Sustainability of C-Reactive Protein (CRP) Apheresis in Acute Myocardial Infarction (AMI) - Results from a Supplementary Data Analysis of the Explorative CAMI-1 Study

In the multicenter, non-randomized, exploratory C-reactive protein (CRP) Apheresis in Myocardial Infarction (CAMI-1) study, CRP apheresis after ST-Elevation Myocardial Infarction (STEMI) significantly decreased blood CRP concentrations in humans. Cardiac damage was assessed by Cardiac Magnetic Resonance (CMR1) 3-9 d after onset of STEMI symptoms and quantified by myocardial infarct size (IS; %), left ventricular ejection fraction (LVEF; %), circumferential strain (CS) and longitudinal strain (LS) Compared with the control group (n=34), cardiac damage was significantly lower in the apheresis group (n=32). These findings suggested improved wound healing due to CRP apheresis already within few days after the STEMI event. In the current supplementary data analysis of CAMI-1, we have tested by a follow-up CMR (CMR2) after an average of 88 (65-177) d whether the effect of CRP apheresis is clinically maintained. After this time period wound healing in STEMI is considered complete. Whereas patients with low CRP production and a CRP gradient cut off of <0.6 mg/L/h in the hours after STEMI (9 of 32 patients in the CRP apheresis group) did not significantly benefit from CRP apheresis in CMR2, patients with high CRP production and a CRP gradient cut off of >0.6 mg/L/h (23 of 32 patients in the CRP apheresis group) showed significant treatment benefit. In the latter patients, CMR2 revealed a lower IS (-5.4%; p=0.05), a better LVEF (+6.4%; p=0.03), and an improved CS (-6.1%; p=0.005). No significant improvement, however, was observed for LS (-2.9%; p=0.1). These data suggest a sustained positive effect of CRP apheresis on the heart physiology in STEMI patients with high CRP production well beyond the period of its application. The data demonstrate the sustainability of the CRP removal from plasma which is associated with less scar tissue.