Increasing trends in hospital care burden of atrial fibrillation in Korea, 2006 through 2015

Association of cardiovascular health and incident atrial fibrillation in elderly population

OBJECTIVE

To evaluate whether baseline and changes in cardiovascular health (CVH) were related to incident atrial fibrillation (AF) risk in the elderly population.

METHODS

From the Korea National Health Insurance Service-Senior cohort, we included 208 598 participants without prior AF (median age: 70 (IQR 66-74) years; 90 916 (43.6%) men) who underwent national health check-ups between 1 January 2005 and 31 December 2012. Using the six metrics of the American Heart Association, participants were categorised as having low, moderate and high CVH.

RESULTS

Over a median follow-up of 7.2 years, 7818 cases of incident AF occurred. In multivariable analysis, moderate (HR: 0.90; 95% CI: 0.86 to 0.94) and high (HR: 0.81; 95% CI: 0.73 to 0.91) CVH status at baseline were associated with a lower risk of incident AF. However, in 109 695 participants with changes in CVH between the first and second check-ups, the direction of change in CVH scores showed no consistent association with future AF incidence. In newly diagnosed participants with AF, the incidence of the composite outcome (stroke, major bleeding and all-cause death) decreased with every 1-point increase in the baseline CVH score (HR: 0.94; 95% CI: 0.89 to 0.99).

CONCLUSIONS

In the general elderly population, better baseline CVH metrics were associated with lower incident AF risk. In participants with newly diagnosed AF, better CVH was also associated with lower incidence of future composite outcomes. However, the direction of change in CVH status within 2 years showed an inconsistent influence on incident AF risk.

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.

Associations of hypertension burden on subsequent dementia: a population-based cohort study

In this nationwide cohort study, we assessed the effects of hypertension burden and blood pressure (BP) control on dementia in different age subgroups. From the Korean National Health Insurance Service-Health Screening cohort from January 1, 2005 to December 31, 2013, we enrolled 428,976 subjects aged 40-79 years without previous diagnosis of dementia or stroke. During a mean follow-up of 7.3 ± 1.5 years, 9435 (2.2%) were diagnosed with dementia. Per 10 mmHg increase in systolic BP (SBP), risk of dementia was increased by 22% (95% confidence interval [CI] 1.15-1.30) in subjects aged 40-59 years and 8% (95% CI 1.04-1.11) in subjects aged 60-69 years. No significant associations were observed in subjects aged ≥ 70 years. Among subjects aged 40-59 years, both vascular and Alzheimer's dementia risks were increased with increasing SBP. Increasing hypertension burden (proportion of days with increased BP) was associated with higher dementia risk (hazard ratio [HR] 1.09 per 10% increase, 95% CI 1.08-1.10). Among patients with baseline SBP ≥ 140 mmHg, optimal follow-up SBP (120-139 mmHg) was associated with decreased dementia risk (HR 0.69, 95% CI 0.50-0.95). Hypertension burden was associated with higher risks of dementia. Adequate BP control was associated with lower risk of dementia in individuals aged < 70 years.

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.

Changes in Cardiovascular Risk Factors and Cardiovascular Events in the Elderly Population

Background

This study examines changes in the ideal cardiovascular health (CVH) status and whether these changes are associated with incident cardiovascular disease (CVD) and mortality in the elderly Asian population.

Methods and Results

In the Korea National Health Insurance Service–Senior cohort aged ≥60 years, 208 673 participants without prior CVD, including 109 431 who showed changes in CVH status, were assessed. The association of the changes in cardiovascular risk factors with incident CVD was assessed from 2004 to 2014 in the elderly (aged 60–74 years) and very elderly (≥75 years) groups. During the follow‐up period (7.1 years for CVD and 7.2 years for mortality), 19 429 incident CVD events and 24 225 deaths occurred. In both the elderly and very elderly participants, higher CVH status resulted in a lower risk of CVD and mortality. In the very elderly participants, compared with consistently low CVH, consistently high CVH (subhazard ratio, 0.41; 95% CI, 0.23–0.73) was associated with a lower risk of CVD. This trend was consistently observed in the elderly population. In the very elderly participants, total cholesterol level was not informative enough for the prediction of CVD events. In both the elderly and very elderly groups, body mass index and total cholesterol were not informative enough for the prediction of all‐cause mortality.

Conclusions

In both the elderly and very elderly Asian populations without CVD, a consistent relationship was observed between the improvement of a composite metric of CVH and the reduced risk of CVD. Body mass index and total cholesterol were not informative enough for the prediction of all‐cause mortality in both the elderly and very elderly groups.

Less dementia after catheter ablation for atrial fibrillation: a nationwide cohort study

AIMS

Accumulating evidence shows that atrial fibrillation (AF) is associated with an increased risk of dementia. Catheter ablation for AF prolongs the duration of sinus rhythm, thereby improving the quality of life. We investigated the association of catheter ablation for AF with the occurrence of dementia.

METHODS AND RESULTS

Using the Korean National Health Insurance Service database, among 194 928 adults with AF treated with ablation or medical therapy (antiarrhythmic or rate control drugs) between 1 January 2005 and 31 December 2015, we studied 9119 patients undergoing ablation and 17 978 patients managed with medical therapy. The time-at-risk was counted from the first medical therapy, and ablation was analysed as a time-varying exposure. Propensity score-matching was used to correct for differences between the groups. During a median follow-up of 52 months, compared with patients with medical therapy, ablated patients showed lower incidence and risk of overall dementia (8.1 and 5.6 per 1000 person-years, respectively; hazard ratio 0.73, 95% confidence interval 0.58-0.93). The associations between ablation and dementia risk were consistently observed after additionally censoring for incident stroke (hazard ratio 0.76, 95% confidence interval 0.61-0.95) and more pronounced in cases of ablation success whereas no significant differences observed in cases of ablation failure. Ablation was associated with lower risks of dementia subtypes including Alzheimer's disease and vascular dementia.

CONCLUSION

In this nationwide cohort of AF patients treated with catheter ablation or medical therapy, ablation was associated with decreased dementia risk. This relationship was evident after censoring for stroke and adjusting for clinical confounders.

Treatment timing and the effects of rhythm control strategy in patients with atrial fibrillation: nationwide cohort study

OBJECTIVE

To investigate whether the results of a rhythm control strategy differ according to the duration between diagnosis of atrial fibrillation and treatment initiation.

DESIGN

Longitudinal observational cohort study.

SETTING

Population based cohort from the Korean National Health Insurance Service database.

PARTICIPANTS

22 635 adults with atrial fibrillation and cardiovascular conditions, newly treated with rhythm control (antiarrhythmic drugs or ablation) or rate control strategies between 28 July 2011 and 31 December 2015.

MAIN OUTCOME MEASURE

A composite outcome of death from cardiovascular causes, ischaemic stroke, admission to hospital for heart failure, or acute myocardial infarction.

RESULTS

Of the study population, 12 200 (53.9%) were male, the median age was 70, and the median follow-up duration was 2.1 years. Among patients with early treatment for atrial fibrillation (initiated within one year since diagnosis), compared with rate control, rhythm control was associated with a lower risk of the primary composite outcome (weighted incidence rate per 100 person years 7.42 in rhythm control v 9.25 in rate control; hazard ratio 0.81, 95% confidence interval 0.71 to 0.93; P=0.002). No difference in the risk of the primary composite outcome was found between rhythm and rate control (weighted incidence rate per 100 person years 8.67 in rhythm control v 8.99 in rate control; 0.97, 0.78 to 1.20; P=0.76) in patients with late treatment for atrial fibrillation (initiated after one year since diagnosis). No significant differences in safety outcomes were found between the rhythm and rate control strategies across different treatment timings. Earlier initiation of treatment was linearly associated with more favourable cardiovascular outcomes for rhythm control compared with rate control.

CONCLUSIONS

Early initiation of rhythm control treatment was associated with a lower risk of adverse cardiovascular outcomes than rate control treatment in patients with recently diagnosed atrial fibrillation. This association was not found in patients who had had atrial fibrillation for more than one year.

Changes in Cardiovascular Health Status and Risk of Sudden Cardiac Death in Older Adults

PURPOSE

Cardiovascular health (CVH) status is associated with several cardiovascular outcomes; however, correlations between changes in CVH status and risk of sudden cardiac death (SCD) are unknown. We aimed to evaluate associations between changes in CVH status and risk of SCD and all-cause death in older adults.

MATERIALS AND METHODS

We used data from the Korea National Health Insurance Service-Senior cohort database (2005-2012). Six metrics from the American Heart Association (smoking, body mass index, physical activity, blood pressure, total cholesterol, and fasting blood glucose) were used to calculate CVH scores. Changes in CVH status between two health checkups were categorized as low to low, low to high, high to low, and high to high.

RESULTS

We included 105200 patients whose CVH status for an initial and follow-up health checkup (2-year interval) was available. During a median of 5.2 years of follow-up after a second health checkup, 688 SCDs occurred. Compared to patients with a persistent low CVH status, those with a consistently high CVH status had a reduced risk of SCD [adjusted hazard ratio (HR), 0.69; 95% confidence interval (CI), 0.56-0.86] and all-cause death (adjusted HR, 0.74; 95% CI, 0.69-0.78). The risk of all-cause death followed similar trends. However, an inconsistent linear relationship was observed for changes in CVH status and the risk of SCD, but not of all-cause death.

CONCLUSION

Maintaining a high CVH status was associated with future risks of SCD and all-cause death among an older adult population.

Incidence and predictors of hospitalization in patients with atrial fibrillation: results from the Chinese atrial fibrillation registry study

Background

Patients with atrial fibrillation (AF) underwent a high risk of hospitalization, which has not been paid much attention to in practice. Therefore, we aimed to assess the incidence, causes and predictors of hospitalization in AF patients.

Methods

From August 2011 to December 2017, a total number of 20,172 AF patients from the Chinese Atrial Fibrillation Registry (China-AF) Study were prospectively selected for this study. We described the incidence, causes of hospitalization by age groups and sex. The Fine-Gray competing risk model was employed to identify predictors of first all-cause and first cause-specific hospitalization.

Results

After a mean follow-up of 37.3 ± 20.4 months, 7,512 (37.2%) AF patients experienced one or more hospitalizations. The overall incidence of all-cause hospitalization was 24.0 per 100 patient-years. Patients aged < 65 years were predominantly hospitalized for AF (42.1% of the total hospitalizations); while patients aged 65–74 and ≥ 75 years were mainly hospitalized for non-cardiovascular diseases (43.6% and 49.3%, respectively). We found patients complicated with heart failure (HF)[hazard ratio (HR) 1.10, 95% confidence interval (CI) 1.02–1.18], established coronary artery disease (CAD) (HR 1.24, 95%CI 1.17–1.33), ischemic stroke/transient ischemic attack (TIA) (HR 1.22, 95%CI 1.15–1.30), diabetes (HR 1.14, 95%CI 1.08–1.20), chronic obstructive pulmonary disease (COPD) (HR 1.28, 95%CI 1.02–1.62), gastrointestinal disorder (HR 1.37, 95%CI 1.21–1.55), and renal dysfunction (HR 1.24, 95%CI 1.09–1.42) had higher risks of hospitalization.

Conclusions

More than one-third of AF patients included in this study were hospitalized at least once during over 3-year follow-up. The main cause for hospitalization among the elderly patients (≥ 65 years) is non-cardiovascular diseases rather than AF. Multidisciplinary management of comorbidities should be advocated to reduce hospitalization in AF patients older than 65 years old.

Clinical Registryhttp://www.chictr.org.cn/showproj.aspx?proj=5831. Unique identifier: ChiCTR-OCH-13003729. The registration date is October 22, 2013.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-021-01951-5.

Risk for osteoporotic fractures in patients with atrial fibrillation using different oral anticoagulants

Background

We aimed to investigate the comparative risk of fracture among patients with atrial fibrillation (AF) treated with warfarin or non-vitamin K antagonist oral anticoagulants (NOACs).

Methods

Using the Korean National Health Insurance Service database, patients with AF who received a prescription for apixaban, dabigatran, rivaroxaban, or warfarin between 2013 and 2016 were included. Risk of major fractures (osteoporotic hip, vertebral, or pelvic fractures) were compared using inverse probability of treatment weighting.

Results

There were 70,481 patients identified (41.3% women; mean [SD] age 70.5 [11.3] years); 16,992 apixaban, 22,514 dabigatran, 27,998 rivaroxaban, and 29,390 warfarin users. During a median follow-up of 390 days, 2412 major fractures occurred with weighted incidences per 100 patient-years of 2.56 for apixaban, 2.39 for dabigatran, 2.78 for rivaroxaban, and 3.43 for warfarin. NOAC use was associated with a lower risk for fracture than warfarin use: HR 0.70 (95% confidence interval [CI] 0.57–0.86) for apixaban, HR 0.69 (95% CI 0.60–0.78) for dabigatran, and HR 0.79 (95% CI 0.70–0.90) for rivaroxaban. In head-to-head comparisons between NOACs, there was no significant difference between apixaban and dabigatran. Rivaroxaban was associated with a higher risk for fracture than dabigatran (HR 1.15, 95% CI 1.02–1.31).

Conclusion

In patients with AF, NOAC use may result in a lower risk for osteoporotic fracture compared with warfarin use. Fracture risk does not seem to be altered by the choice of NOAC type, except for rivaroxaban. These associations may help inform benefit–risk assessments when choosing between the different anticoagulant types.

Reduction of mortality by catheter ablation in real-world atrial fibrillation patients with heart failure

Whether catheter ablation for atrial fibrillation (AF) improves survival and affects other outcomes in real-world heart failure (HF) patients is unclear. This study aimed to evaluate whether ablation reduces death, and other outcomes in real-world AF patients with HF. Among 834,735 patients with AF from 2006 to 2015 in the Korean National Health Insurance Service database, 3173 HF patients underwent AF ablation. Propensity score weighting was used to correct for differences between the groups. During median 54 months follow-up, the risk of all-cause death in ablated patients was less than half of that in patients with medical therapy (2.8 vs. 6.2 per 100 person-years; hazard ratio [HR] 0.42, 95% confidence interval [CI] 0.27–0.65, p < 0.001). Ablation was related with lower risk of cardiovascular death (HR 0.38, 95% CI 0.32–0.62, p < 0.001), HF admission (HR 0.39, 95% CI 0.33–0.46, p < 0.001) and stroke/systemic embolism (HR 0.44, 95% CI 0.37–0.53, p < 0.001). In subgroup analysis, the risk of all-cause death was reduced in most subgroups except in the elderly (≥ 75 years) and strictly anticoagulated patients. Ablation may be associated with reduced risk of all-cause death and cardiovascular death in real-world AF patients with HF, supporting the role of AF ablation in patients with HF.

Prevention of Dementia in Patients with Atrial Fibrillation

Atrial fibrillation (AF) has been associated with an increased risk of dementia. Although there does not appear to be solid evidence that any specific treatment prevents or delays AF-associated cognitive decline, evidence is accumulating regarding the possible treatment strategies for preventing dementia. In this review, we summarize the evidence linking AF to dementia and critically appraise the proposed treatment strategies.

Atrial fibrillation (AF) is the most common form of arrhythmia in the elderly population and increases stroke risk by a factor of 4- to 5-fold. There is increasing evidence to suggest that incident AF may contribute to the development of dementia, independent of overt stroke. In particular, relatively younger patients with AF are more prone to dementia development than older patients with AF. Evidence is accumulating regarding the possible treatment strategies for preventing dementia in patients with AF. Oral anticoagulation may be effective for reducing the risk of dementia, even in patients with low stroke risks. Among oral anticoagulants, the use of non-vitamin K antagonists have been associated with a considerably decreased risk of dementia than warfarin. Moreover, successful catheter ablation for AF has also been associated with decreased dementia risk compared to medical therapy, suggesting that restoration of sinus rhythm, and not the ablation procedure itself, as the important mechanism in the prevention of AF-associated dementia. Among midlife patients with AF, there appeared to be a U-shaped association of blood pressure (BP) and a linear association of hypertension with dementia risk. A BP of 120 to 129/80 to 84 mmHg has been identified as the optimal range. Finally, integrated management of AF was associated with a reduced risk of dementia in AF patients.

Atrial fibrillation in low- and middle-income countries: a narrative review

Preventing premature non-communicable disease mortality necessitates a thorough review of one of the most important risk factors for stroke, which is atrial fibrillation (AF). The latter and AF-related stroke are still considered to be problems of high-income countries and are frequently overlooked in low- and middle-income countries (LMICs). In this narrative review, we provide an overview of studies that evaluated at least one of the following determinants of AF burden in LMICs: current epidemiology and trends, stroke prevention, health outcomes, and economic burden. Studies focusing on samples close to the general population (including community- and primary care-based samples) indicate sex-specific prevalence rates up to 7.4% in LMICs. Although AF prevalence is still higher in high-income countries than LMICs, the gap in AF burden between these two groups has been reducing in the past three decades. Oral anticoagulant (OAC) therapy for stroke prevention is underused in LMICs, and there are little data on OAC therapy in relation to stroke risk scores, such as CHA2DS2-VASc. Available data also points to higher morbidity and mortality for patient with AF in LMICs than their counterparts in high-income countries. Data on the consequent economic burden in LMICs is scarce, but it is reasonable to consider it will follow the same trend as that observed for health outcomes. Raising the visibility of AF as a public health problem in LMICs is necessary as a first step to providing adequate care for patients with this condition.

Association between clustering of unhealthy lifestyle factors and risk of new-onset atrial fibrillation: a nationwide population-based study

We aimed to investigate the association between the combination of unhealthy lifestyle and risk of AF. Subjects aged 66 years who underwent health examination from 2009 to 2015 were included. The cohort was divided into 8 groups by the combination of unhealthy lifestyle including current smoking, heavy drinking (> 30 g/day), and lack of regular exercise, and followed up for new-onset AF till December 31, 2017. Among 1,719,401 subjects, 47,334 had incident AF (5.5 per 1000 person-years) during a 5-year mean follow-up period. Lack of regular exercise was the most powerful factor to be associated with a higher risk of AF as a single factor (adjusted hazard ratio 1.11, 95% confidence interval 1.08–1.13). Amongst combinations of two unhealthy lifestyle factors, current smoking with heavy drinking, lack of regular exercise with heavy drinking, and lack of regular exercise with current smoking were associated with a 6%, 15%, and 20% higher risks of AF, respectively. A cluster of three unhealthy lifestyle components was associated with a 22% higher risk of AF. Increased numbers of unhealthy lifestyle factors were associated with a higher risk of incident AF. These findings support the promotion of a healthy lifestyle to lower the risk of new-onset AF.

Cardiovascular- and Bleeding-Related Hospitalization Rates With Edoxaban Versus Warfarin in Patients With Atrial Fibrillation Based on Results of the ENGAGE AF–TIMI 48 Trial

Background

The ENGAGE AF–TIMI 48 trial (Effective Anticoagulation With Factor Xa Next Generation in Atrial Fibrillation–Thrombolysis in Myocardial Infarction 48) demonstrated noninferiority of once-daily 60 mg (30 mg dose-reduced) edoxaban compared with warfarin for prevention of stroke/systemic embolism in patients with atrial fibrillation. No previous analysis has explored the impact of treatment with edoxaban versus warfarin on rates of hospitalizations.

Methods

Detailed healthcare resource utilization data from ENGAGE AF–TIMI 48 for the 14 024 randomized patients who received at least one dose of study drug were used to compare the rates of bleeding- and cardiovascular-related hospitalizations for edoxaban versus warfarin. Hospitalization rates were calculated for each treatment group, and relative rates were estimated using Poisson regression. The influence of patient characteristics on the impact of edoxaban versus warfarin was evaluated through the inclusion of interaction terms.

Results

The overall rate of cardiovascular- or bleeding-related hospitalization was significantly lower for edoxaban than warfarin (relative rate [RR], 0.91 [95% CI, 0.85–0.97], P =0.003). Rates of hospitalizations for cardiovascular reasons (RR, 0.91 [95% CI, 0.85–0.97], P =0.004), stroke (RR, 0.80 [95% CI, 0.72–0.88], P <0.0001), and for each stroke subtype (ischemic: RR, 0.89 [95% CI, 0.81–0.99], P =0.03; hemorrhagic: RR, 0.60 [95% CI, 0.54–0.68], P <0.0001) were also lower for edoxaban. Notably, significantly greater reductions with edoxaban versus warfarin were seen for ischemic stroke–related hospitalizations in vitamin K antagonist naive patients and patients with CHADS 2 scores 4 to 6, previous stroke or transient ischemic attack, age ≥75, and no previous coronary artery disease. For nonstroke bleeding–related hospitalizations, greater reductions with edoxaban were seen in vitamin K antagonist naive patients, patients with CHADS 2 scores 4 to 6, and patients with moderate renal dysfunction.

Conclusions

Edoxaban 60 mg (30 mg dose-reduced) was associated with a significantly lower overall rate of cardiovascular- or bleeding-related hospitalization and significant reductions in the subcategories of cardiovascular-related, stroke-related, bleed-related, and nonstroke cardiovascular–related hospitalizations, when compared with warfarin. These results suggest the potential for cost offsets with edoxaban, with even greater reductions in higher-risk patients.

Registration:

URL: https://www.clinicaltrials.gov ; Unique identifier: NCT00781391

Comparative clinical outcomes of dronedarone and sotalol in Asian patients with atrial fibrillation: a nationwide cohort study

We aimed to evaluate the effectiveness and safety of dronedarone versus sotalol in real-world practice in Asian patients with atrial fibrillation (AF). Using the Korean nationwide claims database from August 2013 to December 2016, we identified patients with AF recently prescribed dronedarone or sotalol and analyzed the hospitalization risk and all-cause death until December 2017. Overall, 3119 and 1575 patients treated with dronedarone and sotalol, respectively, were included. After propensity score weighting, no significant differences were observed between the treatment groups. Dronedarone use was associated with a lower risk of all-cause hospitalization than sotalol use (hazard ratio [HR], 0.79; 95% confidence interval [CI], 0.70–0.88). The dronedarone group demonstrated a significantly lower risk of cardiovascular (CV) hospitalization than the sotalol group (HR 0.62, 95% CI 0.53–0.72); however, no significant difference was observed in non-CV hospitalization. No difference in the risk of all-cause death was observed between groups. The dronedarone group was significantly less likely to receive nonpharmacological treatment for AF than the sotalol group (HR 0.63, 95% CI 0.51–0.77). In a large-scale population of Asian patients with AF, dronedarone was associated with a lower risk of CV hospitalization and a lower need for nonpharmacological treatment for AF than sotalol.

Understanding the Attitudes of Clinicians and Patients Toward a Self-Management eHealth Tool for Atrial Fibrillation: Qualitative Study

Background

Atrial fibrillation (AF) is the most common heart rhythm disorder and poses a growing disease burden worldwide because of an aging population. A multidisciplinary approach with an emphasis on patient education and self-management has been demonstrated to improve outcomes for AF through the engagement of patients in their own care. Although electronic tools (e-tools) such as apps have been proposed to provide patient education and facilitate self-management, there have been few studies to guide the development of these tools for patients with AF.

Objective

This study aims to explore the perceptions of patients and health care providers (HCPs) and their attitudes toward the use of e-tools for the self-management of AF. It also seeks to elicit the factors that contribute to these attitudes.

Methods

Semistructured qualitative interviews with HCPs and patients were conducted to understand the interpretations and expectations of an e-tool that would be used for the self-management of AF. Interview data were analyzed using an exploratory thematic analysis approach to uncover emergent themes and infer ideas of preferred features in a device. A modified technology acceptance model was developed as a framework to help interpret these findings. Data from the HCPs and patients were compared and contrasted.

Results

Both patients and HCPs thought that an e-tool would be useful in the self-management of AF. Although both groups favored educational content and monitoring of blood pressure, patients expressed more passivity toward self-care and an ambivalence toward the use of technology to monitor their medical condition. This appears to be related to factors such as a patient’s age, social support, and their attitudes toward technology. Instead, they favored using the app to contact their HCPs.

Conclusions

This study provides insights into significant differences in the attitudes of patients and HCPs toward the use of e-tools for self-care against their priorities. Understanding patients’ motivations and their needs are key to ensuring higher acceptance of such tools.

What Is the Ideal Blood Pressure Threshold for the Prevention of Atrial Fibrillation in Elderly General Population?

Intensive blood pressure (BP) lowering in patients with hypertension at increased risk of cardiovascular disease has been associated with a lowered risk of incident atrial fibrillation (AF). It is uncertain whether maintaining the optimal BP levels can prevent AF in the general elderly population. We included 115,866 participants without AF in the Korea National Health Insurance Service-Senior (≥60 years) cohort from 2002 to 2013. We compared the influence of BP on the occurrence of new-onset AF between octogenarians (≥80 years) and non-octogenarians (<80 years) subjects. With up to 6.7 ± 1.7 years of follow-up, 4393 incident AF cases occurred. After multivariable adjustment for potentially confounding clinical covariates, the risk of AF in non-octogenarians was significantly higher in subjects with BP levels of <120/<80 and ≥140/90 mm Hg, with hazard ratios of 1.15 (95% confidence interval (CI), 1.03-1.28; p < 0.001) and 1.14 (95% CI, 1.04-1.26; p < 0.001), compared to the optimal BP levels (120-129/<80 mm Hg). In octogenarians, the optimal BP range was 130-139/80-89 mm Hg, higher than in non-octogenarians. A U-shaped relationship for the development of incident AF was evident in non-octogenarians, and BP levels of 120-129/<80 mm Hg were associated the lowest risk of incident AF. Compared to non-octogenarians, the lowest risk of AF was associated with higher BP levels of 130-139/80-89 mm Hg amongst octogenarians.

Application of the simple atrial fibrillation better care pathway for integrated care management in frail patients with atrial fibrillation: A nationwide cohort study

BACKGROUND

The benefit of integrated care management was unknown in frail atrial fibrillation (AF) patients. This study evaluated whether compliance with the atrial fibrillation Better Care (ABC) pathway for integrated care management would improve clinical outcomes in frail AF patients.

METHODS

From the Korea National Health Insurance Service database, 262,987 nonvalvular AF patients were enrolled between 1 January 2005 and 31 December 2015. For each patient, the Hospital Frailty Risk Score and category were calculated retrospectively using all available ICD-10 diagnostic codes. Patients were divided into three frailty-based risk categories: low (<5 points, n = 221,542), intermediate (5-15 points, n = 37,341), and high risk (>15 points, n = 4,104).

RESULTS

Over a mean follow-up of 5.9 (interquartile range 3.2, 9.4) years, in high frailty risk patients, the ABC group had lower rates of all-cause death (6.5 vs 17.5 per 100 person-years, P < .001; hazard ratio [HR] 0.74; 95% confidence interval [CI] 0.56-0.97) but was nonsignificant for the composite outcome (10.5 vs 26.0 per 100 person-years, P = .101; HR 0.79; 95% CI 0.59-1.05) compared with the Non-ABC group. When the three frailty categories were compared, the greatest benefit on mortality was seen in the high frailty group (pint < 0.001), but for the composite outcome, there was no statistical interaction for the three frailty categories (pint = 0.063).

CONCLUSIONS

Compliance with the simple ABC pathway is associated with improved outcomes in AF patients with high frailty risk. Given the high healthcare burden associated with frail AF patients, integrated AF management should be implemented to improve outcomes in these patients.

Label Adherence of Direct Oral Anticoagulants Dosing and Clinical Outcomes in Patients With Atrial Fibrillation

Background Dose adjustment of non-vitamin K antagonist oral anticoagulants (NOACs) is indicated in some patients with atrial fibrillation (AF), based on selected patient factors or concomitant medications. We assessed the frequency of label adherence of NOAC dosing among AF patients and the associations between off-label NOAC dosing and clinical outcomes. Methods and Results We evaluated 53 649 AF patients treated with an NOAC using Korean National Health Insurance Service database during the period from 2013 to 2016. NOAC doses were classified as either underdosed or overdosed, consistent with Korea Food and Drug Administration labeling. Cox proportional hazards regression was performed to investigate the effectiveness and safety outcomes including stroke or systemic embolism, major bleeding, and all-cause mortality. Overall, 16 757 NOAC-treated patients (31.2%) were underdosed, 4492 were overdosed (8.4%), and 32 400 (60.4%) were dosed appropriately according to drug labeling. Compared with patients with label adherence, those who were underdosed or overdosed were older (aged 71±8 and 75±7 years versus 70±9 years, respectively; P<0.001) and had higher CHA₂DS₂-VASc scores (4.6±1.7 and 5.3±1.7 versus 4.5±1.8, respectively; P<0.001). NOAC overdosing was associated with increased risk for stroke or systemic embolism (5.76 versus 4.03 events/100 patient-years, P<0.001), major bleeding (4.77 versus 2.94 events/100 patient-years, P<0.001), and all-cause mortality (5.43 versus 3.05 events/100 patient-years, P<0.001) compared with label-adherent use. Conclusions In real-world practice, a significant proportion (almost 2 in 5) of AF patients received NOAC doses inconsistent with drug labeling. NOAC overdosing is associated with worse clinical outcomes in Asian AF patients.

The Effect of Integrated Care Management on Dementia in Atrial Fibrillation

Clinical outcomes of patients with atrial fibrillation (AF) can be improved by an integrated care approach. We analyzed whether adherence with the AF Better Care (ABC) pathway for integrated care management would reduce the risk of dementia in a nationwide AF cohort. Using the National Health Insurance Service database of Korea, 228,026 non-valvular AF patients were retrospectively evaluated between 2005 and 2015. Patients meeting all criteria of the ABC pathway were classified as the "ABC" group and those not classified as the "non-ABC" group. During a median (25th, 75th percentiles) follow-up of 6.0 (3.3, 9.5) years, the ABC group had lower rates and risk of overall dementia (0.17 vs. 1.11 per 100 person-years, p < 0.001; hazard ratio (HR) 0.80; 95% CI 0.73-0.87) and both Alzheimer's (HR 0.79, 95% CI 0.71-0.88) and vascular dementia (HR 0.76, 95% CI 0.59-0.98) than the non-ABC group. The stratified analysis showed that the ABC pathway reduced the risk of dementia regardless of sex, comorbidities, and in patients with high stroke risk. Adherence with the ABC pathway is associated with a reduced risk of dementia in AF patients. Due to the high medical burden of AF, it is necessary to implement integrated AF management to reduce the risk of dementia.

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.

Catheter Ablation Improves Mortality and Other Outcomes in Real-World Patients With Atrial Fibrillation

Background

It is still controversial whether catheter ablation for atrial fibrillation (AF) improves survival and other outcomes in patients with AF. This study evaluated whether ablation reduces death and other events in nationwide real‐world Asian patients with AF.

Methods and Results

From the Korean National Health Insurance Service database, 194 928 adult patients (aged ≥18 years) with newly diagnosed AF were treated with ablation or medical therapy (antiarrhythmic or rate control drugs) between January 1, 2005, and December 1, 2015. Among these patients, this study included 9185 with ablation and 18 770 with medical therapy. The time at risk was counted from the first medical therapy, and ablation was analyzed as a time‐varying covariate. Inverse probability of treatment weighting was used to correct for differences between the groups. After weighting, the 2 cohorts had similar background characteristics. During a median (25th, 75th percentiles) follow‐up of 43 (19, 81) months, ablation of AF was associated with lower incidence and risk of composite outcome, including death, heart failure admission, and stroke/systemic embolism (2.5 and 6.4 per 100 person‐years, respectively; hazard ratio [HR], 0.47; 95% CI, 0.43–0.52; P<0.001), all‐cause death (1.0 and 3.6 per 100 person‐years; HR, 0.41; 95% CI, 0.36–0.47; P<0.001), heart failure admission (0.7 and 1.9 per 100 person‐years; HR, 0.43; 95% CI, 0.37–0.50), and ischemic stroke/systemic embolism (1.1 and 2.8 per 100 person‐years; HR, 0.39; 95% CI, 0.34–0.44) than medical therapy.

Conclusions

Ablation may be associated with lower risk of death, heart failure admission, and ischemic stroke/systemic embolism in real‐world Asian patients with AF.

Temporal Trends of Emergency Department Visits of Patients with Atrial Fibrillation: A Nationwide Population-Based Study

We aimed to describe temporal trends in emergency department (ED) visits of patients with atrial fibrillation (AF) over 12 years. A repeated cross-sectional analysis of ED visits in AF patients using the Korean nationwide claims database between 2006 and 2017 were conducted. We identified AF patients who had ≥1 ED visits. The incidence of ED visits among total AF population, cause of ED visit, and clinical outcomes were evaluated. During 12 years, the annual numbers of AF patients who attended ED at least once a year continuously increased (40,425 to 99,763). However, the annual incidence of ED visits of AF patients was stationary at about 30% because the number of total AF patients also increased during the same period. The most common cause of ED visits was cerebral infarction. Although patients had a higher risk profile over time, the 30-day and 90-day mortality after ED visit decreased over time. ED visits due to ischemic stroke, intracranial hemorrhage, and myocardial infarction decreased, whereas ED visits due to AF, gastrointestinal bleeding, and other major bleeding slightly increased among total AF population over 12 years. A substantial proportion of AF patients attended ED every year, and the annual numbers of AF patients who visited the ED significantly increased over 12 years. Optimized management approaches in a holistic and integrated manner should be provided to reduce ED visits of AF patients.

'Real-world' observational studies in arrhythmia research: data sources, methodology, and interpretation. A position document from European Heart Rhythm Association (EHRA), endorsed by Heart Rhythm Society (HRS), Asia-Pacific HRS (APHRS), and Latin America HRS (LAHRS)

The field of observational studies or "real world studies" is in rapid development with many new techniques introduced and increased understanding of traditional methods. For this reason the current paper provides an overview of current methods with focus on new techniques. Some highlights can be emphasized: We provide an overview of sources of data for observational studies. There is an overview of sources of bias and confounding. Next There is an overview of causal inference techniques that are increasingly used. The most commonly used techniques for statistical modelling are reviewed with focus on the important distinction of risk versus prediction. The final section provides examples of common problems with reporting observational data.

Do age-associated changes of voltage-gated sodium channel isoforms expressed in the mammalian heart predispose the elderly to atrial fibrillation?

Atrial fibrillation (AF) is the most common cardiac arrhythmia worldwide. The prevalence of the disease increases with age, strongly implying an age-related process underlying the pathology. At a time when people are living longer than ever before, an exponential increase in disease prevalence is predicted worldwide. Hence unraveling the underlying mechanics of the disease is paramount for the development of innovative treatment and prevention strategies. The role of voltage-gated sodium channels is fundamental in cardiac electrophysiology and may provide novel insights into the arrhythmogenesis of AF. Na_v1.5 is the predominant cardiac isoform, responsible for the action potential upstroke. Recent studies have demonstrated that Na_v1.8 (an isoform predominantly expressed within the peripheral nervous system) is responsible for cellular arrhythmogenesis through the enhancement of pro-arrhythmogenic currents. Animal studies have shown a decline in Na_v1.5 leading to a diminished action potential upstroke during phase 0. Furthermore, the study of human tissue demonstrates an inverse expression of sodium channel isoforms; reduction of Na_v1.5 and increase of Na_v1.8 in both heart failure and ventricular hypertrophy. This strongly suggests that the expression of voltage-gated sodium channels play a crucial role in the development of arrhythmias in the diseased heart. Targeting aberrant sodium currents has led to novel therapeutic approaches in tackling AF and continues to be an area of emerging research. This review will explore how voltage-gated sodium channels may predispose the elderly heart to AF through the examination of laboratory and clinical based evidence.

The difference of burden of ectopic beats in different types of atrial fibrillation and the effect of atrial fibrillation type on stroke risk in a prospective cohort of patients with atrial fibrillation (CODE-AF registry)

The relationship between atrial fibrillation (AF) type and stroke risk is still controversial. We investigated the difference of burden of atrial ectopic beats in different types of AF and the effect of the AF type on stroke risk in patients with non-valvular AF. In the prospective, multicenter observational registry with more than about 10,000 AF patients, 8883 non-valvular AF patients (mean age, 67.0 years; 36% were women) with eligible follow-up visits participated. We compared the burden of ectopic beats and stroke risk between patients with paroxysmal AF (n = 5,808) and non-paroxysmal AF (n = 3,075). The patients with a non-paroxysmal type of AF were older, male-predominant and had a higher prevalence of comorbidities and had more anticoagulation and rhythm control treatment than those with paroxysmal AF. In terms of the difference in burden of ectopic beats, patients with non-paroxysmal AF had a higher proportion of atrial premature beats (APBs) (paroxysmal vs. non-paroxysmal, median 3% vs. 5%; p = 0.001) in 24 hours Holter monitoring. During a median follow-up period of 16.8 months (Interquartile range [IQR], 11.67-20.52), a total of 82 (0.92%) patients experienced ischemic stroke with incidence rates of 0.50 and 1.09 events per 100 person-year for paroxysmal and non-paroxysmal AF, respectively. The cumulative incidence of stroke events was significantly higher in non-paroxysmal AF than in paroxysmal AF (p < 0.001). The risk of ischemic stroke was higher in non-paroxysmal AF with an adjusted hazard ratio (HR) of 2.08 (95% confidence interval [CI], 1.33-3.25; p = 0.001) than in paroxysmal AF. The type of AF was associated with an increased risk of stroke, along with the difference of burden of ectopic beats (specially in APBs) in different types of AF. These results suggest that the type of AF should be considered in stroke prevention and decision-making for oral anticoagulation in AF patients.

Blood Pressure Control and Dementia Risk in Midlife Patients With Atrial Fibrillation

Atrial fibrillation (AF) is associated with increased risk of cognitive impairment and dementia, even with no overt stroke. Hypertension has been a potentially modifiable risk factor for dementia, especially in midlife (<70 years) individuals. We aimed to investigate the associations of blood pressure (BP) and hypertension burden with dementia risk among midlife AF patients. From the Korean National Health Insurance Service database, we enrolled 171 228 incident AF patients aged 50 to 69 years with no prior dementia from 2005 to 2016. During a mean of 6.6 years of follow-up, 9909 patients received a first-time diagnosis of dementia. U-shaped relationships were noted between systolic or diastolic BP and dementia risk: A 10 mm Hg increase or decrease in systolic BP starting from 120 mm Hg was associated with 4.4% (95% CI, 2.7%-6.0%) and 4.6% (95% CI, 0.1%-8.2%) higher dementia risk, respectively. An increase or decrease in diastolic BP starting from 80 mm Hg also increased dementia risk. In subtype analyses, Alzheimer disease increases with BP decrease whereas vascular dementia increases according to BP increase. When BP changes over time were accounted for in time-updated models, BP of 120 to 129/80 to 84 mm Hg was associated with the lowest dementia risk. Increasing hypertension burden (the proportion of days with increased BP during follow-up) was associated with higher dementia risk (hazard ratio, 1.10 per 10% increase [95% CI, 1.08-1.12]). Among midlife AF patients, there were a U-shaped association of BP and a log-linear association of hypertension burden with dementia risk. Minimizing the burden of hypertension in AF patients might help to prevent dementia.

Current Anticoagulant Usage Patterns and Determinants in Korean Patients with Nonvalvular Atrial Fibrillation

PURPOSE

Stroke prevention in patients with atrial fibrillation (AF) is influenced by many factors. Using a contemporary registry, we evaluated variables associated with the use of warfarin or direct oral anticoagulants (OACs).

MATERIALS AND METHODS

In the prospective multicenter CODE-AF registry, 10529 patients with AF were evaluated. Multivariate analyses were performed to identify variables associated with the use of anticoagulants.

RESULTS

The mean age of the patients was 66.9±14.4 years, and 64.9% were men. The mean CHA₂DS₂-VASc and HAS-BLED scores were 2.6±1.7 and 1.8±1.1, respectively. In patients with high stroke risk (CHA₂DS₂-VASc ≥2), OACs were used in 83.2%, including direct OAC in 68.8%. The most important factors for non-OAC treatment were end-stage renal disease [odds ratio (OR) 0.27; 95% confidence interval (CI): 0.19-0.40], myocardial infarct (OR 0.53; 95% CI: 0.40-0.72), and major bleeding (OR 0.57; 95% CI: 0.39-0.84). Female sex (OR 1.40; 95% CI: 1.21-1.61), cancer (OR 1.78; 95% CI: 1.38-2.29), and smoking (OR 1.60; 95% CI: 1.15-2.24) were factors favoring direct OAC use over warfarin. Among patients receiving OACs, the rate of combined antiplatelet agents was 7.8%. However, 73.6% of patients did not have any indication for a combination of antiplatelet agents.

CONCLUSION

Renal disease and history of valvular heart disease were associated with warfarin use, while cancer and smoking status were associated with direct OAC use in high stroke risk patients. The combination of antiplatelet agents with OAC was prescribed in 73.6% of patients without definite indications recommended by guidelines.

Stroke and Systemic Embolism and Other Adverse Outcomes of Heart Failure With Preserved and Reduced Ejection Fraction in Patients With Atrial Fibrillation (from the COmparison study of Drugs for symptom control and complication prEvention of Atrial Fibrillation [CODE-AF])

It is unknown whether heart failure (HF) with preserved ejection fraction (HFpEF) and HF with reduced ejection fraction (HFrEF) carry a similar risk of stroke or systemic embolism (SE) and other outcomes in patients with nonvalvular atrial fibrillation (AF). A prospective, multicenter outpatient registry with echocardiographic data which enrolled 10,589 patients from June 2016 to May 2019 was analyzed. In this registry, 935 (8.8%) patients had HF, and the proportions of patients with HFpEF and HFrEF were 43.2% and 56.8%, respectively. During follow-up over 1.33 years, 11 (2.07 per 100 person-years [PYR]) and 5 (0.76 per 100 PYR) patients had stroke/SE in the HFpEF and HFrEF groups, respectively, whereas 102 patients (0.84 per 100 PYR) had these sequelae in the no-HF group. The HFpEF group had a significantly higher cumulative incidence of stroke/SE (p = 0.004) and risk of stroke/SE (adjusted hazard ratio [HR] 2.23, 95% confidence interval [CI] 1.19 to 4.18) than the no-HF group. The risk of stroke/SE in the HFpEF group compared with that in the no-HF group was consistently increased even in patients on oral anticoagulation therapy (adjusted HR 2.55, 95% CI 1.31 to 4.96). There was a correlation between larger left atrial size and risk of stroke/SE (adjusted HR 1.53, 95% CI 1.03 to 2.29), but not between reduced left ventricular ejection fraction and this risk. In conclusion, these results suggest that strict oral anticoagulation therapy helps reduce the risk of stroke/SE in patients with nonvalvular AF and HFpEF, especially in those with a larger left atrial size.

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

Background and Objectives

Nationwide social inequalities of oral anticoagulation (OAC) usage after the introduction of non-vitamin K antagonist oral anticoagulants (NOACs) have not been well identified in patients with atrial fibrillation (AF). This study assessed overall rate and social inequalities of OAC usage after the introduction of NOAC in Korea.

Methods

Between January 2002 and December 2016, we identified 888,540 patients with AF in the Korea National Health Insurance system database. The change of OAC rate in different medical systems after the introduction of NOAC were evaluated.

Results

In all population, overall OAC use increased from 13.2% to 23.4% (p for trend <0.001), and NOAC use increased from 0% to 14.6% (p for trend <0.001). Compared with pre-reimbursement (0.48%), the annual increase of OAC use was significantly higher after partial (1.16%, p<0.001), and full reimbursement of OAC (3.72%, p<0.001). Full reimbursement of NOAC (adjusted odds ratio, 2.10; 95% confidence interval, 2.04–2.15) was independently associated with higher OAC use. However, the difference of overall OAC usage between tertiary referral hospitals and nursing or public health centers increased from 17.9% in 2010 to 36.8% in 2016. Moreover, usage rate of NOAC was significantly different among different medical systems from 37.2% at the tertiary referral hospital and 5.5% at nursing or public health centers.

Conclusions

Introduction of NOACs in routine practice for stroke prevention in AF was associated with improved rates of overall OAC use. However, significant practice-level variations in OAC and NOAC use remain producing social inequalities of OAC despite full reimbursement.

Prevalence and Associated Stroke Risk of Human Immunodeficiency Virus-Infected Patients With Atrial Fibrillation - A Nationwide Cohort Study

BACKGROUND

Patients infected with human immunodeficiency virus (HIV) are at increased risk of cardiovascular diseases. However, little is known regarding the risk of ischemic stroke in HIV-infected individuals with atrial fibrillation (AF).

METHODS AND RESULTS

From the Korean National Health Insurance Service (NHIS) database from January 1, 2005 to December 31, 2016, we analyzed 962,116 patients with prevalent non-valvular AF aged ≥18 years. The overall HIV prevalence in AF patients was 0.17% (1,678 of 962,116). Oral anticoagulant (OAC)-naïve non-valvular AF (NVAF) patients with HIV had increased risks of ischemic stroke/systemic embolism (SE) [adjusted hazard ratio (HR) 1.37; 95% confidence interval (CI), 1.21-1.54], and major bleeding (adjusted HR 1.29; 95% CI, 1.15-1.46), compared with those without HIV. The incidence of ischemic stroke/SE in NVAF patients with HIV without any risk factors was similar to that of those without HIV at intermediate risk (i.e., male CHA2DS2-VASc score of 1) (2.04 vs. 2.18 events per 100 person-years). However, the use of OACs in AF patients with HIV was suboptimal, being only 8.9% at the time of AF diagnosis and 31.8% throughout the study period.

CONCLUSIONS

The risks of ischemic stroke/SE and major bleeding were significantly higher in HIV-infected patients compared with non-HIV-infected patients with AF. Despite this, the actual use of OACs among AF patients with HIV was suboptimal.

Atrial fibrillation classification based on convolutional neural networks

Background

The global age-adjusted mortality rate related to atrial fibrillation (AF) registered a rapid growth in the last four decades, i.e., from 0.8 to 1.6 and 0.9 to 1.7 per 100,000 for men and women during 1990–2010, respectively. In this context, this study uses convolutional neural networks for classifying (diagnosing) AF, employing electrocardiogram data in a general hospital.

Methods

Data came from Anam Hospital in Seoul, Korea, with 20,000 unique patients (10,000 normal sinus rhythm and 10,000 AF). 30 convolutional neural networks were applied and compared for the diagnosis of the normal sinus rhythm vs. AF condition: 6 Alex networks with 5 convolutional layers, 3 fully connected layers and the number of kernels changing from 3 to 256; and 24 residual networks with the number of residuals blocks (or kernels) varying from 8 to 2 (or 64 to 2).

Results

In terms of the accuracy, the best Alex network was one with 24 initial kernels (i.e., kernels in the first layer), 5,268,818 parameters and the training time of 89 s (0.997), while the best residual network was one with 6 residual blocks, 32 initial kernels, 248,418 parameters and the training time of 253 s (0.999). In general, the performance of the residual network improved as the number of its residual blocks (its depth) increased.

Conclusion

For AF diagnosis, the residual network might be a good model with higher accuracy and fewer parameters than its Alex-network counterparts.

Characteristics and management of stroke in Korea: 2014–2018 data from Korean Stroke Registry

Background

Lifestyle changes and evolving healthcare practices in Korea have influenced disease patterns and medical care. Since strokes have high disease burden in countries with aging populations, it is necessary to evaluate the associated recent disease characteristics and patient care patterns. The Korean Stroke Registry is a nationwide, multicenter, prospective, hospital-based stroke registry in Korea used to monitor these changes across the population.

Aims

We aimed to evaluate the recent status of clinical characteristics and management of stroke cases in order to identify changes in the Korean population across time.

Methods

This study used Korean Stroke Registry data from patients experiencing ischemic stroke or transient ischemic attack patients, between 2014 and 2018. We analyzed data on demographics, risk factors, stroke subtypes, and treatments that included thrombolysis.

Results

A total of 39,291 patients (mean age 68.0 ± 13.0, 58.3% male) were analyzed. The proportions of hypertension, diabetes mellitus, dyslipidemia, atrial fibrillation, and prior stroke were 63.4%, 30.9%, 27.7%, 19.4%, and 17.1%, respectively. In the stroke subtype analysis, the frequency of large artery atherosclerosis was highest (32.6%), followed by cardioembolism (21.3%) and small vessel occlusion (19.9%). Acute reperfusion therapy was conducted in 15.3% of cases (11.7% using intravenous tPA and 7.3% using intra-arterial thrombectomy). Intra-arterial thrombectomy also demonstrated a steep increasing trend over time (RR 1.095 (1.060–1.131), p < 0.001).

Conclusions

This study provided analysis of nationwide, hospital-based, quality-controlled data from the Korean Stroke Registry database regarding changes in the characteristics, risk factors, and treatments of strokes in Korea.

The optimal drug adherence to maximize the efficacy and safety of non-vitamin K antagonist oral anticoagulant in real-world atrial fibrillation patients

Aims

To investigate the association between adherence to non-vitamin K antagonist oral anticoagulant (NOAC) and clinical outcomes and to determine the optimal cut-off level of NOAC adherence among patients with atrial fibrillation (AF).

Methods and results

Using the Korean National Health Insurance Service database, we identified 96 197 patients with non-valvular AF who initiated NOAC or warfarin in 2013–16. We compared clinical outcomes between adherent [proportion of days covered (PDC) ≥80%] vs. non-adherent (PDC &lt;80%) NOAC users, and further with warfarin users. We assessed the outcomes according to different levels of adherence. The proportion of adherent NOAC users was 64.0%. Compared with non-adherent NOAC users, adherent NOAC users were at lower risks of ischaemic stroke/systemic embolism (SE) [adjusted hazard ratio (aHR) 0.73, 95% confidence interval (CI) 0.69–0.79], and myocardial infarction (aHR 0.82, 95% CI 0.72–0.93), whereas there was no significant risk alteration for major bleeding (aHR 1.01, 95% CI 0.91–1.11). Compared with warfarin, non-adherent NOAC use failed to have better efficacy against ischaemic stroke/SE (aHR 0.99, 95% CI 0.93–1.05) and rather had increased risk of myocardial infarction (aHR 1.13, 95% CI 1.03–1.25). In NOAC users, the risks of adverse outcomes decreased according to gradual increase of adherence rates with the lowest risks in ≥90%, except for major bleeding in which there were no significant associations.

Conclusions

In an adherence level-dependent fashion, adherent use of NOAC showed better clinical outcomes without increasing bleeding risk. Maintaining ≥90% of adherence optimizes effectiveness of NOAC therapy without compromising its safety.

Use of rivaroxaban in patients attending a hematology unit in clinical practice

Aim: To determine drug persistence and rates of events among patients treated with rivaroxaban in a hematology unit. Methods: Retrospective study of patients that started treatment with rivaroxaban, in the hematology unit of a tertiary hospital. Results: A total of 161 patients were included, of whom 83.9% had atrial fibrillation and 11.2% venous thromboembolism, and 76.4% of patients were taking rivaroxaban 20 mg, 22.4% 15 mg and 1.2% 10 mg. After a follow-up of 1.8 ± 1.1 years, only four patients (2.5%) discontinued treatment. Rates of thromboembolic events, major bleeding/clinically relevant nonmajor bleeding and intracranial hemorrhage were 1.1, 2.8, 0.3 events per 100 patient-years, respectively. Conclusion: In patients attended in a hematology unit, medication persistence was high, and the incidence of outcomes low.

Long-Term Impact of Newly Diagnosed Atrial Fibrillation During Critical Care: A South Korean Nationwide Cohort Study

BACKGROUND

The long-term risks of thromboembolism and mortality are unknown in patients who survived following atrial fibrillation (AF) newly diagnosed during critical care.

METHODS

Using the Korean National Health Insurance Service database, we identified 30,869 adults who survived for > 6 months following AF newly diagnosed during critical care (ICU-AF), 269,751 control subjects with non-ICU AF (AF-control), and 439,868 control subjects without AF (No-AF) from 2005 to 2013. We performed propensity score matching and compared the risks of stroke/systemic embolism and all-cause mortality.

RESULTS

The adjusted hazard ratios (HRs) for long-term stroke/systemic embolism in the patients with ICU-AF were 0.93 (95% CI, 0.88-0.98) compared with the AF-control group and 1.50 (95% CI, 1.42-1.60) compared with the No-AF group. The adjusted HRs of the ICU-AF group for long-term mortality were 1.73 (95% CI, 1.70-1.83) and 3.20 (95% CI, 3.08-3.33) compared with the AF-control and No-AF groups, respectively. The risks of stroke/systemic embolism and mortality were significantly higher in the ICU-AF group than in the No-AF group after excluding patients with AF recurrence (adjusted HR, 1.08; 95% CI, 1.01-1.17), regardless of the causes of critical care and cardiovascular or noncardiovascular surgery.

CONCLUSIONS

The patients who survived following AF newly diagnosed during critical care remained at a higher risk of long-term stroke/systemic embolism and mortality than the patients without AF regardless of AF recurrence and the causes of critical care. Close follow-up and continuous anticoagulation might be needed for these patients.

Cost-Effectiveness of Rivaroxaban Compared to Warfarin for Stroke Prevention in Atrial Fibrillation

BACKGROUND AND OBJECTIVES

Rivaroxaban is noninferior to warfarin for preventing stroke or systemic embolism in patients with high-risk atrial fibrillation (AF) and is associated with a lower rate of intracranial hemorrhage (ICH). We assessed the cost-effectiveness of rivaroxaban compared to adjusted-dose warfarin for the prevention of stroke in patients with nonvalvular AF.

METHODS

We built a Markov model using the Korean Health Insurance Review & Assessment Service database. The base-case analysis assumed a cohort of patients with prevalent AF who were aged 18 years or older without contraindications to anticoagulation.

RESULTS

Number of patients with CHA₂DS₂-VASc scores 0, 1 and ≥2 were 56 (0.2%), 1,944 (6.3%) and 28,650 (93.5%), respectively. In patients with CHA₂DS₂-VASc scores ≥2, the incidence rate of ischemic stroke was 3.11% and 3.76% in warfarin and rivaroxaban groups, respectively. The incidence rates of ICH were 0.42% and 0.15%, and those of gastrointestinal bleeding were 0.32% and 0.15% in warfarin and rivaroxaban, respectively. Patients with AF treated with rivaroxaban lived an average of 11.8 quality-adjusted life years (QALYs) at a lifetime treatment cost of $20,886. Those receiving warfarin lived an average of 11.4 QALYs and incurred costs of $17,151. Patients with rivaroxaban gained an additional 0.4 QALYs over a lifetime with an additional cost of $3,735, resulting in an incremental cost-effectiveness ratio of $9,707 per QALY.

CONCLUSIONS

Patients who had been treated with rivaroxaban may be a cost-effective alternative to warfarin for stroke prevention in Korean patients with AF.

Antithrombotic Medication and the Risk of Vitreous Hemorrhage in Atrial Fibrillation: Korean National Health Insurance Service National Cohort

PURPOSE

Antithrombotic therapy could be related with nuisance bleeding. This study investigated whether vitreous hemorrhage (VH) is associated with specific types of antithrombotic medication in patients with atrial fibrillation (AF).

MATERIALS AND METHODS

In the Korean National Health Insurance Service National Sample Cohort, we identified 9352 antiplatelet/anticoagulant-treated AF patients. The occurrence of VH was compared between warfarin (n=1493) and a propensity score (PS)-matched antiplatelet group (n=1493) and between warfarin (n=1493) and a PS-matched warfarin+antiplatelet group (n=1493).

RESULTS

The outcomes of VH were lower in the warfarin than in the matched antiplatelet (1.45 vs. 3.72 events/1000 patient-years) and matched warfarin+antiplatelet groups (1.45 vs. 6.87 events/1000 patient-years). Compared with warfarin, the risk of VH increased with antiplatelet [adjusted hazard ratio (aHR) 3.90; 95% confidence interval (CI) 1.22-12.4, p=0.022] and warfarin+antiplatelet agents (aHR 4.39, 95% CI 1.74-11.2, p=0.002). Compared with warfarin only, warfarin+antiplatelet agents increased the risk of VH in patients ≥65 years, regardless of gender and hypertension. The risk of VH was significantly higher with dual antiplatelet therapy (aHR: 5.02, 95% CI: 1.56-16.2, p=0.007) or in dual (aHR: 5.02, 95% CI: 1.74-14.5, p=0.003) or triple therapy using warfarin and antiplatelet agents than with warfarin monotherapy (aHR: 6.12, 95% CI: 1.76-21.3, p=0.004).

CONCLUSION

Dual antiplatelet or triple therapy increased the risk of VH significantly, compared to warfarin monotherapy. Considering the low efficacy of preventing ischemic stroke and high risk of bleeding, dual or triple therapy using warfarin and antiplatelet agents should be avoided to prevent VH in AF patients.

2018 Korean Guideline of Atrial Fibrillation Management

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia in the general population. The Korean Heart Rhythm Society organized a Korean AF Management Guideline Committee and analyzed all available studies regarding the management of AF, including studies on Korean patients. This guideline is based on recent data of the Korean population and the recent guidelines of the European Society of Cardiology, European Association for Cardio-Thoracic Surgery, American Heart Association, and Asia Pacific Heart Rhythm Society. Expert consensus or guidelines for the optimal management of Korean patients with AF were achieved after a systematic review with intensive discussion. This article provides general principles for appropriate risk stratification and selection of anticoagulation therapy in Korean patients with AF. This guideline deals with optimal stroke prevention, screening, rate and rhythm control, risk factor management, and integrated management of AF.

Cardiac biomarkers predict mortality in emergency patients presenting with atrial fibrillation

Objectives

To assess the predictive value of N-terminal pro-brain natriuretic peptide (NT-proBNP) and high-sensitive troponin T (hs-TnT) serum levels for mid-term mortality in patients presenting with symptomatic atrial fibrillation (AF) to an emergency department.

Methods

Non-interventional cohort/follow-up study, including consecutive patients presenting to a tertiary care university emergency department due to symptomatic AF between 2012 and 2016. Multivariable Cox proportional hazard regression models were used to estimate the mortality rates and hazards per 100 patient-years (pry) for NT-proBNP and hs-TnT serum levels in quintiles.

Results

2574 episodes of 1754 patients (age 68 (IQR 58–75) years, female gender 1199 (44%), CHA₂DS₂-VASc 3 (IQR 1–4)) were recorded. Following the exclusion of incomplete datasets, 1780 episodes were available for analysis. 162 patients deceased during the mid-term follow-up (median 23 (IQR 4–38) months); the mortality rate was 4.72/100 pry. Hazard for death increased with every quintile of NT-proBNP by 1.53 (HR; 95% CI 1.27 to 1.83; p<0.001) and by 1.31 (HR; 95% CI 1.10 to 1.55; p=0.002) with every quintile of hs-TnT in multivariate Cox-regression analysis. No interaction between NT-proBNP and hs-TnT levels could be observed.

Conclusion

Elevated NT-proBNP and hs-TnT levels are independently associated with increased mid-term mortality in patients presenting to an emergency department due to symptomatic AF.

Trial registration number

NCT03272620; Results.

Stroke Prevention in Atrial Fibrillation: Focus on Asian Patients

Atrial fibrillation (AF) is the most common arrhythmia conferring a fivefold increased risk of stroke. Stroke prevention is the cornerstone of management of patients with AF. Asians have a generally higher incidence of AF-related risks of stroke and bleeding (particularly intracranial bleeding), compared with non-Asians. Despite the well-documented efficacy and relative safety of oral anticoagulation for stroke prevention among Asians, the suboptimal use of oral anticoagulation remains common. The current narrative review aims to provide a summary of the available evidence on stroke prevention among patients with AF focused on the Asia region, regarding stroke and bleeding risk evaluation, the performance of oral anticoagulation, and current use of thromboprophylaxis.