Atrial fibrillation-related stroke in women: Evidence and inequalities in epidemiology, mechanisms, clinical presentation, and management

Are Socioeconomic Factors Associated With Atrial Fibrillation Sex-Dependent? A Narrative Review

Atrial fibrillation (AF), the most prevalent cardiac arrhythmia, poses a significant public health and economic burden. Although socioeconomic factors such as income and education have been implicated in AF incidence and outcomes, the potential sex-specific associations remained underexplored. This narrative review aimed to fill this gap by synthesizing existing literature on the sex-specific impact of socioeconomic factors on AF incidence, treatment, and outcome. Among these socioeconomic factors, we identified income and education as the most frequently cited determinants. Nevertheless, the magnitude and direction of these sex differences remained inconsistent across studies. The review uncovered that many studies did not include sex in the analysis when assessing the impact of socioeconomic factors on AF. We highlighted that there is a paucity of studies employing sex-stratified reporting and sex interaction analyses, thereby hindering a deeper understanding of these relationships.

Ischaemic stroke in women with atrial fibrillation: temporal trends and clinical implications

BACKGROUND AND AIMS

Female sex has been linked with higher risk of ischaemic stroke (IS) in atrial fibrillation (AF), but no prior study has examined temporal trends in the IS risk associated with female sex.

METHODS

The registry-linkage Finnish AntiCoagulation in Atrial Fibrillation (FinACAF) study included all patients with AF in Finland from 2007 to 2018. Ischaemic stroke rates and rate ratios were computed.

RESULTS

Overall, 229 565 patients with new-onset AF were identified (50.0% women; mean age 72.7 years). The crude IS incidence was higher in women than in men across the entire study period (21.1 vs. 14.9 events per 1000 patient-years, P < .001), and the incidence decreased both in men and women. In 2007-08, female sex was independently associated with a 20%-30% higher IS rate in the adjusted analyses, but this association attenuated and became statistically non-significant by the end of the observation period. Similar trends were observed when time with and without oral anticoagulant (OAC) treatment was analysed, as well as when only time without OAC use was considered. The decrease in IS rate was driven by patients with high IS risk, whereas in patients with low or moderate IS risk, female sex was not associated with a higher IS rate.

CONCLUSIONS

The association between female sex and IS rate has decreased and become non-significant over the course of the study period from 2007 to 2018, suggesting that female sex could be omitted as a factor when estimating expected IS rates and the need for OAC therapy in patients with AF.

Optimal Strategies to Select Warfarin Dose for Thai Patients with Atrial Fibrillation

Background: Warfarin has been the mainstay treatment for the prevention of stroke and systemic thromboembolism in patients with atrial fibrillation (AF). The optimal starting dose of warfarin remains unclear. Objective: To investigate the most optimal dosing strategies for warfarin starting dose in Thai patients with AF. Material and Methods: We enrolled consecutive AF patients who were starting on warfarin and resulting in a stable INR of 2.0-3.0 at two consecutive time points. We measured the dose of warfarin at which INR achieved the target range. The optimal dosage was defined as the difference from the actual dose within 20%. We compared strategies of warfarin dosing, including warfarin dosing formula, 2.5 mg, 3 mg and 5 mg doses. The primary endpoints were the proportions of patients in optimal, underdosing, and overdosing categories. Results: Among 1207 patients visiting the Outpatient Clinic between October 2011 and September 2021, 531 patients were identified with AF and INR in the therapeutic range of 2.0-3.0 on at least two consecutive visits. The mean age of participants was 68 ± 11 years, and men accounted for 44.4% of the population. The warfarin dosing formula resulted in optimal dosing in 37% and overdosing in 24% of cases, whereas the 2.5 mg, 3 mg and 5 mg doses resulted in optimal dosing in 36%, 39%, and 11%, and overdosing in 33%, 44% and 88% of patients, respectively (p < 0.01). Conclusions: In Thai patients with AF, the optimal warfarin starting dose may be 2.5 mg, 3 mg or a simplified warfarin dosing formula, whereas the 5 mg dose should be avoided due to the high risk of overdosing.

Sex and stroke risk factors: A review of differences and impact

OBJECTIVES

There is an increase in stroke incidence risk over the lifetime of women, given their longer life expectancy. However, an alarming trend for sex disparities, particularly in certain stroke risk factors, shows a concerning need for focus on sex differences in stroke prevention and treatment for women. In this article, we are addressing sex differences in both traditional and sex-specific stroke risk factors.

METHODS

We searched PubMed from inception to December 2022 for articles related to sex differences and risk factors for stroke. We reviewed full-text articles for relevance and ultimately included 152 articles for this focused review.

RESULTS

Women are at increased risk for stroke from both traditional and non-traditional stroke risk factors. As women age, they have a higher disease burden of atrial fibrillation, increased risk of stroke related to diabetes, worsening lipid profiles, and higher prevalence of hypertension and obesity compared to men. Further, women carry sex hormone-specific risk factors for stroke, including the age of menarche, menopause, pregnancy, and its complications, as well as hormonal therapy. Men have a higher prevalence of tobacco use and atrial fibrillation, as well as an increased risk for stroke related to hyperlipidemia. Additionally, men have sex-specific risks related to low testosterone levels.

CONCLUSIONS

By identifying biological sex-specific risk factors for stroke, developing robust collaborations, researching, and applying the knowledge for risk reduction strategies, we can begin to tailor prevention and reduce the global burden of stroke morbidity and mortality.

Detection of atrial fibrillation using an implantable loop recorder in patients with previous cryptogenic stroke: the SPIDER-AF registry (Stroke Prevention by Increasing DEtection Rates of Atrial Fibrillation)

BACKGROUND

The use of implantable loop recorder (ILR) to detect atrial fibrillation (AF) in patients with a history of cryptogenic stroke (CS) has seldom been investigated in "real-world" settings.

OBJECTIVE

This study aimed to present the results of the Stroke Prevention by Increasing DEtection Rates of Atrial Fibrillation (SPIDER-AF) registry.

METHOD

SPIDER is a multicentric, observational registry, including 35 facilities all over Germany. It enrolled outpatients without AF history and with CS before ILR implantation.

RESULTS

We included 500 patients (mean age 63.1 ± 12.7 years), 304 (60.8%) were males, with previous stroke (72.6%) and TIA (27.4%). After inclusion, all were followed for at least 12 months. AF was detected in 133 (26.8%), 25.3% of patients with previous stroke and 29.9% with TIA (p = 0.30). AF was detected after a median of 121.5 days (IQR 40.5-223.0). AF was primarily paroxysmal (95.7% after stroke, 100% after TIA). In 19.5% (n = 26) anticoagulation was not administered after AF detection. Mean CHA2DS2-VASc score (OR 1.22; CI 1.01-1.49; p = 0.037) and age > 70 years (OR 0.41; CI 0.19-0.88; p = 0.0020) correlated with AF. Repeat cerebrovascular events at follow-up (28; 5.6%) correlated with AF (OR = 2.17; CI 1.00-4.72; p = 0.049). AF (p = 0.91) and recurrent events (p = 0.43) occurred similarly in females and males.

CONCLUSIONS

In the context of cryptogenic strokes ILRs are a valuable tool for early detection of AF. In a real-world scenario, the anticoagulation therapy remains inadequate despite diagnosed AF in a relevant subset of patients requiring optimization of patient management.

Sex Differences in Thrombin Generation in Patients with Acute Ischemic Stroke

Sex differences in stroke exist, including variation in stroke risk and outcome. Differences in thrombin generation may contribute to this variation between females and males. To examine this, we assessed sex differences in thrombin generation between females and males with acute ischemic stroke and the relationship to blood cell gene expression. In 97 patients with acute ischemic stroke, thrombin generation was measured by thrombin generation assay. Blood cell gene expression was measured by microarray. Differences in thrombin generation between sexes were identified and the relationship to blood cell gene expression examined. Genes associated with sex differences in thrombin generation were analyzed by functional pathway analysis. Females and males had similar overall capacity to generate thrombin. The peak thrombin generated in females was 468.8 nM (SD 91.6), comparable to males (479.3nM;SD 90.8; p = 0.58). Lag time, time to peak thrombin, and endogenous thrombin potential were also similar between females and males. While overall thrombin generation was comparable between females and males with stroke, differences in genes that promote this thrombin generation exist. Females with high peak thrombin had an increase in genes that promote thrombosis, and platelet activation. In contrast, males with high peak thrombin had a decrease in genes involved in thrombus degradation. Females and males with acute ischemic stroke have similar capacity to generate thrombin, however, differences may exist in how this thrombin generation is achieved, with females having increased thrombin signaling, and platelet activation, and males having decreased thrombus degradation. This suggests regulatory differences in thrombosis may exist between females and males that may contribute to sex differences in stroke.

The Impact of Sex-Specific Survival on the Incidence of Dementia in Parkinson's Disease

OBJECTIVE

The aim of our study is to analyze sex-specific patterns of Parkinson's disease dementia (PDD) incidence. We are investigating the extent to which sex differences in survival after initial Parkinson's disease (PD) diagnosis influence differences in PDD risk among PD patients.

METHODS

We used a random sample of German longitudinal health claims data of persons ages 50+ (2004-2019; n = 250,000) and identified new PD cases ages 65+ who were followed-up for a PDD diagnosis or death between 2006 and 2017. We performed Cox and competing-risk regression models, with death as competing event, to calculate PDD hazard ratios (HR) adjusted for age at PD onset, PD severity as measured by the modified Hoehn and Yahr (HY) scale, comorbidities, and medications.

RESULTS

Of 2195 new PD cases, 602 people died before PDD and 750 people developed PDD by the end of 2017. The adjusted risk of PDD differs by sex, with men having a higher PDD risk than women. When accounting for death, men and women do not differ in their PDD risk (HR = 1.02, P = 0.770). Sex-specific analyses showed significant age and severity effects in women (age: HR = 1.05, P < 0.001; HY 3-5 vs. 0-2.5: HR = 1.46, P = 0.011), but not in men.

CONCLUSION

Older age at first PD diagnosis and higher disease severity increase PDD risk, but this association is attenuated for PD men when controlling for death. This implies that the most frail PD men die rapidly before receiving a dementia diagnosis, whereas women with PD survive at higher rates, regardless of their age at onset and disease severity. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Gender-Based Clinical, Therapeutic Strategies and Prognosis Differences in Atrial Fibrillation

BACKGROUND

There are limited data on gender-based differences in atrial fibrillation (AF) treatment and prognosis. We aimed to examine gender-related differences in medical attention in an emergency department (ED) and follow-up (FU) among patients diagnosed with an AF episode and to determine whether there are gender-related differences in clinical characteristics, therapeutic strategies, and long-term adverse events in this population.

METHODS

We performed a retrospective observational study of patients who presented to a tertiary hospital ER for AF from 2010 to 2015, with a minimum FU of one year. Data on medical attention received, mortality, and other adverse outcomes were collected and analyzed.

RESULTS

Among the 2013 patients selected, 1232 (60%) were female. Women were less likely than men to be evaluated by a cardiologist during the ED visit (11.5% vs. 16.6%, p = 0.001) and were less likely to be admitted (5.9% vs. 9.5%, p < 0.05). Electrical cardioversion was performed more frequently in men, both during the first episode (3.4% vs. 1.2%, p = 0.001) and during FU (15.9% vs. 10.6%, p < 0.001), despite a lower AF recurrence rate in women (9.9% vs. 18.1%). During FU, women had more hospitalizations for heart failure (26.2% vs. 16.1%, p < 0.001).

CONCLUSIONS

In patients with AF, although there were no gender differences in mortality, there were significant differences in clinical outcomes, medical attention received, and therapeutic strategies. Women underwent fewer attempts at cardioversion, had a lower probability of being evaluated by cardiologists, and showed a higher probability of hospitalization for heart failure. Being alert to these inequities should facilitate the adoption of measures to correct them.

Utility of short-term telemetry heart rhythm monitoring and CHA2DS2-VASc stratification in patients presenting with suspected cerebrovascular accident

BACKGROUND

Inpatient telemetry heart rhythm monitoring overuse has been linked to higher healthcare costs.

AIM

To evaluate if CHA₂DS₂-VASc score could be used to indicate if a patient admitted with possible cerebrovascular accident (CVA) or transient ischemic attack (TIA) requires inpatient telemetry monitoring.

METHODS

A total of 257 patients presenting with CVA or TIA and placed on telemetry monitoring were analyzed retrospectively. We investigated the utility of telemetry monitoring to diagnose atrial fibrillation/flutter and the CHA₂DS₂-VASc scoring tool to stratify the risk of having CVA/TIA in these patients.

RESULTS

In our study population, 63 (24.5%) of the patients with CVA/TIA and telemetry monitoring were determined to have no ischemic neurologic event. Of the 194 (75.5) patients that had a confirmed CVA/TIA, only 6 (2.3%) had an arrhythmia detected during their inpatient telemetry monitoring period. Individuals with a confirmed CVA/TIA had a statistically significant higher CHA₂DS₂-VASc score compared to individuals without an ischemic event (3.59 vs 2.61, P < 0.001).

CONCLUSION

Given the low percentage of inpatient arrhythmias identified, further research should focus on discretionary use of inpatient telemetry on higher risk patients to diagnose the arrhythmias commonly leading to CVA/TIA. A prospective study assessing event rate of CVA/TIA in patients with higher CHA₂DS₂-VASc score should be performed to validate the CHA₂DS₂-VASc score as a possible risk stratifying tool for patients at risk for CVA/TIA.

The Impact of Sex and Gender on Stroke

Women face a disproportionate burden of stroke mortality and disability. Biologic sex and sociocultural gender both contribute to differences in stroke risk factors, assessment, treatment, and outcomes. There are substantial differences in the strength of association of stroke risk factors, as well as female-specific risk factors. Moreover, there are differences in presentation, response to treatment, and stroke outcomes in women. This review outlines current knowledge of impact of sex and gender on stroke, as well as delineates research gaps and areas for future inquiry.

Racial and ethnic disparities in coronary, vascular, structural, and congenital heart disease

Cardiovascular disease (CVD) remains the leading cause of death in the United States. However, percutaneous interventional cardiovascular therapies are often underutilized in Blacks, Hispanics, and women and may contribute to excess morbidity and mortality in these vulnerable populations. The Society for Cardiovascular Angiography and Interventions (SCAI) is committed to reducing racial, ethnic, and sex-based treatment disparities in interventional cardiology patients. Accordingly, each of the SCAI Clinical Interest Councils (coronary, peripheral, structural, and congenital heart disease [CHD]) participated in the development of this whitepaper addressing disparities in diagnosis, treatment, and outcomes in underserved populations. The councils were charged with summarizing the available data on prevalence, treatment, and outcomes and elucidating potential reasons for any disparities. Given the huge changes in racial and ethnic composition by age in the United States (Figure 1), it was difficult to determine disparities in rates of diagnosis and we expected to find some racial differences in prevalence of disease. For example, since the average age of patients undergoing transcatheter aortic valve replacement (TAVR) is 80 years, one may expect 80% of TAVR patients to be non-Hispanic White. Conversely, only 50% of congenital heart interventions would be expected to be performed in non-Hispanic Whites. Finally, we identified opportunities for SCAI to advance clinical care and equity for our patients, regardless of sex, ethnicity, or race.

Dynamics of Atrial Fibrillation Mechanisms and Comorbidities

Atrial fibrillation (AF) contributes to morbidity and mortality of millions of individuals. Its molecular, cellular, neurohumoral, and hemodynamic pathophysiological mechanisms are complex, and there is increasing awareness that a wide range of comorbidities can contribute to AF-promoting atrial remodeling. Moreover, recent research has highlighted that AF risk is not constant and that the temporal variation in concomitant conditions contributes to the complexity of AF dynamics. In this review, we provide an overview of fundamental AF mechanisms related to established and emerging comorbidities or risk factors and their role in the AF-promoting effects. We focus on the accumulating evidence for the relevance of temporally dynamic changes in these risk factors and the consequence for AF initiation and maintenance. Finally, we highlight the important implications for future research and clinical practice resulting from the dynamic interaction between AF risk factors and mechanisms.

Female Sex as a Thromboembolic Risk Factor in the Era of Nonvitamin K Antagonist Oral Anticoagulants

Sex-specific differences have been definitively demonstrated in cardiovascular (CV) diseases. These differences can also impact on the effects of CV therapies. Female sex is recognized as an independent predictor of thromboembolic risk, particularly in older patients. Most of strokes are due to atrial fibrillation (AF). Women affected by AF have higher stroke risk compared to men. The introduction of novel oral anticoagulants (NOACs) for long-term anticoagulation completely changed the anticoagulant therapeutic approach and follow-up of patients affected by nonvalvular atrial fibrillation (NVAF). CHA2DS2-VASc stroke risk scoring in use in the current international guidelines attributes 1 point to “female sex”. Besides, no anticoagulation is indicated for AF female patients without other risk factors. Interestingly, NOACs seem to normalize the differences between males and females both in terms of safety and efficacy, whereas residual higher stroke risk and systemic embolism persist in AF women treated with vitamin K antagonist anticoagulants VKA with optimal time in therapeutic range. Based on the CHA2DS2-VASc score, NOACs represent the preferred choice in NVAF patients. Moreover, complete evaluation of apparently lower risk factor along with concomitant clinical conditions in AF patients appears mandatory, particularly for female patients, in order to achieve the most appropriate anticoagulant treatment, either in male or in female patients. The present review was performed to review sex differences in AF-related thromboembolic risk reported in the literature and possibly highlight current knowledge gaps in prevention and management that need further research.

ArrhythmoGenoPharmacoTherapy

This review is focusing on the understanding of various factors and components governing and controlling the occurrence of ventricular arrhythmias including (i) the role of various ion channel-related changes in the action potential (AP), (ii) electrocardiograms (ECGs), (iii) some important arrhythmogenic mediators of reperfusion, and pharmacological approaches to their attenuation. The transmembrane potential in myocardial cells is depending on the cellular concentrations of several ions including sodium, calcium, and potassium on both sides of the cell membrane and active or inactive stages of ion channels. The movements of Na+, K+, and Ca2+ via cell membranes produce various currents that provoke AP, determining the cardiac cycle and heart function. A specific channel has its own type of gate, and it is opening and closing under specific transmembrane voltage, ionic, or metabolic conditions. APs of sinoatrial (SA) node, atrioventricular (AV) node, and Purkinje cells determine the pacemaker activity (depolarization phase 4) of the heart, leading to the surface manifestation, registration, and evaluation of ECG waves in both animal models and humans. AP and ECG changes are key factors in arrhythmogenesis, and the analysis of these changes serve for the clarification of the mechanisms of antiarrhythmic drugs. The classification of antiarrhythmic drugs may be based on their electrophysiological properties emphasizing the connection between basic electrophysiological activities and antiarrhythmic properties. The review also summarizes some important mechanisms of ventricular arrhythmias in the ischemic/reperfused myocardium and permits an assessment of antiarrhythmic potential of drugs used for pharmacotherapy under experimental and clinical conditions.

Atrial fibrillation-related stroke in women: Evidence and inequalities in epidemiology, mechanisms, clinical presentation, and management

Background

Atrial fibrillation (AF) is the most common clinical arrhythmia and one of the major causes of stroke, heart failure, sudden death, and cardiovascular morbidity. Despite substantial advances in (interventional) rhythm control treatment during the last decade, anticoagulation for stroke prevention remains a major component of AF treatment.

Hypothesis

There are important sex‐specific differences in AF‐related stroke, resulting from sex‐specific mechanisms and therapeutic differences.

Methods

This review summarizes available data on sex differences in risk assessment and prevention of stroke and highlights current knowledge gaps in AF‐related stroke mechanisms, prevention and management that warrant further research.

Results

Increased thrombotic risk in women is multifactorial, involving hormonal changes after menopause, structural, endocrine and lifestyle/social factors and their interactions. It is clear from randomized studies that women benefit from anticoagulant treatment and that their bleeding risk is similar to men. Women should therefore receive equivalent treatment to men, based on the validated criteria for anticoagulation therapy. However, women are not represented equally in the large randomized studies and sex‐related information in many fields is lacking.

Conclusions

Female sex is an established risk factor for stroke in AF patients. The evidence for sex‐specific differences in stroke risk assessment and stroke prevention is accumulating. However, the underlying biological mechanisms remain incompletely understood and further studies are required in order to decrease AF‐related morbidity and mortality.