Assessing the contribution of fibrinogen in predicting risk of death in men with peripheral arterial disease

• Published in: Journal of thrombosis and haemostasis 2009-02, Vol.7 (2), p.270-276
• Main Authors: BARTLETT, J. W., DE STAVOLA, B. L., MEADE, T. W.
• Format: Article
• Language: English
• Subjects: Aged; Aged, 80 and over; Cause of Death; Death; fibrinogen; Fibrinogen - analysis; Humans; Male; Middle Aged; Models, Statistical; Odds Ratio; peripheral arterial disease; Peripheral Vascular Diseases - mortality; Predictive Value of Tests; predictiveness curves; Randomized Controlled Trials as Topic; Risk; risk prediction; Survival Analysis
• ISSN: 1538-7933; 1538-7836; 1538-7836
• DOI: 10.1111/j.1538-7836.2008.03236.x

Background: Although fibrinogen is known to be an independent population‐level risk factor for cardiovascular disease in healthy individuals, less is known about its value for individual‐level risk prediction. Objectives: To assess the independent contribution of plasma fibrinogen to risk prediction in men with peripheral arterial disease. Patients and methods: We used data from the 785 men randomized to placebo in the Lower Extremity Arterial Disease Event Reduction (LEADER) trial. Men were followed at 6‐monthly intervals up to 3 years, during which 116 patients died. Multivariable standard and pooled logistic regression were used to model odds of death in the next 3 years or in a 6‐month interval. The c‐statistic and predictiveness curves were used to assess improvement in predictive ability. Results: Fibrinogen measured at baseline was an independent predictor of all‐cause mortality risk (adjusted odds ratio [OR] 1.44, 95% confidence interval [CI] 1.02–1.94, for a 1 g L−1 increase). Adding baseline fibrinogen to a set of other risk factors did not, however, substantially improve predictive ability. Similarly, fibrinogen measured at the start of a 6‐month interval was independently associated with odds of death in the next 6 months (adjusted OR 1.65; 95% CI  0.96–2.73). Again, predictiveness curves with and without fibrinogen did not substantially differ, although the c‐statistic increased by 0.011. Conclusions: Although fibrinogen was independently associated with both 6‐month and 3‐year mortality risk, individual‐level risk prediction was not substantially improved by including fibrinogen in risk models.