Social Inequalities of Oral Anticoagulation after the Introduction of Non-Vitamin K Antagonists in Patients with Atrial Fibrillation

All-Cause Death and Major Adverse Events in Atrial Fibrillation with Frailty: Observations from the Korea National Health Insurance Service Data

Background

Atrial fibrillation (AF) is an indicator of frailty in old patients. This study aimed to investigate the effect of frailty on the use of oral anticoagulants (OAC) and clinical outcomes in a nationwide cohort of patients with new-onset AF.

Methods

This study included 451,368 participants without AF from the Korea National Health Insurance Service-Health Screening cohort between 2002 and 2009. The Hospital Frailty Risk Score was retrospectively calculated for each patient using all available International Classification of Disease 10th revision diagnostic codes. According to the aggregate score, patients were divided into two groups: the participants without frailty ( < 5 points) and the participants with frailty ( ≥ 5 points). The primary outcome was death from any cause, and the secondary outcomes were cardiovascular death, ischemic stroke, major bleeding, and heart failure admission.

Results

With up to 7.2 ± 1.5 years of follow-up, 11,953 participants (median age, 67 [interquartile range, 59.5-74.5] years; 7200 [60.2%] males) developed new-onset AF. Among the patients with AF, 3224 (26.9%) had frailty. Frailty was significantly associated with old age, female sex, polypharmacy, and other comorbidities. In patients with AF, frailty was negatively associated with OAC prescription after new-onset AF (p < 0.001). Compared to patients without frailty, patients with frailty had a significantly higher incidence and risk of all-cause death (hazard ratio [HR] 2.88, 95% confidence interval [CI] 2.65-3.14), cardiovascular death (HR 2.42, 95% CI 2.10-2.80), ischemic stroke (HR 2.25, 95% CI 2.02-2.51), major bleeding (HR 2.44, 95% CI 2.17-2.73), and heart failure admission (HR 1.29, 95% CI 1.09-1.52). In subgroup analysis, when compared to the non-OAC group, the risks associated with frailty were significantly lower in the OAC group for all-cause death, cardiovascular death, ischemic stroke, and heart failure admission.

Conclusions

Frailty was negatively associated with the use of OAC and was a predictor of poor prognosis owing to the association of frailty with death, thromboembolic events, bleeding, and heart failure admission. However, OAC use was associated with lower risks related to frailty for all-cause death and major adverse cardiovascular events in patients with AF.

Oral anticoagulants and concurrent rifampin administration in tuberculosis patients with non-valvular atrial fibrillation

BACKGROUND

Evidence and guidelines for Non-vitamin K antagonist oral anticoagulants (NOACs) use when prescribing concurrent rifampin for tuberculosis treatment in patients with non-valvular atrial fibrillation (NVAF) are limited.

METHODS

Using the Korean National Health Insurance Service database from January 2009 to December 2018, we performed a population-based retrospective cohort study to assess the net adverse clinical events (NACE), a composite of ischemic stroke or systemic embolism and major bleeding, of NOACs compared with warfarin among NVAF patients taking concurrent rifampin administration for tuberculosis treatment. After a propensity matching score (PSM) analysis, Cox proportional hazards regression was performed in matched cohorts to investigate the clinical outcomes.

RESULTS

Of the 735 consecutive patients selected, 465 (63.3%) received warfarin and 270 (36.7%) received NOACs. Among 254 pairs of patients after PSM, the crude incidence rate of NACE was 25.6 in NOAC group and 32.8 per 100 person-years in warfarin group. There was no significant difference between NOAC and warfarin use in NACE (hazard ratio [HR], 0.74; 95% confidence interval [CI], 0.48-1.14; P = 0.172). Major bleeding was the main driver of NACE, and NOAC use was associated with a statistically significantly lower risk of major bleeding than that with warfarin use (HR, 0.63; 95% CI, 0.40-1.00; P = 0.0499).

CONCLUSIONS

In our population-based study, there was no statically significant difference in the occurrence of NACE between NOAC and warfarin use. NOAC use may be associated with a lower risk of major bleeding than that with warfarin use.

Impact of Socioeconomic Status on Emergency Department Visits in Patients With Atrial Fibrillation: A Nationwide Population-Based Cohort Study

Background Socioeconomic status (SES) differences could influence management and clinical outcomes in patients with atrial fibrillation (AF), reflecting health inequalities. The authors aimed to investigate emergency department (ED) visits in patients with AF according to SES level. Methods and Results The authors performed a cross-sectional analysis of ED visits in patients with nonvalvular AF using the Korean National Health Insurance Service database in 2016. The patients were divided into health premium quartiles and medical aid groups, with quartile 4 the highest SES and medical aid the lowest SES. Among patients with AF, patients who had ≥1 ED visits in 2016 were identified. The prevalence and cause of ED visits, 30- and 90-day mortality, and rehospitalization risk after ED visits were evaluated. Among the total 371 017 AF patients, 99 306 patients visited the ED in 2016. The medical aid group showed the highest ED visit rate (n=11 833, 38.0%), and patients with the highest quartile of SES (quartile 4 group) showed the lowest ED visit rate (n=38 037, 30.0%). The most common cause of ED visits was cerebral infarction in all groups. The 30- and 90-day mortality rates and rehospitalization risk after ED visits was higher in groups with lower SES. Conclusions Patients with AF and with lower SES had a higher risk of ED visit rate, higher 30- and 90-day mortality rates, and rehospitalization risk after ED visit. Tailored AF management according to different SES levels in patients with AF is needed to improve clinical outcomes.

Change of mortality of patients with acute ischemic stroke before and after 2015

Introduction

Advances in the diagnosis and management of acute ischemic stroke (AIS) and the increased use of mechanical thrombectomy (MT) have improved the quality of care and prognosis of patients with AIS since 2015. We investigated the changing trends in mortality of patients with AIS in Korea before and after 2015.

Materials and methods

A retrospective cohort study was conducted using combined anonymized data from the Acute Stroke Assessment Registry of Korea and the Health Insurance Review & Assessment Service database. Patients with ischemic stroke with precise onset time and initial National Institute of Health Stroke Scale records were included.

Results

Patients receiving MT treatment increased from 256 (2.7%) pre-2015 to 1,037 (3.9%) post-2015 (p < 0.001). Overall mortality significantly decreased from pre-2015 to post-2015. In pre-2015, intravenous thrombolysis (IVT) administered within 2 h significantly reduced 3-month mortality when compared with non-IVT. While, in post-2015, IVT administered within 2 h significantly reduced the 3-month, 1-year, 2-year, and 4-year mortality (p < 0.05). MT only reduced 1-year mortality pre-2015; however, MT significantly reduced the 3-month, 1-year, and 2-year mortality post-2015 (p < 0.05). Post-stroke antiplatelet and anticoagulant drugs significantly reduced the 3-month, 1-year, 2-year, and 4-year mortality post-2015.

Discussion

Since 2015, faster IVT has significantly reduced the short- and long-term mortality in patients with AIS; MT reduced the 3-month, 1-year, and 2-year mortality. Post-stroke antithrombotic medication has significantly lowered the 2- and 4-year mortality since 2015.

Conclusions

Changing trends in AIS management since 2015 have improved the prognosis of patients with AIS.

Risk of Dementia After Smoking Cessation in Patients With Newly Diagnosed Atrial Fibrillation

IMPORTANCE

Incident atrial fibrillation (AF) is associated with an increased risk of dementia. However, data on the association between smoking cessation after AF diagnosis and dementia risk are limited.

OBJECTIVE

To evaluate the association between changes in smoking status after AF diagnosis and dementia risk.

DESIGN, SETTING, AND PARTICIPANTS

This nationwide cohort study with 126 252 patients used data from the Korean National Health Insurance Service database, including patients who had a national health checkup examination within 2 years before and after AF diagnosis between January 1, 2010, and December 31, 2016. Based on their smoking status, participants were classified as never smokers, ex-smokers, quit smokers, and current smokers. Ex-smokers were defined as those who had quit smoking before the first examination and remained quit until the second examination. Patients who were current smokers at the first health examination but had quit smoking before the second examination were classed as quit smokers. The index date was the second health examination. Patients were followed up until dementia, death, or the study period ended (December 31, 2017), whichever occurred first. Data were analyzed from January 13, 2020, to March 29, 2022.

EXPOSURES

Smoking cessation after newly diagnosed AF.

MAIN OUTCOMES AND MEASURES

Dementia, including Alzheimer disease and vascular dementia, was the primary outcome. Cox proportional hazards regression model was used to estimate hazard ratios.

RESULTS

A total of 126 252 patients (mean [SD] age, 62.6 [12.0] years; 61.9% men) were included in the analysis. The mean (SD) CHA2DS2-VASc score, which measures the risk of ischemic stroke, was 2.7 (1.7). Smoking status of the total study population was as follows: 65 579 never smokers (51.9%), 34 670 ex-smokers (27.5%), 8919 quit smokers (7.1%), and 17 084 current smokers (13.5%). During a median of 3 years of follow-up, dementia occurred in 5925 patients (1.11 per 1000 person-years). After multivariable adjustment, the risk of quit smokers was significantly lower than that of current smokers (hazard ratio, 0.83 [95% CI, 0.72-0.95]).

CONCLUSIONS AND RELEVANCE

The findings of this cohort study suggest that all types of smoking were associated with a significantly higher risk of dementia in patients with new-onset AF. Smoking cessation after AF diagnosis was associated with a lower risk of dementia than among current smokers. These findings may support promoting smoking cessation to reduce dementia risk in patients with new-onset AF.

Drug Utilization Pattern of Oral Anticoagulants in Patients with Atrial Fibrillation: A Nationwide Population-Based Study in Korea

INTRODUCTION

Treatment persistence for anticoagulant therapy is important in preventing thromboembolism in nonvalvular atrial fibrillation (NVAF) patients. Understanding drug utilization pattern and treatment changes in oral anticoagulant (OAC) users may facilite better NVAF management. Thus, our study aimed to examine OAC treatment patterns preceding events leading to switch or discontinuation and medication adherence in Korean NVAF patients.

METHODS

We conducted a drug utilization study on all Korean patients with atrial fibrillation (AF) newly prescribed OACs between July 2015 and November 2016 using the national claims data. We assessed treatment changes such as switching and discontinuation from index OAC and relevant events preceding the change and examined patient characteristics as predictors of changes that occurred among OAC users. Medication adherence was compared among OAC users by calculating the medication possession ratio (MPR).

RESULTS

A total of 48,389 NVAF patients were identified who initiated OACs within the study period. Most initiated nonvitamin K antagonist oral anticoagulants (NOACs) (22% apixaban, 24% dabigatran, 37% rivaroxaban), and 18% initiated warfarin. The frequency of switch to another OAC was 8.8% for apixaban, 16.1% for dabigatran, 6.6% for rivaroxaban, and 19.1% for warfarin. The frequency of discontinuation was lower for apixaban (22.9%), dabigatran (26.3%), and rivaroxaban (25.7%) than warfarin (31.6%). Compared to warfarin, NOAC users were less likely to switch treatment. Thromboembolic event was the most common clinical event preceding switch from warfarin to NOAC and from NOAC to warfarin. Discontinuation of OAC was often preceded by a bleeding event. Patients who initiated apixaban showed significantly higher mean MPR compared to those on dabigatran and warfarin.

CONCLUSION

In real-world practice in Korea, we have observed treatment change to be common in OAC users. Our results indicate better medication adherence with NOACs than with warfarin. (ClinicalTrials.gov registration number NCT03572972).

Association of Gender With Clinical Outcomes in a Contemporary Cohort of Patients With Atrial Fibrillation Receiving Oral Anticoagulants

We evaluated the relationship between biological sex and adverse clinical events in a contemporary atrial fibrillation (AF) cohort, mainly those taking direct oral anticoagulants, among patients with more-than-intermediate risk of stroke. Sex-based differences are noted in the outcomes of patients with AF who used anticoagulants, primarily vitamin K antagonist. The stroke or systemic embolism risk and major bleeding risk did not differ between the sexes, although women had a lower risk of all-cause mortality in contemporary anticoagulation for AF. Female may not be a risk factor for adverse clinical events associated with anticoagulation for AF.

Background and Objectives

In patients with atrial fibrillation (AF), females taking vitamin K antagonist are at higher risk of stroke or systemic embolism (SSE), bleeding and all-cause death than males. This study investigated the relationship between sex and adverse clinical events in a contemporary AF patient cohort taking anticoagulation.

Methods

This prospective multicenter AF registry study comprised 6,067 patients with AF (mean age, 70±9 years; men, 59%) with intermediate to high risk of stroke (CHA₂DS₂-VAscore ≥1) and receiving oral anticoagulation therapy. Adverse clinical outcomes, including SSE, bleeding, death were evaluated in patients stratified by sex and anticoagulation patterns.

Results

Women were older and used more direct oral anticoagulants (85% vs. 78%, p<0.001) than men. During a median (25^th and 75^th percentiles) follow-up of 30 (24, 38) months, the incidence rate and risk of SSE (0.7 in women vs. 0.7 in men per 100 person-years) and major bleeding (0.1 in women vs. 0.1 in men per 100 person-years) were not different between the sexes. However, women had a lower all-cause death rate (0.4 in women vs. 0.6 in men per 100 person-years, hazard ratio: 0.48, 95% confidence interval: 0.25–0.91, p=0.025) than men.

Conclusions

In contemporary anticoagulation for AF, SSE and major bleeding risks did not differ between sexes. However, women showed a lower risk of all-cause death rate than men, indicating that the use of oral anticoagulants for treating AF in females does not appear to be a risk factor for adverse clinical events.

Trial Registration

ClinicalTrials.gov Identifier: NCT02786095

Worldwide trends in oral anticoagulant use in patients with atrial fibrillation from 2010 to 2018: a systematic review and meta-analysis

AIMS

Non-vitamin K antagonist oral anticoagulants (NOACs) are effective and safe alternatives compared with vitamin K antagonists (VKAs) for thromboembolic prevention in atrial fibrillation (AF), while antiplatelets are no longer recommended. However, to which extent NOAC introduction and guideline updates have increased OAC use in AF, is unclear. Therefore, worldwide trends in real-life prescribing of OACs, NOACs, VKAs, and antiplatelet monotherapy in AF patients were investigated.

METHODS AND RESULTS

Using PubMed and Embase, observational nationwide cohort studies on annual prevalent and/or incident OAC use in non-selected AF patients since 2010 were included. A meta-analysis of single proportions was performed. Twenty-one studies were included assessing prevalent and incident use among 9 758 637 and 197 483 OAC-eligible AF patients, respectively. Worldwide prevalence and incidence of OAC users increased from 0.42 [95% confidence interval (CI) 0.22-0.65] and 0.43 (95% CI 0.37-0.49) in 2010 to 0.78 (95% CI 0.77-0.78) and 0.75 (95% CI 0.74-0.76) in 2018, respectively. Prevalent and incident NOAC users increased globally from 0 in 2010 to 0.45 (95% CI 0.45-0.46) and 0.68 (95% CI 0.67-0.69) in 2018, respectively, whereas prevalent and incident VKA use decreased from 0.42 (95% CI 0.22-0.65) and 0.42 (95% CI 0.36-0.49) in 2010 to 0.32 (95% CI 0.32-0.32) and 0.06 (95% CI 0.06-0.07) in 2018, respectively. Prevalent antiplatelet monotherapy use decreased from 0.37 (95% CI 0.32-0.42) in 2010 to 0.09 (95% CI 0.09-0.10) in 2018.

CONCLUSION

The proportion of OAC users worldwide almost doubled following NOAC introduction. As one-quarter of OAC-eligible AF subjects were not anticoagulated and 9% were only treated with antiplatelets in 2018, there is still room for improvement.

Factors Influencing the Selection of Non-Vitamin K Antagonist Oral Anticoagulants for Stroke Prevention in Patients With Non-Valvular Atrial Fibrillation

BACKGROUND

Major atrial fibrillation (AF) guidelines recommend non-vitamin K antagonist oral anticoagulants (NOACs) over warfarin, except in rare clinical circumstances based on 4 randomized controlled trials comparing each NOAC with warfarin. We aimed to investigate the current NOAC prescription behaviors in alignment with the recent clinical evidence available.

METHOD

We conducted a cross-sectional analysis of NOAC-using patients with non-valvular atrial fibrillation (NVAF) who were aged ≥65 years on the index date (July 1, 2018) based on nationwide claims data. The types of NOACs being taken were analyzed using chi-squared tests, and factors influencing NOAC selection were identified using multinomial logistic regression analysis.

RESULTS

A total of 6,061 patients were included. Among the 4 NOACs, rivaroxaban was the most used NOAC. Patients aged ≥75 years (odds ratio [OR] = 1.270, confidence interval [CI] = 1.089-1.450) and women (OR = 1.148, CI = 1.011-1.284) were more likely to use apixaban relative to rivaroxaban. Patients with prior stroke/transient ischemic attack/thromboembolism had higher odds of using dabigatran (OR = 1.508, CI = 1.312-1.704) and apixaban (OR = 1.186, CI = 1.026-1.346). Patients with renal disease had higher odds of using apixaban (OR = 1.466, 95% CI = 1.238-1.693). These findings are consistent with the efficacy and safety profiles reported in pivotal trials and observational studies comparing individual NOACs.

CONCLUSION

Among the 4 NOACs, rivaroxaban was the most commonly used NOAC. Apixaban was preferred for patients aged ≥75 years, females, and patients with renal disease.

Safety and long-term outcomes of catheter ablation according to sex in patients with atrial fibrillation: A nationwide cohort study

BACKGROUND

Catheter ablation is more effective than antiarrhythmic drug therapy alone in patients with atrial fibrillation (AF). However, there are limited data on the outcomes of AF ablation according to sex. The purpose of this study was to evaluate gender differences in the actual outcomes after catheter ablation for atrial fibrillation.

METHODS

Of 801,710 patients with AF in the Korean National Health Insurance Service database, we identified 9175 patients without valvular heart disease who underwent AF ablation between 2006 and 2015 and assessed 30-day safety and one-year effectiveness outcomes according to sex.

RESULTS

Of the 9175 patients who underwent AF ablation, 2206 (24%) were female. Women, compared to men, were older (60.8 ± 10.2 vs. 56.0 ± 10.5 years), had higher CHA₂DS₂-VASc (3.5 ± 1.7 vs. 2.0 ± 1.6), higher HAS-BLED (2.6 ± 1.3 vs. 2.4 ± 1.2), and higher Charlson comorbidity index scores (3.8 ± 2.6 vs. 3.1 ± 2.5) (p < 0.001 for all). Following ablation, there was no significant difference in the risk of 30-day complications, including hemorrhage and tamponade, between women and men. In multivariable analyses, there were no significant differences in all-cause hospitalization (adjusted hazard ratio [HR] 1.05, 95% confidence interval [CI] 0.91-1.22, p = 0.489) and AF rehospitalization (adjusted HR 1.16, 95% CI 0.96-1.40, p = 0.135). Women were less likely to undergo cardioversion (adjusted HR 0.72, 95% CI 0.62-0.84, p < 0.001) but were more likely to be re-hospitalized for heart failure (adjusted HR 1.86, 95% CI 1.11-3.11, p = 0.019).

CONCLUSION

Women who underwent AF ablation did not differ from men in terms of the risk of complications and all-cause hospitalization in this study. The small increased risk in women reported in previous studies may be related to residual confounding, particularly from insufficient control for age and comorbidities.

Smoking Cessation after Diagnosis of New-Onset Atrial Fibrillation and the Risk of Stroke and Death

Limited data are available regarding the impact of smoking cessation after atrial fibrillation (AF) diagnosis on clinical outcomes. Using the Korean National Health Insurance Service database, we included patients newly diagnosed with AF and categorized them into four groups as follows: (i) never smokers, (ii) ex-smokers, (iii) smoking cessation after AF diagnosis ("quitters"), and (iv) current smokers. The primary outcomes were incident ischemic stroke and all-cause death during follow-up. Fatal ischemic stroke and death from cerebrovascular events were evaluated as secondary outcomes. Among 97,637 patients (mean age, 61 years; mean CHA₂DS₂-VASc score, 2.3), 6.9% stopped smoking after AF diagnosis. The mean follow-up duration was 3.2 ± 2.0 years. After multivariable adjustment, quitters had lower risks of ischemic stroke (hazard ratio (HR), 0.702; 95% confidence interval (CI), 0.595-0.827) and all-cause death (HR, 0.842; 95% CI, 0.748-0.948) than current smokers. Quitters after AF diagnosis were associated with lower risks of fatal ischemic stroke (HR, 0.454; 95% CI, 0.287-0.718) and death from cerebrovascular events (HR, 0.664; 95% CI, 0.465-0.949) compared with current smokers. Quitting smoking may reduce the risk of ischemic stroke, the severity of ischemic stroke, and the incidence of cerebrovascular events in patients with new-onset AF.

Off-label underdosed apixaban use in Asian patients with non-valvular atrial fibrillation

AIMS

To compare the effectiveness and safety of off-label underdosed apixaban with on-label standard dose apixaban in Asian patients with atrial fibrillation (AF).

METHODS AND RESULTS

Using the Korean nationwide claims database, we identified patients who were prescribed apixaban and did not fulfil the dose reduction criteria for apixaban between January 2015 and December 2017. A multivariable Cox hazard regression model was performed, and hazard ratios (HRs) for ischemic stroke, major bleeding (MB), all-cause death, and composite outcome were analysed. Compared to patients prescribed on-label standard dose apixaban (n = 4,194), patients prescribed off-label underdosed apixaban (n = 2,890) showed a higher risk of ischemic stroke (adjusted HR [aHR], 1.38; 95% confidence interval [CI], 1.06-1.81), all-cause death (aHR, 1.19; 95% CI, 1.01-1.39), and the composite outcome (aHR, 1.17; 95% CI, 1.03-1.34), but with no significant differences in MB between the two groups. Among the patients who did not meet any dose reduction criteria, off-label underdosed apixaban use was associated with a significantly higher risk of ischemic stroke than on-label standard dose apixaban use (aHR, 1.85; 95% CI, 1.25-2.73). Among the patients who met a single dose reduction criterion, off-label underdosed apixaban use was associated with a higher risk of all-cause death than on-label standard dose apixaban (aHR, 1.32; 95% CI, 1.07-1.64).

CONCLUSION

The off-label underdosed apixaban group showed higher risks of ischemic stroke, all-cause death, and composite clinical outcomes than the on-label standard dose apixaban group, but both showed comparable risks of MB. Label-adherence to apixaban dosing should be emphasised to achieve the best clinical outcomes for Asian patients with AF.

Cardiovascular Research Using the Korean National Health Information Database

The Korean National Health Information Database (NHID) contains nationwide claims data, including sociodemographic data, health care utilization, health screening data, and healthcare provider information. To compensate for the limitations of randomized clinical trials, real-world observational studies using claims data have emerged as a novel research tool. We summarized the structure of the Korean NHID and the recent researches conducted in the field of cardiovascular science. Epidemiological studies, prescription patterns, temporal trends, comparison of effectiveness and safety of treatments, variability index using laboratory data, and rare intractable disease constitute interesting topics of research in cardiovascular science using the NHID. The operational definition of covariates and clinical outcomes is important for researchers interested in using the NHID data as new tools to prove their hypothesis. A step-by-step approach adopted by a team of data scientists, epidemiologists, statisticians, and clinical researchers may be most effective while designing research studies. The ultimate direction of research using the NHID should aim to improve the welfare of the public by promoting public health, reducing medical costs, and guiding healthcare policies.