Prognostic Influence of Increased Fibrinogen and C-Reactive Protein Levels in Unstable Coronary Artery Disease

Abstract

Background The prognostic influences of fibrinogen and C-reactive protein levels and their relations to myocardial damage in unstable coronary artery syndromes have not been well described. Methods and Results Fibrinogen and C-reactive protein were determined at inclusion and related to outcome after 5 months in 965 patients with unstable angina or non–Q-wave myocardial infarction randomized to 5 weeks with low-molecular-weight heparin or placebo. The probabilities of death were 1.6%, 4.6%, and 6.9% ( P =.005) and the probabilities of death and/or myocardial infarction were 9.3%, 14.2%, and 19.1% ( P =.002), respectively, in patients stratified by tertiles of fibrinogen (<3.38, 3.38 to 3.99, and ≥4.0 g/L). The probabilities of death were 2.2%, 3.6%, and 7.5% ( P =.003) after stratification of patient data by tertiles of C-reactive protein level (<2, 2 to 10, and >10 mg/L). In logistic multiple regression analysis, increased fibrinogen levels were independently associated with the incidence of death and/or myocardial infarction ( P =.013), and elevated C-reactive protein level was associated with the incidence of death ( P =.012). The increased relative risk of subsequent death or myocardial infarction in individuals with an elevated fibrinogen level was consistent in most subgroups evaluated; although significantly so only in patients with signs of myocardial damage. Conclusions Increased levels of both fibrinogen and C-reactive protein are associated with a worse outcome in patients with unstable coronary artery disease. The increased risk associated with elevated fibrinogen levels is independent of, and additive to, the prognostic influence of myocardial damage.