Unloading the Left Ventricle Before Reperfusion in Patients With Anterior ST-Segment–Elevation Myocardial Infarction

Abstract

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 first 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. Efficacy 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 identifier: NCT03000270.

Different associations between left atrial size and 2.5-year clinical outcomes in patients with anterior versus non-anterior wall ST-elevation myocardial infarction

“…ST-elevation myocardial infarction (STEMI) is a leading life-threatening disease worldwide. 1 Although primary percutaneous coronary intervention has been approved as the gold standard therapy for patients with STEMI over the past 20 years, [2][3][4] patients with anterior wall STEMI have a worse prognosis than those with non-anterior wall STEMI. 5 Therefore, developing prognostic markers for patients with STEMI is essential to enable clinicians to develop risk stratifications for these patients.…”

Early cardiac unloading with ImpellaCP™ in acute myocardial infarction with ventricular septal defect

“…ImpellaCP is currently indicated for both elective and emergent high‐risk percutaneous coronary interventions in the setting of LV dysfunction. It has also been adopted for LV unloading in STEMI patients without cardiogenic shock prior to percutaneous reperfusion, to reduce the ischaemia reperfusion injury and overall myocardial damage by myocardial preconditioning …”

Left ventricular end‐diastolic pressure in acute myocardial infarction: A loaded target in need of unloading

“…The trial confirmed the feasibility of Impella implantation before PCI in anterior STEMI and provided an early signal of safety to allow for the development of a pivotal trial. A subanalysis of the DTU pilot trial data showed that among patients with a larger AAR, as determined by ST‐segment sum elevation >6 mm, unloading for 30 min before reperfusion was associated with smaller infarct size compared to unloading and immediate reperfusion (44.1% vs. 59.9%, respectively, p = 0.04) …”

“…A subanalysis of the DTU pilot trial data showed that among patients with a larger AAR, as determined by ST-segment sum elevation >6 mm, unloading for 30 min before reperfusion was associated with smaller infarct size compared to unloading and immediate reperfusion (44.1% vs. 59.9%, respectively, p = 0.04). 5 Coupled with decades of research showing that elevated ventricular load (LVEDP) is associated with poor outcomes, both the NCSI study and the DTU pilot trial suggest for the first that with further study, "unloading the loaded STEMI patient with or without cardiogenic shock" may improves clinical outcomes for patient with STEMI. ORCID Navin K. Kapur https://orcid.org/0000-0002-8302-6796…”