Circulation. 2019;139:337–346. DOI: 10.1161/CIRCULATIONAHA.118.038269 January 15, 2019 337 Editorial, see p 347 BACKGROUND: In ST-segment–elevation myocardial infarction (STEMI), infarct size correlates directly with heart failure and mortality. Preclinical testing has shown that, in comparison with reperfusion alone, mechanically unloading the left ventricle (LV) before reperfusion reduces infarct size and that 30 minutes of unloading activates a cardioprotective program that limits reperfusion injury. The DTU-STEMI pilot trial (Door-To- Unload in STEMI Pilot Trial) represents the frst exploratory study testing whether LV unloading and delayed reperfusion in patients with STEMI without cardiogenic shock is safe and feasible. METHODS: In a multicenter, prospective, randomized exploratory safety and feasibility trial, we assigned 50 patients with anterior STEMI to LV unloading by using the Impella CP followed by immediate reperfusion (U- IR) versus delayed reperfusion after 30 minutes of unloading (U-DR). The primary safety outcome was a composite of major adverse cardiovascular and cerebrovascular events at 30 days. Effcacy parameters included the assessment of infarct size by using cardiac magnetic resonance imaging. RESULTS: All patients completed the U-IR (n=25) or U-DR (n=25) protocols with respective mean door-to-balloon times of 72 versus 97 minutes. Major adverse cardiovascular and cerebrovascular event rates were not statistically different between the U-IR versus U-DR groups (8% versus 12%, respectively, P=0.99). In comparison with the U-IR group, delaying reperfusion in the U-DR group did not affect 30-day mean infarct size measured as a percentage of LV mass (15±12% versus 13±11%, U-IR versus U-DR, P=0.53). CONCLUSIONS: We report that LV unloading using the Impella CP device with a 30-minute delay before reperfusion is feasible within a relatively short time period in anterior STEMI. The DTU-STEMI pilot trial did not identify prohibitive safety signals that would preclude proceeding to a larger pivotal study of LV unloading before reperfusion. An appropriately powered pivotal trial comparing LV unloading before reperfusion to the current standard of care is required. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov . Unique identifer: NCT03000270. © 2018 American Heart Association, Inc. Navin K. Kapur, MD et al ORIGINAL RESEARCH ARTICLE Unloading the Left Ventricle Before Reperfusion in Patients With Anterior ST- Segment–Elevation Myocardial Infarction A Pilot Study Using the Impella CP https://www.ahajournals.org/journal/circ Circulation The full author list is available on page 345. Key Words: heart-assist devices ◼ heart failure ◼ heart ventricles ◼ myocardial infarction ◼ reperfusion injury Sources of Funding, see page 345 Downloaded from http://ahajournals.org by on May 25, 2020