Epidemiology of venous thromboembolism in the Framingham Heart Study

Background Reports of the crude incidence of venous thromboembolism (VTE) in Western countries vary widely. Data regarding risk factors, incidence and recurrence of VTE from deeply-phenotyped community-based cohort studies are needed. Objectives To study the incidence, associated mortality, and predisposing factors of VTE in the prospective, longitudinal community-based Framingham Heart Study. Patients/Methods The study sample consisted of the Framingham Heart Study Original, Offspring, Third Generation, and Omni cohorts (N = 9754). Incidence rates (IR) were standardized to the 2000 US population. Cox proportional hazards regression models were used to study risk factor associations. Results During 1995–2014 (total follow-up time 104,091 person-years [median 9.8 (range 0–20) years]), 297 incident VTE events were observed. Age-adjusted IR of VTE was 20.3/10,000 (95% CI 17.9–22.6). Of the events 120 (40%) were pulmonary embolism (PE) and 177 (60%) were deep venous thrombosis (DVT); 29% were unprovoked, 40% provoked, and 31% cancer-related. Cancer-related VTE was associated with high mortality at 30 days (24.2%), 1 year (66.3%), and 5 years (75.6%). In multivariable models, age and obesity, but no other traditional cardiovascular risk factors, were significantly associated with VTE (hazard ratio [HR] per 10-year increase in age 1.69, 95% CI 1.48–1.92; HR for obesity (BMI ≥ 30 kg/m²) 1.88, 95% CI 1.44–2.45). Conclusions We provide data on the epidemiology of VTE. VTE is associated with significant mortality, and prognosis after cancer-related VTE is particularly poor. Traditional cardiovascular risk factors beyond age and obesity are not associated with VTE.