Thromb Haemost 2018; 118(07): 1296-1304
DOI: 10.1055/s-0038-1651482
Stroke, Systemic or Venous Thromboembolism
Georg Thieme Verlag KG Stuttgart · New York

Dynamic Changes of CHA2DS2-VASc Score and the Risk of Ischaemic Stroke in Asian Patients with Atrial Fibrillation: A Nationwide Cohort Study

Minjae Yoon
1  Division of Cardiology, Department of Internal Medicine, Severance Cardiovascular Hospital, Yonsei University College of Medicine, Seoul, Korea
,
Pil-Sung Yang
2  Department of Cardiology, CHA Bundang Medical Center, CHA University, Seongnam, Korea
,
Eunsun Jang
1  Division of Cardiology, Department of Internal Medicine, Severance Cardiovascular Hospital, Yonsei University College of Medicine, Seoul, Korea
,
Hee Tae Yu
1  Division of Cardiology, Department of Internal Medicine, Severance Cardiovascular Hospital, Yonsei University College of Medicine, Seoul, Korea
,
Tae-Hoon Kim
1  Division of Cardiology, Department of Internal Medicine, Severance Cardiovascular Hospital, Yonsei University College of Medicine, Seoul, Korea
,
Jae-Sun Uhm
1  Division of Cardiology, Department of Internal Medicine, Severance Cardiovascular Hospital, Yonsei University College of Medicine, Seoul, Korea
,
Jong-Youn Kim
1  Division of Cardiology, Department of Internal Medicine, Severance Cardiovascular Hospital, Yonsei University College of Medicine, Seoul, Korea
,
Hui-Nam Pak
1  Division of Cardiology, Department of Internal Medicine, Severance Cardiovascular Hospital, Yonsei University College of Medicine, Seoul, Korea
,
Moon-Hyoung Lee
1  Division of Cardiology, Department of Internal Medicine, Severance Cardiovascular Hospital, Yonsei University College of Medicine, Seoul, Korea
,
Gregory Y. H. Lip
1  Division of Cardiology, Department of Internal Medicine, Severance Cardiovascular Hospital, Yonsei University College of Medicine, Seoul, Korea
3  Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, United Kingdom
4  Aalborg Thrombosis Research Unit, Department of Clinical Medicine, Aalborg University, Aalborg, Denmark
,
Boyoung Joung
1  Division of Cardiology, Department of Internal Medicine, Severance Cardiovascular Hospital, Yonsei University College of Medicine, Seoul, Korea
› Author Affiliations
Funding This study was supported by a research grant from the Basic Science Research Program through the National Research Foundation of Korea funded by the Ministry of Education, Science and Technology (NRF-2012R1A2A2A02045367), and grants from the Korean Healthcare technology R&D project funded by the Ministry of Health & Welfare (HI16C0058, HI15C1200). The funding sources played no role in the design, conduct or reporting of this study.
Further Information

Publication History

21 March 2018

27 March 2018

Publication Date:
03 May 2018 (eFirst)

Abstract

Background Stroke risk in atrial fibrillation (AF) is often assessed at initial presentation, and risk stratification performed as a ‘one off’. In validation studies of risk prediction, baseline values are often used to ‘predict’ events that occur many years later. Many clinical variables have ‘dynamic’ changes over time, as the patient is followed up. These dynamic changes in risk factors may increase the CHA2DS2-VASc score, stroke risk category and absolute ischaemic stroke rate.

Objective This article evaluates the ‘dynamic’ changes of CHA2DS2-VASc variables and its effect on prediction of stroke risk.

Patients and Methods From the Korea National Health Insurance Service database, a total of 167,262 oral anticoagulant-naive non-valvular AF patients aged ≥ 18 years old were enrolled between January 1, 2002, and December 31, 2005. These patients were followed up until December 31, 2015.

Results At baseline, the proportions of subjects categorized as ‘low’, ‘intermediate’ or ‘high risk’ by CHA2DS2-VASc score were 15.4, 10.6 and 74.0%, respectively. Mean CHA2DS2-VASc score increased annually by 0.14, particularly due to age and hypertension. During follow-up of 10 years, 46.6% of ‘low-risk’ patients and 72.0% of ‘intermediate risk’ patients were re-classified to higher stroke risk categories. Among the original ‘low-risk’ patients, annual ischaemic stroke rates were significantly higher in the re-classified ‘intermediate’ (1.17 per 100 person-years, p < 0.001) or re-classified ‘high-risk’ groups (1.44 per 100 person-years, p = 0.048) than consistently ‘low-risk’ group (0.29 per 100 person-years). The most recent CHA2DS2-VASc score and the score change with the longest follow-up had the best prediction for ischaemic stroke.

Conclusion In AF patients, stroke risk as assessed by the CHA2DS2-VASc score is dynamic and changes over time. Rates of ischaemic stroke increased when patients accumulated risk factors, and were re-classified into higher CHA2DS2-VASc score categories. Stroke risk assessment is needed at every patient contact, as accumulation of risk factors with increasing CHA2DS2-VASc score translates to greater stroke risks over time.

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


Note

Minjae Yoon and Pil-Sung Yang contributed equally to the article. Gregory Y. H. Lip and Boyoung Joung are senior co-authors of the article.


Authors' Contributions

M. Yoon and P.S. Yang drafted the manuscript, had full access to all of the data and takes responsibility for the integrity of the data and the accuracy of the data analysis. E. Jang, H.T. Yu, T.H. Kim, J.S. Uhm, J.Y. Kim, H.N. Pak and M.H. Lee contributed to data collection. B. Joung and G.Y.H.L. contributed to data interpretation, critical revision and final approval of the manuscript.


Supplementary Material