STEMI-DTU
Left Ventricular Unloading Before Reperfusion in Anterior STEMI Without Cardiogenic Shock
Presented by Navin Kapur — Tufts Medical Center
Subspecialty: Acute MI
Published in JACC
Key Result
LV unloading with Impella CP for 30 min before PCI did NOT reduce infarct size vs immediate PCI (30.8% vs 31.9%, NS) in anterior STEMI without shock. Device-related bleeding/vascular complications were significantly higher (34% vs 6%).
What did this trial find?
The STEMI-DTU trial randomized 527 patients with anterior STEMI without cardiogenic shock to LV unloading with Impella CP for 30 minutes before PCI versus immediate PCI alone. The trial was neutral: infarct size was not significantly different (30.8% vs 31.9%, p=0.50), while device-related bleeding and vascular complications were significantly higher (34% vs 6%). There is substantial expert commentary, with investigators framing the results as informative for future research while outside commentators emphasize the clear negative risk-benefit ratio and the long history of failed infarct-size reduction strategies.
Why does this trial matter?
Real controversy and meaningful interpretation debate. Investigators frame the neutral result optimistically (delayed PCI didn't increase infarct size, biological signal may exist, future studies warranted), while outside experts like Kandzari emphasize the unequivocal negative risk-benefit ratio and the long history of failed infarct-reduction strategies. There is genuine tension between the sponsor/investigator narrative ('landmark trial opening new chapters') and the independent clinical assessment ('sixfold bleeding increase with no efficacy benefit'). The trial also raises questions about whether the hypertensive patient population limited Impella effectiveness.
Study Design
Multinational, randomized controlled trial across 55 hospitals in 6 countries
Clinical Implications
Routine use of LV unloading with Impella CP followed by a 30-minute delay before PCI is not supported compared to immediate PCI in anterior STEMI without shock. The higher bleeding rate raises safety concerns. Immediate reperfusion remains the standard of care.
Abstract
The STEMI-DTU trial evaluated whether mechanical left ventricular unloading with a transvalvular micro-axial flow pump (Impella CP) for 30 minutes prior to PCI could reduce infarct size compared to immediate PCI alone in patients with anterior ST-segment elevation myocardial infarction (STEMI) without cardiogenic shock. The trial randomized 527 adults from 55 hospitals across the US, Germany, Italy, Switzerland, Canada, and the UK. The primary endpoint was infarct size normalized to left ventricular mass measured by cardiac MRI 3-5 days after PCI. The trial did not meet its primary endpoint: infarct size was 30.8% in the Impella group versus 31.9% in the control group (not significant). The 30-day rate of device-related major bleeding or vascular complications was 30.8% in the intervention group, exceeding the pre-defined performance goal of 26.5%. Bleeding rates were significantly higher with the device (34% vs 6%). One-year mortality showed a non-statistically significant difference of 3.6% vs 5.1%.