IMPRESS in STEMI

Background:
Primary angioplasty is currently the optimal reperfusion therapy. Patients with large anterior STEMI have a high risk of developing poor left ventricular (LV) function and a higher mortality. Anterior STEMI patients with heart rate >100/min and/or systolic blood pressure <100 mmHg may qualify as pre-shock patients and are usually treated with IABP, as these patients may benefit from mechanical assistance. However, the currently available and frequently used IABP in these patients has not demonstrated any long-term benefit. The percutaneous Impella may be superior when compared with IABP as it directly unloads the left ventricle, improves coronary circulation and produces a
maximum output of 2,5L/min.

Design:
Multi-center, randomized, prospective two-arm trial with either Impella* or IABP therapy after PCI for acute anterior ST segment elevation myocardial infarction in pre-shock patients. Blinded evaluation of endpoints.

Objective:
The primary objective of this study is to determine whether treatment with Impella compared with IABP therapy after primary PCI reduces infarct size and results in a higher residual left ventricular ejection fraction in acute anterior wall myocardial infarction treated by PCI.

Patients:
130 Patients treated with primary PCI for acute anterior wall STEMI with a heart rate >100/min and/or systolic blood pressure <100 mmHg and clinical signs of pre-shock

Methods:
After oral informed consent has been obtained, the patient is randomized to either treatment with the Impella device or IABP.

Primary efficacy endpoint:
Infarct size after 4 months measured as residual left ventricular ejection fraction (LVEF) assessed by MRI in patients treated with Impella versus IABP.

Secondary efficacy endpoints:
• LV volumes measured by MRI.
• Infarct size measured by MRI.
• Infarct size measured by echocardiography before PCI, before discharge and after 4 months
• Enzymatic infarct size and several other biochemical parameters
• The need for and duration of mechanical ventilation, inotropic therapy or dialysis for renal failure
• Duration of hospitalization and stay at the intensive care and coronary care unit
• The functional class according to the NYHA-Classification at 30 days, 4 months and after 1 year

The primary safety endpoint is the composite of death, myocardial infarction, target vessel revascularization and stroke (MACCE)

The secondary safety endpoint is the occurrence of device failure or malfunction, ventricular arrhythmias, severe vascular events or hemolysis.

The primary objective of this study is to determine whether treatment with Impella compared with IABP therapy after primary PCI reduces infarct size and results in a higher residual left ventricular ejection fraction in acute anterior wall myocardial infarction treated by PCI.

Data collection takes place before randomization (echocardiography, laboratory measurements),
during hospital stay (laboratory and hemodynamic measurements, etc)
at discharge (laboratory measurements, echocardiography), 30 day telephone follow-up (NYHA class);

4 month follow-up (MRI, echocardiography, lab etc) and 1 year clinical follow-up (lab, NYHA class, etc).

Throughout the study, adverse events and medications are registered.

Patients in cardiogenic pre-shock after ST-elevation myocardial infarction, treated by primary PCI, are randomized to either treatment with the Impella device, a percutaneous left ventricular assist device, to support cardiac pump function; or to standard treatment with IABP (intra-aortic balloon pump), which also has the purpose of supporting the left ventricle.