Increased risk of major bleeding after a minor bleed during treatment with vitamin K antagonists is determined by fixed common risk factors.
J Thromb Haemost. 2016 Mar 14;
Authors: van Rein N, le Cessie S, van Vliet IP, Reitsma PH, van der Meer FJ, Lijfering WM, Cannegieter SC
BACKGROUND: Patients who encounter a minor bleeding during treatment with vitamin K antagonists (VKAs) are at 3-fold increased risk for subsequent major bleeding. The nature of the underlying risk factors is largely unknown.
OBJECTIVES: To provide leads why patients with minor bleeds are at increased risk of subsequent major bleeds, such as whether risk factors are of a transient or a fixed nature.
METHODS: Patients who started VKA treatment between 2003 and 2013 were included. Exposure started from the minor bleed until 3 months later. We used two analyses: a Cox model in which we adjusted for several known risk factors. Second, a case-crossover (CCO) design, which corrects for all fixed risk factors (like chronic diseases and genes) as patients are compared with themselves. The combination of both analyses gives insight as to whether the association of minor with major bleeds is due to fixed or transient risk factors.
RESULTS: Out of 26 130 Patients who were included and followed for 61 672 years, 7194 experienced a minor and 913 a major bleed. The Cox model indicated that patients with minor bleeds were at 2.5-fold increased risk of experiencing subsequent major bleeding after adjustment for known risk factors, while the CCO gave risk estimates around unity (OR 0.9, 95% confidence interval 0.5-1.5).
CONCLUSIONS: The combination of both analyses indicates that minor bleeds are markers for fixed and currently unknown risk factors for major bleeding events. This article is protected by copyright. All rights reserved.
PMID: 26988994 [PubMed - as supplied by publisher]