Risk of ischemic stroke and utility of CHA₂DS₂‐VASc score in women and men with atrial fibrillation

Abstract

Background The magnitude of increased risk of stroke in women with atrial fibrillation (AF) remains uncertain. Hypothesis We investigated the risk of ischemic stroke and death in women and men with AF, and the risk associated with individual non‐sex CHA2DS2‐VASc risk factors. Methods Retrospective cohort study of 231 077 (48.1% women) nonselected patients with AF not receiving oral anticoagulation from 2006 to 2014. Data from cross‐linked national Swedish registers. The outcome was the first occurrence of ischemic stroke or death. Median age was 82 and 75 years in women and men, respectively. Mean follow‐up was 2.5 years. Results Hazard ratios, adjusted for non‐sex CHA2DS2‐VASc risk factors, for women vs men were 1.53, 95% CI: 1.49‐1.58 for ischemic stroke and 1.24, 95% CI: 1.22‐1.26 for death, respectively. When divided into age groups the differences in ischemic stroke rates between women and men were attenuated. In patients with only one non‐sex CHA2DS2‐VASc risk factor allotted 1 point, ischemic stroke rates per 100 person‐years were 1.22 in women (n = 9838) and 1.02 in men (n = 15 609), respectively, P < .006. In both women and men, age of 65 to 74 years was associated with higher ischemic stroke risk compared to other non‐sex CHA2DS2‐VASc risk factors allotted 1 point. Conclusions The risk of ischemic stroke was 1.5‐fold higher in women compared to men but this association appears to be the result of confounding by age. In the low risk end, the CHA2DS2‐VASc risk score underestimates the ischemic stroke risk conferred by age 65 to 74 years, while it overestimates the risk conferred by female sex.

Association of the CHA2D(S2)-VASc Score and Its Components With Overt and Silent Ischemic Brain Lesions in Patients With Atrial Fibrillation

“…Female sex was neither associated with clinically overt nor with silent ischemic brain lesions in our cohort, which is in contrast to other reports suggesting that women have a higher risk of (overt) stroke than men ( 15 , 22 ). Regarding silent ischemic brain lesions, analyses from the Atherosclerosis Risk in Communities Study showed that female sex was not related to an increased risk of silent brain infarcts ( 23 ).…”

“…Interestingly, in our cohort, although associated with clinically overt ischemic brain lesions, hypertension was not associated with silent brain lesions. This finding may be explained by the fact that measured systolic blood pressure in our cohort was nearly 20 mmHg lower compared to other study populations (20,21) Female sex was neither associated with clinically overt nor with silent ischemic brain lesions in our cohort, which is in contrast to other reports suggesting that women have a higher risk of (overt) stroke than men (15,22). Regarding silent ischemic brain lesions, analyses from the Atherosclerosis Risk in Communities Study showed that female sex was not related to an increased risk of silent brain infarcts (23).…”

Female Sex as a Risk Modifier for Stroke Risk in Atrial Fibrillation: Using CHA2DS2-VASc versus CHA2DS2-VA for Stroke Risk Stratification in Atrial Fibrillation: A Note of Caution

“…In a large Swedish cohort of unselected AF patients, Tomasdottir et al showed that associated stroke rates were different when using a point-based approach than when using a disease-specific risk factors approach stratified according to sex. 28 They argued that the excess stroke risk observed among females was score level dependent, but this itself does not allow inference on the magnitude of excess risk that female sex contributes within each level of the score.…”

“…Some studies support the existence of a sex-specific stroke risk variation according to CHA 2 DS 2 -VASc score levels. 28,30 These observations have led to the implementation of the CHA 2 DS 2 -VA score as the preferred stroke risk score for guiding anticoagulation decisions in patients with AF in the recent guidelines from Australia and New Zealand, 31 despite the lack of any comparative formal risk score validation. Although tempting, the maneuvre of completely ignoring the well-established sexdifferences in stroke risk may have deleterious consequences.…”

Comorbidities associated with different levels of total cholesterol in male and female acute ischemic stroke patients

“…Men and women differ in their clinical risk factors with respect to various predictors of severity among AIS patients. [ 6 ] While the exact reason for this phenomenon is not clear, some studies have reported a correlation between stroke and changes in arterial structure and that biochemical variables including triglyceride level and total cholesterol levels may contribute to stroke severity. [ 7 ] While the role of triglycerides in the risk of ischemic stroke remains controversial, [ 8 , 9 ] a strong association between elevated levels of triglycerides and increased risk of ischemic stroke in men and women in the general population has been reported.…”