The risk and cause of death according to prevalent atrial fibrillation and the role of CHA2DS2-VASc score to stratify the risk of all-cause and cardiovascular death
Authors: Kim Y , Lee S R , Choi E K , Ahn H J , Bae N Y , Lee K Y , Choi J M , Ahn H J , Kwon S I , Han K D , Oh S , Lip G 
Published: November 2023

Abstract

Background
Atrial fibrillation (AF) is the most common cardiac arrhythmia, and its prevalence is rapidly increasing. AF is associated with increased risks of stroke and all-cause death. Understanding the causes of death (COD), the relative risks of each cause in AF patients compared to non-AF population, and finding out modalities to stratify the risk of death among AF patients is essential to plan optimal care of AF patients.

Purpose
We aimed to analyze the COD of AF patients and the relative risk of death from specific causes in AF patients compared to non-AF population using a nationwide population based cohort. Also, we identified the role of CHA2DS2-VASc score to stratify the risk for all-cause death and death from cardiovascular causes in AF patients.

Methods
Using the Korean nationwide claims database, subjects who received nationwide health screening examination at 2009 and aged 40 or older were included (n=7,240,800). Patients with missing values in health examinations were excluded. Finally, 6,87,929 patients were included: 40,585 patients with AF and 6,837,344 subjects without AF. COD were classified by diagnostic codes.

Results
A total of 490,807 deaths were reported during follow-up (incidence rate of all-cause death: non-AF group, 19.1 and AF group, 34.2 per 1000 person-years). In AF group, cardiovascular diseases were the most common COD occupying 39.8% of all-death, whereas only 19% of non-AF subjects died due to cardiovascular diseases (Figure A). The proportion of death from cerebrovascular diseases in the AF group was two times higher than that of the non-AF group (15.1% vs. 7.5%, respectively). Compared to non-AF group, AF group was associated with a significantly higher risk of all-cause death (hazard ratio [HR] 1.739, 95% confidence interval [CI] 1.708-1.771, p &lt;0.001) (Figure B). AF group was associated with higher risks of death from cardiovascular diseases and death from cerebrovascular diseases by almost 3-fold than non-AF group (HR [95% CI], 2.899 [2.814-2.985] for death from cardiovascular diseases; 2.899 [2.814-2.985] for death from cerebrovascular diseases, all p &lt;0.001) (Figure B). Among AF patients, the risks of all-cause, cardiovascular, and cerebrovascular death were well-stratified by CHA2DS2-VASc scores (Figure C). The increases of HRs by increases of CHA2DS2-VASc score were more prominent in the risk of death from cerebrovascular diseases, followed by death from cardiovascular causes, and all-cause death.

Conclusions
Compared to non-AF subjects, AF patients showed higher risks of death from cardiovascular and cerebrovascular diseases. The risks of death from cardiovascular and cerebrovascular diseases were clearly stratified according to CHA2DS2-VASc score. Integrated management for AF patients should be focused on to prevent death from cardiovascular and cerebrovascular causes. CHA2DS2-VASc score could help to stratify the risk of all-cause death and death from specific causes in AF patients.