Article Text

Research paper
Recent time trends in incidence, outcome and premorbid treatment of atrial fibrillation-related stroke and other embolic vascular events: a population-based study
  1. Gabriel S C Yiin,
  2. Dominic P J Howard,
  3. Nicola L M Paul,
  4. Linxin Li,
  5. Ziyah Mehta,
  6. Peter M Rothwell
  7. on behalf of the Oxford Vascular Study
  1. Stroke Prevention Research Unit, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, Oxfordshire, UK
  1. Correspondence to Professor Peter M Rothwell, Stroke Prevention Research Unit, Nuffield Department of Clinical Neurosciences, Level 6, West Wing, John Radcliffe Hospital, Oxford OX3 9DU, UK; peter.rothwell{at}clneuro.ox.ac.uk

Abstract

Background Prevalence of atrial fibrillation (AF) is increasing, due partly to the ageing population. The Birmingham Atrial Fibrillation Treatment of the Aged (BAFTA) Trial, published in 2007, provided strong evidence of the effectiveness of warfarin at age≥80 years, but the impact on incidence of AF-related stroke and peripheral embolic vascular events is uncertain.

Methods We studied age-specific incidence and outcome of all AF-related incident strokes and systemic emboli from 2002 to 2012 in the Oxford Vascular Study.

Results Of 3096 acute cerebral or peripheral vascular events, 748 (24.2%) were AF-related. Of the 597 disabling/fatal incident ischaemic strokes, 369 occurred at age ≥80 years, of which 124 (33.6%) were in non-anticoagulated patients with known prior AF. There was no reduction in incident AF-related events after 2007 at all ages (n=231 vs 211; adjusted RR=1.11, 0.91 to 1.36, p=0.29) or at age ≥80 (137 vs 135, RR=1.15, 0.94 to 1.40, p=0.17). Scope for improved prevention at older ages was considerable. Among 208 patients with incident AF-related events at age ≥80 and known prior AF, only 19 (9.1%) were anticoagulated. Of the 189 patients not anticoagulated, 166 (87.8%) had no major disability prior to the event and 167 (88·4%) had a high embolism risk score, of whom 139 (83.2%) were also at low risk of complications. Yet, 125/167 (74.9%) were dead or institutionalised after the event. Potentially preventable embolic events outnumbered warfarin-related intracerebral haemorrhages by about 15-fold (280 vs 19), rising to 50-fold (189 vs 4) at age ≥80 years.

Conclusions We found no reduction in incidence of AF-related vascular events since publication of the BAFTA trial. A third of all disabling/fatal strokes occur in non-anticoagulated patients with known prior AF.

This is an Open Access article distributed in accordance with the terms of the Creative Commons Attribution (CC BY 4.0) license, which permits others to distribute, remix, adapt and build upon this work, for commercial use, provided the original work is properly cited. See: http://creativecommons.org/licenses/by/4.0/

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Footnotes

  • Contributors GSCY collected and analysed the data, and wrote the paper. DPJH, LL and NLMP collected and analysed the data. ZM performed the data analysis. PMR designed the study and wrote the paper.

  • Funding The Oxford Vascular Study is funded by the Wellcome Trust, Wolfson Foundation, British Heart Foundation, Dunhill Medical Trust, UK Stroke Association, National Institute for Health Research (NIHR) Oxford Biomedical Research Centre. PMR has a Wellcome Trust Senior Investigator Award and an NIHR Senior Investigator Award.

  • Competing interests None declared.

  • Patient consent Obtained.

  • Ethics approval The Oxford Vascular Study has been approved by our local research ethics committee.

  • Provenance and peer review Not commissioned; externally peer reviewed.

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