Relation of fibrinogen to cardiovascular events is independent of preclinical cardiovascular disease: the Strong Heart Study.

Background: It is unclear whether fibrinogen predicts cardiovascular events independently of echocardiographic cardiovascular abnormalities and traditional risk factors.
Methods: We studied 2671 American Indians who participated in the second Strong Heart Study examination (1993-1995) and were observed for an average of 50 +/- 6 months. Participants with baseline overt coronary artery disease or a plasma creatinine level > or =3 mg/dL were excluded. Left ventricular hypertrophy, elevated arterial stiffness, and subnormal myocardial contractility were assessed by echocardiography.
Results: Prevalences of echocardiographic abnormalities and cardiovascular event rates were higher with higher fibrinogen levels. Incident cardiovascular events (n = 158) and deaths (n = 64) were more frequent in participants with elevated fibrinogen levels (>400 mg/dL) than in participants with lower fibrinogen levels, as was the prevalence of echocardiographic abnormalities (both P <.01). Incident cardiovascular fatal and nonfatal events and cardiovascular deaths were 4 and 8 times higher, respectively, in participants with both elevated fibrinogen levels and echocardiographic abnormalities than in participants with neither echocardiographic abnormalities nor elevated fibrinogen levels. However, participants with fibrinogen levels >400 mg/dL had a 2 times greater relative risk of cardiovascular events or mortality, independent of both risk factors and echocardiographic abnormalities.
Conclusions: In a population-based sample of adults without clinical evidence of coronary artery disease at baseline, fibrinogen levels predicted cardiovascular events independent of traditional risk factors, left ventricular hypertrophy, elevated arterial stiffness, and subnormal myocardial systolic function.