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We aimed to evaluate the long-term risk of ischemic stroke/systemic embolism of hyperthyroidism-related AF.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.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; P0.001). 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; P0.001). This difference was also observed in the CHAHyperthyroidism-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.

Background An association has been identified between mitral valve prolapse (MVP) and sudden cardiac arrest (SCA), and ventricular arrhythmias (VA). This study aimed to elucidate predictive factors for SCA or VA in MVP patients. Methods MVP patients who underwent cardiac magnetic resonance (CMR) were retrospectively included. Patients with other structural heart disease or causes of aborted SCA were excluded. Clinical characteristics (sex, age, body mass index, histories of diabetes, hypertension, and dyslipidemia) and electrocardiographic (PR interval, QRS duration, corrected QT interval, inverted T wave in the inferior leads, bundle branch block, and atrial fibrillation), echocardiographic [mitral regurgitation grade, prolapsing mitral leaflet, and right ventricular systolic pressure (RVSP)], and CMR [left atrial volume index, both ventricular ejection fractions, both ventricular end-diastolic and systolic volume indexes, prolapse distance, mitral annular disjunction, systolic curling motion, presence of late gadolinium enhancement (LGE), LGE volume and proportion] parameters were analyzed. Results Of the 85 patients [age, 54.0 (41.0–65.0) years; 46 men], seven experienced SCA or VA. Younger age and wide QRS complex were observed more often in the SCA/VA group than in the no-SCA/VA group. The SCA/VA group exhibited lower RVSP, more systolic curling motion and LGE, greater LGE volume, and higher LGE proportion. The presence of LGE [hazard ratio (HR), 19.8; 95% confidence interval (CI) 2.65–148.15; P = 0.004], LGE volume (HR 1.08; 95% CI 1.02–1.14; P = 0.006) and LGE proportion (HR 1.32; 95% CI 1.08–1.60; P = 0.006) were independently associated with higher risk of SCA or VA in MVP patients together with systolic curling motion in each model. Conclusions The presence of systolic curling motion, high LGE volume and proportion, and the presence of LGE on CMR were independent predictive factors for SCA or VA in MVP patients.

Objective: The excess risk of atrial fibrillation in relation to the presence of proteinuria associated with hypertension has not been well elucidated. We aimed to determine the effect of hypertension and/or proteinuria on the incidence of atrial fibrillation. Second, we evaluated whether the associations with temporal changes in proteinuria status on the incidence of atrial fibrillation. Methods and results: A total of 85 434 participants with hypertension and 125 912 participants without hypertension with age at least 60 years from the Korea National Health Insurance Service-Senior cohort were included. Amongst controls (participants without proteinuria and hypertension), hypertension only, proteinuria only, and hypertension with proteinuria groups, the adjusted incidences of atrial fibrillation were 0.51, 0.69. 0.78 and 0.99 per 100 person-years, respectively after inverse probability of treatment weighting. Compared with controls, the weighted risks of atrial fibrillation in the hypertension only, proteinuria only and hypertension with proteinuria groups were increased by 37% (hazard ratio 1.37, 95% confidence interval, CI 1.30–1.44, P = 0.001), 55% (hazard ratio 1.55, 95% CI 1.28–1.88, P

Rationale: Atrial fibrillation (AF) is the most common cardiac arrhythmia diagnosed in clinical practice. Genome-wide association studies have identified AF-associated common variants across 100+ genomic loci, but the mechanism underlying the impact of these variant loci on AF susceptibility in vivo has remained largely undefined. One such variant region, highly associated with AF, is found at 1q24, close to PRRX1 , encoding the paired-related homeobox 1 transcription factor. Objective: To identify the mechanistic link between the variant region at 1q24 and AF predisposition. Methods and Results: The mouse orthologue of the noncoding variant genomic region ( R1A ) at 1q24 was deleted using CRISPR genome editing. Among the genes sharing the topologically associated domain with the deleted R1A region ( Kifap3 , Prrx1 , Fmo2 , and Prrc2c ), only the broadly expressed gene Prrx1 was downregulated in mutants, and only in cardiomyocytes. Expression and epigenetic profiling revealed that a cardiomyocyte lineage-specific gene program ( Mhrt , Myh6 , Rbm20 , Tnnt2 , Ttn , and Ckm ) was upregulated in R1A −/− atrial cardiomyocytes and that Mef2 (myocyte enhancer factor)-binding motifs were significantly enriched at differentially accessible chromatin sites. Consistently, Prrx1 suppressed Mef2-activated enhancer activity in HL-1 cells. Mice heterozygous or homozygous for the R1A deletion were susceptible to atrial arrhythmia induction, had atrial conduction slowing and more irregular RR intervals. Isolated R1A −/− mouse left atrial cardiomyocytes showed lower action potential upstroke velocities and sodium current, as well as increased systolic and diastolic calcium concentrations compared with controls. Conclusions: The noncoding AF variant region at 1q24 modulates Prrx1 expression in cardiomyocytes. Cardiomyocyte-specific reduction of Prrx1 expression upon deletion of the noncoding region leads to a profound induction of a cardiac lineage-specific gene program and to propensity for AF. These data indicate that AF-associated variants in humans may exert AF predisposition through reduced PRRX1 expression in cardiomyocytes.

BACKGROUND It is unclear whether catheter ablation is beneficial for frail elderly patients with atrial fibrillation (AF). This study evaluated the effect of ablation on outcomes in frail elderly patients with AF.Methods and Results:From the Korean National Health Insurance Service database, 194,928 newly diagnosed AF patients were treated with ablation or medical therapy (rhythm or rate control) between 2005 and 2015. Among these patients, the study included 1,818 (ablation; n=119) frail and 1,907 (ablation; n=230) non-frail elderly (≥75 years) patients. Propensity score matching was used to correct for differences between groups. During 28 months (median) follow up, the risk of all-cause death, composite outcome (all-cause death, heart failure admission, stroke/systemic embolism, and sudden cardiac arrest), and each outcome did not change after ablation in frail elderly patients. However, in non-frail elderly patients, ablation was associated with a lower risk of all-cause death (3.5 and 6.2 per 100 person-years; hazard ratio [HR] 0.48; 95% confidence interval [CI] 0.30-0.79; P=0.004), and composite outcome (6.9 and 11.2 per 100 person-years; HR 0.54; 95% CI 0.38-0.75; P

Background The relationship between the characteristics of cardiac implantable electronic device (CIED) leads and subclinical cardiac perforations remains unclear. This study aimed to evaluate the incidence of subclinical cardiac perforation among various CIED leads using cardiac computed tomography (CT). Methods A total of 271 consecutive patients with 463 CIED leads, who underwent cardiac CT after CIED implantation, were included in this retrospective observational study. Cardiac CT images were reviewed by one radiologist and two cardiologists. Subclinical perforation was defined as traversal of the lead tip past the outer myocardial layer without symptoms and signs related to cardiac perforation. We compared the subclinical cardiac perforation rates of the available lead types. Results A total of 219, 49, and 3 patients had pacemakers, implantable cardioverter-defibrillators, and cardiac resynchronization therapy, respectively. The total subclinical cardiac perforation rate was 5.6%. Subclinical cardiac perforation by screw-in ventricular leads was significantly more frequent than that caused by tined ventricular leads (13.3% vs 3.3%, respectively, p = 0.002). There were no significant differences in the incidence of cardiac perforation between atrial and ventricular leads, screw-in and tined atrial leads, pacing and defibrillator ventricular leads, nor between magnetic resonance (MR)-conditional and MR-unsafe screw-in ventricular leads. Screw-in ventricular leads were significantly associated with subclinical cardiac perforation [odds ratio, 4.554; 95% confidence interval, 1.587–13.065, p = 0.005]. There was no case subclinical cardiac perforation by septal ventricular leads. Conclusions Subclinical cardiac perforation by screw-in ventricular leads is not rare. Septal pacing may be helpful in avoiding cardiac perforation.

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

Aims This study aimed to elucidate the risk for stroke and systemic embolism (SE) in patients with atrial fibrillation and heart failure (HF) according to HF type. Methods and results A total of 10 780 patients with atrial fibrillation were enrolled in a multicentre prospective registry and divided according to HF type: no‐HF, HF with preserved ejection fraction (EF) (HFpEF), HF with mid‐range EF (HFmrEF), and HF with reduced EF (HFrEF). Each group included 237 age‐matched and sex‐matched patients (age, 69.0 ± 10.3 years; men, 69.6%). The baseline characteristics, cumulative incidence, and hazard ratios for stroke/SE and major bleeding were compared across the groups. Patients with HF accounted for 10.3% of the total population; HFpEF, HFmrEF, and HFrEF represented 43.7%, 23.6%, and 32.7% of the patients with HF, respectively. The CHA2DS2‐VASc score was significantly higher in the HFpEF, HFmrEF, and HFrEF groups than in the no‐HF group. The annual stroke/SE incidence rates were 2.8%, 0.7%, 1.1%, and 0.9% in the HFpEF, HFmrEF, HFrEF, and no‐HF groups, respectively. The cumulative incidence of stroke/SE was significantly highest in the HFpEF group at 22.8 ± 10.0 months (P = 0.020). The stroke/SE risk was higher in the HFpEF group than in the HFmrEF and HFrEF groups (hazard ratio, 3.192; 95% confidence interval, 1.039–9.810; P = 0.043). E/e' value was an independent risk factor for stroke/SE. There were no significant differences in the incidence of major bleeding across the groups. Conclusions The stroke/SE risk was the highest in the HFpEF group and comparable between the HFmrEF and HFrEF groups.

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.

Funding Acknowledgements Type of funding sources: None. Introduction The risk of procedure-related complications and rhythm outcomes differ between men and women after atrial fibrillation catheter ablation (AFCA). We evaluated whether consistent sex differences existed in mapping and rhythm outcomes in repeat ablation procedures. Methods Among 3,282 patients in the registry, we analysed 443 consecutive patients (24.6% female, 58.5 ± 10.3 years old, 61.5% paroxysmal AF) who underwent a second AFCA. We compared the clinical factors, mapping, left atrial (LA) pressure, complications, and long-term clinical recurrences after propensity score matching. Results The LA volume index (43.1 ± 18.6 vs. 35.8 ± 11.6 ml/m2, p Conclusions During the repeat AFCA procedures, PV reconnections were lower in women than men, and the existence of extra-PV triggers and an LA pressure elevation was more significant, which resulted in poor rhythm outcomes.

Background/Aims: Comparative occurrence of ischemic stroke for rhythm versus rate control strategy in patients with non-valvular atrial fibrillation (NVAF) is still inconclusive. The purpose of this study was to investigate whether the rhythm control strategy is associated with a lower risk of ischemic stroke compared to the rate control strategy in NVAF patients. Methods: The CODE-AF registry prospectively enrolled 6,280 consecutive pa tients who were treated for NVAF at 10 tertiary referral centers in South Korea. Of these, 2,513 NVAF patients (age, 67 ± 10 years; male, 61.8%) were clinically followed up for over 1-year and divided into rate and rhythm control groups. Results: Those treated with the rhythm control strategy were younger and had less proportions of underlying disease compared to those treated with the rate control strategy. After the propensity matching analysis, those treated with the rhythm control strategy had similar baseline characteristics including the CHA2DS2-VASC score compared to those treated with the rate control strategy. The rate of oral anticoagulation, all bleeding, and hospitalization were also simi larly between the two groups. The incidence rate of ischemic stroke in the rhythm control group was significantly lower than in the rate control group (0.7 vs. 6.9 per 1,000 person-years, p = 0.011). Conclusions: The rhythm control strategy demonstrated a beneficial effect to lower the risk of ischemic stroke during a 1-year follow-up compared to the rate control strategy.

Background Short QT syndrome is a rare, inherited channelopathy associated with sudden cardiac arrest (SCA) but the characteristics and prognosis of short QT interval (SQTI) in Korean patients remain unclear. This study aimed to determine the clinical characteristics and outcomes of SQTI in a Korean population. Methods Consecutive patients with SQTI from January 1999 to March 2019 in three university hospitals in South Korea were recruited. SQTI was defined as a Bazett’s formula-corrected QT interval (QTc) ≤ 340 ms in serial electrocardiograms. Age- and sex-matched patients with a normal QTc and without overt cardiovascular disease were included in a 1:4 ratio. Clinical and ECG features and outcomes were compared between patients with and without SQTI. Results 34 patients with SQTI [age, 23.5 (21–30.5) years; 31 male] were followed up for 4.8 (2.0–7.8) years. Early repolarization, tall T wave, and U wave were significantly more frequent in patients with SQTI than in those without SQTI. QT dispersion [44.0 (28.0–73.0) vs. 20.0 (12.0–35.0) ms, P P P = 0.030) and ventricular arrhythmia (VA)/SCA (8.7% vs. 0%, P = 0.007) were significantly more frequent in patients with SQTI than in those without. SQTI was significantly associated with AF [odds ratio, 5.911; 95% confidence interval, 1.257–27.808; P = 0.025] and VA/SCA. Conclusions In this subset of Korean population, SQTI was associated with AF and VA/SCA.

Aims The aim of this study is to determine the relationship between alcohol consumption and atrial fibrillation (AF)-related adverse events in the AF population. Methods and results A total of 9411 patients with nonvalvular AF in a prospective observational registry were categorized into four groups according to the amount of alcohol consumption—abstainer-rare, light ( Conclusion Our findings suggest that heavy alcohol consumption increases the risk of adverse events in patients with AF, whereas light or moderate alcohol consumption does not.

Aims Optimal medical therapy after cardiac resynchronization therapy (CRT) implantation is important in heart failure (HF) with reduced ejection fraction (HFrEF) patients. Although sacubitril/valsartan (SV) is a mainstay in the treatment of HFrEF, its efficacy in the management of CRT non‐responders has not been emphasized. We aimed to investigate the efficacy of SV in CRT non‐responders. Methods and results We analysed 175 HFrEF patients who received CRT implantation between January 2010 and January 2019. CRT responder was defined as a decrease in left ventricular (LV) end‐systolic volume > 15% on echocardiography 6 months after implantation. Medical records were retrospectively reviewed. Patients underwent follow‐up for HF rehospitalization, heart transplantation (HT), implantation of a LV assistant device (LVAD), cardiac death, and all‐cause death. Among the study population, 164 patients were evaluated for CRT response; 54 (33%) were CRT non‐responders. Four patients (6%) who received SV before CRT implantation were excluded, leaving 50 patients for analysis. Twenty‐two non‐responders (44%) received SV. There was no significant difference in baseline characteristics between SV users and non‐users (n = 28). During follow‐up, SV users had significantly lower incidence of all‐cause death [1 (5%) vs. 10 (36%), P = 0.022] and tended to have lower HF rehospitalization [6 (27%) vs. 16 (57%), P = 0.068] and cardiac death (including HT and LVAD implant) [2 (9%) vs. 10 (36%), P = 0.064]. Kaplan–Meier survival analysis revealed that SV use was associated with a lower risk of cardiac death (including HT and LVAD implant) (log‐rank P = 0.029). Conclusions SV treatment was related to a lower incidence of cardiac death including HT and LVAD implant in CRT non‐responders. The optimization of HF management, including SV, should be considered in CRT non‐responders.

Background/Aims The current study aimed to elucidate a time-course change in left atrial volume after cardiac resynchronization therapy (CRT) and to verify factors associated with left atrial volume reduction (LAVR) and its prognostic implications. Methods The records of 97 patients were retrospectively reviewed after CRT. Echocardiographic data were analyzed at baseline before CRT, at early follow-up (FU) (≤ 1 year, median 6 months), and at late FU (median 30 months). Left ventricular volume response (LVVR) was defined as 15% reduction in left ventricular (LV) end-systolic volume (ESV). LAVR was classified into two groups by the median value at early FU: LAVR (≥ 7.5%) and no LAVR (< 7.5%). Results LV ESV index continuously decreased from baseline to early FU and from early FU to late FU (106.1 ± 47.4 mL/m2 vs. 87.6 ± 51.6 mL/m2 vs. 72.5 ± 57.1 mL/m2). LA volume index decreased from baseline to early FU, but there were no reductions thereafter (51.8 ± 21.9 mL/m2 vs. 45.1 ± 19.6 mL/m2 vs. 44.9 ± 23.0 mL/m2). The only echocardiographic factor associated with LAVR was change in E velocity (odds ratio [OR], 1.04; p = 0.002). Early LAVR (OR, 10.05; p = 0.002) was an independent predictor for late LVVR. Conclusions LAVR was related to reduction in E velocity, suggesting its relation with optimization of LV filling pressure. Early LAVR was a predictor for LVVR to CRT in long-term FU.

Background and objectives A prolonged QTc interval is associated with an increased risk of a stroke or atrial fibrillation (AF). However, its direct causal relationship with AF associated a stroke has not been proven yet. To examine whether QTc interval is causally linked with risk of stroke in AF patients, we used the Mendelian randomization analysis. Subjects and methods Among 2742 patients (73.6% male; 58.2 ± 11.0 years old; 69.5% with paroxysmal AF) who underwent AF catheter ablation, we analyzed 1766 patients who had preablation sinus rhythm electrocardiograms off antiarrhythmic drugs after excluding amiodarone users. Among them, 1213 subjects had genome-wide association study dataset analyzable for the Mendelian randomization. We explored the mechanistic relationships between QTc interval (ms) and the risk of a stroke by analyzing the Mendelian randomization (1213 subjects) after reviewing 35 genetic polymorphisms associated with the QTc in 31 European descent studies. Results Among the patients in the higher quartile with a higher QTc, CHA2DS2-VASc score (p p p 2DS2-VASc score (β, 4.63E−5; 95% confidence interval, 3.57E−6–8.90E−5; p = 0.034) and ischemic strokes (odds ratio, 1.01; 95% confidence interval, 1.00–1.01; p = 0.027). However, there was no direct causal relationship between the QTc and CHA2DS2-VASc score or a prior stroke in either the one-sample or two-sample Mendelian randomizations. Conclusion The QTc was independently associated with the CHA2DS2-VASc score and strokes among the patients with AF who underwent catheter ablation, despite no genetically direct causal relationship.

PurposeDose reduction of non-vitamin K antagonist oral anticoagulants (NOACs) is indicated in patients with atrial fibrillation (AF) with renal impairment. This study investigated anticoagulation patterns and outcomes in patients with chronic kidney disease (CKD).Materials and methodsIn a prospective observational registry (CODE-AF), 3445 patients with non-valvular AF including 1129 with CKD (estimated glomerular filtration rate ≤ 60 mL min−1 1.73 m−2) were identified between June 1, 2016, and July 3, 2017.ResultsCompared with patients with no-CKD, patients with CKD more frequently had a high stroke risk (94.9% vs. 67.0%,p p p = 0.001) and rivaroxaban (0% vs. 79.5%,p = 0.001) were lower in patients with RIDR. However, the underdose rate of apixaban was not different (62.5% vs. 53.9%,p = 0.089). The overdose rate of dabigatran (7.5% vs. 0%) and rivaroxaban (13.7% vs. 0%) was higher in RIDR than in no-RIDR patients. Stroke/transient ischemic attack was significantly higher in CKD patients (1.4 vs. 0.6 per 100 person-years,p = 0.045). Aspirin significantly increased minor bleeding in CKD patients compared with controls (p = 0.037).ConclusionCKD patients might have a high stroke risk and NOAC usage rate. The underdose rate of NOACs decreased in CKD patients, except for apixaban. Aspirin significantly increased minor bleeding in CKD patients.

Longer atrial fibrillation (AF) durations have higher recurrence rates after rhythm control. However, there is limited data on the effect of the AF duration on recurrence after atrial fibrillation catheter ablation (AFCA). In the present study, we investigated the rhythm outcome of AFCA according to the AF duration based on the first electrocardiogram (ECG) diagnosis.We included 1005 patients with AF (75% male, 59 ± 11 years old) who underwent AFCA and whose first ECG diagnosis time point was evident. The clinical characteristics and rhythm outcomes were compared based on the AF duration (≤3 years, n = 537;3 years, n = 468) and AF burden (paroxysmal atrial fibrillation [PAF], n = 387; persistent atrial fibrillation [PeAF], n = 618). Longer AF durations were associated with older age (P = .020), larger left atrial size (P = .009) and a higher number of patients with hypertension (P .001) or PeAF (P .001). During 24 ± 22 months of follow-up, the postablation clinical recurrence rate was higher in patients with a longer AF duration (logrank P = .002). The AF recurrence rate was significantly higher in PeAF patients with an AF duration3 years (logrank P = 0.009), but not in subjects with PAF (logrank P = .939). In a multivariate Cox regression analysis, a longer AF duration was significantly associated with a higher clinical recurrence rate after AFCA in PeAF patients (adjusted hazard ratio, 1.06; range, 1.03-0.10; P = 0.001), but not PAF.Although longer AF duration was associated with higher clinical recurrence rates after AFCA, the rate was significant in patients with PeAF lasting3 years, but not in PAF patients.

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.

Background/Aims: Efforts to reduce stroke in patients with atrial fibrillation (AF) have focused on increasing physician adherence to oral anticoagulant (OAC) guidelines; however, the high early discontinuation rate of vitamin K antagonists (VKAs) is a lim itation. Although non-VKA OACs (NOACs) are more convenient to administer than warfarin, their lack of monitoring may predispose patients to nonpersistence. We com pared the persistence of NOAC and VKA treatment for AF in real-world practice. Methods: In a prospective observational registry (COmparison study of Drugs for symptom control and complication prEvention of Atrial Fibrillation [CODE-AF] regis try), 7,013 patients with nonvalvular AF (mean age 67.2 ± 10.9 years, women 36.4%) were consecutively enrolled between June 2016 and June 2017 from 10 tertiary hospitals in Korea. This study included 3,381 patients who started OAC 30 days before enrollment (maintenance group) and 572 patients who newly started OAC (new-starter group). The persistence rate of OAC was evaluated. Results: In the maintenance group, persistence to OAC declined during 6 months, to 88.3% for VKA and 95.5% for NOAC (p < 0.0001). However, the persistence rate was not different among NOACs. In the new-starter group, persistence to OAC declined during 6 months, to 78.9% for VKA and 92.1% for NOAC (p < 0.0001). The persistence rate was lower for rivaroxaban (83.7%) than apixaban (94.6%) and edoxaban (94.1%, p < 0.001). In the new-starter group, diabetes, valve disease, and cancer were related to nonper sistence of OAC. Conclusions: Nonpersistence was significantly lower with NOAC than VKA in both the maintenance and new-starter groups. In only the new-starter group, apixaban or edox aban showed higher persistence rates than rivaroxaban.

Background: Extra-pulmonary vein triggers can play a significant role in atrial fibrillation recurrence after catheter ablation. We explored the characteristics of the extra-pulmonary vein (PV) triggers in de novo and repeat atrial fibrillation (AF) catheter ablation (AFCA).Methods: We included 2,118 patients who underwent a de novo AFCA (women 27.6%, 59.2 ± 10.9 years old, paroxysmal AF 65.9%) and 227 of them conducted repeat procedures. All included patients underwent isoproterenol provocation tests at the end of the procedure, and then we analyzed extra-PV triggers-related factors.Results: Extra-PV triggers were documented in 11.7% of patients undergoing de novo AFCA (1.22 ± 0.46 foci per patient) and 28.6% undergoing repeat AFCA (1.49 ± 0.73 foci per patient). Older age and higher LA volume index in de novo procedures and women, diabetes, and higher parasympathetic nerve activity (heart rate variability) in repeat-AFCA were independently associated with the existence of extra-PV triggers. The septum (19.9%), coronary sinus (14.7%), and superior vena cava (11.2%) were common extra-PV foci. Among 46 patients who were newly found to have mappable extra-PV triggers upon repeat procedures, 15 (32.6%) matched with the previous focal or empirical extra-PV ablation sites. The rate of AF recurrence was significantly higher in patients with extra-PV triggers than in those without after de novo (HR 1.91, 95% CI 1.54–2.38, p < 0.001) and repeat procedures (HR 2.68, 95% CI 1.63–4.42, p < 0.001).Conclusions: Extra-PV triggers were commonly found in AF patients with significant remodeling and previous empirical extra-PV ablation. The existence of extra-PV triggers was independently associated with poorer rhythm outcomes after the de novo and repeat AFCA.

Background: Little is known about the prognostic value of nutritional status among patients undergoing atrial fibrillation (AF) catheter ablation (AFCA). We compared the risk of procedure-related complications and long-term rhythm outcomes of AFCA according to nutritional status.Methods: We included 3,239 patients undergoing de novo AFCA in 2009-2020. Nutritional status was assessed using the controlling nutritional status (CONUT) score. The association between malnutrition and the risk of AFCA complications or long-term rhythm outcomes was evaluated. We validated the effects of malnutrition using an external cohort of 360 patients undergoing AFCA in 2013-2016.Results: In the study population (26.8% women, median age: 58 years), 1,005 (31.0%) had malnutrition (CONUT scores ≥ 2); 991 (30.6%) had mild (CONUT 2–4) and 14 (0.4%) had moderate-to-severe (CONUT ≥ 5) malnutrition. The overall complication rates after AFCA were 3.3% for normal nutrition, 4.2% for mild malnutrition, and 21.4% for moderate-to-severe malnutrition. Moderate-to-severe malnutrition [odds ratio (OR) 6.456, 95% confidence interval (CI) 1.637-25.463, compared with normal nutrition], older age (OR 1.020 per 1-year increase, 95% CI 1.001-1.039), female sex (OR 1.915, 95% CI 1.302-2.817), and higher systolic blood pressure (OR 1.013 per 1-mmHg increase, 95% CI 1.000-1.026) were independent predictors for the occurrence of complications. In the validation cohort, malnutrition (CONUT ≥ 2) was associated with a 2.87-fold higher risk of AFCA complications (95% CI 1.174-7.033). The association between malnutrition and a higher risk of AFCA complications was consistently observed regardless of body mass index and sex. Malnutrition did not affect rhythm outcomes during the median follow-up of 40 months (clinical recurrence: 37.0% in normal nutrition vs. 36.5% in malnutrition).Conclusion: Malnutrition, which is common in patients undergoing AFCA, was associated with a substantially higher risk for complications after AFCA.

Introduction: Whereas, high-power short-duration (HPSD) radiofrequency (RF) ablation is generally used in atrial fibrillation (AF) catheter ablation (CA), its efficacy, safety, and influence on autonomic function have not been well established in a large population. This study compared HPSD-AFCA and conventional power (ConvP)-AFCA in propensity score matched-population.Methods: In 3,045 consecutive patients who underwent AFCA, this study included 1,260 patients (73.9% male, 59 ± 10 years old, 58.2% paroxysmal type) after propensity score matching: 315 in 50~60W HPSD group vs. 945 in the ConvP group. This study investigated the procedural factors, complication rate, rhythm status, and 3-month heart rate variability (HRV) between the two groups and subgroups.Results: Procedure time was considerably short in the HPSD group (135 min in HPSD vs. 181 min in ConvP, p < 0.001) compared to ConvP group, but there was no significant difference in the complication rate (2.9% in HPSD vs. 3.7% in ConvP, p = 0.477) and the 3-month HRV between the two groups. At the one-year follow-up, there was no significant difference in rhythm outcomes between the two groups (Overall, Log-rank p = 0.885; anti-arrhythmic drug free, Log-rank p = 0.673). These efficacy and safety outcomes were consistently similar irrespective of the AF type or ablation lesion set. The Cox regression analysis showed that the left atrium volume index estimated by computed tomography (HR 1.01 [1.00–1.02]), p = 0.003) and extra-pulmonary vein triggers (HR 1.59 [1.03–2.44], p = 0.036) were independently associated with one-year clinical recurrence, whereas the HPSD ablation was not (HR 1.03 [0.73–1.44], p = 0.887).Conclusion: HPSD-AFCA notably reduced the procedure time with similar rhythm outcomes, complication rate, and influence on autonomic function as ConvP-AFCA, irrespective of the AF type or ablation lesion set.

Background: The efficacy of cryoballoon pulmonary vein isolation (Cryo-PVI) is equivalent to that of radiofrequency pulmonary vein isolation in patients with paroxysmal atrial fibrillation (AF). We aimed to compare the efficacy and safety profile of Cryo-PVI and high-power, short-duration (HPSD) radiofrequency catheter ablation (RFCA) in patients with AF. Methods: We prospectively randomized 314 patients with paroxysmal AF (men, 71.3%; 59.9±10.9 years old) to either the Cryo-PVI group (n=156) or HPSD-RFCA group (n=158). Cavotricuspid isthmus ablation and linear ablation from the superior vena cava to the right atrial septum in addition to pulmonary vein isolation were carried out in the majority of patients in the HPSD-RFCA group. The primary end point was AF recurrence after a single procedure; secondary end points were the recurrence pattern, cardioversion rate, follow-up heart rate variability, and response to antiarrhythmic drugs. Results: After a mean follow-up of 9.8±5.1 months, the clinical recurrence rate did not significantly differ between the two groups (log-rank P =0.840). The rate of recurrence as atrial tachycardia ( P >0.999), cardioversion ( P =0.999), and 3-month heart rate variability (high frequency; P =0.506) did not significantly differ. During the final follow-up, sinus rhythm was maintained without antiarrhythmic drugs in 70.5% of the Cryo-PVI group and 73.4% of the HPSD-RFCA group ( P =0.567). No significant difference was found in the major complication rate between the two groups (3.8% versus 0.6%; P =0.066), but total procedure time was significantly shorter in the Cryo-PVI group (78.5±20.2 versus 124.5±37.1 minutes; P Conclusions: In patients with paroxysmal AF, the Cryo-PVI is an effective rhythm-control strategy with a shorter procedure time compared with the HPSD-RFCA. Registration: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT03920917.

Background: It is unclear whether atrial fibrillation (AF) catheter ablation (AFCA) improves the left ventricular (LV) diastolic function. We evaluated the 1-year change in the H2FPEF score, which reflects the degree of LV diastolic function, after AFCA among patients with a normal LV systolic function.Methods and Results: We included 1,471 patients (30.7% female, median age 60 years, paroxysmal-type AF 68.6%) who had available H2FPEF scores at baseline and at 1-year after AFCA to evaluate the 1-year change in the H2FPEF score (ΔH2FPEF score[1−yr]) after AFCA. Baseline high H2FPEF scores (≥6) were independently associated with the female sex, left atrium (LA) diameter, LV mass index, pericardial fat volume, and a low estimated glomerular filtration rate. One year after AFCA, decreased ΔH2FPEF scores[1−yr] were associated with baseline H2FPEF scores of ≥6 [OR, 4.19 (95% CI, 2.88–6.11), p < 0.001], no diabetes [OR, 0.60 (95% CI, 0.37–0.98), p = 0.04], and lower pericardial fat volume [OR, 0.99 (95% CI, 0.99–1.00), p = 0.003]. Increased ΔH2FPEF scores[1−yr] were associated with a baseline H2FPEF score of p < 0.001] and sustained AF after a recurrence within 1 year [SustainAF[1−yr]; OR, 1.89 (95% CI, 1.01–3.54), p = 0.048]. Throughout a 56-month median follow-up, an increased ΔH2FPEF score[1−yr] resulted in a poorer rhythm outcome of AFCA (at 1 year, log-rank p = 0.003; long-term, log-rank p = 0.010).Conclusions: AFCA appears to improve LV diastolic dysfunction. However, SustainAF[1−yr] may contribute to worsening LV diastolic dysfunction, and it was shown by increased ΔH2FPEF scores[1−yr], which was independently associated with higher risk of AF recurrence rate after AFCA.Clinical Trial Registration:ClinicalTrials.gov Identifier: NCT02138695.

Objectives This study explored whether complete electrical isolation of the left atrial (LA) posterior wall improves the rhythm outcome of catheter ablation of persistent atrial fibrillation (AF). Background Although the STAR AF2 (Substrate and Trigger Ablation for Reduction of Atrial Fibrillation Trial Part II) proved no additional benefit of empirical extra-pulmonary vein (PV) LA ablation, the long-term recurrence rate after circumferential PV isolation (CPVI) alone remains high. Methods We randomly assigned 217 patients with persistent AF (83.1% men, age 58.7 ± 10.8 years, 73.3% long-standing persistent AF) to ablation with CPVI alone (CPVI group) or CPVI with a POsterior wall Box Isolation (POBI group). The endpoint of the POBI group was the elimination of the posterior atrial potentials by roof and posterior inferior lines and touch-up focal ablation. Results After a mean follow-up of 16.2 ± 8.8 months, the clinical recurrence rate did not significantly differ between the 2 groups (23.8% vs. 26.5%; p = 0.779) in the CPVI and POBI groups. The recurrence rate for atrial tachycardias (16.0% vs. 11.1%; p = 0.913) and cardioversion rates (6.7% vs. 13.7%; p = 0.093) to control clinical recurrences also did not significantly differ between the 2 groups. At the final follow-up, sinus rhythm was maintained without antiarrhythmic drug in 50.5% and 55.9% in the CPVI and POBI groups, respectively (p = 0.522). No significant difference was found in the major complication rates between the 2 groups, but the total ablation time was significantly longer in the POBI group (4,289 ± 1,837 s vs. 5,365 ± 2,358 s; p Conclusions In patients with persistent AF, an empirical complete POBI did not improve the rhythm outcome of catheter ablation or influence the type of recurrent atrial arrhythmia. (Comparison of Circumferential Pulmonary Vein Isolation Alone Versus Linear Ablation in Addition to Circumferential Pulmonary Vein Isolation for Catheter Ablation in Persistent Atrial Fibrillation: Prospective Randomized Controlled Trial; NCT02721121).

Background/Aims Atrial arrhythmia (AA) occasionally occurs after lung transplantation (LT); however, risk factors for AA and their impact on clinical outcomes are inconsistent. We aimed to investigate the incidence, predisposing factors, and clinical outcomes of AA after LT. Methods We retrospectively evaluated 153 consecutive patients who underwent LT between January 2010 and August 2016. An AA episode was defined as a documented atrial fibrillation (AF), atrial flutter, or atrial tachycardia on 12-lead electrocardiography or episodes lasting ≥ 30 seconds on telemetry monitoring. Results The mean follow-up time was 22.0 ± 19.1 months. Postoperative AA occurred in 46 patients (30.1%) after LT. Patients with postoperative AA were older, had larger body surface area, and had an increased incidence of paroxysmal AF prior to transplantation, idiopathic pulmonary fibrosis, and postoperative tracheostomy than patients without AA. Preoperative right atrial pressure (RAP) (odds ratio [OR], 1.19; p = 0.005) and longer periods of mechanical ventilation (OR, 1.03; p = 0.008) were found to be independent risk factors for AA after surgery. Development of AA was a significant predictor of long-term overall mortality (hazard ratio, 2.75; p = 0.017). Conclusions Patients with elevated preoperative RAP and long-term ventilator care had a higher risk of AA after LT. Further, AA after LT was associated with poor long-term survival.

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.

Although exercise prevents cardiovascular disease and mortality, vigorous exercise and endurance athletics can cause atrial fibrillation (AF). However, no large cohort study has assessed the relationship between physical activity and AF in the general population. We assessed the effect of physical activity at different energy expenditures on the incidence of AF. We studied 501,690 individuals without pre-existing AF (mean age, 47.6 ± 14.3 years; 250,664 women [50.0%]) included in the Korean National Health Insurance Service database. The physical activity level was assessed using a standardized self-reported questionnaire at baseline. During a median follow-up of 4 years, 3,443 participants (1,432 women [41.6%]) developed AF. The overall incidence of AF at follow-up was 1.79 per 1,000 person-years. The subjects who met the recommended physical activity level (500–1,000 metabolic equivalent task [MET] minutes/week) had a 12% decreased AF risk (adjusted hazard ratio [HR]: 0.88, 95% confidence interval [CI]: 0.80–0.97), but not the insufficiently (1–500 MET-minutes/week; HR: 0.94, 95% CI: 0.86–1.03) and highly active subjects (≥1,000 MET-minutes/week; HR: 0.93, 95% CI: 0.85–1.03). The recommended minimum key target range of physical activity level was associated with the maximum benefit for reduced AF risk in the general population. The dose-response relationship between physical activity level and AF risk showed a U-shaped pattern. Although exceeding the key target range attenuated this benefit, it did not increase the AF risk beyond that during inactivity.

Although the hemodynamic burden and structural substrate contribute to valvular atrial fibrillation (VAF) mechanisms, the role of catheter ablation has rarely been reported. We investigated the clinical characteristics, mapping findings, and long-term rhythm outcomes after catheter ablation of hemodynamically corrected VAF.We compared 77 patients with VAF (46.8% male, 52.7±8.8 years old, 46.8% paroxysmal AF, 24.7% with maze procedures) and 2244 patients with non-VAF (NVAF) who underwent catheter ablation. Among the VAF patients, 44 (57.1%) had mechanical valve AF (MV-AF) and 33 (42.9%) underwent a prior mitral valvuloplasty (MVP-AF). We analyzed the catheter ablation rhythm outcomes for MV-AF and MVP-AF.The left atrial (LA) diameter was greater (p0.001), LA voltage lower (p0.001), and procedure-related complication rate higher (mainly sinus node dysfunction, p=0.004) for VAF than NVAF. During 70.2±1.8 months of follow-up, the rhythm outcome of VAF did not significantly differ from that of NVAF after catheter ablation (log rank p=0.399), even after excluding patients with maze procedures (log rank p=0.629). The clinical recurrence rates did not differ between the MV-AF and MVP-AF groups (log rank p=0.244), or between patients with prior maze procedures and those without (log rank p=0.651). The main conduction recovery sites of previous maze procedures were the perimitral (84.2%) and cavotricuspid isthmus (84.2%) areas, and recurrence mechanisms were macroreentry (63.2%) and focal/microreentry (26.3%) at scar border zones.Although hemodynamically corrected VAF was associated with advanced LA remodeling, the rhythm outcome did not significantly differ from that of NVAF after catheter ablation.

Background Few studies have investigated the prognostic value of cardiac implantable electronic device (CIED)-detection of sleep-disordered breathing (SDB) for risk stratification of cardiovascular events. In the Device-Detected CArdiac Tachyarrhythmic events and Sleep-disordered breathing (DEDiCATES) study, we aim to determine whether device-detected SDB events are associated with increased risk of cardiac arrhythmias or other cardiovascular outcomes. Methods and design Six-hundred patients (300 patients with low-voltage pacing devices and 300 with high-voltage defibrillator devices) who have dual chamber CIEDs with AP Scan™ function (Boston Scientific Inc., Marlborough, MA, USA) are planned to be enrolled in this study. AP Scan reports the average number of sleep disturbance events per hour per night in the form of a Respiratory Disturbance Index (RDI). The daily RDI values are to be used for quantitative measurement of the severity and burden of SDB. CIED-detected atrial high rate episodes (AHREs) and clinical atrial tachyarrhythmia will be assessed as the primary outcomes over a follow-up period of 2 years. Correlations between CIED-detected SDB and AHRE burdens will be analyzed. The secondary outcomes are CIED-detected or clinical ventricular arrhythmic events, stroke, heart failure hospitalization, mortality, and quality of life. Conclusion This study will determine the prognostic value of automated diagnostic function of CIED for SDB, which will help to improve the cardiovascular prognoses of CIED patients by enabling convenient and accurate assessments of SDB events.

목적: 심방세동과 말기 콩팥병이 동반된 환자에서 항응고제의 치료는 아직 명확히 정립되지 않았다. 본 연구에서는 이러한 환자에서 와파린과 항혈전제의 효과 및 안정성을 비교해 보았다. 방법: 본 연구에서는 2004년 1월부터 2014년 7월까지 단일기관에서 심방세동과 말기 콩팥병을 진단받은 총 256명의 환자 중 와파린(n = 53)이나 항혈전제(n = 105)를 투여받는 CHA2DS2-VASc 점수 1점 이상의 158명(나이, 63.7 ± 12.2세; 남성, n = 103)이 본 연구에 포함되었다. 결과: 총 추적 조사 기간 동안(31.0 ± 29.4개월), 10건의 혈전색전 사건과 29건의 주요 출혈 사건이 발생하였다. 혈전색전 사건의 발생은 와파린군과 항혈전제군 사이에 유의한 차이를 보이지 않았다(1.9%와 8.6%, p = 0.166). 주요 출혈 사건의 발생은 항혈전제군보다 와파린군에서 유의하게 높은 발생률을 보였다(32.1%와 11.4%, p = 0.002). 와파린의 사용은 주요 출혈 사건 발생을 증가시키는 주요한 위험인자였으나(HR, 3.44; 95% CI, 1.60-7.36; p = 0.001) 혈전색전 사건의 발생의 감소와는 통계적으로 유의한 관계를 보이지 않았다(HR, 0.34; 95% CI, 0.04-2.70; p = 0.306). 결론: 심방세동과 말기 콩팥병을 동반한 환자에서 와파린의 사용은 항혈전제와 비교하였을 때 출혈 사건의 위험을 증가시킨다. 결론: 심방세동과 말기 콩팥병을 동반한 환자에서 와파린의 사용은 항혈전제와 비교하였을 때 출혈 사건의 위험을 증가시킨다.

To assess the effects of body mass index (BMI) variability on the incidence of new-onset atrial fibrillation (AF), stroke, cardiovascular (CV) risk factors, and CV outcomes in a general Asian population.Data from the National Health Insurance Service-Health Screening cohort in Korea were used: 171,324 patients without AF were included, and BMI measurements occurred biennially from January 1, 2002, through December 31, 2009. Patient outcomes were followed through 2013. The BMI intraindividual variability between visits was measured.During mean ± SD follow-up of 47.4±3.9 months, 1959 patients (1.1%) developed new-onset AF. Overweight or obesity (BMI ≥25) had a greater risk of new-onset AF compared with BMI of 20 to 22.5, with a hazard ratio (HR) of 1.24 (95% CI, 1.10-1.41; P.001). In underweight or normal-weight participants (initial BMI25), a 1-kg/mIn the underweight and normal-weight Asian population, BMI variability, especially weight gain, was related to increased risk of new-onset AF and myocardial infarction. Avoiding weight gain is important to improve CV outcomes.

Background Chronic anticoagulation is recommended in patients with hypertrophic cardiomyopathy (HCM) and atrial fibrillation (AF). Non-vitamin K antagonist oral anticoagulants (NOACs) are an alternative to warfarin, but there are limited data to support their use in patients with HCM and AF. We sought to compare thromboembolic events, bleeding, and mortality between NOAC and warfarin in patients with HCM and AF. Methods From the Korean National Health Insurance Service database during the period from January 1, 2011, to December 31, 2016, we identified a warfarin-treated group of patients with HCM and AF (n = 955) who were compared with a 1:2 propensity-matched NOAC treated group (n = 1,504). Results After a median follow-up of 16 months, the incidence rates of ischemic stroke and major bleeding were similar between NOAC- and warfarin-treated patients with HCM and AF. NOAC-treated patients had lower incidence rates for all-cause mortality (5.11 and 10.13 events per 100 person-years for NOAC and warfarin groups) and the composite of fatal cardiovascular events (0.77 and 1.80 events per 100 person-years). Compared with warfarin, use of NOACs was associated with a significantly lower risk of all cause-mortality (hazard ratio, 0.43; 95% CI, 0.32-0.57) and composite fatal cardiovascular events (hazard ratio, 0.39; 95% CI, 0.18-0.82). Conclusions Compared with warfarin, patients with HCM and AF on NOACs had similar stroke and major bleeding risks, but lower all-cause mortality and composite fatal cardiovascular events. Our data suggest that patients with HCM and AF can be safely and effectively treated with NOACs.

Funding Acknowledgements Type of funding sources: None. Introduction Although high-power short-duration (HPSD) radiofrequency (RF) energy is commonly utilized in atrial fibrillation (AF) catheter ablation (CA), its efficacy, safety, and autonomic neural effects have not yet been evaluated in a large patient number. We compared HPSD-AFCA and conventional power (ConvP)-AFCA after propensity score matching. Methods Among 3,221 consecutive AF ablation patients, we included 1,720 patients (74.4% male, 59 ± 10 years old, 56.5% paroxysmal type) who underwent AFCA after propensity score matching: 430 in 50∼60W HPSD group vs. 1,290 in the ConvP group. We evaluated the procedural factors, complication risk, rhythm outcome, and 3-month heart rate variability (HRV) between the two groups and subgroups. Results Procedure times were significantly shorter in the HPSD group (p Conclusions HPSD-AFCA significantly shortened the procedure time with similar rhythm outcomes, complication risks, and autonomic neural effects as ConvP-AFCA, regardless of the AF type or ablation lesion set. Abstract Figure.

Funding Acknowledgements Type of funding sources: None. Introduction Although atrial fibrillation (AF) catheter ablation is effective for rhythm control, in some patients it is hard to maintain sinus rhythm in spite of repeated AF catheter ablation (AFCA) procedures and anti-arrhythmic drugs (AADs). We explored the pre-procedural predictors for poor responders to AFCA and tested whether artificial intelligence (AI) assists the prediction of poor responders in the independent cohort by determining the invasive parameters. Methods Among 1,214 patients who underwent AFCA and regular rhythm follow-up for 56.2 ± 33.8 months (59 ± 11 years, 73.5% male, 68.6% paroxysmal AF), we differentiated 92 poor responders defined as those with sustained AF despite repeat AFCAs, AADs, or electrical cardioversion. Using the Youden index, we identified advanced LA remodeling with lower LA voltage under 1.109mV. AI model, which was derived from development cohort using medical record, was applied to predict LA voltage Results The patients with lower LA voltage under 1.109mV showed significantly poorer rhythm outcomes (Log-rank p Conclusions The patients with advanced atrial remodeling with low LA voltage, which can be predicted by an AI, showed significantly higher recurrence of AF after AFCA with AADs or cardioversion. AI may assist to select these poor responder patients before the AFCA procedure. Abstract Figure.

Background: The efficacy of antiarrhythmic drugs (AAD) can vary in patients with atrial fibrillation (AF), and the PITX2 gene affects the responsiveness of AADs. We explored the virtual AAD (V-AAD) responses between wild-type and PITX2+/−-deficient AF conditions by realistic in silico AF modeling.Methods: We tested the V-AADs in AF modeling integrated with patients' 3D-computed tomography and 3D-electroanatomical mapping, acquired in 25 patients (68% male, 59.8 ± 9.8 years old, 32.0% paroxysmal type). The ion currents for the PITX2+/− deficiency and each AAD (amiodarone, sotalol, dronedarone, flecainide, and propafenone) were defined based on previous publications.Results: We compared the wild-type and PITX2+/− deficiency in terms of the action potential duration (APD90), conduction velocity (CV), maximal slope of restitution (Smax), and wave-dynamic parameters, such as the dominant frequency (DF), phase singularities (PS), and AF termination rates according to the V-AADs. The PITX2+/−-deficient model exhibited a shorter APD90 (p < 0.001), a lower Smax (p < 0.001), mean DF (p = 0.012), PS number (p < 0.001), and a longer AF cycle length (AFCL, p = 0.011). Five V-AADs changed the electrophysiology in a dose-dependent manner. AAD-induced AFCL lengthening (p < 0.001) and reductions in the CV (p = 0.033), peak DF (p < 0.001), and PS number (p < 0.001) were more significant in PITX2+/−-deficient than wild-type AF. PITX2+/−-deficient AF was easier to terminate with class IC AADs than the wild-type AF (p = 0.018).Conclusions: The computational modeling-guided AAD test was feasible for evaluating the efficacy of multiple AADs in patients with AF. AF wave-dynamic and electrophysiological characteristics are different among the PITX2-deficient and the wild-type genotype models.

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 p p p

Introduction Risk for stroke and systemic embolism (SE) in patients with atrial fibrillation (AF) and heart failure (HF) with mid-range (mr) ejection fraction (EF) is not well known. Methods Total 10,780 patients (age, 66.8±11.1 years; men, 64.7%) with AF were included in a prospective, multicenter AF registry. The patients were grouped into four according to HF type: no-HF, HF with preserved EF (HFpEF), HFmrEF, and HF with reduced EF (HFrEF). Baseline characteristics, cumulative incidence and hazard ratios for stroke/SE, major bleeding, and mortality were compared among the four groups. Results Proportion of patients with HF was 10.3%: HFpEF, 43.7%; HFmrEF, 23.6%; HFrEF, 32.7%. CHA2DS2-VASc score was significantly higher in the HFpEF, HFmrEF, and HFrEF groups than the no-HF group (4.0±1.7, 3.8±1.8, 3.5±1.8, and 2.5±1.6, respectively). Oral anticoagulants were administered in 83.6% of patients with CHA2DS2-VASc score ≥1. Annual incidence of stroke/SE was 2.0% in HFpEF group, 0.6% in HFmrEF group, 1.1% in HFrEF group, and 0.7% in no-HF group for 23.0±9.5 months of follow-up period. Cumulative incidence of stroke/SE was significantly higher in the HFpEF group than the no-HF and HFmrEF groups (p Conclusions Risk for stroke/SE is highest in HFpEF and lowest in HFmrEF in patients with AF and HF. Figure 1 Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): National Research Foundation of Korea

Background Persistent atrial fibrillation (PeAF) can change to paroxysmal AF (PAF) after antiarrhythmic drug medication and cardioversion. Purpose We investigated whether electrical posterior box isolation (POBI) may improve rhythm outcome of catheter ablation in those patient group. Methods We prospectively randomized 114 patients with PeAF to PAF (male 75%, 59.8±9.9 years old) to circumferential pulmonary vein isolation (CPVI) alone group (n=57) and additional POBI group (n=57). The primary end-point was AF recurrence after a single procedure, and the secondary end-point was a recurrence pattern, cardioversion rate, and the response to antiarrhythmic drugs (AADs). Results After a mean follow-up of 22.5±9.4 months, the clinical recurrence rate did not significantly differ between the two groups (29.8% vs. 28.1%, p=0.836; log rank p=0.815) The recurrence rate for atrial tachycardias (17.6% vs. 43.8%, p=0.141) was higher in POBI group, but the cardioversion rates (13.5% vs. 8.5%, p=0.434) were not significantly different between two groups. At the final follow-up, sinus rhythm was maintained without antiarrhythmic drug in 52.6% in CPVI group and 59.7% of POBI group (p=0.452). No significant difference was found in the major complication rates between the two groups (5.3% vs. 1.8%, p=0.618), but the total ablation time was significantly longer in the POBI group (4397±842 sec vs. 5337±1517 sec, p Conclusion In patients with persistent AF converted to paroxysmal AF by AAD, the addition of POBI to CPVI did not improve the rhythm outcome of catheter ablation nor influence overall safety. Funding Acknowledgement Type of funding source: None

Background It is unclear whether catheter ablation is beneficial in frail patients with AF. Purpose This study aimed to evaluate whether catheter ablation reduces death and other outcomes in real-world frail patients with atrial fibrillation (AF). Methods Out of 801,710 patients with AF in the Korean National Health Insurance Service database from 2006 to 2015, 1,411 frail patients underwent AF ablations. The Hospital Frailty Risk Score were calculated retrospectively. Inverse probability of treatment weighting (IPTW) was used to categorize ablation and non-ablation frail groups. Results After IPTW, the two cohorts had similar background characteristics. During a median follow-up of 4.7 years (interquartile range: 2.2–7.8), the risk of death in frail patients with ablations was reduced by 65% compared to frail patients without ablations (2.0 and 6.4 per 100 person-years, respectively; hazard ratio [HR] 0.35; 95% confidence interval [CI] 0.25–0.50; P Conclussion Ablation may be associated with lower incidences of death, heart failure, and acute myocardial infarction in real-world frail patients with AF, supporting the role of AF ablation in these patients. The effect of frailty risk on the outcome of ablation should be evaluated in further studies. Funding Acknowledgement Type of funding source: None

Background Although atrial fibrillation (AF) burden was known to be related to the risk of ischemic stroke (IS), clinical evidence regarding intracranial hemorrhage (ICH) or comparison of the patients after AF catheter ablation (AFCA) and the non-AF population are limited. Objective We explored the risks of IS and ICH after AFCA or medical therapy (Med) in the AF population and the matched non-AF population. Methods We compared 1,629 with AFCA (Yonsei AF cohort), 3,258 with Med (Korean National Health Insurance Sharing Service [KNHISS] database), and 3,258 non-AF population (KNHISS database) after 1:2:2 propensity-score match in terms of clinical characteristics and medications (57±12 years old, 22.1% female). IS and ICH were determined by ICD code, brain imaging, and hospital admission in Med and non-AF groups. All AFCA patients underwent regular rhythm follow-up, and the medications including antithrombotic therapies were evaluated for 52±23 months. Results 1. Among AFCA group, the annualized IS rate was significantly higher in the patients with sustaining recurrence of AF/atrial tachycardia (AT) after the last ablation procedure than those remaining in sinus rhythm (SR) (0.87% vs. 0.24%, p=0.017; HR 4.87 [1.36–17.49], p=0.015; log rank p=0.003). 2. The annualized ICH rate was 0% in SR group and 0.06% in sustaining recurrent AF/AT group after AFCA (p=0.361, log rank p=0.545). 3. The annualized IS rate was significantly higher in Med group (1.09%) than in AFCA group (0.30%, p 4. The annualized ICH rates were 0.17% in Med group, 0.06% AFCA group (p=0.023, log rank p=0.042 vs. Med; p=0.172, log rank p=0.193 vs. non-AF), and 0.12% in non-AF group (p=0.226, log rank p=0.241 vs. Med), respectively. Conclusion Post-procedural AF burden influence the risk of IS. AFCA significantly reduces the risks of both IS and ICH to the extent of non-AF population compared to Med group. Funding Acknowledgement Type of funding source: None

Background AF is a progressive disease, and the mechanism underlying long-term recurrence after AFCA is unclear. Purpose This study explored the potential mechanisms of long-term recurrence (LTR) of atrial fibrillation (AF) 3-years after AF catheter ablation (AFCA). Methods Among 2,209 consecutive patients who underwent AFCA, 1,325 (59±11 years, 72.5% male) who underwent regular rhythm follow-ups for >3-years were enrolled. Among them, 659 patients remained in sinus rhythm (SR), 327 recurred after 3–12 months (short-term recurrence; STR), 235 after 1–3 years (mid-term recurrence; MTR), and 104 after 3-years (long-term recurrence; LTR). Two hundred eighteen recurrent patients underwent repeat procedures: 112, 80, and 26 in the STR, MTR, and LTR groups, respectively. Results The pre-ablation left atrial (LA) dimensions were larger in the STR (p Conclusions The LTR group had a similar baseline LA size and significantly lower LA voltage than the SR group. In the repeat procedures, the LTR group had fewer reconnected PVs, but extra-PV triggers were more common than in the STR and MTR groups. Funding Acknowledgement Type of funding source: Public Institution(s). Main funding source(s): Ministry of Health and Welfare, Ministry of Science, ICT & Future Planning (MSIP).

Background Predictors are not well known for long-lasting sinus rhythm after atrial fibrillation catheter ablation (AFCA). Purpose We investigated the pre-procedural clinical factors associated with the patients with 5-year long-term atrial fibrillation (AF) free after AFCA. Methods Among 2,085 patients who underwent de novo AFCA, 934 patients (58±11 years, 73.1% male, 66.0% paroxysmal AF), who underwent guidelines-based rhythm follow-up longer than 5-years, were included in this study. We compared 340 patients who never showed AF recurrence for 5-years and 594 patients with AF/ atrial tachycardia (AT) recurrence at least a single episode. Cut-off values of pericardial fat volume and electrocardiogram (ECG) parameters were obtained by Youden index. Results 1. The patients with AF-free for 5-years (AF-Free-5yrs) had higher proportion of paroxysmal AF (p Conclusions Pericardial fat volume ( Funding Acknowledgement Type of funding source: None

Background This study aimed to investigate the cardiac manifestations of coronavirus disease 2019 (COVID-19). Methods From February to March 2020, we prospectively and retrospectively enrolled consecutive patients diagnosed with COVID-19. Patient's data such as the demographic characteristics, symptoms, vital signs, laboratory and radiologic findings, electrocardiographic, and echocardiographic data, including the global longitudinal strain (GLS) of both ventricles, were obtained. Results Forty patients (median age, 58 years; 50% men) were enrolled in the initial analysis. Patients were classified into severe and nonsevere groups based on the current guidelines. The 13 patients in the severe group were significantly older, had a greater prevalence of bilateral pneumonia and leukocytosis, and higher aspartate transaminase levels than patients in the nonsevere group. Patients in the severe group had a slightly lower left ventricular ejection fraction (LVEF) than those in the nonsevere group (median [interquartile range], 61.0% [58.5%, 62.3%] vs. 66.7% [60.6%, 69.8%], P = 0.015). In a subgroup of 34 patients in whom GLS could be analyzed, patients in the severe group had a significantly impaired left ventricular GLS (LVGLS) than those in the nonsevere group (−18.1% [−18.8%, −17.1%] vs. −21.7% [−22.9%, −19.9%], P = 0.001). There were no significant differences in total wall (RVGLStotal, −19.3% [−23.9%, −18.4%] vs. −24.3% [−26.0%, −22.6%], P = 0.060) and free wall (RVGLSfw, −22.7% [−27.2%, −18.6%] vs. −28.8% [−30.4%, −24.1%], P = 0.066) right ventricle GLS (RVGLS). Conclusion Patients with severe COVID-19 had lower LVEF and LVGLS. RVGLS was not different between patients with severe and nonsevere COVID-19., Graphical Abstract

Background: Short QT syndrome is a rare, inherited channelopathy associated with sudden cardiac arrest (SCA) but characteristics and prognosis of short QT interval (SQTI) in Asian patients remain unclear. This study aimed to determine clinical characteristics of and outcomes in patients with SQTI in an Asian population.Methods: Consecutive patients with SQTI were recruited. SQTI was defined as a Bazett’s formula-corrected QT interval (QTc) ≤340 ms in serial electrocardiograms. Age- and sex-matched patients with a normal QTc and without overt cardiovascular disease were included at a 1:4 ratio. Clinical and ECG features and outcomes were compared between patients with and without SQTI. Results: Thirty-four patients with SQTI [age, 23.5 (21–30.5) years; 31 male] were followed up for 4.8 (2.0–7.8) years. Early repolarization, tall T wave, and U wave were significantly more frequent in patients with SQTI than the patients without SQTI. QT dispersion [44.0 (28.0–73.0) vs. 20.0 (12.0–35.0) ms, PPP=0.030) and ventricular arrhythmia (VA)/SCA (8.7% vs 0%, P=0.007) were significantly more frequent in patients with SQTI than patients without SQTI. SQTI was significantly associated with AF [odds ratio, 5.911; 95% confidence interval, 1.257–27.808; P=0.025] and VA/SCA.Conclusions: In this Asian population, SQTI was associated with AF and VA/SCA.

Background: Persistent atrial fibrillation (AF) can change to paroxysmal AF after antiarrhythmic drug medication and cardioversion. We investigated whether electrical posterior box isolation (POBI) may improve rhythm outcome of catheter ablation in those patient groups. Methods: We prospectively randomized 114 patients with persistent AF to paroxysmal AF (men, 75%; 59.8±9.9 years old) to circumferential pulmonary vein isolation (CPVI) alone group (n=57) and additional POBI group (n=57). Primary end point was AF recurrence after a single procedure, and secondary end points were recurrence pattern, cardioversion rate, and response to antiarrhythmic drugs. Results: After a mean follow-up of 23.8±10.2 months, the clinical recurrence rate did not significantly differ between the CPVI alone and additional POBI group (31.6% versus 28.1%; P =0.682; log-rank P =0.729). The recurrences as atrial tachycardias (5.3% versus 12.3%; P =0.134) and cardioversion rates (5.3% versus 10.5%; P =0.250) were not significantly different between the CPVI and POBI groups. At the final follow-up, sinus rhythm was maintained without antiarrhythmic drug in 52.6% of CPVI group and 59.6% of POBI group ( P =0.450). No significant difference was found in major complication rates between the two groups (5.3% versus 1.8%; P =0.618), but the total ablation time was significantly longer in the POBI group (4187±952 versus 5337±1517 s; P Conclusions: In patients with persistent AF converted to paroxysmal AF by antiarrhythmic drug, the addition of POBI to CPVI did not improve the rhythm outcome of catheter ablation or influence overall safety, while leading to longer ablation time. Registration: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT02176616.