Hemostatic factors, inflammatory markers, and risk of incident venous thromboembolism: The Multi-Ethnic Study of Atherosclerosis

Background: Several hemostatic factors and inflammatory markers are associated with the risk of incident venous thromboembolism (VTE), however, most existing data are from case-control studies in Caucasian populations.

Objectives: We aimed to prospectively confirm previous findings and explore less studied biomarkers in relation to VTE risk in a multi-racial/multi-ethnic cohort.

Methods: Circulating levels of factor VIII, fibrinogen, D-dimer, plasmin-antiplasmin complex (PAP), C-reactive protein (CRP), and interleukin-6 (IL-6) were measured at baseline (2000-2002) in 6706 participants of the Multi-Ethnic Study of Atherosclerosis. Incident VTE was identified using hospitalization discharge codes from baseline to December 31, 2015. Hazard ratios (HRs) of VTE were estimated in Cox regression models.

Results: There were 227 events during a median of 14 years of follow-up. Compared with participants in the lowest quartile, the HRs for those above the 95th percentile and p for trend across categories were 3.50 (95% confidence interval [CI] 1.98-6.19; p < .001) for D-dimer, 1.49 (95% CI 0.84-2.63; p = .02) for factor VIII, 1.32 (95% CI 0.76-2.28; p = .99) for fibrinogen, 1.92 (95% CI 1.08-3.42; p = .15) for PAP, 1.68 (95% CI 0.81-3.48; p = .08) for CRP, and 2.55 (95% CI 1.15-5.66; p = .07) for IL-6, after adjustment for demographics and body mass index. For CRP and IL-6, follow-up was restricted to 10 years because of violations of the proportional hazards assumption. No significant interactions by age/ethnicity were observed.

Conclusions: We demonstrated a fairly novel association between PAP and risk of incident VTE, and contributed further prospective confirmation regarding the associations of D-dimer, factor VIII, and IL-6 with VTE.