Sex Differences in Dabigatran Use, Safety, And Effectiveness In a Population-Based Cohort of Patients With Atrial Fibrillation

Sex-specific considerations in cardiovascular drug therapy

Despite major advances in cardiac research over the past three decades, cardiovascular disease (CVD) still remains the leading cause of morbidity and mortality in women and men worldwide. However, a major challenge for health care providers is that the current guidelines for cardiovascular drug therapies do not consider the impact of sex in the development of treatment plan for optimizing therapies for women. Clinical research in recent years suggests significant pharmacological and pharmacokinetic differences between females and males, which have been attributed in part to differences in body composition, plasma protein binding capacity, drug metabolism, and excretion. Herein, we provide a comprehensive review regarding sex-specific differences and drugs commonly used for CVDs in women and men. Understanding how sex-related differences influence drug efficacy and CVD outcomes is crucial for not only optimizing treatment strategies for women and men but also to encourage the implementation of specific guidelines that address sex difference as a consideration for the treatment of CVDs.

Sex and gender differences in the use of oral anticoagulants for non-valvular atrial fibrillation: A population-based cohort study in primary health care in catalonia

Objectives: To describe the sex and gender differences in the treatment initiation and in the socio-demographic and clinical characteristics of all patients initiating an oral anticoagulant (OAC), and the sex and gender differences in prescribed doses and adherence and persistence to the treatment of those receiving direct oral anticoagulants (DOAC). Material and methods: Cohort study including patients with non-valvular atrial fibrillation (NVAF) who initiated OAC in 2011-2020. Data proceed from SIDIAP, Information System for Research in Primary Care, in Catalonia, Spain. Results: 123,250 people initiated OAC, 46.9% women and 53.1% men. Women were older and the clinical characteristics differed between genders. Women had higher risk of stroke than men at baseline, were more frequently underdosed with DOAC and discontinued the DOAC less frequently than men. Conclusion: We described the dose adequacy of patients receiving DOAC, finding a high frequency of underdosing, and significantly higher in women in comparison with men. Adherence was generally high, only with higher levels in women for rivaroxaban. Persistence during the first year of treatment was also high in general, being significantly more persistent women than men in the case of dabigatran and edoxaban. Dose inadequacy, lack of adherence and of persistence can result in less effective and safe treatments. It is necessary to conduct studies analysing sex and gender differences in health and disease.

Gender Differences in Atrial Fibrillation: From the Thromboembolic Risk to the Anticoagulant Treatment Response

Atrial fibrillation (AF) is the most common cardiac arrhythmia associated with an increased thromboembolic risk. The impact of the female sex as an independent risk factor for thromboembolic events in AF is still debated. Background and Objectives: The aim of this review is to evaluate the gender-related differences in cardioembolic risk and response to anticoagulants among AF patients. Materials and Methods: The PubMed database is used to review the reports about gender differences and thromboembolic risk in atrial fibrillation. Results: Non-vitamin K oral anticoagulants (NOACs) represent the gold standard for thromboembolic risk prevention in patients with non-valvular atrial fibrillation (NVAF). Despite a similar rate of stroke and systemic embolism (SE) among men and women in NOACs or vitamin K antagonists (VKAs) treatment, the use of NOACs in AF women is associated with a lower risk of intracranial bleeding, major bleeding, and all-cause mortality than in men. Conclusions: The female sex can be defined as a stroke risk modifier rather than a stroke risk factor since it mainly increases the thromboembolic risk in the presence of other risk factors. Further studies about the efficacy and safety profile of NOACs according to sex are needed to support clinicians in performing the most appropriate and tailored anticoagulant therapy, either in male or female AF patients.

Representation of Females in Atrial Fibrillation Clinical Practice Guidelines

BACKGROUND

Atrial fibrillation (AF) is the most common arrhythmia in males and females worldwide, and its prevalence is increasing. Management of AF is guided by evidence-based clinical practice guidelines which provide recommendations based on available evidence. The extent of sex-specific data in the AF literature used to provide guideline recommendations has not been investigated. Therefore, using the 2020 Canadian Cardiovascular Society (CCS) Atrial Fibrillation Management Guidelines as example, the purpose of this study was to review female representation and the reporting of sex-disaggregated data in the studies referenced in AF guidelines.

METHODS

Randomized controlled trials (RCTs), prospective and retrospective cohorts, were screened to calculate the proportion of study participants who were female and to establish whether studies provided sex disaggregated analyses. The participant prevalence ratio (PPR), a quotient of the female participant rate and the prevalence of females in the AF population, was calculated for each study.

RESULTS

A total of 885 studies included in the CCS guidelines were considered. Of those, 467 met the inclusion criteria. Overall, females represented 39.1% of the population in all studies and RCTs had the lowest proportions of females (33.8%, PPR: 0.70). Of studies with sex-disaggregated analyses (n=140 (29.9%)), single centered RCTs, and retrospective cohorts had the lowest and highest rate of sex-specific analyses respectively (11.5% vs 32.5%).

CONCLUSION

The evidence used to derive guideline recommendations may be inadequate for sex-specific recommendations. Until enough data can support female specific guidelines, increased inclusion of females in AF studies, may aid in the precision of recommendations.

Association of Sex With Stroke and Bleeding Risk of Apixaban and Rivaroxaban in Elderly Atrial Fibrillation Patients Using Propensity Score Weights

Background

Evidence from clinical trials suggests a differential effect of sex on the effectiveness and safety of direct oral anticoagulants (DOACs) for stroke prophylaxis in atrial fibrillation (AF).

Methods

This population-based cohort study examined the independent effect of sex on hemorrhage and ischemic stroke in 23,884 patients (55% females; age ≥ 66 years) with AF starting apixaban or rivaroxaban treatment in Ontario, Canada. Patients were followed for 90 days after their DOAC prescription. Using female sex as the exposure of interest, differences in baseline characteristics were balanced between sexes using inverse probability weights based on propensity scores. Applying weighted modified Poisson regression, risk ratios (RRs) were estimated for major hemorrhage, ischemic stroke/systemic embolism/transient ischemic attack (hereafter stroke), myocardial infarction, and all-cause mortality, with males as a reference.

Results

Females were older, had higher predicted stroke risk (based on CHADS₂ score), and had fewer comorbidities than did males. Males had a higher prevalence of coronary artery disease, diabetes, and cancer, and similar predicted bleeding risk (based on HAS-BLED score). After weighting, baseline characteristics were well balanced. The 90-day risks for hemorrhage (RR 0.96; 95% confidence interval [CI] 0.80-1.15; P = 0.69) and stroke (RR 1.01; 95% CI 0.86-1.19; P = 0.94) were similar between sexes, which remained true when assessing each DOAC separately by dosing regimen. Compared to males, females had a lower risk for myocardial infarction (RR 0.66; 95% CI 0.52-0.84; P = 0.0008), and for all-cause mortality (RR 0.76; 95% CI 0.67-0.87; P < 0.0001).

Conclusions

Our findings do not suggest an association of sex with the 90-day risk of hemorrhage or ischemic stroke in older AF patients prescribed apixaban or rivaroxaban.

Sex differences in treatment strategy and adverse outcomes among patients 75 and older with atrial fibrillation in the MarketScan database

BACKGROUND

Women with atrial fibrillation (AF) experience greater symptomatology, worse quality of life, and have a higher risk of stroke as compared to men, but are less likely to receive rhythm control treatment. Whether these differences exist in elderly patients with AF, and whether sex modifies the effectiveness of rhythm versus rate control therapy has not been assessed.

METHODS

We studied 135,850 men and 139,767 women aged ≥ 75 years diagnosed with AF in the MarketScan Medicare database between 2007 and 2015. Anticoagulant use was defined as use of warfarin or a direct oral anticoagulant. Rate control was defined as use of rate control medication or atrioventricular node ablation. Rhythm control was defined by use of anti-arrhythmic medication, catheter ablation or cardioversion. We used multivariable Poisson and Cox regression models to estimate the association of sex with treatment strategy and to determine whether the association of treatment strategy with adverse outcomes (bleeding, heart failure and stroke) differed by sex.

RESULTS

At the time of AF, women were on average (SD) 83.8 (5.6) years old and men 82.5 (5.2) years, respectively. Compared to men, women were less likely to receive an anticoagulant or rhythm control treatment. Rhythm control (vs. rate) was associated with a greater risk for heart failure with a significantly stronger association in women (HR women = 1.41, 95% CI 1.34-1.49; HR men = 1.21, 95% CI 1.15-1.28, p < 0.0001 for interaction). No sex differences were observed for the association of treatment strategy with the risk of bleeding or stroke.

CONCLUSION

Sex differences exist in the treatment of AF among patients aged 75 years and older. Women are less likely to receive an anticoagulant and rhythm control treatment. Women were also at a greater risk of experiencing heart failure as compared to men, when treated with rhythm control strategies for AF. Efforts are needed to enhance use AF therapies among women. Future studies will need to delve into the mechanisms underlying these differences.

Effectiveness and Safety of Dabigatran Compared to Vitamin K Antagonists in Non-Asian Patients with Atrial Fibrillation: A Systematic Review and Meta-Analysis

BACKGROUND AND OBJECTIVE

Real-life data about the use of dabigatran in patients with non-valvular atrial fibrillation are warranted. The objective of this systematic review and meta-analysis was to assess the effectiveness and safety of dabigatran, globally and stratified by dose (110/150 mg twice daily), vs vitamin K antagonists in non-Asian patients with non-valvular atrial fibrillation from "real-world" studies.

METHODS

A systematic review was performed according to Cochrane methodological standards. The results were reported according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses Statement) statement. The ROBINS-I tool was used to assess bias risk. MEDLINE and EMBASE, from inception up to May 2021, using appropriate controlled vocabulary and free search terms, were searched.  RESULTS: A total of 34 studies, corresponding to 37 articles involving 1,600,722 participants (1,154,283 exposed to vitamin K antagonists and 446,439 to dabigatran) were eligible for this review. Dabigatran 150 mg reduced the risk of ischemic stroke compared with vitamin K antagonists, with a 14% risk reduction (hazard ratio [HR] 0.86, 95% confidence interval [CI] 0.74-0.98). Globally, dabigatran reduced the risk of all-cause mortality compared with vitamin K antagonists (HR 0.76, 95% CI 0.69-0.84), with a greater effect observed with dabigatran 150 mg (HR 0.65, 95% CI 0.58-0.73). There was a trend towards a lower risk of myocardial infarction with dabigatran 150 mg (HR 0.86, 95% CI 0.71-1.04). Regarding the primary safety outcomes, dabigatran (either at a dose of 150 mg or 110 mg) reduced the risk of major bleeding compared with vitamin K antagonists (HR 0.77, 95% CI 0.70-0.83), as well as the risk of intracranial bleeding (HR 0.44, 95% CI 0.39-0.50) and fatal bleeding (HR 0.76, 95% CI 0.60-0.95), but with a slight increase in gastrointestinal bleeding risk (HR 1.16, 95% CI 1.08-1.26).

CONCLUSIONS

Dabigatran has a favorable impact on effectiveness and safety outcomes compared with vitamin K antagonists in real-world populations.

The effect of sex on the efficacy and safety of dual antithrombotic therapy with dabigatran versus triple therapy with warfarin after PCI in patients with atrial fibrillation (a RE-DUAL PCI subgroup analysis and comparison to other dual antithrombotic therapy trials)

Background

The RE‐DUAL PCI trial demonstrated that in patients with nonvalvular atrial fibrillation (AF) undergoing percutaneous coronary intervention (PCI), dual therapy with dabigatran and a P2Y₁₂ inhibitor, either clopidogrel or ticagrelor, reduced the risk of bleeding without an increased risk of thromboembolic events as compared to triple therapy with warfarin in addition to a P2Y₁₂ inhibitor and aspirin. What remains unclear is whether this effect is consistent between males and females undergoing PCI.

Hypothesis

The reduction in risk of bleeding without increased risk of thromboembolic events with dual therapy with dabigatran and a P2Y₁₂ inhibitor in comparison to triple therapy with warfarin, a P2Y₁₂ inhibitor and aspirin is consistent in females and males.

Methods

The primary safety endpoint was the first International Society on Thrombosis and Hemostasis (ISTH) major bleeding event (MBE) or clinically relevant non‐major bleeding event (CRNMBE). The efficacy endpoint was the composite of death, thromboembolic event (stroke, myocardial infarction, and systemic embolism) or unplanned revascularization. Cox proportional hazard regression analyses were applied to calculate corresponding hazard ratios and interaction p values for each endpoint.

Results

A total of 655 women and 2070 men were enrolled. The risk of major or CRNM bleeding was lower with both dabigatran 110 mg dual therapy and dabigatran 150 mg dual therapy compared with warfarin triple therapy in female and male patients (for 110 mg: females: HR 0.69, 95% CI 0.47–1.01, males: HR 0.46, 95% CI 0.37–0.59, interaction p value: 0.084 and for 150 mg: females HR 0.74, 95% CI 0.48–1.16, males HR 0.71, 95% CI 0.56–0.90, interaction p value: 0.83). There was also no detectable difference in the composite efficacy endpoint of death, thromboembolic events or unplanned revascularization between dabigatran dual therapy and warfarin triple therapy, with no statistically significant interaction between sex and treatment (interaction p values: 0.73 and 0.72, respectively).

Conclusions

Consistent with the overall study results, the risk of bleeding was lower with dabigatran 110 mg and 150 mg dual therapy compared with warfarin triple therapy, and risk of thromboembolic events was comparable with warfarin triple therapy independent of the patient's sex.

Dose specific effectiveness and safety of DOACs in patients with non-valvular atrial fibrillation: A Canadian retrospective cohort study

BACKGROUND

Direct oral anticoagulants (DOACs) have been proven to be effective and safe for prevention of ischemic stroke and systemic embolism in patients with non-valvular atrial fibrillation (NVAF). However, suboptimal adherence, variable dosing and use in patient populations that otherwise would have been excluded from clinical trials may impact the efficacy and safety profile of DOACs in a routine care setting. We compared stroke, bleeding, and mortality rates on and off therapy for standard and low-dose DOACs (apixaban, rivaroxaban, dabigatran) versus warfarin in a Canadian cohort. We also assessed persistence of DOACs compared to warfarin.

METHODS

We conducted six 1-1 propensity-score matched retrospective cohort analyses using Quebec health administrative databases (2011-2017). NVAF patients (≥18 years) covered by the public medication insurance plan entered the cohort on the first OAC dispensation date. We excluded those with OAC use in the previous year or stroke or bleeding diagnoses in the previous two years. Follow-up ended at death, March 2017 or end of medication coverage by the public plan. Time-dependent Cox regression was applied.

RESULTS

We evaluated 10,893 patients initiated on apixaban (7206 standard, 3687 low-dose), 10,190 on rivaroxaban (7396 standard, 2794 low-dose), 5884 on dabigatran (2756 standard, 3128 low-dose), and propensity score-matched warfarin users. Across standard-dose DOACs, compared to warfarin, stroke risks were similar; bleeding risks were lower with apixaban (hazard ratio 0.63; 95% confidence interval 0.52-0.77) and dabigatran (0.47; 0.35-0.64) but not rivaroxaban (0.93; 0.79-1.10); death risks were lower with all DOACs. For low-dose DOACs, rivaroxaban demonstrated higher stroke (1.79; 1.21-2.64) and bleeding risks (1.37; 1.09-1.73); other agents had stroke risks similar to warfarin and bleeding risks lower than warfarin; only low-dose dabigatran had lower death risk (0.59; 0.52-0.68). Treatment discontinuation was lower with DOACs versus warfarin with the exception of low-dose rivaroxaban. The risks of stroke were 2-4 folds higher during time off any OAC versus time on warfarin. The risks of death were higher, while the risks of bleeding were generally lower during times off any OAC.

CONCLUSIONS

Standard-dose DOACs had similar stroke, better persistence and mortality profiles than warfarin. Only standard dose apixaban and dabigatran had better bleeding profiles than warfarin. Low-dose rivaroxaban had worse persistence, stroke and bleeding profiles than warfarin, while low-dose apixaban and dabigatran had similar stroke and better bleeding profiles. Real-world use of DOACs may explain some of the differences observed in Canadian routine care versus the phase III clinical trials.

Comparison of the Efficacy and Safety Outcomes of Edoxaban in 8040 Women Versus 13 065 Men With Atrial Fibrillation in the ENGAGE AF-TIMI 48 Trial

Supplemental Digital Content is available in the text.

Background:

Female sex is an independent risk factor for stroke and systemic embolic events in patients with atrial fibrillation. This study aimed to examine the efficacy and safety profile of edoxaban in women versus men.

Methods:

The ENGAGE AF-TIMI 48 trial (Effective Anticoagulation with Factor Xa Next Generation in Atrial Fibrillation-Thrombolysis in Myocardial Infarction 48) randomly assigned 21 105 patients (8040 women) with atrial fibrillation and CHADS₂ score ≥2 either to a higher-dose edoxaban regimen, a lower-dose edoxaban regimen, or warfarin. The primary end points of the trial were the composite of stroke or systemic embolic events (efficacy), and International Society on Thrombosis and Haemostasis–defined major bleeding (safety).

Results:

In comparison with men, women were older, had lower body weight, were more likely to have hypertension and renal dysfunction, but less likely to smoke, drink alcohol, or have diabetes or coronary artery disease. Pretreatment endogenous factor Xa activity was significantly higher in women than in men (92.5% versus 86.1%, P<0.001). Treatment with edoxaban in women resulted in greater peak edoxaban concentration and inhibition of endogenous factor Xa in comparison with men, resulting in similar endogenous factor Xa activity between the sexes 2 to 4 hours after dose. Treatment with higher-dose edoxaban regimen (versus warfarin) resulted in similar reduction in the risk of stroke/systemic embolic events (women: hazard ratio [HR], 0.87 [0.69–1.11], men: HR, 0.87 [0.71–1.06]; P-interaction=0.97) and major bleeding (women: HR, 0.74 [0.59–0.92], men: HR, 0.84 [0.72–0.99]; P-interaction=0.34) in women and men. However, women assigned to higher-dose edoxaban regimen experienced greater reductions in hemorrhagic stroke (HR, 0.30 [95% CI, 0.15–0.59] versus HR, 0.70 [95% CI, 0.46–1.06]), intracranial bleeding (HR, 0.20 [95% CI, 0.10–0.39] versus HR, 0.63 [95% CI, 0.44–0.89]), and life-threatening or fatal bleeding (HR, 0.25 [95% CI, 0.15–0.42] versus HR, 0.72 [95% CI, 0.54–0.96]) than men (each P-interaction<0.05).

Conclusions:

Despite many differences in baseline characteristics between women and men and higher baseline endogenous factor Xa levels in women, the intensity of anticoagulation achieved with edoxaban between the sexes was similar. Treatment with higher-dose edoxaban regimen resulted in an even greater reduction in hemorrhagic stroke and several serious bleeding outcomes in women than in men, whereas the efficacy profile was similar between sexes.

Women discontinue antihypertensive drug therapy more than men. Evidence from an Italian population-based study

OBJECTIVE

Several factors affect adherence to antihypertensive drug treatment, but whether these factors include a sex difference is unclear. Aim of the study was to compare persistence with antihypertensive drug therapy between men and women in a large cohort of patients.

METHODS

The 60 526 residents of the Italian Lombardy Region aged 40-80 years newly treated with antihypertensive drugs during 2010 were identified and followed for 1 year after the first prescription. Discontinuation of treatment was defined as lack of prescription renewal for at least 90 days. Log-binomial regression models were fitted to estimate the risk ratio of treatment discontinuation in relation to sex. Other than for the whole population, analyses were stratified according to age, comorbidity status and the initial antihypertensive treatment strategy.

RESULTS

Thirty-seven percent of the patients discontinued the drug treatment during follow-up. Compared with women, men had a 10% lower risk of discontinuation of drug treatment (95% confidence interval: 8-12). Persistence on antihypertensive treatment was better in men than in women, this being the case in both younger (40-64 years) and older patients (65-80 years), in patients starting treatment with any major antihypertensive drug and in patients who had a low comorbidity status. There was no evidence that men and women had a different risk of treatment discontinuation when their comorbidity status was worse, or initial antihypertensive treatment was based on drug combinations.

CONCLUSION

Our data show that in a real-life setting, men are more persistent to antihypertensive drug therapy than women.

The 2020 Canadian Cardiovascular Society/Canadian Heart Rhythm Society Comprehensive Guidelines for the Management of Atrial Fibrillation

The Canadian Cardiovascular Society (CCS) atrial fibrillation (AF) guidelines program was developed to aid clinicians in the management of these complex patients, as well as to provide direction to policy makers and health care systems regarding related issues. The most recent comprehensive CCS AF guidelines update was published in 2010. Since then, periodic updates were published dealing with rapidly changing areas. However, since 2010 a large number of developments had accumulated in a wide range of areas, motivating the committee to complete a thorough guideline review. The 2020 iteration of the CCS AF guidelines represents a comprehensive renewal that integrates, updates, and replaces the past decade of guidelines, recommendations, and practical tips. It is intended to be used by practicing clinicians across all disciplines who care for patients with AF. The Grading of Recommendations, Assessment, Development and Evaluations (GRADE) system was used to evaluate recommendation strength and the quality of evidence. Areas of focus include: AF classification and definitions, epidemiology, pathophysiology, clinical evaluation, screening and opportunistic AF detection, detection and management of modifiable risk factors, integrated approach to AF management, stroke prevention, arrhythmia management, sex differences, and AF in special populations. Extensive use is made of tables and figures to synthesize important material and present key concepts. This document should be an important aid for knowledge translation and a tool to help improve clinical management of this important and challenging arrhythmia.

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.

Patient Adherence to Novel Oral Anticoagulants (NOACs) for the Treatment of Atrial Fibrillation and Occurrence of Associated Bleeding Events: A Systematic Review and Meta-analysis

BACKGROUND

Real-world evidence from published observational studies of adherence to Novel Oral Anticoagulants (NOACs) medications and associated clinical outcome events in Atrial Fibrillation (AF) patients, was reviewed systematically.

METHODS

Observational studies assessing patient adherence to NOACs conducted on AF patients between September 2010 and June 2016 were identified by systematic searching keywords to locate eligible studies, in accordance with Cochrane guidelines. PubMed, Scopus and Google Scholar databases were searched to identify the studies. Meta-analysis was performed using a random effects model with DerSimonian-Laird weighting to obtain pooled effect sizes.

RESULTS

From 185 potentially relevant citations, 6 studies, comprising 1.6 million AF patients, were included. Among these, successful adherence to NOACs occurred in 75.6%. Adherence levels were higher in patients treated with dabigatran (72.7%) compared with those treated with apixaban (59.9%) or rivaroxaban (59.3%). However, adherence was still suboptimal (relative to an expected 80% adherence rate). Bleeding events in non-adherent patients were found to be 7.5%.

CONCLUSION

Suboptimal adherence to NOACs among AF patients was highlighted as a significant risk factor that may affect clinical outcomes, with a higher percentage of non-adherent patients having bleeding events. There is an urgent need for research on the effects of specific interventions to improve patient adherence to NOACs and to assess the related outcome factors that may be associated with adherence.

Sex Differences in Oral Anticoagulation and Outcomes of Stroke and Intracranial Bleeding in Newly Diagnosed Atrial Fibrillation

Background

Female sex is an independent predictor of stroke in patients with atrial fibrillation (AF). Older data suggest undertreatment with anticoagulation among women compared with men. However, it is unknown if novel therapies and updated guidelines have impacted sex differences in AF treatment and outcomes.

Methods and Results

We performed a retrospective cohort study of 2.3 million women and men with a new diagnosis of AF and CHA₂DS₂‐VASc ≥2 from Marketscan US commercial claims data from 2008 to 2015 to determine whether women with AF remain undertreated and whether this difference mediates observed differences in outcomes. There were 358 649 patients with newly diagnosed AF (43% women). Compared with men, women were older, with higher CHA₂DS₂‐VASc scores, and higher comorbidity burden (P<0.0001 for all). Oral anticoagulation‐eligible women with CHA₂DS₂‐VASc scores ≥2 were more likely to not receive anticoagulation (50.0% women versus 43.9% men). Women, compared with men, had a higher risk of ischemic stroke (adjusted hazard ratio [aHR], 1.27; 95% CI, 1.21–1.32; P<0.0001) and hospitalization (aHR, 1.06; 95% CI, 1.05–1.07, P<0.0001) but had a lower risk of intracranial bleeding (aHR, 0.91; 95% CI, 0.83–0.99, P=0.03). In mediation analysis, nonreceipt of oral anticoagulation partially mediated the observed increased risk of stroke and decreased risk of intracranial bleeding in women.

Conclusions

In the care of newly diagnosed AF in the United States, women, compared with men, are less likely to receive oral anticoagulation. This appears to mediate the increased risk of both stroke and hospitalization but also appears to mediate lower observed intracranial bleeding risk.

Comparative effectiveness and safety of oral anticoagulants for atrial fibrillation: A retrospective cohort study

Oral anticoagulants (OACs) are high-priority medications, frequently used with clinically important benefit and serious harm. Our objective was to compare the safety and effectiveness of direct-acting oral anticoagulants (DOACs) versus warfarin in a population where anticoagulation management and DOACs were readily available. A retrospective cohort study of all adults living in British Columbia with a diagnosis of atrial fibrillation and a first prescription for an OAC was conducted. Co-primary outcomes were ischemic stroke and systemic embolism, and major bleeding. Secondary outcomes included a net clinical outcome composite and analysis of discontinuation, switching, and key subgroups. We estimated the effects of treatment using time-to-event models with high-dimensional propensity score adjustment to control confounding. After adjustment for prescribing bias, a cohort (n = 20,113, 43.8% female, mean age 72.4 years) with a mean follow-up of 18.1 months showed that patients taking warfarin tended to be poorer, sicker, and less likely to have a cardiologist prescriber. Outcome event rates were not significantly different for DOACs compared to warfarin [adjusted rate ratio of 1.15 (0.91, 1.46) for systemic embolism, 0.94 (0.82, 1.08) for major bleeding, and 0.98 (0.90, 1.06) for net clinical outcome]. Only the effect of age on net clinical outcome met our strict criteria for predicting which group might be superior. Switch of drug class was associated with increased risk of events (p < 0.003). In this population, we found no difference in important clinical outcomes between warfarin and DOACs. Switching compared to not switching was associated with harm.

Risk of Major Gastrointestinal Bleeding With New vs Conventional Oral Anticoagulants: A Systematic Review and Meta-analysis

BACKGROUND & AIMS

There is controversy over whether use of non-vitamin K antagonist oral anticoagulants (NOACs) associates with increased risk of major gastrointestinal bleeding (GIB) compared with conventional therapies (such as vitamin K antagonists or anti-platelet agents). We performed a systematic review and meta-analysis of data from randomized controlled trials and high-quality real-world studies.

METHODS

We performed a systematic search of the MEDLINE, EMBASE, Cochrane Library, and ClinicalTrials.gov Website databases (through Oct 12, 2018) for randomized controlled trials and high-quality real-world studies that reported major GIB events in patients given NOACs or conventional therapy. Relative risks (RRs) for randomized controlled trials and adjusted hazard ratios (aHRs) for real-world studies were calculated separately using random-effects models.

RESULTS

We analyzed data from 43 randomized controlled trials (183,752 patients) and 41 real-world studies (1,879,428 patients). The pooled major rates of GIB for patients on NOACs (1.19%) vs conventional treatment (0.92%) did not differ significantly (RR from randomized controlled trials, 1.09; 95% CI, 0.91-1.31 and aHR from real-world studies, 1.02; 95% CI, 0.94-1.10; P_interaction=.52). Rivaroxaban, but not other NOACs, was associated with an increased risk for major GIB (RR from randomized controlled trials, 1.39; 95% CI, 1.17-1.65 and aHR from real-world studies, 1.14; 95% CI, 1.04-1.23; P_interaction = .06). Analyses of subgroups, such as patients with different indications, dosage, or follow-up time, did not significantly affect results. Meta-regression analysis failed to detect any potential confounding to impact the primacy outcome.

CONCLUSIONS

In a systematic review and meta-analysis of data from randomized controlled trials and real-world studies, we confirmed that there is no significant difference in risk of major GIB between patients receiving NOACs vs conventional treatment. Rivaroxaban users had a 39% increase in risk for major GIB.

Sex Differences in Care Need and Survival in Patients Admitted to Nursing Home Poststroke

BACKGROUND

Women are more likely to be admitted to nursing home after stroke than men. Differences in patient characteristics and outcomes by sex after institutionalization are less understood. We examined sex differences in the characteristics and care needs of patients admitted to nursing home following stroke and their subsequent survival.

METHODS

We identified patients with stroke newly admitted to nursing home between April 2011 and March 2016 in Ontario, Canada, with follow-up until March 2018 using linked administrative data. We calculated prevalence ratios and 95% confidence intervals (CIs) for the primary outcomes of dependence for activities of daily living, cognitive impairment, frailty, health instability, and symptoms of depression or pain, comparing women to men. The secondary outcome was all-cause mortality.

RESULTS

Among 4831 patients, 60.9% were women. Compared to men, women were older (median age [interquartile range, IQR]: 84 [78, 89] vs. 80 [71, 86]), more likely to be frail (prevalence ratio 1.14, 95% CI [1.08, 1.19]), have unstable health (1.45 [1.28, 1.66]), and experience symptoms of depression (1.25 [1.11, 1.40]) or pain (1.21 [1.13, 1.30]), and less likely to have aggressive behaviors (0.87 [0.80, 0.94]). Overall median survival was 2.9 years. In a propensity-score-matched cohort, women had lower mortality than men (hazard ratio 0.85, 95% CI [0.77, 0.94]), but in the age-stratified survival analysis, the survival advantage in women was limited to those aged 75 years and older.

CONCLUSIONS

Despite lower subsequent mortality, women admitted to nursing home after stroke required more care than men. Pain and depression are two treatable symptoms that disproportionately affect women.

National trends in hospital admission, case fatality, and sex differences in atrial fibrillation-related strokes

BACKGROUND AND AIM

Atrial fibrillation is associated with increased risk of ischemic stroke and its global prevalence is increasing. We aimed to describe the contemporary temporal trends in hospital admissions, case fatality rate, as well as sex differences in atrial fibrillation-related stroke in Canada.

METHODS

We conducted a retrospective cohort study using Canadian national administrative data to identify admissions to hospital for stroke with comorbid atrial fibrillation between 1 April 2007 and 31 March 2016. We determined temporal trends in the crude and the age- and sex-standardized admission and case fatality rates. We also evaluated for any sex differences in these outcomes.

RESULTS

There were 222,100 admissions to hospital for ischemic (n = 182,990) or hemorrhagic (n = 39,110) stroke. Comorbid atrial fibrillation was present in 20.2% of admissions for ischemic strokes and 10.1% for hemorrhagic strokes. Over the study period, the age-sex adjusted proportion of admissions with atrial fibrillation increased from 16.3% to 20.5% (p = 0.02) for ischemic stroke and was stable for hemorrhagic stroke. In-hospital case fatality rate decreased for ischemic stroke with and without comorbid atrial fibrillation. Women aged 65 years and older with ischemic stroke were more likely to have comorbid atrial fibrillation compared to men, while this association was reversed in younger women. There were no sex differences in the case fatality rate for people with atrial fibrillation-related ischemic stroke.

CONCLUSION

Atrial fibrillation is present in an increasing proportion of people hospitalized in Canada with ischemic stroke and disproportionately affects older women. Renewed focus is needed on atrial fibrillation-related stroke prevention with particular attention to sex disparities.

Safety of direct oral anticoagulants in real-world clinical practice: translating the trials to everyday clinical management

INTRODUCTION

Direct oral anticoagulants (DOACs) may be regarded as some of the most successful innovations in recent times. These drugs which were specifically developed to overcome the challenges posed by warfarin did just that and in the process, have changed the outlook towards stroke prevention with anticoagulation. The decade of experience with these drugs that has resulted in the availability of large scale data on their safety profile has aided this. Areas covered: This review examines existing real-world studies (RWS) and their interpretation to better appreciate how they either complement or contradict findings from the hallmark trials. Specific focus has been made on the safety of DOACs, on their risks of major bleeding, intra-cranial haemorrhage (ICH), gastro-intestinal (GI) bleeding and all-cause mortality compared to warfarin and each other. DOAC use in the elderly and other sub-groups are briefly discussed. Expert opinion: Results for safety outcomes according to 'real world evidence' (RWE) are in-keeping with randomised controlled trials (RCTs) and currently, all 4 DOACs have been deemed at least as effective as warfarin, while demonstrating superiority in some aspects. While real world studies act as a complementary source of knowledge, traditional RCTs remain the gold standard for determining cause-effect relationships.

Sex differences in stroke and major adverse clinical events in patients with atrial fibrillation: A systematic review and meta-analysis of 993,600 patients

BACKGROUND

Atrial fibrillation (AF) is the most commonly diagnosed arrhythmia, which is associated with an increased risk of stroke. Several studies have suggested that female AF patients could have a greater risk for stroke and thromboembolic events (TE).

METHODS

A systematic literature review update and meta-analysis was conducted using Pubmed. The search used the terms "atrial fibrillation", "gender", "sex", "female", "women", "stroke", "thromboembolism". Main aim of the study was to compare and male AF patients for occurrence of stroke and TE. Secondary outcomes were: major bleeding, cardiovascular (CV) death and all-cause death.

RESULTS

Forty-four studies were included in the analysis including 993,603 patients (48.9% women). After pooling the data, there was a higher risk of stroke for women vs. male AF patients (hazard ratio [HR]: 1.24; 95% confidence intervals [CIs]: 1.14-1.36). Overall, TE risk was not different between female and male patients, despite sensitivity analysis left some uncertainties. No sex differences were found for major bleeding, CV death and all-cause death. A significant relationship between increasing age and the difference in stroke risk between female and male AF patients was found (Delta HR: 1.01; 95% CI: 1.00-1.03 for each year of age increase).

CONCLUSIONS

Female patients with AF are at increased risk of stroke compared to men. A significant relationship between increasing age and stroke risk in women compared to men was found, most evident at age > 65 years. Female sex may act as a stroke risk modifier, particularly in elderly and very elderly AF subjects, conferring a significant increase in stroke risk.

Advances in Cardiovascular Health in Women over the Past Decade: Guideline Recommendations for Practice

Cardiovascular disease (CVD) remains the number one cause of death in women. It is estimated that 44 million women in the United States are either living with or at risk for heart disease. This article highlights the recent significant progress made in improving care, clinical decision-making, and policy implications for women with CVD. We provide our perspective supported by evidence-based advances in cardiovascular research and clinical care guidelines in seven areas: (1) primary CVD prevention and community heart care, (2) secondary prevention of CVD, (3) stroke, (4) heart failure and cardiomyopathies, (5) ischemia with nonobstructive coronary artery disease, (6) spontaneous coronary artery dissection, and (7) arrhythmias and device therapies. Advances in these fields have improved the lives of women living with and at risk for heart disease. With increase awareness, partnership with national organizations, sex-specific research, and changes in policy, the morbidity and mortality of CVD in women can be further reduced.

Gender-related Differences in Management of Nonvalvular Atrial Fibrillation in an Asian Population

Background and Objectives

Gender-related differences in health care utilization for atrial fibrillation (AF) are increasingly recognized. However, large cohort data for examining gender-related differences in AF are lacking in Asian populations.

Methods

The Registry for Comparison Study of Drugs for Symptom Control and Complication Prevention of AF (CODE-AF Registry) is a prospective observational cohort-study that enrolled participants at 10 tertiary hospitals in South Korea. Baseline characteristics retrieved from the CODE-AF Registry were analyzed.

Results

A total of 6,274 patients were recruited (mean age 67±11 years, mean CHA₂DS₂-VASc score 2.7±1.7, 63% male, 65% paroxysmal AF) from June 2016 to April 2017. Women underwent less electric cardioversion (12.3% vs. 19.6%, p<0.001), less radiofrequency ablation (12.4% vs. 17.9%, p<0.001), and less antiarrhythmic drug therapy (44.7% vs. 49.5%, p<0.001), despite having more severe symptoms (symptom class III or IV, 45.8% vs. 37.5%, p<0.001). Among patients with a CHA₂DS₂-VA score of 2 or more, a slightly higher proportion of women were taking oral anticoagulants than men (85.7% vs. 81.9%, p=0.002), and non-vitamin K antagonist oral anticoagulant (NOAC) use was more prevalent in women than men (70.4% vs. 62.3%, p<0.001). Insufficient NOAC dosing was very common, more so in women than men (61.5% vs. 56.3%, p<0.001).

Conclusions

Female patients with AF were treated more conservatively and rhythm control strategies were used less frequently than in males, even though the female patients with AF had more severe symptoms. While insufficient NOAC dosing was common in both sex, it was significantly more frequent in women.

Outcomes of Dabigatran and Warfarin for Atrial Fibrillation in Contemporary Practice: A Retrospective Cohort Study

BACKGROUND

Dabigatran (150 mg twice daily) has been associated with lower rates of stroke than warfarin in trials of atrial fibrillation, but large-scale evaluations in clinical practice are limited.

OBJECTIVE

To compare incidence of stroke, bleeding, and myocardial infarction in patients receiving dabigatran versus warfarin in practice.

DESIGN

Retrospective cohort.

SETTING

National U.S. Food and Drug Administration Sentinel network.

PATIENTS

Adults with atrial fibrillation initiating dabigatran or warfarin therapy between November 2010 and May 2014.

MEASUREMENTS

Ischemic stroke, intracranial hemorrhage, extracranial bleeding, and myocardial infarction identified from hospital claims among propensity score-matched patients starting treatment with dabigatran or warfarin.

RESULTS

Among 25 289 patients starting dabigatran therapy and 25 289 propensity score-matched patients starting warfarin therapy, those receiving dabigatran did not have significantly different rates of ischemic stroke (0.80 vs. 0.94 events per 100 person-years; hazard ratio [HR], 0.92 [95% CI, 0.65 to 1.28]) or extracranial hemorrhage (2.12 vs. 2.63 events per 100 person-years; HR, 0.89 [CI, 0.72 to 1.09]) but were less likely to have intracranial bleeding (0.39 vs. 0.77 events per 100 person-years; HR, 0.51 [CI, 0.33 to 0.79]) and more likely to have myocardial infarction (0.77 vs. 0.43 events per 100 person-years; HR, 1.88 [CI, 1.22 to 2.90]). However, the strength and significance of the association between dabigatran use and myocardial infarction varied in sensitivity analyses and by exposure definition (HR range, 1.13 [CI, 0.78 to 1.64] to 1.43 [CI, 0.99 to 2.08]). Older patients and those with kidney disease had higher gastrointestinal bleeding rates with dabigatran.

LIMITATION

Inability to examine outcomes by dabigatran dose (unacceptable covariate balance between matched patients) or quality of warfarin anticoagulation (few patients receiving warfarin had available international normalized ratio values).

CONCLUSION

In matched adults with atrial fibrillation treated in practice, the incidences of stroke and bleeding with dabigatran versus warfarin were consistent with those seen in trials. The possible relationship between dabigatran and myocardial infarction warrants further investigation.

PRIMARY FUNDING SOURCE

U.S. Food and Drug Administration.

Dabigatran in real-world atrial fibrillation

In the RE-LY clinical trial, dabigatran presented a better effectiveness/ safety profile when compared to warfarin. However, clinical trials are not very representative of the real-world setting. We aimed to assess the performance of dabigatran in real-world patients with atrial fibrillation (AF) by means of a systematic review and meta-analysis of observational comparison studies with vitamin K antagonists (VKA). We searched PubMed, Embase and Scopus databases until November 2015 and selected studies according to the following criteria: observational study performed with nonvalvular AF patients; reporting adjusted hazard ratios (HR) of clinical events in a follow-up period; for dabigatran 75 mg, 110 mg or 150 mg versus VKA. Twenty studies were selected which included 711,298 patients, 210,279 of which were treated with dabigatran and the remaining 501,019 with VKA. Ischaemic stroke incidence was of 1.65 /100 patient-years for dabigatran and 2.85/100 patient-years for VKA (HR 0.86, 95 % confidence interval of 0.74–0.99). Major bleeding rate was 3.93/100 patient-years for dabigatran and 5.61/100 patient-years for VKA (0.79, 0.69–0.89). Risk of mortality (0.73, 0.61–0.87) and intracranial bleeding (0.45, 0.38–0.52) were significantly lower in patients treated with dabigatran when compared to patients on VKA. Risk of gastrointestinal (GI) bleeding was significantly higher in patients treated with dabigatran (1.13, 1.00–1.28). No significant difference was observed in risk of myocardial infarction (0.99, 0.89–1.11). In this combined analysis of real-world observational comparison studies with VKA, dabigatran was associated with a lower risk of ischaemic stroke, major bleeding, intracranial bleeding and mortality, higher risk of GI bleeding and a similar risk of myocardial infarction.

Supplementary Material to this article is available online at www.thrombosis-online.com.

Risk of myocardial infarction and death in patients with atrial fibrillation treated with dabigatran or vitamin K antagonists

The safety of dabigatran versus adjusted-dose vitamin K antagonist (VKA) treatment is the subject of debate. We evaluated the risk of myocardial infarction (MI) or mortality in patients with atrial fibrillation (AF) treated in clinical practice with dabigatran or a VKA. We performed a meta-analysis of observational studies that included an adjusted or matched analysis and reported MI, or death in AF patients treated with dabigatran or a VKA. Ten published analyses met the inclusion criteria. Of the 539,559 patients, 17,365 (3%) patients were on dabigatran 110 mg twice daily (bid), 150,948 (28%) were on dabigatran 150 mg bid, and 371,246 (69%) were on VKA. Adjusted risk for MI versus VKA was 0.71 (0.47–1.07; p=0.10) in patients starting oral anticoagulant (OAC) treatment with dabigatran 110 mg, 0.82 (0.71–0.96; p=0.01) in patients starting dabigatran 150 mg, 1.40 (1.04–1.88; p=0.03) in patients switching OAC treatment to dabigatran 110 mg, and 1.28 (0.88–1.87; p=0.19) in patients switching OAC treatment to dabigatran 150 mg, with statistical homogeneity in each subgroup. Risk of death was consistently lower in patients treated with dabigatran 110 mg (HR 0.79; 0.65–0.96; p=0.02) or 150 mg (HR 0.65; 0.57–0.73; p<0.00001) versus VKA. In conclusion, dabigatran use, as currently prescribed in routine practice for AF patients, was associated with a lower risk of MI in OAC-naïve patients treated with dabigatran 150 mg compared with VKA, and a higher risk of MI in patients switching from VKA to dabigatran 110 mg. Risk of death was lower in AF patients treated with either dose of dabigatran versus VKA.

Gender Differences in the Trends of Hospitalizations for Acute Stroke Among Patients With Atrial Fibrillation in the United States: 2005 to 2014

Female gender was included in stroke prediction algorithms in an attempt to improve anticoagulation rates in women with atrial fibrillation (AF). It is unclear if these efforts reduced stroke burden in women with AF. To bridge this literature gap, using the Nationwide Inpatient Sample, we assessed gender differences in the trends of hospitalizations for stroke among patients with AF in the United States in 2005 to 2014. International classification of diseases, 9th revision, clinical modification codes were used to abstract AF and stroke diagnoses. From 2005 to 2014, 18,413,291 hospitalizations of women with AF and 18,035,866 hospitalizations of men with AF were reported. Of these, 740,635 hospitalizations in women and 595,730 hospitalizations in men had stroke as the primary diagnosis. Age-adjusted stroke hospitalizations increased in women (443 per million in 2005 to 495 per million in 2014) as well as in men (351 per million in 2005 to 453 per million in 2014) (p trend < 0.001). Further, anticoagulation rates increased in women (11.5% in 2005 to 24.0% in 2014) as well as in men (11.7% in 2005 to 24.9% in 2014). Stroke hospitalizations involving anticoagulated patients with AF decreased in women (411 per million in 2005 to 347 per million in 2014) as well as in men (402 per million in 2005 to 311 per million in 2014) (p trend < 0.001). In conclusion, although we noted an increasing trend of stroke hospitalizations in both genders, it is reassuring to note that stroke hospitalizations involving anticoagulated patients with AF is decreasing in both genders and in particular among women.

Sex-Specific Comparative Effectiveness of Oral Anticoagulants in Elderly Patients With Newly Diagnosed Atrial Fibrillation

BACKGROUND

Sex-specific comparative effectiveness of direct oral anticoagulants among patients with nonvalvular atrial fibrillation is not known. Via this retrospective cohort study, we assessed the sex-specific, comparative effectiveness of direct oral anticoagulants (rivaroxaban and dabigatran), compared to each other and to warfarin among patients with atrial fibrillation.

METHODS AND RESULTS

Elderly (aged ≥66 years) Medicare beneficiaries enrolled in Medicare Part D benefit plan from November 2011 to October 2013 with newly diagnosed atrial fibrillation formed the study cohort (65 734 [44.8%] men and 81 137 [55.2%] women). Primary outcomes of inpatient admissions for ischemic strokes and major bleeding were compared across the 3 drugs (rivaroxaban: 20 mg QD, dabigatran: 150 mg BID, or warfarin) using 3-way propensity-matched samples. In men, rivaroxaban use decreased stroke risk when compared with warfarin use (hazard ratio, 0.69; 95% confidence interval, 0.48-0.99; P=0.048) and dabigatran use (hazard ratio, 0.66; 95% confidence interval, 0.45-0.96; P=0.029) and was associated with a similar risk of any major bleeding when compared with warfarin and dabigatran. In women, although ischemic stroke risk was similar in the 3 anticoagulant groups, rivaroxaban use significantly increased the risk for any major bleeding when compared with warfarin (hazard ratio, 1.20; 95% confidence interval, 1.03-1.42; P=0.021) and dabigatran (hazard ratio, 1.27; 95% confidence interval, 1.09-1.48; P=0.011).

CONCLUSIONS

The reduced risk of ischemic stroke in patients taking rivaroxaban, compared with dabigatran and warfarin, seems to be limited to men, whereas the higher risk of bleeding seems to be limited to women.

Temporal Trends in the Use and Comparative Effectiveness of Direct Oral Anticoagulant Agents Versus Warfarin for Nonvalvular Atrial Fibrillation: A Canadian Population-Based Study

BACKGROUND

Direct oral anticoagulants (DOACs) are noninferior to warfarin for stroke prevention in atrial fibrillation (AF). We aimed to determine the population risk of stroke and death in incident AF, stratified by anticoagulation status and type, and the temporal trends of oral anticoagulation practice in the post-DOAC approval period.

METHODS AND RESULTS

We conducted a population-based cohort study of incident nonvalvular AF cases using administrative health data in Alberta, Canada. We used Cox proportional hazards modeling with anticoagulation status as a time-varying exposure and adjusted for age (continuous), sex, congestive heart failure, hypertension, diabetes mellitus, prior transient ischemic attack or ischemic stroke, myocardial infarction, peripheral artery disease, and chronic kidney disease. Primary outcome was the composite of stroke and death. Among 34 965 patients with incident AF (56.0% male, median age 73 years), relative to warfarin, DOAC use was associated with decreased risk of all stroke and death (hazard ratio: 0.90; 95% confidence interval, 0.83-0.97) and decreased hemorrhagic stroke (hazard ratio: 0.60; 95% confidence interval, 0.40-0.91]) but a similar risk of ischemic stroke (hazard ratio: 1.12; 95% confidence interval, 0.94-1.34]). During this time period, DOAC use increased rapidly, surpassing warfarin, but the total oral anticoagulation use in the population remained stable, even in the subgroup with the highest thromboembolic risk.

CONCLUSIONS

In a real-world population-based study of patients with incident AF, anticoagulation with DOACs was associated with decreased risk of stroke and death compared with warfarin. Despite a rapid uptake of DOACs in clinical practice, the total proportion of AF patients on anticoagulation has remained stable, even in high-risk patients.

Sex Differences in the Use of Oral Anticoagulants for Atrial Fibrillation: A Report From the National Cardiovascular Data Registry (NCDR®) PINNACLE Registry

BACKGROUND

Despite higher thromboembolism risk, women with atrial fibrillation have lower oral anticoagulation (OAC) use compared to men. The influence of the CHA2DS2-VASc score or the introduction of non-vitamin K OACs on this relationship is not known.

METHODS AND RESULTS

Using the PINNACLE National Cardiovascular Data Registry from 2008 to 2014, we compared the association of sex with OAC use (warfarin or non-vitamin K OACs) overall and by CHA2DS2-VASc score and examined temporal trends in OAC use by sex. Multivariable regression models assessed the association between sex and OAC use in those with CHA2DS2-VASc scores ≥2. Temporal analyses assessed changes in OAC use by sex over time. Of the 691 906 atrial fibrillation patients, 48.5% were women. Women were significantly less likely than men to use any OAC overall (56.7% versus 61.3%; P<0.001) and at all levels of CHA2DS2-VASc score (adjusted risk ratio 9% to 33% lower, all P<0.001). Compared to other thromboembolic risk factors, female sex was associated with lower use of OAC (risk ratio 0.90, 95%CI 0.90-0.91). Over time, non-vitamin K OAC use increased at a slightly higher rate in women (56.2% increase per year, 95%CI 54.6% to 57.9%) compared to men (53.6% increase per year, 95%CI 52.0% to 55.2%), yet women remained less likely to receive any OAC at all time points (P<0.001).

CONCLUSIONS

Among patients with atrial fibrillation, women were significantly less likely to receive OAC at all levels of the CHA2DS2-VASc score. Despite increasing non-vitamin K OAC use, women had persistently lower rates of OAC use compared to men over time.

Gender differences in clinical presentation and 1-year outcomes in atrial fibrillation

OBJECTIVES

Our objective was to examine gender differences in clinical presentation, management and prognosis of atrial fibrillation (AF) in a contemporary cohort.

METHODS

In 6412 patients, 39.7% women, of the PREvention oF thromboembolic events - European Registry in Atrial Fibrillation, we examined gender differences in symptoms, risk factors, therapies and 1-year incidence of adverse outcomes.

RESULTS

Men with AF were on average younger than women (mean±SD: 70.1±10.7 vs 74.1±9.7 years, p<0.0001). Women more frequently had at least one AF-related symptom at least occasionally compared with men (95.4% in women, 89.8% in men, p<0.0001). Prescription of oral anticoagulation was similar, with an increase of non-vitamin K antagonist oral anticoagulants from 5.9% to 12.6% in women and from 6.2% to 12.6% in men, p<0.0001 for both.Men were more frequently treated with electrical cardioversion and ablation (20.6% and 6.3%, respectively) than women (14.9% and 3.3%, respectively), p<0.0001. Women had 65% (OR: 0.35; 95% CI (0.22 to 0.56)) lower age-adjusted and country-adjusted odds of coronary revascularisation, 40% (OR: 0.60; (0.38 to 0.93)) lower odds of acute coronary syndrome and 20% (OR: 0.80; (0.68 to 0.96)) lower odds of heart failure at 1 year. There were no statistically significant gender differences in 1-year stroke/transient ischaemic attack/arterial thromboembolism and major bleeding events.

CONCLUSION

In a 'real-world' European AF registry, women were more symptomatic but less likely to receive invasive rhythm control therapy such as electrical cardioversion or ablation. Further study is needed to confirm that these differences do not disadvantage women with AF.

Effectiveness and Safety of Non-vitamin K Antagonist Oral Anticoagulants for Atrial Fibrillation and Venous Thromboembolism: A Systematic Review and Meta-analyses

PURPOSE

The findings from the observational studies comparing the effectiveness and safety of non-vitamin K antagonist oral anticoagulants (NOACs) versus vitamin K antagonists (VKAs) for atrial fibrillation (AF) and venous thromboembolism (VTE) are inconsistent. We conducted separate meta-analyses examining the efficacy/effectiveness and safety of NOACs versus VKAs by disease (AF vs VTE), study design (randomized controlled trials [RCTs] vs observational studies), and NOAC (dabigatran, rivaroxaban, apixaban, and edoxaban).

METHODS

The main data sources included PubMed/MEDLINE, EMBASE, Web of Science, CINAHL, and Scopus from January 1, 2005, to February 15, 2016. We searched for Phase III RCTs and observational studies comparing NOACs versus VKAs. The primary outcomes were stroke/systemic embolism (SE) for AF; recurrent VTE/fatal pulmonary embolism (PE) for VTE; and major bleeding for both conditions. Secondary outcomes included stroke and myocardial infarction (MI) for AF, recurrent deep vein thrombosis (DVT)/PE for VTE, and mortality, intracranial hemorrhage (ICH), and gastrointestinal bleeding for both conditions. Pooled hazard ratios (HRs) were reported by using inverse variance-weighted random effects models.

FINDINGS

A total of 13 RCTs and 27 observational studies (AF, n = 32; VTE, n = 8) were included. For AF, dabigatran and VKAs were comparable for stroke/SE risk in 1 RCT (HR, 0.77 [95% CI, 0.57-1.03]) and 6 observational studies (HR, 1.03 [95% CI, 0.83-1.27]). Rivaroxaban had a 20% decreased risk of stroke/SE in 3 RCTs (HR, 0.80 [95% CI, 0.67-0.95]) compared with VKA, but the effect was nonsignificant in 3 observational studies (HR, 0.78 [95% CI, 0.59-1.04]). Apixaban decreased stroke/systemic embolism risk (HR, 0.79 [95% CI, 0.66-0.95]) compared with VKA in 1 RCT, but edoxaban was comparable to VKA (HR, 0.99 [95% CI, 0.77-1.28]) in 1 RCT (no observational studies available for apixaban/edoxaban). Dabigatran, apixaban, and edoxaban decreased the risk of hemorrhagic stroke, mortality, major bleeding, and ICH by 10% to 71% compared with VKAs but not rivaroxaban. For VTE, NOACs and VKAs were comparable for recurrent VTE/fatal PE/DVT/PE risk in 7 RCTs and 1 observational study. The 7 RCTs demonstrated a 32% to 69% decreased risk of major bleeding for dabigatran, rivaroxaban, and apixaban compared with VKAs. No difference was shown in 1 rivaroxaban observational study (HR, 0.77 [95% CI, 0.40-1.49]) and 1 edoxaban RCT (HR, 0.84 [95% CI, 0.59-1.20]). Except for dabigatran, the NOACs had a 61% to 86% decreased risk of ICH and gastrointestinal bleeding.

IMPLICATIONS

Overall, NOACs were comparable or superior to VKAs. Although no observational studies are currently available for apixaban/edoxaban, a few notable inconsistencies exist for dabigatran (ischemic stroke, MI) and rivaroxaban (stroke/SE, major bleeding in VTE) between RCTs and observational studies. Individualizing NOAC/VKA therapy based on benefit/safety profiles and patient characteristics is suggested.

Atrial Fibrillation and Ventricular Arrhythmias: Sex Differences in Electrophysiology, Epidemiology, Clinical Presentation, and Clinical Outcomes

Sex-specific differences in the epidemiology, pathophysiology, clinical presentation, clinical treatment, and clinical outcomes of atrial fibrillation (AF), sustained ventricular arrhythmias, and sudden cardiac death are recognized. Sex hormones cause differences in cardiac electrophysiological parameters between men and women that may affect the risk for arrhythmias. The incidence and prevalence of AF is lower in women than in men. However, because women live longer and AF prevalence increases with age, the absolute number of women with AF exceeds that of men. Women with AF are more symptomatic, present with more atypical symptoms, and report worse quality of life in comparison with men. Female sex is an independent risk factor for death or stroke attributable to AF. Oral anticoagulation therapy for stroke prevention has similar efficacy for men and women, but older women treated with warfarin have a higher residual risk of stroke in comparison with men. Women with AF are less likely to receive rhythm control antiarrhythmic drug therapy, electric cardioversion, or catheter ablation in comparison with men. The incidence and prevalence of sustained ventricular arrhythmias and sudden cardiac death are lower in women than in men. Women receiving implantable cardioverter defibrillators for primary prevention of sudden cardiac death are less likely to experience sustained ventricular arrhythmias in comparison with men. In contrast, women receiving a cardiac resynchronization therapy implantable cardioverter defibrillator for the treatment of heart failure are more likely to benefit than men. Women are less likely to be referred for implantable cardioverter defibrillator therapy despite current guideline recommendations. Women are more likely to experience a significant complication related to implantable cardioverter defibrillator implantation in comparison with men. Whether sex differences in treatment decisions reflect patient preferences or treatment biases requires further study.

Atrial fibrillation in women: treatment

Sex-specific differences in the epidemiology, pathophysiology, presentation, prognosis, and treatment of atrial fibrillation (AF) are increasingly recognized. Women with AF generally experience worse symptoms, poorer quality of life, and have higher risk of stroke and death than men with AF. Effective treatment of the arrhythmia in women is critical to reduce the rate of adverse events. We review the current evidence on sex-specific differences in the utilization and outcomes of treatments for AF, including rate-control and rhythm-control strategies, and stroke-prevention therapy. In addition, we provide a critical evaluation of potential disparities and biases in health-care use that might be associated with differences in the outcomes between women and men. We underscore current knowledge gaps that need to be addressed in future studies to improve the management of AF in women. In particular, we suggest several strategies to produce high-quality evidence from randomized clinical trials for women with AF.

Safety of non-vitamin K antagonist oral anticoagulants - coronary risks

INTRODUCTION

Since the approval and commercialization of non-vitamin K antagonist oral anticoagulants (NOACs; apixaban, dabigatran, edoxaban, and rivaroxaban) several studies and meta-analyses have raised safety concerns regarding myocardial infarction (MI) risk among NOAC-treated patients, particularly with dabigatran. Uncertainty remains regarding the coronary risk associated with dabigatran, and whether this putative risk also applies to the other NOACs.

AREAS COVERED

In this review, the coronary risks of NOACs based on findings from placebo-controlled trials are discussed, and randomized controlled trials and major cohort studies in AF patients are also appraised. We performed a random-effect meta-analysis, including both interventional trials and observational studies ("real-world" data). Further estimates were retrieved from the meta-analysis of coronary risk among NOAC-treated patients with concomitant AF and coronary disease.

EXPERT OPINION

Currently, the best available data from both clinical trials and observational studies do not support the claim that patients treated with NOACs, including dabigatran, are at increased coronary risk. However, a definitive conclusion cannot be made (especially regarding dabigatran) and further data are required to address the coronary risks, mostly of high-risk patients. As with any therapeutic intervention, the possible complications should be balanced against the potential benefits at an individual patient level.

Practical Guide to Direct New Oral Anticoagulant Use for Secondary Stroke Prevention in Atrial Fibrillation

OPINION STATEMENT

Anticoagulation remains the optimal treatment choice for secondary stroke prevention of AF. The vitamin K antagonists (VKAs) have been the choice of treatment for the last 60 years, but the new oral anticoagulants are now a safe option for treatment of non-valvular AF (NVAF) in the right patient population, taking into account age, renal function, bleeding risk, cardiovascular comorbidities, cost, and drug interactions.