Modifiable lifestyle factors and lifetime risk of atrial fibrillation: longitudinal data from the Korea NHIS-HealS and UK Biobank cohorts.

BACKGROUND: The reason for higher incidence of atrial fibrillation (AF) in Europe compared with East Asia is unclear. We aimed to investigate the association between modifiable lifestyle factors and lifetime risk of AF in Europe and East Asia, along with race/ethnic similarities and disparities. METHODS: 1:1 propensity score matched pairs of 242,763 East Asians and 242,763 White Europeans without AF were analyzed. Modifiable lifestyle factors considered were blood pressure, body mass index, cigarette smoking, diabetes, alcohol consumption, and physical activity, categorized as non-adverse or adverse levels. Lifetime risk of AF was estimated from the index age of 45 years to the attained age of 85 years, accounting for the competing risk of death. RESULTS: The overall lifetime risk of AF was higher in White Europeans than East Asians (20.9% vs 15.4%, p < 0.001). The lifetime risk of AF was similar between the two races in individuals with non-adverse lifestyle factor profiles (13.4% vs 12.9%, p = 0.575), whereas it was higher in White Europeans with adverse lifestyle factor profiles (22.1% vs 15.8%, p < 0.001). The difference in the lifetime risk of AF between the two races increased as the burden of adverse lifestyle factors worsened (1 adverse lifestyle factor; 4.3% to ≥ 3 adverse lifestyle factors; 11.2%). Compared with East Asians, the relative risk of AF in White Europeans was 23% and 62% higher for one (hazard ratio [HR] 1.23, 95% confidence interval [CI] 1.16-1.29) and ≥ 3 adverse lifestyle factors (HR 1.62, 95% CI 1.51-1.75), respectively. CONCLUSIONS: The overall higher lifetime risk of AF in White Europeans compared with East Asians might be attributable to adverse lifestyle factors. Adherence to healthy lifestyle factors was associated with the lifetime risk of AF of about 1 in 8 regardless of race/ethnicity.

Associations of combined polygenic risk score and glycemic status with atrial fibrillation, coronary artery disease and ischemic stroke.

BACKGROUND: It is unknown whether high hemoglobin A1c (HbA1c) is associated with increases in the risk of cardiovascular disease among individuals with elevated genetic susceptibility. We aimed to investigate the association between HbA1c and atrial fibrillation (AF), coronary artery disease (CAD), and ischemic stroke according to the polygenic risk score (PRS). METHODS: The UK Biobank cohort included 502,442 participants aged 40-70 years who were recruited from 22 assessment centers across the United Kingdom from 2006 to 2010. This study included 305,605 unrelated individuals with available PRS and assessed new-onset AF, CAD, and ischemic stroke. The participants were divided into tertiles based on the validated PRS for each outcome. Within each PRS tertiles, the risks of incident events associated with HbA1c levels were investigated and compared with HbA1c < 5.7% and low PRS. Data were analyzed from November 2022 to May 2023. RESULTS: Of 305,605 individuals, 161,605 (52.9%) were female, and the mean (SD) age was 56.6 (8.1) years. During a median follow-up of 11.9 (interquartile range 11.1-12.6) years, the incidences of AF, CAD, and ischemic stroke were 4.6, 2.9 and 1.1 per 100 person-years, respectively. Compared to individuals with HbA1c < 5.7% and low PRS, individuals with HbA1c ≥ 6.5% and high PRS had a 2.67-times higher risk for AF (hazard ratio [HR], 2.67; 95% confidence interval (CI), 2.43-2.94), 5.71-times higher risk for CAD (HR, 5.71; 95% CI, 5.14-6.33) and 2.94-times higher risk for ischemic stroke (HR, 2.94; 95% CI, 2.47-3.50). In the restricted cubic spline models, while a U-shaped trend was observed between HbA1c and the risk of AF, dose-dependent increases were observed between HbA1c and the risk of CAD and ischemic stroke regardless PRS tertile. CONCLUSIONS: Our results suggest that the nature of the dose-dependent relationship between HbA1c levels and cardiovascular disease in individuals with different PRS is outcome-specific. This adds to the evidence that PRS may play a role together with glycemic status in the development of cardiovascular disease.

Clinical Implications of Polypharmacy for Patients with New-Onset Atrial Fibrillation Based on Real-World Data: Observations from the Korea National Health Insurance Service Data.

Background: Polypharmacy is commonly observed in atrial fibrillation (AF) and is associated with poorer clinical outcomes. Our study aimed to elucidate the polypharmacy prevalence, its associated risk factors, and its relationship with adverse clinical outcomes using a 'real-world' database. Methods: This study included 451,368 subjects without prior history of AF (median age, 54 [interquartile range, 48.0-63.0] years; 207,748 [46.0%] female) from the Korea National Health Insurance Service-Health Screening (NHIS-HealS) database between 2002 and 2013. All concomitant medications prescribed were collected, and the intake of five or more concomitant drugs was defined as polypharmacy. During the follow-up, all-cause death, major bleeding events, transient ischemic attack (TIA) or ischemic stroke, and admission due to worsened heart failure were recorded. Results: Based on up to 7.7 (6.8-8.3) years of follow-up and 768,306 person-years, there were 12,241 cases of new-onset AF identified. Among patients with new-onset AF (40.0% females, median age 63.0 [54.0-70.0] years), the polypharmacy prevalence was 30.9% (3784). For newly diagnosed AF, factors, such as advanced age (with each increase of 10 years, odds ratios (OR) 1.32, 95% confidence interval (CI) 1.26-1.40), hypertension (OR 4.00, 95% CI 3.62-4.43), diabetes mellitus (OR 3.25, 95% CI 2.86-3.70), chronic obstructive pulmonary disease (COPD) (OR 3.00, 95% CI 2.51-3.57), TIA/ischemic stroke (OR 2.36, 95% CI 2.03-2.73), dementia history (OR 2.30, 95% CI 1.06-4.98), end-stage renal disease (ESRD) or chronic kidney disease (CKD) (OR 1.97, 95% CI 1.38-2.82), and heart failure (OR 1.95, 95% CI 1.69-2.26), were found to be independently correlated with the incidence of polypharmacy. Polypharmacy significantly increased the incidence and risk of major bleeding (adjusted hazard ratio (aHR) 1.26, 95% CI 1.12-1.41). The study observed a statistically significant increase in the incidence of all-cause mortality, however, the risk for all-cause mortality elevated but did not show significance (aHR 1.11, 95% CI 0.99-1.24). The risk of stroke and admission for heart failure did not change with polypharmacy. Conclusions: In our investigation using data from a nationwide database, polypharmacy was widespread in new-onset AF population and was related to major bleeding events. However, polypharmacy does not serve as an independent risk factor for adverse outcomes, with exception of major bleeding event. For AF patients, ensuring tailored medication for comorbidities as well as reducing polypharmacy are essential considerations.

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.

Associations of Homeostatic Model Assessment for Insulin Resistance Trajectories With Cardiovascular Disease Incidence and Mortality.

BACKGROUND: Whether trends in insulin resistance changes are related to the risk of cardiovascular disease (CVD) incidence and mortality remains unclear. We aimed to examine the association of homeostatic model assessment for insulin resistance (HOMA-IR) trajectories with CVD incidence and mortality. METHODS: Data from 6755 adults aged 40 to 69 years in the Korea Epidemiology and Genome Study were analyzed. During the exposure period (2001-2006), participants were classified into the increasing HOMA-IR trajectory group and the stable HOMA-IR trajectory group using a latent class mixture model. During the event accrual period (2007-2018), information about CVD and mortality were collected. RESULTS: During the median 9.83-year event accrual period, there were 379 (5.6%) new-onset CVD, 535 (7.9%) all-cause mortality, 102 (1.5%) CVD mortality, and 47 (0.7%) major adverse cardiovascular event mortality cases. Compared with the stable HOMA-IR trajectory group, the fully adjusted hazard ratios (95% CIs) for the increasing HOMA-IR trajectory group were 1.59 (1.04-2.44) for incident CVD, 1.87 (1.30-2.69) for all-cause mortality, 2.33 (1.11-4.89) for CVD mortality, and 3.67 (1.38-9.76) for major adverse cardiovascular event mortality. CONCLUSIONS: An increasing HOMA-IR appears to be independently and positively related to incident CVD, all-cause mortality, CVD mortality, and major adverse cardiovascular event mortality. Early lifestyle interventions for individuals with increasing HOMA-IR trend could be a practical strategy to prevent CVD and CVD mortality.

Atrial Fibrillation and Dementia: A Report From the AF-SCREEN International Collaboration.

Growing evidence suggests a consistent association between atrial fibrillation (AF) and cognitive impairment and dementia that is independent of clinical stroke. This report from the AF-SCREEN International Collaboration summarizes the evidence linking AF to cognitive impairment and dementia. It provides guidance on the investigation and management of dementia in patients with AF on the basis of best available evidence. The document also addresses suspected pathophysiologic mechanisms and identifies knowledge gaps for future research. Whereas AF and dementia share numerous risk factors, the association appears to be independent of these variables. Nevertheless, the evidence remains inconclusive regarding a direct causal effect. Several pathophysiologic mechanisms have been proposed, some of which are potentially amenable to early intervention, including cerebral microinfarction, AF-related cerebral hypoperfusion, inflammation, microhemorrhage, brain atrophy, and systemic atherosclerotic vascular disease. The mitigating role of oral anticoagulation in specific subgroups (eg, low stroke risk, short duration or silent AF, after successful AF ablation, or atrial cardiopathy) and the effect of rhythm versus rate control strategies remain unknown. Likewise, screening for AF (in cognitively normal or cognitively impaired patients) and screening for cognitive impairment in patients with AF are debated. The pathophysiology of dementia and therapeutic strategies to reduce cognitive impairment warrant further investigation in individuals with AF. Cognition should be evaluated in future AF studies and integrated with patient-specific outcome priorities and patient preferences. Further large-scale prospective studies and randomized trials are needed to establish whether AF is a risk factor for cognitive impairment, to investigate strategies to prevent dementia, and to determine whether screening for unknown AF followed by targeted therapy might prevent or reduce cognitive impairment and dementia.

Effects of radiofrequency catheter ablation for premature ventricular complexes originating from the right ventricular outflow tract on right ventricular function.

INTRODUCTION: This study aimed to elucidate the relationship between premature ventricular complexes (PVCs) and right ventricular (RV) dysfunction, and the effects of radiofrequency catheter ablation (RFCA) on RV function. METHODS: A total of 110 patients (age, 50.8 ± 14.4 years; 30 men) without structural heart disease who had undergone RFCA for RV outflow tract (RVOT) PVCs were retrospectively included. RV function was assessed using fractional area change (FAC) and global longitudinal strain (GLS) before and after RFCA. Clinical data were compared between the RV dysfunction (n = 63) and preserved RV function (n = 47) groups. The relationship between PVC burden and RV function was analyzed. Change in RV function before and after RFCA was compared between patients with successful and failed RFCA. RESULTS: PVC burden was significantly higher in the RV dysfunction group than in the preserved RV function group (p < .001). FAC and GLS were significantly worse in proportion to PVC burden (p < .001 and p < .001, respectively). The risk factor associated with RV dysfunction was PVC burden [odds ratio (95% confidence interval), 1.092 (1.052-1.134); p < .001]. Improvement in FAC (13.0 ± 8.7% and -2.5 ± 5.6%, respectively; p < .001) and GLS (-6.8 ± 5.7% and 2.1 ± 4.2%, respectively; p < .001) was significant in the patients with successful RFCA, compared to the patients in whom RFCA failed. CONCLUSIONS: Frequent RVOT PVCs are associated with RV dysfunction. RV dysfunction is reversible by successful RFCA.

Learning Curve Analyses for Left Bundle Branch Area Pacing with Conventional Stylet-Driven Pacing Leads.

Background: Physiological conduction system pacing has attracted attention to overcome the dyssynchrony problems of conventional right ventricular pacing (RVP). Left bundle branch area pacing (LBBAP), which complements short combing of His bundle pacing (HBP), has emerged and has proven its efficiency and safety. In addition, initial experiences of LBBAP were mainly using lumen-less pacing lead, and the feasibility of stylet-driven pacing lead (SDL) was also established. The purpose of this study is to evaluate the learning curve for LBBAP using SDL. Methods: The study enrolled 265 patients who underwent LBBAP or RVP performed by operators without previous LBBAP experience at Yonsei University Severance Hospital in Korea between December 2020 and October 2021. LBBAP was performed using SDL with an extendable helix. The learning curve was evaluated by analyzing fluoroscopy and procedure times. And, before and after reaching the learning curve, we evaluated how much the time required for the LBBAP differed from the time required for the RVP. Results: LBBAP was successful in 50 of 50 (100.0%) patients left bundle branch pacing was successful in 49 of 50 (98.0%). In 50 patients who underwent LBBAP, mean fluoroscopy and procedural times were 15.1 ± 13.5 minutes and 59.9 ± 24.8 minutes, respectively. The plateau of fluoroscopy time reached in the 25th case and the plateau of procedure time reached in the 24th case. Conclusion: During the initial experience with LBBAP, fluoroscopy and procedural times improved with increasing operator experience. For operators who were experienced in cardiac pacemaker implantation, the steepest part of the learning curve was over the first 24-25 cases. It is shorter than the previously reported learning curves of HBP.

Late recurrence of atrial fibrillation 5 years after catheter ablation: predictors and outcome.

AIMS: Atrial fibrillation (AF) is a chronic progressive disease that continuously recurs even after successful AF catheter ablation (AFCA). We explored the mechanism of long-term recurrence by comparing patient characteristics and redo-ablation findings. METHODS AND RESULTS: Among the 4248 patients who underwent a de novo AFCA and protocol-based rhythm follow-up at a single centre, we enrolled 1417 patients [71.7% male, aged 60.0 (52.0-67.0) years, 57.9% paroxysmal AF] who experienced clinical recurrences (CRs), and divided them according to the period of recurrence: within one year (n = 645), 1-2 years (n = 339), 2-5 years (n = 308), and after 5 years (CR>5 yr, n = 125). We also compared the redo-mapping and ablation outcomes of 198 patients. In patients with CR>5 yr, the proportion of paroxysmal AF was higher (P = 0.031); however, the left atrial (LA) volume (quantified by computed tomography, P = 0.003), LA voltage (P = 0.003), frequency of early recurrence (P < 0.001), and use of post-procedure anti-arrhythmic drugs (P < 0.001) were lower. A CR>5 yr was independently associated with a low LA volume [odds ratio (OR) 0.99 (0.98-1.00), P = 0.035], low LA voltage [OR 0.61 (0.38-0.94), P = 0.032], and lower early recurrence [OR 0.40 (0.23-0.67), P < 0.001]. Extra-pulmonary vein triggers during repeat procedures were significantly greater in patients with a CR>5 yr, despite no difference in the de novo protocol (P for trend 0.003). The rhythm outcomes of repeat ablation procedures did not differ according to the timing of the CR (log-rank P = 0.330). CONCLUSIONS: Patients with a later CR exhibited a smaller LA volume, lower LA voltage, and higher extra-pulmonary vein triggers during the repeat procedure, suggesting AF progression.

Early Rhythm Control Therapy for Atrial Fibrillation in Low-Risk Patients : A Nationwide Propensity Score-Weighted Study.

BACKGROUND: Rhythm control is associated with lower risk for adverse cardiovascular outcomes compared with usual care among patients recently diagnosed with atrial fibrillation (AF) with a CHA2DS2-VASc score of approximately 2 or greater in EAST-AFNET 4 (Early Treatment of Atrial Fibrillation for Stroke Prevention Trial). OBJECTIVE: To investigate whether the results can be generalized to patients with low stroke risk. DESIGN: Population-based cohort study. SETTING: Nationwide claims database of the Korean National Health Insurance Service. PARTICIPANTS: 54 216 patients with AF having early rhythm control (antiarrhythmic drugs or ablation) or rate control therapy that was initiated within 1 year of the AF diagnosis. MEASUREMENTS: The effect of early rhythm control on the primary composite outcome of cardiovascular death, ischemic stroke, hospitalization for heart failure, or myocardial infarction was compared between eligible and ineligible patients for EAST-AFNET 4 (CHA2DS2-VASc score, approximately 0 to 1) using propensity overlap weighting. RESULTS: In total, 37 557 study participants (69.3%) were eligible for the trial (median age, 70 years; median CHA2DS2-VASc score, 4), among whom early rhythm control was associated with lower risk for the primary composite outcome than rate control (hazard ratio, 0.86 [95% CI, 0.81 to 0.92]). Among the 16 659 low-risk patients (30.7%) who did not meet the inclusion criteria (median age, 54 years; median CHA2DS2-VASc score, 1), early rhythm control was consistently associated with lower risk for the primary outcome (hazard ratio, 0.81 [CI, 0.66 to 0.98]). No significant differences in safety outcomes were found between the rhythm and rate control strategies regardless of trial eligibility. LIMITATION: Residual confounding. CONCLUSION: In routine clinical practice, the beneficial association between early rhythm control and cardiovascular complications was consistent among low-risk patients regardless of trial eligibility. PRIMARY FUNDING SOURCE: The Ministry of Health and Welfare and the Ministry of Food and Drug Safety, Republic of Korea.

Comparative Bleeding Risk in Patients with Atrial Fibrillation with Cancer versus Without Cancer from Nationwide Prospective Cohort.

Comparison of the bleeding risk for long-term oral anticoagulation (OAC) in patients with nonvalvular atrial fibrillation (AF) with and without cancers has been inconsistent. This study aimed to clarify the differences in the bleeding risk in patients with AF with cancers and those without cancers during the long-term OAC.The CODE-AF prospective registry enrolled 5,902 consecutive patients treated for AF at 10 tertiary referral centers in Korea. Of the enrolled patients, 464 (7.8%) were diagnosed with cancers and were followed for all stroke and bleeding events (net composite events).The age, CHA2DS2-VASC, and HAS-BLED scores were similar between AF patients with and without cancers. Male population greatly comprised patients with AF with cancers. They were equally prescribed with direct OAC compared to those without cancers. The incidence rate for clinically relevant nonmajor (CRNM) bleeding events was higher in the patients with AF with cancers than in those without cancers (4.4 per 100 person-years versus 2.8 per 100 person-years, P = 0.023), and net composite events were also more frequent in patients with AF with cancers than in those without cancers (6.4 per 100 person-years versus 4.0 per 100 person-years, P = 0.004). Patients with AF with cancers showed a significantly higher rate of CRNM bleeding (hazard ratio [HR] 1.54, confidence interval [CI] 1.05-2.25, P = 0.002) than those without cancers.Based on the AF cohort, AF with cancers could face a significantly higher risk for CRNM bleeding events in the long-term OAC than those without cancers.

Effectiveness and Safety of Anticoagulation Therapy in Frail Patients With Atrial Fibrillation.

BACKGROUND: Frail patients with atrial fibrillation (AF) are less likely to receive anticoagulation than nonfrail patients with AF despite frailty being associated with poorer clinical outcomes including stroke. Using a population-based cohort, we sought to assess the effectiveness and safety of oral anticoagulants (OACs) in frail patients with AF. METHODS: This retrospective cohort study analyzed 83 635 patients aged at least 65 years with AF and frailty (≥5 Hospital Frailty Risk Score) between January 1, 2013 and December 31, 2016 from the Korean National Health Insurance Service database. To account for the differences between patients receiving OAC or not and across different OAC regimens, propensity score-weighting was used. Net adverse clinical event, defined as the first event of ischemic stroke, major bleeding, or cardiovascular death, was compared. In addition, each individual outcome was examined separately. RESULTS: In the study population (57.1% women; mean age, 78.5±7.2 years), a total of 14 968 net adverse clinical event, 3718 ischemic stroke, 5536 major bleeding, and 6188 cardiovascular death occurred. In comparison with no OAC use, OAC use was associated with lower risks of net adverse clinical event (hazard ratio, 0.78 [95% CI, 0.75-0.82]), ischemic stroke (hazard ratio, 0.91 [95% CI, 0.86-0.97]), and cardiovascular death (hazard ratio, 0.52 [95% CI, 0.49-0.55]), but no difference was observed for major bleeding (hazard ratio, 1.02 [95% CI, 0.95-1.10]). Compared with warfarin, all four individual direct OAC were associated with decreased risks of net adverse clinical event, ischemic stroke, major bleeding, and cardiovascular death. The associations for OAC use (compared to no OAC use) or direct OAC use (compared to warfarin) with favorable outcomes were more prominent in individuals with a higher CHA2DS2-VASc score of at least 3. CONCLUSIONS: Among frail patients with AF, OAC treatment was associated with a positive net clinical outcome. Direct OACs provided lower incidences of stroke, bleeding, and mortality, compared with warfarin.

Association between Physical Activity and the Risk of Mortality and Hospitalization in Older Korean Adults with Heart Failure.

Background: Regular exercise improves the functional ability and quality of life of patients with heart failure (HF). However, studies on the results of intensity of exercise in the older population are scarce, especially in the Asian population. Method and Results: A total of 8982 older people (age ≥ 65 years) with HF were selected from the Korean National Health Insurance Service-Senior database (2005-2012). Participants were stratified according to the levels of physical activity per week as follows: (1) inactive group; (2) insufficiently active group: 1-499 metabolic equivalent task minutes (MET-min)/week; (3) active group: 500-999 MET-min/week; and (4) highly active group: ≥ 1000 MET-min/week. During a median follow-up period of 3.2 years, the incidence and risk of mortality were reduced in the insufficiently active (6.7 vs. 4.2 per 100 person-years, adjusted hazard ratio [HR], 0.82; 95% confidence interval [CI], 0.71-0.94; p < 0.001), active (3.8 per 100 person-years; HR, 0.81; 95% CI, 0.70-0.95; p = 0.010), and highly active (2.4 per 100 person-years; HR, 0.52; 95% CI, 0.41-0.67; p < 0.001) groups compared to inactive patients. Conclusions: In older Asians with HF, increased physical activity reduced the risk of all-cause mortality. The mortality-reducing benefit started at a lower physical activity compared to the World Health Organization guideline (500-999 MET-min/week), and the risk decreased with more physical activity.

Small extracellular vesicles derived from patients with persistent atrial fibrillation exacerbate arrhythmogenesis via miR-30a-5p.

Small extracellular vesicles (sEVs) are nanometer-sized membranous vesicles that contribute to the pathogenesis of atrial fibrillation (AF). Here, we investigated the role of sEVs derived from patients with persistent AF in the pathophysiology of AF. First, we evaluated the pathological effects of sEVs derived from the peripheral blood of patients with persistent AF (AF-sEVs). AF-sEVs treatment reduced cell viability, caused abnormal Ca2+ handling, induced reactive oxygen species (ROS) production and led to increased CaMKII activation of non-paced and paced atrial cardiomyocytes. Next, we analyzed the miRNA profile of AF-sEVs to investigate which components of AF-sEVs promote arrhythmias, and we selected six miRNAs that correlated with CaMKII activation. qRT-PCR experiment identified that miR-30a-5p was significantly down-regulated in AF-sEVs, paced cardiomyocytes, and atrial tissues of patients with persistent AF. CaMKII was predicted by bioinformatics analysis as a miR-30a-5p target gene and validated by a dual luciferase reporter; hence, we evaluated the effects of miR-30a-5p on paced cardiomyocytes and validated miR-30a-5p as a pro-arrhythmic signature of AF-sEVs. Consequently, AF-sEVs-loaded with miR-30a-5p attenuated pacing-induced Ca2+-handling abnormalities, whereas AF-sEVs-loaded with anti-miR-30a-5p reversed the change in paced cardiomyocytes. Taken together, the regulation of CaMKII by miR-30a-5p revealed that miR-30a-5p is a major mediator for AF-sEVs-mediated AF pathogenesis. Accordingly, these findings suggest that sEVs derived from patients with persistent AF exacerbate arrhythmogenesis via miR-30a-5p.

Association of rhythm control with incident dementia among patients with atrial fibrillation: a nationwide population-based cohort study.

BACKGROUND: Atrial fibrillation (AF) increases the risk of dementia, and catheter ablation of AF may be associated with a lower risk of dementia. We investigated the association of a rhythm-control strategy for AF with the risk of dementia, compared with a rate-control strategy. METHODS: This population-based cohort study included 41,135 patients with AF on anticoagulation who were newly treated with rhythm-control (anti-arrhythmic drugs or ablation) or rate-control strategies between 1 January 2005 and 31 December 2015 from the Korean National Health Insurance Service database. The primary outcome was all-cause dementia, which was compared using propensity score overlap weighting. RESULTS: In the study population (46.7% female; median age: 68 years), a total of 4,039 patients were diagnosed with dementia during a median follow-up of 51.7 months. Rhythm control, compared with rate control, was associated with decreased dementia risk (weighted incidence rate: 21.2 versus 25.2 per 1,000 person-years; subdistribution hazard ratio [sHR] 0.86, 95% confidence interval [CI] 0.80-0.93). The associations between rhythm control and decreased dementia risk were consistently observed even after censoring for incident stroke (sHR 0.89, 95% CI 0.82-0.97) and were more pronounced in relatively younger patients and those with lower CHA2DS2-VASc scores. Among dementia subtypes, rhythm control was associated with a lower risk of Alzheimer's disease (sHR 0.86, 95% CI 0.79-0.95). CONCLUSIONS: Among anticoagulated patients with AF, rhythm control was associated with a lower risk of dementia, compared with rate control. Initiating rhythm control in AF patients with fewer stroke risk factors might help prevent subsequent dementia.

Increased risk of ischemic stroke and systemic embolism in hyperthyroidism-related atrial fibrillation: A nationwide cohort study.

BACKGROUND: We aimed to evaluate the long-term risk of ischemic stroke/systemic embolism of hyperthyroidism-related AF. METHODS: This retrospective population-based cohort study included records of 1,034,099 atrial fibrillation patients between 2005 and 2016 from the Korean National Health Insurance Service database. After exclusion, we identified 615,724 oral anticoagulation-naïve patients aged ≥18 years with new-onset non-valvular atrial fibrillation, of whom 20,773 had hyperthyroidism-related atrial fibrillation. After 3:1 propensity score matching, ischemic stroke and systemic embolism occurrences were compared between hyperthyroidism-related and non-hyperthyroidism-related ("nonthyroidal") atrial fibrillation patients. RESULTS: After exclusion, we identified 615,724 oral anticoagulation-naïve AF patients of whom 20,773 had hyperthyroidism-related AF. Median follow-up duration was 5.9 years. Hyperthyroidism-related AF patients had significantly higher risks of ischemic stroke and systemic embolism than nonthyroidal AF patients (1.83 vs 1.62 per 100-person year, hazard ratio[HR], 1.13; 95% confidence interval[CI], 1.07 to 1.19; P < 0.001). This risk was 36% higher in hyperthyroidism-related than in nonthyroidal AF patients within 1 year of atrial fibrillation diagnosis (3.65 vs 2.67 per 100-person year, HR, 1.36; 95% CI, 1.24 - 1.50; P < 0.001). This difference was also observed in the CHA2DS2-VASc score subgroup analysis. The risk of ischemic stroke and systemic embolism significantly decreased in patients treated for hyperthyroidism (HR, 0.64; 95% CI, 0.58 to 0.70; P < 0.001). CONCLUSIONS: Hyperthyroidism-related AF patients have high risks of ischemic stroke and systemic embolism like nonthyroidal AF, especially when initially diagnosed. This risk is reduced by treating hyperthyroidism.

Risk of sick sinus syndrome in patients diagnosed with atrial fibrillation: A population-based cohort.

BACKGROUND: Sinoatrial node dysfunction and atrial fibrillation (AF) frequently coexist and interact with each other, often to initiate and perpetuate each other. OBJECTIVE: To determine the effect of AF on the incidence and risk of sick sinus syndrome (SSS). METHODS: The association of incident AF with the development of incident SSS was assessed from 2004 to 2014 in 302 229 SSS- and pacemaker-free subjects aged ≥60 years in the Korea National Health Insurance Service-Senior cohort. RESULTS: During an observation period of 1 854 800 person-years, incident AF was observed in a total of 12 797 subjects (0.69%/year). The incidence of SSS was 3.4 and 0.2 per 1000 person-years in the propensity score-matched incident AF and no-AF groups, respectively. After adjustment, the significantly increased risk of SSS was observed in the incident AF group, with a hazard ratio (HR) of 13.4 (95% confidence interval [CI]: 8.4-21.4). This finding was consistently observed after censoring for heart failure (HR: 16.0; 95% CI: 9.2-28.0) or heart failure/myocardial infarction (HR: 16.6; 95% CI: 9.3-29.7). Incident AF also was associated with an increased risk of pacemaker implantation related with both SSS (HR: 21.8; 95% CI: 8.7-18.4) and atrioventricular (AV) block (HR: 9.5; 95% CI: 4.9-18.4). These results were consistent regardless of sex and comorbidities. CONCLUSION: Incident AF was associated with more than 10 times increased risk of SSS in an elderly population regardless of comorbidities. The risk of pacemaker implantations related with both sinus node dysfunction and AV block was increased in the elderly population with incident AF.

The mortality analysis of primary prevention patients receiving a cardiac resynchronization defibrillator (CRT-D) or implantable cardioverter-defibrillator (ICD) according to guideline indications in the improve SCA study.

BACKGROUND: In primary prevention (PP) patients the utilization of implantable cardioverter-defibrillators (ICD) and cardiac resynchronization therapy-defibrillators (CRT-D) remains low in many geographies, despite the proven mortality benefit. PURPOSE: The objective of this analysis was to examine the mortality benefit in PP patients by guideline-indicated device type: ICD and CRT-D. METHODS: Improve sudden cardiac arrest was a prospective, nonrandomized, nonblinded multicenter trial that enrolled patients from regions where ICD utilization is low. PP patient's CRT-D or ICD eligibility was based upon the 2008 ACC/AHA/HRS and 2006 ESC guidelines. Mortality was assessed according to guideline-indicated device type comparing implanted and nonimplanted patients. Cox proportional hazards methods were used, adjusting for known factors affecting mortality risk. RESULTS: Among 2618 PP patients followed for a mean of 20.8 ± 10.8 months, 1073 were indicated for a CRT-D, and 1545 were indicated for an ICD. PP CRT-D-indicated patients who received CRT-D therapy had a 58% risk reduction in mortality compared with those without implant (adjusted hazard ratio [HR]: 0.42, 95% confidence interval [CI]: 0.28-0.61, p < .0001). PP patients with an ICD indication had a 43% risk reduction in mortality with an ICD implant compared with no implant (adjusted HR: 0.57, 95% CI: 0.41-0.81, p = .002). CONCLUSIONS: This analysis confirms the mortality benefit of adherence to guideline-indicated implantable defibrillation therapy for PP patients in geographies where ICD therapy was underutilized. These results affirm that medical practice should follow clinical guidelines when choosing therapy for PP patients who meet the respective defibrillator device implant indication.

Ethnic similarities in genetic polymorphisms associated with atrial fibrillation: Far East Asian vs European populations.

BACKGROUND: In European ancestry, 111 genetic loci were identified as associated with atrial fibrillation (AF). We explored the reproducibility of those single nucleotide polymorphisms (SNPs) in a genome-wide association study (GWAS) meta-analysis of Far East Asian populations. METHODS: We performed a meta-analysis of the Korean AF network and Japanese AF data sets (9118 cases and 33 467 controls) by an inverse-variance fixed-effects model. We compared the results with 111 previously reported SNPs proven in Europeans after excluding 36 missing loci and a locus with a minor allelic frequency (MAF) < 0.01 in the European population. RESULTS: Among remaining 74 loci, 29 loci were replicated at a P < .05, and 17 of those loci were newly found in the Far East Asian population: 3 loci with a P < 5×10-8 (METTL11B at 1q24, KCNN2 at 5q22 and LRMDA at 10q22), 4 loci at the threshold of the Bonferroni correction of P = 4.5 × 10-4  ~ 5×10-8 (KIF3C at 2p23, REEP3, NRBF2 at 10q21, SIRT1, MYPN at 10q21 and CFL2 at 14q13) and 10 SNPs with a P = .05 ~ 4.5 × 10-4 . Among 18 AF loci with a MAF< 0.01 in the Far East Asian populations, 2 loci (GATA4 at 8q23 and SGCG at 13q12) were replicated after a fine mapping. Twenty-seven AF loci, including a locus, which had a sufficient sample size to get a power of over 80% (with a type 1 error α = 4.5 × 10-4 ), were not replicated in the Far East Asian populations. CONCLUSIONS: We newly replicated 19 AF-associated genetic loci in the European descent among the Far East Asian populations. It highlights the extensive sharing of AF genetic risks across Far East Asian populations.

Atrial fibrillation and the risk of ischaemic strokes or intracranial haemorrhages: comparisons of the catheter ablation, medical therapy, and non-atrial fibrillation population.

AIMS: Although atrial fibrillation (AF) catheter ablation (AFCA) is an effective rhythm control strategy, there is limited data on whether ischaemic stroke (IS) or intracranial haemorrhage (ICH) decreases after AFCA compared with medical therapy or non-AF population. We explored the IS and ICH risk after AFCA or medical therapy in the AF population and matched non-AF population. METHODS AND RESULTS: We compared 1629 patients with AFCA (Yonsei AF ablation cohort), 3258 with medical therapy [Korean National Health Insurance (NHIS) database], and 3258 non-AF subjects (NHIS database) following a 1:2:2 propensity score matching. All AFCA patients underwent regular rhythm follow-ups for 51 ± 29 months. Among the AFCA group, the incidence rate ratio (IRR) of ISs was significantly higher in patients with sustained AF recurrences after the last ablation (0.87%) than in those remaining in sinus rhythm (0.24%, P = 0.017; log rank P = 0.003). The IRR of ISs was significantly higher in the medical therapy (1.09%) than AFCA (0.30%, P < 0.001, log rank P < 0.001 vs. medical therapy) or non-AF groups (0.34%, P < 0.001, log rank P < 0.001 vs. medical therapy; P = 0.673, log rank P = 0.874 vs. AFCA). The IRR of ICHs was 0.17% in the medical therapy, 0.06% in the AFCA (P = 0.023, log rank P = 0.042 vs. medical therapy), and 0.12% in the non-AF group (P = 0.226, log rank P = 0.241 vs. medical therapy; P = 0.172, log rank P = 0.193 vs. AFCA). CONCLUSION: Post-procedural AF control influences the risk of ISs. Atrial fibrillation catheter ablation significantly reduces the risk of both ISs and ICHs to the extent of the non-AF population compared to the medical therapy.