Evaluation of the association between diabetic retinopathy and the incidence of atrial fibrillation: A nationwide population-based study

Prevalence of Non-valvular Atrial Fibrillation Based on Geographical Distribution and Socioeconomic Status in the Entire Korean Population

BACKGROUND AND OBJECTIVES

Prevalence of atrial fibrillation (AF) varies based on geographical location and socioeconomic status. We aimed to evaluate the prevalence of AF and utilization of antithrombotic therapy based on geographical regions and income levels in the entire Korean population.

METHODS

We performed a cross-sectional analysis of Korean adults (aged ≥20 years) using the 2015 National Health Insurance Service database (n=41,505,679). The study population was stratified into 17 geographical regions and 21 income levels.

RESULTS

We identified 276,842 patients diagnosed with AF. Overall prevalence of AF in suburban/rural regions was significantly higher than that observed in urban regions (0.72% vs. 0.61%, respectively, p<0.001). Elderly patients (age ≥75 years) showed a higher prevalence of AF and comorbidities related to AF development showed a higher prevalence among the population residing in suburban/rural regions. Among AF patients with a CHA₂DS₂-VASc score ≥2, oral anticoagulation (OAC) therapy utilization was lower in the suburban/rural regions than that observed in the urban regions (48.2% vs. 51.8%, respectively, p<0.001). The relationship between income levels and AF prevalence showed a J-shaped curve. The OAC prescription rate showed a positive correlation with income levels. Non-vitamin K antagonist oral anticoagulants tended to be more commonly prescribed among the higher income groups.

CONCLUSIONS

Geographical location of residence and income levels were closely associated with the prevalence of AF and antithrombotic therapy utilization. This information may provide further insights for more effective surveillance of AF and stroke prevention for improved clinical outcomes.

Temporal trends of antithrombotic therapy for stroke prevention in Korean patients with non-valvular atrial fibrillation in the era of non-vitamin K antagonist oral anticoagulants: A nationwide population-based study

Background

Following their introduction, the non-vitamin K antagonist oral anticoagulants (NOACs) are increasingly prescribed in Asia for stroke prevention in patients with non-valvular atrial fibrillation (AF). Few contemporary data are available on temporal trends in antithrombotic therapy use in Asian countries, in the era of NOACs.

Methods and results

Using the National Health Insurance Service database of the entire Korean adult AF population, the use of aspirin, vitamin K antagonist, and NOACs between 2008 and 2015 were analyzed (n = 276,246 in 2015). Most of the included cohort had CHA₂DS₂-VASc score ≥ 2 (78.2% in 2008 and 83.2% in 2015), yet approximately 17% were prescribed no antithrombotic therapy throughout the study period. Aspirin prescription consistently decreased (from 48.2% to 31.5%) over time, while OAC prescription significantly increased from 34.7% to 50.6%. NOAC prescriptions accounted for 50% of total OAC prescription in 2015. Similar trends in antithrombotic therapy were found both in men and in women, but women were more likely to be undertreated with OAC. Female gender, presence of vascular disease and prior intracranial hemorrhage were associated with OAC underuse.

Conclusions

Between 2008 and 2015, a greater proportion of AF patients received OAC treatment with increasing NOAC prescription trends in the recent 3 years. A substantial proportion (approx. 50%) of Korean patients with AF still remain undertreated.

Cirrhosis is a risk factor for atrial fibrillation: A nationwide, population-based study

BACKGROUND & AIMS

Information is lacking regarding whether cirrhosis is associated with atrial fibrillation development. We aimed to investigate the incidence and clinical significance of atrial fibrillation in cirrhotic patients.

METHODS

Cirrhotic patients (n=3596; mean age, 54.7±12.3 years; male, 72.5%) without previous atrial fibrillation were selected from the Korean National Health Insurance Service National Sample Cohort database between 2004 and 2008. Age- and sex-matched controls (n=17 980) were randomly sampled in a 5:1 ratio from non-cirrhotic individuals. Both cohorts were followed up for incident atrial fibrillation and death until 2013.

RESULTS

During 9 years of follow-up, atrial fibrillation was newly detected in 113 (3.1%) cirrhosis patients and 385 (2.1%) controls (incidence: 3.48 and 2.16 per 1000 person-years respectively). Cirrhotic patients were at higher risk for atrial fibrillation development compared to controls (hazard ratio, 1.46; 95% confidence interval, 1.18-1.80) after multivariate adjustment. On subgroup analysis, cirrhosis increased the risk for atrial fibrillation, especially in younger (age younger than 65 years) men without comorbidities (CHA₂ DS₂ -VASc score, 0). Cirrhotic patients showed increased overall mortality compared to controls (hazard ratio, 4.80; 95% confidence interval, 4.47-5.15) as well as increased cardiovascular mortality (hazard ratio, 1.37; 95% confidence interval, 1.07-1.75). However, there was no significant association between development of atrial fibrillation and increased mortality in cirrhosis patients (P=.188 and .260).

CONCLUSIONS

Cirrhosis was an independent risk factor for atrial fibrillation development, especially in younger, otherwise healthy men, stressing the importance of cardiac assessment in cirrhotic patients. Meanwhile, atrial fibrillation development in cirrhosis patients was not associated with increased mortality.

Proteinuria Detected by Urine Dipstick Test as a Risk Factor for Atrial Fibrillation: A Nationwide Population-Based Study

Proteinuria is one of the well-known risk factors for cardiovascular disease. However the impact of proteinuria on the incidence of atrial fibrillation (AF) is unclear. In this study, we investigated the association between proteinuria detected using urine dipstick test and the risk of AF. A total of 18,201,275 individuals were analyzed, who had no prior AF and had received biennial health checkups provided by the National Health Insurance Service between 2005 and 2008 in Korea. Incidences of AF were ascertained through the end of 2015. During a mean follow-up of 9.6 years, a total of 324,764 (1.8%) developed AF (1.86 per 1,000 person-years). In Cox regression models, proteinuria was associated with an increased risk of AF: adjusted HR and 95% CI of AF occurrence were 1.13 (1.10-1.16), 1.34 (1.31-1.38), 1.53 (1.48-1.58), 1.82 (1.71-1.94), and 1.86 (1.61-2.16) in individuals with trace, 1+, 2+, 3+, and 4+ proteinuria, respectively, compared with those without proteinuria. The result was consistent even after additional adjustment for estimated glomerular filtration rate. In addition, the risk of AF further increased or decreased according to the follow-up dipstick test results. Thus, proteinuria measured with a dipstick test might be considered a potent risk factor for AF development.

CHA 2 DS 2 -VASc Score (Congestive Heart Failure, Hypertension, Age ≥75 [Doubled], Diabetes Mellitus, Prior Stroke or Transient Ischemic Attack [Doubled], Vascular Disease, Age 65–74, Female) for Stroke in Asian Patients With Atrial Fibrillation

Background and Purpose—

The CHA 2 DS 2 -VASc stroke score (congestive heart failure, hypertension, age ≥75 (doubled), diabetes mellitus, prior stroke or transient ischemic attack (doubled), vascular disease, age 65–74, female) is used in most guidelines for risk stratification in atrial fibrillation (AF), but most data for this score have been derived in Western populations. Ethnic differences in stroke risk may be present. Our objective was to investigate risk factors for stroke in AF and application of the CHA 2 DS 2 -VASc score in an Asian AF population from Korea.

Methods—

A total of 5855 oral anticoagulant–naive nonvalvular AF patients aged ≥20 years were enrolled from Korea National Health Insurance Service Sample cohort from 2002 to 2008 and were followed up until December 2013.

Results—

The incidence rates (per 100 person-years) of ischemic stroke were 3.32 in the total population, being 0.23 in low-risk (CHA 2 DS 2 -VASc score 0 [male] or 1 [female]) and 4.59 in high-risk patients (CHA 2 DS 2 -VASc ≥2). Incidence rates of ischemic stroke or the composite thromboembolism end point showed a clear increase with increasing CHA 2 DS 2 -VASc score. On multivariable analysis, significant associations between CHA 2 DS 2 -VASc risk factors and ischemic stroke were observed; however, the significance of vascular disease or diabetes mellitus was attenuated after multivariate adjustment, and female sex (hazard ratio, 0.73; 95% confidence interval, 0.64–0.84) had a lower risk of ischemic stroke than males. Patients who were categorized as low risk consistently had an event rate <1% per year.

Conclusions—

The performance of CHA 2 DS 2 -VASc score in Asians is comparable with that in Western populations. The score shows good performance in defining the truly-low-risk AF patients for stroke/thromboembolism.

Trends in the incidence and prevalence of atrial fibrillation and estimated thromboembolic risk using the CHA2DS2-VASc score in the entire Korean population

BACKGROUND

Data on the epidemiology of atrial fibrillation (AF) and temporal trends are not well established in the Korean population. We aimed to estimate the incidence and prevalence of AF in Korea between 2008 and 2015.

METHODS

Using the National Health Insurance Service database, we analyzed as a nationwide cohort the entire Korean adult population from 2008 to 2015 (n=41,505,679 in 2015). AF was identified by using diagnostic codes.

RESULTS

During an 8-year period representing 314,311,360 person-years of follow-up, 496,341 individuals were newly diagnosed with AF. The incidence of AF increased to >1.12-fold as follows: from 15.34 to 17.14 per 10,000 person-years (p<0.001). We also found a 1.68-fold increase in the prevalence of AF, from 0.46% in 2008 to 0.67% in 2015 (p<0.001). The incidence and prevalence of AF increased with advancing age. The median age of the AF patients increased from 68 to 71years (p<0.001). The prevalence of diabetes and heart failure in AF subjects increased (p<0.001). The percentage of patients with a CHA₂DS₂-VASc score of ≥2, who were strongly recommended for anticoagulation treatment, increased from 80.2% to 86.8% (p<0.001).

CONCLUSION

The incidence and prevalence of AF gradually increased from 2008 to 2015. The proportion of AF patients who were candidates for anticoagulation therapy also significantly increased owing to population aging and increasing comorbidities (i.e., heart failure and diabetes). These findings may provide a framework to understand the actual disease burden and establish the optimal management strategy for AF.