Background: In patients with acute ST-elevation myocardial infarction (STEMI), the amount of infarcted myocardium (infarct size) is known to be a major predictor for adverse remodeling and recurrent adverse cardiovascular events. Effective cardio-protective strategies with the aim of reducing infarct size are therefore of great interest. Local and systemic inflammation influences the fate of ischemic myocardium and thus, adverse remodeling and clinical outcome. C-reactive protein (CRP) also acts as a potential mechanistic mediator that adversely affects the amount of irreversible myocardial tissue damage after acute myocardial infarction.

Objective: The main objectives of the current study are to investigate the efficacy of selective CRP apheresis, using the PentraSorb®-CRP system, as an adjunctive therapy to standard of care for patients with acute STEMI treated with primary PCI.

Design: Investigator-initiated, prospective, randomized, open-label (outcome assessors masked), controlled, multicenter, two group trial with a two-stage adaptive design.

Innovation: Selective CRP apheresis offers potential to decrease infarct size and consequently improve outcome after PCI for STEMI. This is the first randomized trial investigating the impact of selective CRP apheresis on infarct size in post-STEMI patients. In perspective, the study design allows furthermore to collect robust evidence for the design of a definitive outcome study.

Inclusion Criteria:

1. Diagnosis of first acute STEMI in accordance with the European Society of Cardiology (ESC) Guidelines for the management of acute myocardial infarction in patients presenting with ST-segment elevation
2. Symptoms consistent with STEMI with beginning greater than 30 minutes but less than 12 hours prior to primary percutaneous coronary intervention (PCI)
3. CRP elevation of ≥7 mg/l measured between 6 to 16 hours after primary PCI
4. Eligible for primary PCI
5. Age ≥18 years
6. Written informed consent

Exclusion Criteria:

1. Prior acute myocardial infarction, coronary artery bypass surgery or PCI.
2. Persistent hemodynamic instability (Killip class >2 including cardiogenic shock) or resuscitated cardiac arrest not allowing a CMR scan.
3. The patient is febrile (temperature >38°C) or has experienced an acute infection with fever in the last 14 days.
4. CRP >15 mg/l at time of hospital admission.
5. Chronic inflammatory disease.
6. Known history of severe hepatic failure
7. Chronic kidney disease with a creatinine clearance <30ml/min./1.73m²
8. Contraindication to CMR.
9. Pre-STEMI life expectancy of <1 year
10. Participation in another interventional trial
11. Limited possibility to join the follow-up examinations (e.g. patient lives abroad)
12. Pregnancy