Risk of recurrent venous thromboembolism after discontinuation of vitamin K antagonist treatment: a nested case-control study.
J Thromb Haemost. 2016 Apr 15;
Authors: Martinez C, Katholing A, Folkerts K, Cohen AT
BACKGROUND: Standard treatment of venous thromboembolism (VTE) and prevention of recurrent VTE (rVTE) consists of anticoagulant therapy. Optimal duration of anticoagulation depends on the presence of risk factors of rVTE.
OBJECTIVES: To estimate the risk of rVTE in association with time since discontinuation of vitamin K antagonist (VKA) treatment.
METHODS: Among the UK Clinical Practice Research Datalink with linked information on hospitalization and cause of death, a cohort of patients with first VTE receiving initial VKA treatment between 2001-2013 was formed. Using a nested case-control approach incident rVTEs (cases) were matched to patients with VTE but without rVTE (controls). Adjusted rate ratios (RR) of rVTE associated with time since VKA discontinuation relative to current VKA use were estimated from conditional logistic regression.
RESULTS: The VTE cohort comprised 41,841 patients with 1242 rVTEs and 6205 matched controls. The RR of rVTE was increased within 60 days following VKA discontinuation, RR 2.23 (95% CI 1.71-2.91) and within 61 to 120 days after VKA discontinuation, RR 1.49 (1.08-2.05) relative to current VKA use. The increased RR corresponded to excess incidence rates of 6.72 (3.90-10.06) rVTE cases per 100 person-years within 60 days and of 2.68 (0.42-5.58) in 61 to 120 days after VKA discontinuation.
CONCLUSIONS: VKA discontinuation results in a transient increased risk of rVTE which peaks within 60 days and lasts for up to 120 days after VKA cessation. Specific patient education for symptoms and signs and increased clinical vigilance for recurrences in this period is recommended. This article is protected by copyright. All rights reserved.
PMID: 27079164 [PubMed - as supplied by publisher]