Abiomed has received conditional approval from the FDA to begin MINI-AMI, a prospective, randomised, controlled multi-site trial to assess the potential role of the Impella 2.5 in reducing infarct size in patients with ST-elevation myocardial infarction (STEMI). The primary objective of this study is to evaluate whether the adjunctive use of the Impella 2.5 for 24 hours following primary percutaneous intervention (PCI) for STEMI has the potential to limit the infarction of at-risk myocardium compared to primary PCI with routine post-PCI care.
“This pilot study will determine whether the Impella 2.5 can be the first device to actually shrink infarct size,” said principal investigator Jeffrey Moses, New York-Presbyterian Hospital and Columbia University Medical Center. “Today, heart attack survivors can suffer considerable subsequent disability from damaged heart muscle. The intent of this study is to investigate the unique unloading capabilities of Impella 2.5 and its effect in potentially reducing infarct size and improving quality of life for patients.”
“According to the AHA, within five years after surviving your first heart attack, 33% of men and 43% of women will die,” said Michael R. Minogue, chairman, president and chief executive officer, Abiomed. “This will be the first Impella study to evaluate the potential therapeutic benefits of unloading and reducing the oxygen demand on the heart muscle. We are excited to explore more clinical benefits of Impella with this new, haemodynamically stable patient population.”
The primary endpoint of the study will be a cardiac MRI-assessed ratio of the final infarct area to the total area of myocardium that was at risk. This ratio will be measured at three to five days after treatment and then again at 90 days. A total of 50 patients at five hospital sites will be randomized to Impella 2.5 support or the institution’s standard of care with no circulatory support post-PCI. The study is based on the hypothesis that Impella’s ability to directly unload the left ventricle will reduce overall infarct area relative to the total area at risk which has been demonstrated in previous animal studies.
The MINI-AMI study will enrol patients with acute anterior STEMI or large inferior STEMI, primary PCI performed within five hours of the onset of symptoms, patients undergoing emergent primary PCI of one culprit lesion in one major coronary vessel, and successful revascularisation of the native coronary artery at the end of PCI.
A recently published clinical study, “Prognostic significance of the occurrence of acute heart failure after successful primary percutaneous coronary intervention” by L Savic et al, published in the Journal of Invasive Cardiology, studied 1,074 consecutive STEMI patients who had no signs of heart failure at admission, were not in cardiogenic shock at admission and were treated with successful PCI. This study serves as a reference for the MINI-AMI patient population and demonstrated the following:
- Acute heart failure (AHF) during hospitalisation 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.
The study concluded that even after successful PCI, the occurrence of AHF during hospitalisation remains an independent predictor of 30-day and one year mortality. Additionally, the study noted that further investigation is needed to evaluate whether modification of post-procedural treatment can reduce the incidence of AHF.