Circulating acute phase proteins in relation to extent and composition of coronary atherosclerosis and cardiovascular outcome: results from the ATHEROREMO-IVUS study.

Introduction: We examined whether the acute phase proteins (APPs): Alpha-1-Antitrypsin, Alpha-2-Macroglobulin, Complement C3, ferritin, haptoglobin, and Plasminogen Activator Inhibitor 1 (PAI-1) are associated with cardiovascular outcome, as well as with the extent and composition of coronary atherosclerosis as determined by intravascular ultrasound (IVUS) virtual histology (VH).

Methods: In 2008-2011, IVUS(-VH) imaging of a non-culprit coronary artery was performed in 581 patients from the ATHEROREMO-IVUS study undergoing coronary angiography for acute coronary syndrome (ACS) (n=318) or stable angina pectoris (SAP) (n=263). Coronary atherosclerotic plaque volume, composition (fibrous, fibro-fatty, dense calcium and necrotic core) and vulnerability (VH-derived thin-cap fibroatheroma (TCFA) lesions) were assessed. Major adverse cardiac events (MACE; all-cause mortality, ACS or unplanned coronary revascularization) were assessed during 1-year follow-up. We applied linear, logistic and Cox regression.

Results: Mean age was 61.5 ± 11.4 years and 75.4% were men. Higher ferritin was associated with higher coronary plaque volume (beta [95% CI]: 0.19 [0.07-0.31] percent atheroma volume), for the highest vs the lowest tertile of ferritin; p for linear association=0.013. Higher PAI-1 was associated with higher rates of all-cause mortality or ACS (hazard ratio [95% CI]: 2.98 [1.10-8.06]), for the highest vs the lowest tertile of PAI-1. No clear-cut associations could be demonstrated between APPs and composition of atherosclerosis or plaque vulnerability.

Conclusions: Higher circulating ferritin was associated with higher coronary plaque volume, and higher PAI-1 was associated with higher incidence of all-cause mortality or ACS. None of the APPs displayed consistent associations with composition of atherosclerosis or plaque vulnerability.