Red Cell Distribution Width and Risk of Atrial Fibrillation and Subsequent Thromboembolism: The Tromsø Study

Erin M Hald; Maja-Lisa Løchen; Jostein Lappegård; Trygve S Ellingsen; Ellisiv B Mathiesen; Tom Wilsgaard; Inger Njølstad; Sigrid K Brækkan; John-Bjarne Hansen

doi:10.1055/s-0040-1716417

Red Cell Distribution Width and Risk of Atrial Fibrillation and Subsequent Thromboembolism: The Tromsø Study

TH Open. 2020 Sep 28;4(3):e280-e287. doi: 10.1055/s-0040-1716417. eCollection 2020 Jul.

Authors

Erin M Hald^{1

2}, Maja-Lisa Løchen³, Jostein Lappegård¹, Trygve S Ellingsen¹, Ellisiv B Mathiesen^{1

4}, Tom Wilsgaard³, Inger Njølstad^{1

3}, Sigrid K Brækkan^{1

2}, John-Bjarne Hansen^{1

2}

Affiliations

¹ K.G. Jebsen Thrombosis Research and Expertise Center (TREC), Department of Clinical Medicine, UiT The Arctic University of Norway, Tromsø, Norway.
² Division of Internal Medicine, University Hospital of North Norway, Tromsø, Norway.
³ Epidemiology of Chronic Diseases Research Group, Department of Community Medicine, UiT The Arctic University of Norway, Tromsø, Norway.
⁴ Brain and Circulation Research Group, Department of Clinical Medicine, UiT The Arctic University of Norway, Tromsø, Norway.

Abstract

Introduction Red cell distribution width (RDW) is associated with cardiovascular diseases, including atrial fibrillation (AF) and venous thromboembolism (VTE). Whether RDW is a risk marker for thromboembolic events in AF patients is scarcely known. We aimed to assess the association between RDW and the risk of AF, and AF-related VTE and ischemic stroke, in a population-based cohort. Methods We measured RDW in 26,111 participants from the Tromsø Study (1994-1995), and registered incident AF cases through December 31, 2013. Among participants with AF, first-ever VTEs and ischemic strokes were registered from the date of AF diagnosis through the end of follow-up. We calculated hazard ratios (HRs) with 95% confidence intervals (CIs) for AF by quartiles of RDW. Furthermore, we calculated cause-specific HRs for VTE and ischemic stroke by tertiles of RDW for participants with AF. Results There were 2,081 incident AF cases during a median of 18.8 years of follow-up. Subjects with RDW in the highest quartile (RDW ≥ 13.3%) had 30% higher risk of AF than those in the lowest quartile (RDW ≤ 12.3%). Among those with AF, subjects with RDW in the upper tertile had a doubled risk of ischemic stroke (HR 2.07, 95% CI 1.20-3.57). In contrast, RDW was not associated with incident VTE in subjects with AF. Conclusion RDW was significantly associated with incident AF in a general population. Among subjects with AF, high RDW was associated with ischemic stroke, but not VTE.

Keywords: arterial thrombosis; epidemiological studies; red cell distribution width; venous thrombosis.

Grants and funding

Funding K. G. Jebsen TREC is supported by an independent grant from the K.G. Jebsen Foundation. E.M.H. is in receipt of a grant from the Northern Norway Regional Health Authority.