Results
The age and percentage of each risk factor of the study patients are shown in Table 1. The mean ages were 59.1 ± 11.3 years for male patients and 59.1 ± 10.2 years for female patients. Age between 65 and 74 years and hypertension were the most prevalent risk factors for AF male and female patients, respectively.
Among 12,935 AF male patients with a CHA2DS2-VASc score of 1, there were 1,858 patients (14.4%) who experienced ischemic stroke during follow-up (5.2 ± 4.3 years) with an annual stroke rate of 2.75%. The risk of ischemic stroke ranged from 1.96%/year for patients with vascular diseases to 3.50%/year for those age 65 to 74 years of age (Table 2).
Compared with AF male patients with a CHA2DS2-VASc score of 0, the hazard ratio of ischemic stroke was 1.681 (95% CI: 1.333 to 2.120; p < 0.001) for patients with vascular diseases and increased to 3.085 (95% CI: 2.790 to 3.410; p < 0.001) for those 65 to 74 years of age (Table 2, Central Illustration).
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Central Illustration.
Risk of Ischemic Stroke in AF Patients Stratified by CHA2DS2-VASc Components
For male patients with a CHA2DS2-VASc score of 1 and female patients with a CHA2DS2-VASc score of 2, hazard ratios of ischemic stroke varied depending on individual risk factors but were highest for patients between 65 and 74 years of age compared with male patients with a CHA2DS2-VASc score of 0 and female patients with a CHA2DS2-VASc score of 1 (accounting for female sex). *The risk of ischemic stroke was compared in AF male patients with a CHA2DS2-VASc score of 0 and AF female patients with a CHA2DS2-VASc score of 1. AF = atrial fibrillation; CHA2DS2-VASc = congestive heart failure, hypertension, age 75 years or older, diabetes mellitus, previous stroke or transient ischemic attack, vascular disease, age 65 to 74 years, female; CI = confidence interval.
Among the female patients with AF, 1,174 (14.9%) experienced ischemic stroke during follow-up (5.9 ± 4.4 years), for an annual stroke rate of 2.55%. The risk of ischemic stroke increased from 1.91%/year for patients with hypertension to 3.34%/year for those 65 to 74 years of age. Compared with AF female patients with a CHA2DS2-VASc score of 1 (i.e., female sex only), the hazard ratios of ischemic stroke ranged from 1.711 (95% CI: 1.481 to 1.976; p < 0.001) for patients with hypertension to 3.031 (95% CI: 2.678 to 3.431) for those 65 to 74 years of age (Table 3, Central Illustration).