Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2021 Aug 1;6(8):918-925.
doi: 10.1001/jamacardio.2021.1232.

Evaluation of the Risk of Stroke Without Anticoagulation Therapy in Men and Women With Atrial Fibrillation Aged 66 to 74 Years Without Other CHA2DS2-VASc Factors

Husam Abdel-Qadir  1   2   3   4   5 , Sheldon M Singh  5   6 , Andrea Pang  3 , Peter C Austin  3   4 , Cynthia A Jackevicius  3   4   7   8 , Karen Tu  4   9   10   11   12 , Paul Dorian  5   13 , Dennis T Ko  3   4   5   6
Affiliations

Evaluation of the Risk of Stroke Without Anticoagulation Therapy in Men and Women With Atrial Fibrillation Aged 66 to 74 Years Without Other CHA2DS2-VASc Factors

Husam Abdel-Qadir et al. JAMA Cardiol. .

Abstract

Importance: There are limited clinical trial data and discrepant recommendations regarding use of anticoagulation therapy in patients with atrial fibrillation (AF) aged 65 to 74 years without other stroke risk factors.

Objectives: To evaluate the risk of stroke without anticoagulation therapy in men and women with AF aged 66 to 74 years without other CHA2DS2-VASc (congestive heart failure, hypertension, age ≥75 years, diabetes, stroke, vascular disease, age 65-74 years, female sex) risk factors and examine the association of stroke incidence with patient age.

Design, setting, and participants: A population-based retrospective cohort study was conducted using linked administrative databases. The population included 16 351 individuals aged 66 to 74 years who were newly diagnosed with AF in Ontario, Canada, between April 1, 2007, and March 31, 2017. Exclusion criteria included long-term care residence, prior anticoagulation therapy, valvular disease, heart failure, hypertension, diabetes, stroke, and vascular disease. The cumulative incidence function was used to estimate the 1-year incidence of stroke in patients who did not receive anticoagulation therapy. Fine-Gray regression was used to study the association of patient characteristics with stroke incidence and derive estimates of stroke risk at each age. Death was treated as a competing risk and patients were censored if they initiated anticoagulation therapy. Inverse probability of censoring weights was used to account for patient censoring. Data analysis was performed from May 26, 2019, to December 9, 2020.

Exposures: Atrial fibrillation and age.

Main outcomes and measures: Hospitalizations for stroke.

Results: Of the 16 351 individuals with AF (median [interquartile range] age, 70 [68-72] years), 8352 (51.1%) were men; 6314 individuals (38.6%) started anticoagulation therapy during follow-up. The overall 1-year stroke incidence among patients who did not receive anticoagulation therapy was 1.1% (95% CI, 1.0%-1.3%) and the incidence of death without stroke was 8.1% (95% CI, 7.7%-8.5%). The incidence of stroke was not significantly associated with sex. The estimated 1-year stroke risk increased with patient age from 66 years (0.7%; 95% CI, 0.5%-0.9%) to 74 years (1.7%; 95% CI, 1.3%-2.1%).

Conclusions and relevance: The risk of stroke more than doubled in this study as men and women with AF but no other CHA2DS2-VASc risk factors aged from 66 to 74 years. These data suggest that anticoagulation therapy is more likely to benefit older individuals within this group of patients, whereas younger individuals are less likely to gain net clinical benefit from anticoagulation therapy.

PubMed Disclaimer

Conflict of interest statement

Conflict of Interest Disclosures: Dr Abdel-Qadir reported receiving grants from the University of Toronto and the Heart and Stroke Foundation of Canada during the conduct of the study; personal fees from Amgen and CPC Clinical Research outside the submitted work; and salary support via a National New Investigator Award from the Heart and Stroke Foundation of Canada. Dr Austin is supported by a Mid-Career Investigator Award from the Heart and Stroke Foundation. Dr Tu is supported by a Research Scholar Award from the Department of Family and Community Medicine at the University of Toronto. Dr Jackevicius reported receiving fees from the American Heart Association for serving as an associated editor for Circulation: Cardiovascular Quality Outcomes outside the submitted work. Dr Ko is supported by a Clinician Scientist Award from the Heart and Stroke Foundation of Canada. No other disclosures were reported.

Figures

Figure 1.
Figure 1.. Risk of Hospitalization for Stroke in Patients With Newly Diagnosed Atrial Fibrillation Not Receiving Anticoagulation Therapy
Patients were censored when they started anticoagulation therapy and death was treated as a competing risk. Patient data were weighted by the inverse probability of censoring.
Figure 2.
Figure 2.. Predicted 1-Year Incidence of Stroke at Each Age Between 66 and 74 Years Among Nonanticoagulated Patients Not Receiving Anticoagulation Therapy
Death was treated as a competing risk. Patients were censored when they started anticoagulation and were weighted by the inverse of the probability of censoring. Error bars indicate 95% CI. The dotted line indicates 1-year stroke incidence in the full cohort (1.1%).
See this image and copyright information in PMC

Comment in

References

    1. Hart RG, Pearce LA, Aguilar MI. Meta-analysis: antithrombotic therapy to prevent stroke in patients who have nonvalvular atrial fibrillation. Ann Intern Med. 2007;146(12):857-867. doi: 10.7326/0003-4819-146-12-200706190-00007 - DOI - PubMed
    1. Ruff CT, Giugliano RP, Braunwald E, et al. Comparison of the efficacy and safety of new oral anticoagulants with warfarin in patients with atrial fibrillation: a meta-analysis of randomised trials. Lancet. 2014;383(9921):955-962. doi: 10.1016/S0140-6736(13)62343-0 - DOI - PubMed
    1. Lip GY, Nieuwlaat R, Pisters R, Lane DA, Crijns HJ. Refining clinical risk stratification for predicting stroke and thromboembolism in atrial fibrillation using a novel risk factor-based approach: the euro heart survey on atrial fibrillation. Chest. 2010;137(2):263-272. doi: 10.1378/chest.09-1584 - DOI - PubMed
    1. Gage BF, Waterman AD, Shannon W, Boechler M, Rich MW, Radford MJ. Validation of clinical classification schemes for predicting stroke: results from the National Registry of Atrial Fibrillation. JAMA. 2001;285(22):2864-2870. doi: 10.1001/jama.285.22.2864 - DOI - PubMed
    1. January CT, Wann LS, Calkins H, et al. 2019 AHA/ACC/HRS focused update of the 2014 AHA/ACC/HRS guideline for the management of patients with atrial fibrillation: a report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm Society in collaboration with the Society of Thoracic Surgeons. Circulation. 2019;140(2):e125-e151. doi: 10.1161/CIR.0000000000000665 - DOI - PubMed

Publication types

Grants and funding