Relation of circulating PCSK9 concentration to fibrinogen in patients with stable coronary artery disease

BACKGROUND: Both proprotein convertase subtilisin/kexin type 9 (PCSK9) and fibrinogen have been established as novel markers for atherosclerotic diseases. However, no data are available regarding the relationship between circulating PCSK9 and fibrinogen concentration up to now. OBJECTIVE: To explore the potential link of the circulating PCSK9 concentration to fibrinogen in patients with stable coronary artery disease (CAD). METHODS: We studied 219 eligible consecutive patients with angiographically proven stable CAD. Baseline clinical and laboratory data were collected. Plasma PCSK9 concentration was measured by enzyme-linked immunosorbent assay. High-sensitivity C-reactive protein (hs-CRP), erythrocyte sedimentation rate, D-dimer, and albumin were also measured in all subjects as inflammatory markers. The relation of the circulating PCSK9 concentration to fibrinogen was evaluated. RESULTS: The data indicated that the patients with high PCSK9 concentration tended to have higher fibrinogen levels according to PCSK9 tertiles (P = .037). Spearman correlation analysis revealed a positive relation between plasma PCSK9 concentration and fibrinogen (r = 0.211, P = .002). Additionally, the circulating PCSK9 concentration also correlated positively with total cholesterol, low-density lipoprotein cholesterol, and hs-CRP levels (r = 0.333, P < .001; r = 0.302, P < .001; r = 0.153, P = .023, respectively). In the stepwise multivariate regression analysis, the association between PCSK9 and fibrinogen remained significant (beta = 0.168, P = .011) after adjustment for conventional cardiovascular risk factors including lipid profiles, hs-CRP, and D-dimer. CONCLUSION: The present study first demonstrated that the circulating PCSK9 concentration was positively associated with fibrinogen in patients with stable CAD, suggesting that the interactions of PCSK9 and fibrinogen in the status of atherosclerosis may need further investigation. (C) 2014 National Lipid Association. All rights reserved.