Female Sex Is Not a Uniform Risk Factor in Atrial Fibrillation

Figures

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  Figure 1. Study Design and Population Diagram showing the way subgroups were organized. Our study included nonvalvular atrial fibrillation patients who were further subdivided by age group (<65, 65-74, and ≥75) and sex (female vs male). Female and male patients in each category were then propensity matched in a 1:1 ratio for age, comorbidities, and anticoagulation status to be used in analysis. AF = atrial fibrillation; PM = propensity matching.

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  Figure 2. Kaplan-Meier for Thromboembolic Stroke Risk, <65 Cohort (A) Kaplan-Meier survival analysis curve showing no difference (P = 0.200) in stroke over time between female and male patients <65 years old without any additional stroke risk factors (CHA2DS2-VA = 0) and who were not currently on any anticoagulation. (B) Kaplan-Meier survival analysis curve comparing occurrence of stroke over time between female and male patients <65 years old with CHA2DS2-VA = 1 or 2. There was no significant difference in risk of stroke between female and male cohorts (P = 0.236).

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  Figure 3. Kaplan-Meier for Thromboembolic Stroke Risk, 65 to 74 Cohort (A) Kaplan-Meier survival analysis curve showing no difference (P = 0.512) in occurrence of stroke over time between female and male patients aged 65 to 74 years old without any additional stroke risk factors (CHA2DS2-VA = 1, +1 point for age) and without any anticoagulation. (B) Kaplan-Meier survival analysis curve comparing occurrence of stroke over time between female and male patients aged 65 to 74 years old with CHA2DS2-VA score of 2 or 3 (+1 for age, +1 or +2 for additional risk factor). Patients were propensity matched for other risk factors, including obstructive sleep apnea, tobacco use, atherosclerotic heart disease, and ischemic cardiomyopathy. There was no sex-based difference in stroke risk in this age group (P = 0.167).

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  Figure 4. Kaplan-Meier for Thromboembolic Stroke Risk, ≥75 Cohort (A) Kaplan-Meier survival analysis curve showing significantly increased risk of stroke over time (P = 0.001) in female patients aged ≥75 years old without any additional stroke risk factors (CHA2DS2-VA = 2, including +2 points for age). (B) Kaplan-Meier survival analysis of male and female patients ≥75 years with one additional CHA2DS2-VA risk factor (CHA2DS2-VA = 3 or 4). Unlike younger age groups in the risk modifier analysis, females ≥75 had significantly greater risk of stroke compared to male patients (P = 0.012).

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  Central Illustration. Nonvalvular AF Patients Stratified by Age and Sex After propensity matching for comorbidities and anticoagulation, 1-year stroke risk was compared in female and male patients. Female sex modified stroke risk in presence of greater comorbidity burden and older age (≥75 years old). CHF = congestive heart failure; MI = myocardial infarction; TIA = transient ischemic attack; other abbreviation as in Figure 1.