeffrey Moses, MD, professor of medicine at Columbia University Medical Center and director of interventional cardiovascular therapeutics at Columbia University Medical Center
  • Gregg Stone, MD, professor of medicine at Columbia University College of Physicians and Surgeons and director of cardiovascular research and education at the Center for Interventional Vascular Therapy at New York-Presbyterian Hospital/Columbia University Medical Center
  • James Udelson, MD, chief of the division of cardiology at Tufts Medical Center

Learn more about the STEMI DTU pilot trial. Watch Navin Kapur, MD, co-principal investigator of the STEMI DTU pilot trial discuss the results here. Learn more about ventricular unloading.

Who is the study sponsor?

The STEMI DTU RCT is sponsored by Abiomed, Inc.

How does my hospital participate in the study?

If you are interested in participating in the STEMI DTU Pivotal RCT, please email Abiomed medical affairs.



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Impella heart pumps are FDA approved as a therapy for high-risk PCI and AMI cardiogenic shock. The STEMI DTU RCT is being conducted under an investigational device exemption from the FDA and Impella heart pumps are not FDA approved for use in STEMI patients without cardiogenic shock.


  1. Stone, G.W., et al. (2016). J Am Coll Cardiol, 67(14), 1674-1683.
  2. Benjamin, E.J., et al. (2019). Circulation, 139(10), e56-e528.