Factor V Leiden mutation linked to atrial fibrillation

A novel cohort analysis from the Tromsø Study found that specifically men with factor V Leiden (FVL) mutation have an elevated risk for atrial fibrillation. However, FVL mutation was not identified as a general risk factor for ischaemic stroke [1].

Atrial fibrillation is an established prothrombotic disease that may lead to ischaemic stroke. The FVL mutation is known to be a risk for venous thromboembolism and is also connected with arterial disease and unfavourable outcomes of pregnancies in carriers. The aim of this sub-analysis, presented by PhD student Erin Mathiesen Hald (UiT The Arctic University of Norway, Norway), was to evaluate a possible association of FVL with atrial fibrillation and successive ischaemic stroke.

This analysis included data form a randomly selected sub-cohort of 3,663 subjects from the fourth survey of general population within the Tromsø Study (1994/1995). Blood samples from all participants were analysed for FVL genotype, and cases of atrial fibrillation and ischaemic stroke were determined until 31 December 2012. The risks for atrial fibrillation and ischaemic stroke in patients with FVL mutation were evaluated by calculation of hazard ratios (HR) using Cox proportional hazard regression models.

Among the study subjects, 545 had a diagnosis of atrial fibrillation and 314 suffered an ischaemic stroke. Of the participants, 235 (6.4%) were carriers of ≥ 1 risk allele in FVL. The regression identified an overall 1.4-fold higher risk of atrial fibrillation for study participants who carried an FVL mutation. Interestingly, only men but not women with FVL mutation had a 50% elevated relative risk for atrial fibrillation. Yet, their risk for ischaemic stroke was not significantly raised. Although the hazard of sustaining a stroke was enhanced in people who developed atrial fibrillation (HR 3.22), FVL mutation did not contribute to this risk.

1. Hald EM, et al. PB2052, ISTH Virtual Congress 2020, 12-14 July.

Posted on 8 September 202022 February 2024