Thromb Haemost 2019; 119(07): 1162-1170
DOI: 10.1055/s-0039-1683933
Stroke, Systemic or Venous Thromboembolism
Georg Thieme Verlag KG Stuttgart · New York

Incident Co-Morbidities in Patients with Atrial Fibrillation Initially with a CHA2DS2-VASc Score of 0 (Males) or 1 (Females): Implications for Reassessment of Stroke Risk in Initially ‘Low-Risk’ Patients

Tze-Fan Chao
1  Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
2  Institute of Clinical Medicine, Cardiovascular Research Center, National Yang-Ming University, Taipei, Taiwan
,
Jo-Nan Liao
1  Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
2  Institute of Clinical Medicine, Cardiovascular Research Center, National Yang-Ming University, Taipei, Taiwan
,
Ta-Chuan Tuan
1  Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
2  Institute of Clinical Medicine, Cardiovascular Research Center, National Yang-Ming University, Taipei, Taiwan
,
Yenn-Jiang Lin
1  Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
2  Institute of Clinical Medicine, Cardiovascular Research Center, National Yang-Ming University, Taipei, Taiwan
,
Shih-Lin Chang
1  Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
2  Institute of Clinical Medicine, Cardiovascular Research Center, National Yang-Ming University, Taipei, Taiwan
,
Li-Wei Lo
1  Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
2  Institute of Clinical Medicine, Cardiovascular Research Center, National Yang-Ming University, Taipei, Taiwan
,
Yu-Feng Hu
1  Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
2  Institute of Clinical Medicine, Cardiovascular Research Center, National Yang-Ming University, Taipei, Taiwan
,
Fa-Po Chung
1  Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
2  Institute of Clinical Medicine, Cardiovascular Research Center, National Yang-Ming University, Taipei, Taiwan
,
Tzeng-Ji Chen
3  Department of Family Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
,
Gregory Y. H. Lip*
4  Liverpool Centre for Cardiovascular Science, University of Liverpool and Liverpool Heart and Chest Hospital, Liverpool, United Kingdom
5  Aalborg Thrombosis Research Unit, Department of Clinical Medicine, Aalborg University, Aalborg, Denmark
,
Shih-Ann Chen*
1  Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
2  Institute of Clinical Medicine, Cardiovascular Research Center, National Yang-Ming University, Taipei, Taiwan
› Author Affiliations
Funding This work was supported in part by grants from the Ministry of Science and Technology (MOST 107-2314-B-075-062-MY3), and Taipei Veterans General Hospital (V107B-001, V107B-022, V107C-200), Taipei, Taiwan.
Further Information

Publication History

06 February 2019

22 February 2019

Publication Date:
21 March 2019 (eFirst)

Abstract

Background Oral anticoagulants (OACs) are not recommended for ‘low-risk’ patients with atrial fibrillation (AF). We investigated the incidences of new risk factors developing, and the temporal trends in the CHA2DS2-VASc score in initially ‘low-risk’ AF patients. Second, we propose a reasonable timing interval at which stroke risk should be reassessed for such AF patients.

Methods We studied 14,606 AF patients who did not receive anti-platelet agents or OACs with a baseline CHA2DS2-VASc score of 0 (males) or 1 (females). The CHA2DS2-VASc scores of patients were followed up and updated until the occurrence of ischaemic stroke or mortality or 31 December 2011. The associations between the prescription of warfarin and risk of adverse events once patients' scores changed were analysed. Decile values of durations to incident co-morbidities and from the acquirement of new co-morbidities to ischaemic stroke were studied.

Results During a mean follow-up of 4 years, 7,079 (48.5%) patients acquired at least one new stroke risk factor component(s) with annual risks of 6.35% for hypertension, 3.68% for age ≥ 65 years, 2.77% for heart failure, 1.99% for diabetes mellitus and 0.33% for vascular diseases. The incidence for CHA2DS2-VASc score increments was 12.1%/year. Initiation of warfarin was associated with a lower risk of adverse events (adjusted hazard ratio, 0.530; 95% confidence interval, 0.371–0.755). Among 6,188 patients who acquired new risk factors, 80% would acquire these co-morbidities after 4.2 months of AF diagnosis. The duration from the acquirement of incident co-morbidities to the occurrence of ischaemic stroke was longer than 4.4 months for 90% of the patients.

Conclusion The CHA2DS2-VASc score increases in approximately 12% of initially ‘low-risk’ AF patients each year, and the initiation of warfarin once the score changed was associated with a better prognosis. Three to four months may be a reasonable timing interval at which stroke risk should be reassessed so that OACs could be prescribed in a timely manner for stroke prevention.

Note

This study is based in part on data from the National Health Insurance Research Database provided by the Bureau of National Health Insurance, Department of Health and managed by National Health Research Institutes. The interpretation and conclusions contained herein do not represent those of Bureau of National Health Insurance, Department of Health or National Health Research Institutes.


* Joint senior authors.


Note: The review process for this paper was fully handled by Christian Weber, Editor-in-Chief.