Abiomed's MINI-AMI Study Commenced and CRISP-AMI Results Published

September 19, 2011—Abiomed, Inc. (Danvers, MA) announced that the first patient was enrolled in the MINI-AMI (Minimizing Infarct Size With Impella 2.5 Following PCI for Acute Myocardial Infarction) trial. MINI-AMI is a prospective, randomized, controlled, multicenter study to assess the role of 24 hours of direct unloading of the left ventricle with the company's Impella 2.5 support device to reduce infarct size in patients with ST-segment elevation myocardial infarction (STEMI) without cardiogenic shock.



According to Abiomed, MINI-AMI is a feasibility study designed to determine whether direct unloading of the left ventricle can be effective in treating this stable STEMI patient population. The study will enroll a total of 60 acute myocardial infarction (AMI) patients requiring primary percutaneous coronary inverventions (PCI), including 10 roll-in patients at a maximum of five institutions. Patients will be randomized to a PCI-plus-Impella arm versus a PCI-only arm. Infarct size will be assessed by magnetic resonance imaging. The company noted that although this study is not powered to show a statistical difference in the primary endpoint, the results will provide guidance toward future larger investigations.



Abiomed also announced that results from the CRISP-AMI (Counterpulsation to Reduce Infarct Size Pre-PCI Acute Myocardial Infarction) trial determined that routine intra-aortic balloon pump (IABP) placement before reperfusion in patients with STEMI without cardiogenic shock did not reduce myocardial infarct size. A total of 337 patients were randomized at 30 sites, with one group receiving IABP-plus-PCI treatment and the other group receiving PCI-only treatment. The median infarct size was 37.5% in patients treated with PCI-only and trended larger in the IABP-plus-PCI arm (42.1% infarct size; P = .06). Manesh R. Patel, MD, et al published the CRISP-AMI trial results online ahead of print in the Journal of the American Medical Association.

The company stated that although the CRISP-AMI results did not show an infarct size reduction or clinical benefit of IABP and further discourages its routine use in this category of patients, the study itself has provided insight on the extent of the infarct size in stable STEMI patients and measuring outcomes of AMI beyond the survival benefit.



MINI-AMI Co-Principal Investigator Jeff Moses, MD, commented, “The large infarcts observed in the CRISP-AMI trial overall emphasize a significant clinical need for patients who are treated within recommended door-to-balloon times and still sustain significant myocardial damage. It is a great example of the need for an effective myocardial salvage strategy, which can be provided through direct ventricular unloading by a device such as Impella.”