Hemostatic markers are associated with the risk and prognosis of atrial fibrillation: The ARIC study

Background: Various hemostatic markers are associated with the risk of cardiovascular disease; however, limited information exists on their relationship with the occurrence and prognosis of atrial fibrillation (AF). Objectives: To assess whether hemostatic markers are associated with the incidence and prognosis of AF. Methods: We studied 14,858 men and women in the Atherosclerosis Risk in Communities cohort, aged 45-64 and free of AF at baseline (1987-1989). Fibrinogen, von Willebrand factor (vWf), factor VII activity (VIIc), factor VIII activity (VIIIc), protein C, antithrombin III (ATIII), and activated partial thromboplastin time (aPTT) were measured in blood samples at baseline. AF and other cardiovascular outcomes through 2005 were determined following standardized protocols. Results: During a median follow-up of 16.8 years, 1209 cases of AF were identified. In multivariable Cox models, the hazard ratios (HR) and 95% confidence intervals (CI) of incident AF associated with a 1 - standard deviation (SD) increase in each marker were 1.13 (1.07-1.20) for fibrinogen, 1.17 (1.11-1.23) for vWf, 1.17 (1.11-1.24) for factor VIIIc, 0.93 (0.88-1.00) for factor VIIc, 0.98 (0.92-1.04) for protein C, 1.00 (0.94-1.06) for aPTT and 1.00 (0.95-1.06) for ATIII. Greater factor VIIIc, fibrinogen and vWf were consistently associated with a higher risk of cardiovascular outcomes and mortality in those with and without incident AF, while greater protein C was associated with a lower risk of ischemic stroke. Conclusion: Several hemostatic markers are associated with the incidence of AF independently of other cardiovascular risk factors. Their role in the risk stratification of AF patients should be further studied.