Introduction: Elevated coagulation factor VIII activity has been associated with increased risk for both venous and arterial thrombosis. The current study evaluated the influence of Factor VIII levels and interactions with gender on all cause mortality in a large Austrian cohort.
Patients and methods: During 1991 and 2003, 11203 individuals, first ever request for laboratory analyses of FVIII: C, age > or =18 years, were included in this study. The median observation period was 5 years covering a total of 46000 person-years. The death rate was 17.1%.
Results: Compared to individuals within the reference category (FVIII: C <94%) hazard ratios gradually increased from 1.4 (95% CI: 1.1-1.8) in the 152-170% category (5th decile) to finally 4.4 (95% CI: 3.5-5.5) in the >313% category (highest decile, all p < 0.05). The association between FVIII: C levels and mortality remained essentially unchanged when considering non-cancer mortality, all cause vascular mortality or mortality due to ischemic heart disease. Compared to males females with elevated FVIII: C had a worse outcome resulting in higher hazard ratios reaching 6.8 (95% CI: 4.6-9.9) within the highest decile compared to males (HR: 3.4 (95% CI: 2.6-4.5)).
Conclusions: In our large patient cohort we might be able to demonstrate for the first time that FVIII: C plasma activity is strongly associated with all cause mortality. Additionally, FVIII: C appears to interact with gender. Especially in women FVIII: C might help identifying high-risk cohorts, which might benefit from individualized prevention strategies.