Abiomed Receives FDA Approval to Conduct MINI-AMI Study With Impella 2.5

December 2, 2010—Abiomed, Inc. (Danvers, MA) announced that it has received conditional approval from the US Food and Drug Administration to begin MINI-AMI, a prospective, randomized, controlled multicenter trial to assess the potential role of the company's Impella 2.5 in reducing infarct size in patients with ST-elevation myocardial infarction (STEMI). Jeffrey Moses, MD, will be MINI-AMI's principal investigator.

The study's objective is to evaluate whether the adjunctive use of the Impella 2.5 for 24 hours after primary percutaneous coronary intervention (PCI) for STEMI has the potential to limit the infarction of at-risk myocardium compared to primary PCI with routine post-PCI care.

According to Abiomed, the MINI-AMI study will enroll 50 patients at five hospital sites. Patients will be randomized to Impella 2.5 support or the institution's standard of care with no circulatory support post-PCI. Investigators will enroll patients with acute anterior STEMI or large inferior STEMI, primary PCI performed within 5 hours of the onset of symptoms, patients undergoing emergent primary PCI of one culprit lesion in one major coronary vessel, and with successful revascularization of the native coronary artery at the end of the PCI procedure.

The primary endpoint of the study will be a cardiac ratio as assessed by magnetic resonance imaging of the final infarct area to the total area of myocardium that was at risk. This ratio will be measured at 3 to 5 days after treatment and at 90 days.

The company stated that the study is based on the hypothesis that the Impella's ability to directly unload the left ventricle will reduce the overall infarct area relative to the total area at risk, which has been demonstrated in previous animal studies.

Abiomed noted that a recent clinical study serves as a reference for the MINI-AMI patient population. That study, “Prognostic Significance of the Occurrence of Acute Heart Failure After Successful Primary Percutaneous Coronary Intervention,” was published by Lidija Savic, MD, et al in the Journal of Invasive Cardiology (2010;22:307–311). In the study, the investigators enrolled 1,074 consecutive STEMI patients who had no signs of heart failure at admission, were not in cardiogenic shock at admission, and were treated successfully with PCI. The study demonstrated:

• Acute heart failure (AHF) during hospitalization occurred in 11.1% of patients in this study;
• 81.8% of these AHF patients died in the first 30 days;
• In some patients, even timely and successful PCI cannot prevent extensive myocardial damage;
• Patients who developed AHF had a lower ejection fraction;
• There was no significant difference between groups regarding the duration of symptoms or door-to-needle time.

In that study, Dr. Savic and colleagues concluded that even after successful PCI, the occurrence of AHF during hospitalization remains an independent predictor of 30-day and 1-year mortality. Additionally, they advised that further investigation is needed to evaluate whether modification of postprocedural treatment can reduce the incidence of AHF.