Risk of venous thromboembolism in first-degree relatives of affected patients compared with general population.
Relatives' venous thromboembolism risk nearly 10-fold higher when index case had early, multiple-relative venous thromboembolism
Risk of venous thromboembolism in first-degree relatives of affected patients compared with general population.
Determining venous thromboembolism (venous thromboembolism) risk among first-degree relatives (first-degree relatives) of venous thromboembolism patients requires effective risk assessment.
We aimed to evaluate venous thromboembolism risk in first-degree relatives of index cases (index cases) compared to the general population.
A cross-sectional family study (France, Canada) and a population-based study in the Brest district (France) were conducted.
risk climbs sharply when relatives cluster and clotting starts young
Among the 2617 first-degree relatives of 507 index cases with venous thromboembolism, 123 had venous thromboembolism (annual incidence: 1.2 per 1000 person-years).
Of 367,911 Brest district inhabitants, 576 had venous thromboembolism (annual incidence: 1.6 per 1000 person-years).
Compared with the general population, first-degree relatives had a higher venous thromboembolism risk when the index cases had unprovoked venous thromboembolism (standardised incidence ratio 1.31, 95%CI 1.11-1.53), had venous thromboembolism before 47 years (standardised incidence ratio 3.28, 95%CI 2.69-3.85) or when ≥2 first-degree relatives were affected (standardised incidence ratio 1.51, 95%CI 1.14-1.88).
First-degree relatives venous thromboembolism risk is significantly higher when the index cases had unprovoked venous thromboembolism, before 47 years, and/or when multiple first-degree relatives were affected, compared to the general population.