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Background: Artificial intelligence (AI)-enabled sinus rhythm (SR) electrocardiogram (ECG) interpretation can aid in identifying undiagnosed paroxysmal atrial fibrillation (AF) in patients with embolic stroke of undetermined source (ESUS)., Objective: The purpose of this study was to assess the efficacy of an AI model in identifying AF based on SR ECGs in patients with ESUS., Methods: A transformer-based vision AI model was developed using 737,815 SR ECGs from patients with and without AF to detect current paroxysmal AF or predict the future development of AF within a 2-year period. Probability of AF was calculated from baseline SR ECGs using this algorithm. Its diagnostic performance was further tested in a cohort of 352 ESUS patients from 4 tertiary hospitals, all of whom were monitored using an insertable cardiac monitor (ICM) for AF surveillance., Results: Over 25.1-month follow-up, AF episodes lasting ≥1 hour were identified in 58 patients (14.4%) using ICMs. In the receiver operating curve (ROC) analysis, the area under the curve for the AI algorithm to identify AF ≥1 hour was 0.806, which improved to 0.880 after integrating the clinical parameters into the model. The AI algorithm exhibited greater accuracy in identifying longer AF episodes (ROC for AF ≥12 hours: 0.837, for AF ≥24 hours: 0.879) and a temporal trend indicating that the AI-based AF risk score increased as the ECG recording approached the AF onset (P for trend <.0001)., Conclusions: Our AI model demonstrated excellent diagnostic performance in predicting AF in patients with ESUS, potentially enhancing patient prognosis through timely intervention and secondary prevention of ischemic stroke in ESUS cohorts., Competing Interests: Disclosures Dr Joonghee Kim developed the algorithm and founded a start-up company ARPI Inc. He is the CEO of the company. Dr Youngjin Cho works for the company as a research director. All other authors have no conflicts of interest to disclose., (Copyright © 2024 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Background: Left atrial thrombus (LAT) formation is associated with thromboembolic events., Objective: To investigate the incidence and associated factors of LAT in patients with atrial fibrillation (AF) who had been receiving anticoagulation therapy for more than 4 weeks, and to develop a prediction model using clinical and echocardiographic features., Methods: Medical records of 1,122 patients with AF (mean age, 59.4 ± 11.0 years, 58.3% male) who were on anticoagulation more than 4 weeks and underwent transesophageal echocardiography (TEE) were evaluated. The main outcome was the presence of LAT on TEE., Results: Warfarin and non-vitamin K oral anticoagulants were used in 74.4% and 25.6% of the patients at the time of examination, respectively. LAT was present in 60 patients (5.3%). Presence of LAT on TEE was associated with age ≥ 75 years (odds ratio [OR] 2.13 [95% confidence interval, 0.94-4.58]), persistent/permanent AF (OR 2.61 [1.42-4.93]), CHA 2 DS 2 -VASc score ≥ 3 points (OR 1.91 [1.05-3.48]), left ventricular ejection fraction < 40% (OR 2.35 [1.07-4.81]), and severe left atrial enlargement (OR 3.52 [1.89-6.79]). The presence of moderate-to-severe mitral regurgitation was associated with a lower risk of LAT (OR 0.13 [0.04-0.34]). A scoring system composed of the aforementioned predictors showed excellent discrimination performance (area under the curve 0.791 [95% CI, 0.727-0.854])., Conclusions: LAT was present in a considerable number of patients who were already receiving anticoagulation therapy. A prediction model that combines clinical and echocardiographic predictors could be useful in distinguishing patients who require imaging evaluations before left atrial intervention., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany.)

Introduction: The impact of early recurrence of atrial tachyarrhythmia (ERAT) within the 90-day blanking period on long-term outcomes in atrial fibrillation (AF) patients undergoing cryoballoon ablation (CBA) is controversial. This study aimed to assess the relationship between ERAT and late recurrence of atrial tachyarrhythmia (LRAT) post-CBA., Methods: Utilizing data from a multicenter registry in Korea (May 2018 to June 2022), we analyzed the presence and timing of ERAT (<30, 30-60, and 60-90 days) and its association with LRAT risk after CBA. LRAT was defined as any recurrence of AF, atrial flutter, or atrial tachycardia lasting more than 30 s beyond the 90 days., Results: Out of 2636 patients, 745 (28.2%) experienced ERAT post-CBA. Over an average follow-up period of 21.2 ± 10.3 months, LRAT was observed in 874 (33.1%) patients. Patients with ERAT had significantly lower 1-year LRAT freedom compared to those without ERAT (42.6% vs. 85.5%, p < .001). Multivariate analysis identified ERAT as a potential predictor of LRAT, with a hazard ratio (HR) of 3.98 (95% confidence interval [CI], 3.47-4.57). Significant associations were noted across all examined time frames (HR, 3.84; 95% CI, 3.32-4.45 in <30 days, HR, 5.53; 95% CI, 4.13-7.42 in 30-60 days, and HR, 4.29; 95% CI, 3.12-5.89 in 60-90 days). This finding was consistently observed across all types of AF., Conclusion: ERAT during the 90-day blanking period strongly predicts LRAT in AF patients undergoing CBA, indicating a need to reconsider the clinical significance of this period., (© 2024 The Author(s). Journal of Cardiovascular Electrophysiology published by Wiley Periodicals LLC.)

Background: Clinical outcomes after catheter ablation (CA) or pacemaker (PM) implantation for the tachycardia-bradycardia syndrome (TBS) has not been evaluated adequately. We tried to compare the efficacy and safety outcomes of CA and PM implantation as an initial treatment option for TBS in paroxysmal atrial fibrillation (AF) patients., Methods: Sixty-eight patients with paroxysmal AF and TBS (mean 63.7 years, 63.2% male) were randomized, and received CA (n = 35) or PM (n = 33) as initial treatments. The primary outcomes were unexpected emergency room visits or hospitalizations attributed to cardiovascular causes., Results: In the intention-to-treatment analysis, the rates of primary outcomes were not significantly different between the two groups at the 2-year follow-up (19.8% vs. 25.9%; hazard ratio (HR) 0.73, 95% confidence interval (CI) 0.25-2.20, P = 0.584), irrespective of whether the results were adjusted for age (HR 1.12, 95% CI 0.34-3.64, P = 0.852). The 2-year rate of recurrent AF was significantly lower in the CA group compared to the PM group (33.9% vs. 56.8%, P = 0.038). Four patients (11.4%) in the CA group finally received PMs after CA owing to recurrent syncope episodes. The rate of major or minor procedure related complications was not significantly different between the two groups., Conclusion: CA had a similar efficacy and safety profile with that of PM and a higher sinus rhythm maintenance rate. CA could be considered as a preferable initial treatment option over PM implantation in patients with paroxysmal AF and TBS., Trial Registration: KCT0000155., (© 2024. The Author(s).)

Objective: Tricuspid regurgitation (TR) is a progressive disease with high mortality and limited medical treatment options, and its association with atrial fibrillation (AF) has been documented. This study aimed to investigate whether successful rhythm control through catheter ablation for AF could reduce TR severity., Methods: A total of 106 patients with drug-refractory AF with moderate to severe secondary TR who underwent AF ablation were screened from a single-centre ablation registry. Echocardiographic parameter changes (pre-procedure vs 1 day/1 year post-procedure) were analysed. Holter monitoring was performed at 3/6/12 months to assess AF recurrence. The primary outcome was at least one grade TR reduction with its main determinants evaluated., Results: After excluding 36 patients (prior tricuspid valve surgery, intracardiac devices or insufficient data), 70 patients (aged 63.8±9.7 years, 50% female) were analysed. Of these, 17 (24.3%) had severe TR, 55 (78.6%) persistent AF and all restored sinus rhythm with catheter ablation. The primary outcome was achieved in 53 (75.7%) at 1-year assessment (73.6% of moderate and 82.4% of severe TR). There were significant decreases of vena contracta (6.1→3.2 mm) and tricuspid annular diameter (37.3→32.6 mm) at 1 year. Although 25 patients experienced AF recurrence within 1 year, 56 (80%) patients finally maintained sinus rhythm with medical treatment (87% in patients with TR reduction and 59% without). From the multivariate analysis, sinus rhythm maintenance was the most significant determinant of TR reduction (OR 8.3, 95% CI 1.8 to 37.4)., Conclusion: In patients with AF with moderate to severe TR, more than two-thirds of patients experienced reduced TR severity, with notable improvements in echocardiographic parameters. Sinus rhythm maintenance was associated with significant TR reduction., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: There are limited data on the efficacy and safety of direct oral anticoagulants (DOACs) in patients with atrial fibrillation with significant tricuspid regurgitation (TR), which can lead to hepatic dysfunction and intestinal malabsorption. We aimed to compare the efficacy and safety of DOACs and warfarin for patients with atrial fibrillation with significant (moderate to severe) TR., Methods and Results: A total of 1215 patients with significant TR and atrial fibrillation who were treated with warfarin (N=491) or DOACs (N=724) were retrospectively analyzed. The primary outcomes were ischemic stroke, systemic embolic events, and hospitalization for major bleeding. The secondary outcomes were intracranial hemorrhage, hospitalization for gastrointestinal bleeding, all-cause mortality, and a composite outcome. The median follow-up duration was 2.4 years. In the inverse probability treatment weighting-adjusted cohort, DOACs and warfarin had a similar risk for ischemic stroke and systemic embolic events (adjusted hazard ratio [aHR], 0.95 [95% CI, 0.67-1.36]; P =0.79) and major bleeding (aHR, 0.78 [95% CI, 0.57-1.06]; P =0.11). For the secondary outcomes, relative to warfarin, DOACs had a lower risk of intracranial hemorrhage and the composite outcome, and a comparable risk for gastrointestinal bleeding and all-cause mortality. In the subgroup analysis, the effects of DOACs on ischemic stroke and systemic embolic events were comparable to the effects of warfarin, even in patients with inferior vena cava plethora (increased right atrial pressure) or severe TR., Conclusions: In this study, relative to warfarin, DOACs demonstrated comparable efficacy for ischemic stroke and systemic embolic events and major bleeding, with a lower intracranial hemorrhage risk in patients with significant TR and atrial fibrillation, indicating their effectiveness and safety.

Introduction: Patients with atrial fibrillation-related stroke (AF-stroke) are prone to developing rapid ventricular response (RVR). We investigated whether RVR is associated with initial stroke severity, early neurological deterioration (END) and poor outcome at 3 months., Methods: We reviewed patients who had AF-stroke between January 2017 and March 2022. RVR was defined as having heart rate &gt;100 beats per minute on initial electrocardiogram. Neurological deficit was evaluated with National Institutes of Health Stroke Scale (NIHSS) score at admission. END was defined as increase of ≥2 in total NIHSS score or ≥1 in motor NIHSS score within first 72 h. Functional outcome was score on modified Rankin Scale at 3 months. Mediation analysis was performed to examine potential causal chain in which initial stroke severity may mediate relationship between RVR and functional outcome., Results: We studied 568 AF-stroke patients, among whom 86 (15.1%) had RVR. Patients with RVR had higher initial NIHSS score (p &lt; 0.001) and poor outcome at 3 months (p = 0.004) than those without RVR. The presence of RVR [adjusted odds ratio (aOR) = 2.13; p = 0.013] was associated with initial stroke severity, but not with END and functional outcome. Otherwise, initial stroke severity [aOR = 1.27; p = &lt;0.001] was significantly associated with functional outcome. Initial stroke severity as a mediator explained 58% of relationship between RVR and poor outcome at 3 months., Conclusion: In patients with AF-stroke, RVR was independently associated with initial stroke severity but not with END and functional outcome. Initial stroke severity mediated considerable proportion of association between RVR and functional outcome., (© 2023 S. Karger AG, Basel.)

The long-term effect of atrial fibrillation (AF) on the occurrence of significant tricuspid regurgitation (TR) has not been evaluated in depth yet. We aimed to evaluate the incidence and predictors of severe TR in AF patients without structural heart disease (SHD). In 27,797 patients with AF, after excluding those with severe TR, SHD, implanted cardiac device, and no available follow-up echocardiography, clinical data of 4,613 patients (63.0 ± 11.3 years old, 69.7% male) were evaluated. The primary outcome was the occurrence of severe TR on follow-up echocardiography. Severe TR developed in 164 patients (3.6%) during median follow-up of 2.9 years (interquartile range 1.2 to 5.3). Most of the severe TR (72.6%) developed as isolated TR progression, and the others were associated with SHD progression, most commonly mitral regurgitation (68.9%). Severe TR predominantly occurred in older female patients and those with heart failure (HF), chronic kidney disease, persistent AF (PeAF), larger LA, and a higher degree of baseline TR. Specifically, 0.8%, 3.7%, and 34.4% of patients with no, mild, and moderate baseline TR, respectively, had progressed to severe TR (p <0.001). In multivariable analysis, moderate TR (hazard ratio [HR] 12.52 [8.99 to 17.42]), age ≥65 years (HR 2.25 [1.60 to 3.16]), previous HF (HR 1.79 [1.13 to 2.85]), PeAF (HR 1.54 [1.07 to 2.22]), and female gender (HR 1.52 [1.11 to 2.07]) were independent predictors. In conclusion, 3.6% of patients with AF developed severe TR over long-term follow-up, with moderate TR, age, previous HF, PeAF, and female gender as independent predictors., Competing Interests: Declaration of Competing Interest The authors have no conflicts of interest to declare., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background: The clinical benefits and risks of anticoagulation therapy in patients with chronic kidney disease (CKD) are still inconclusive. We describe the outcomes of patients with atrial fibrillation (AF) after anticoagulation therapy according to differences in creatinine clearance (CrCl). We also aimed to determine the patients who could benefit from anticoagulation therapy., Methods: This is a retrospective observational review of patients with AF who were managed at Asan Medical Center (Seoul, Korea) between January 1, 2006, and December 31, 2018. Patients were categorized into groups according to their baseline CrCl by Cockcroft-Gault equation and their outcomes were evaluated (CKD 1, ≥ 90 mL/min; CKD2, 60-89 mL/min; CKD3, 30-59 mL/min; CKD4, 15-29 mL/min; CKD 5, < 15 mL/min). The primary outcome was NACE (net adverse clinical events), defined as a composite of all-cause mortality, thromboembolic events, and major bleeding., Results: We identified 12,714 consecutive patients with AF (mean 64.6 ± 11.9 years, 65.3% male, mean CHA 2 DS 2 -VASc score 2.4 ± 1.6 points) between 2006 and 2017. In patients receiving anticoagulation therapy (n = 4447, 35.0%), warfarin (N = 3768, 84.7%) was used more frequently than NOACs (N = 673, 15.3%). There was a higher 3-year rate of NACE with renal function deterioration (14.8%, 18.6%, 30.3%, 44.0%, and 48.8% for CKD stages 1-5, respectively).The clinical benefit of anticoagulation therapy was most prominent in patients with CKD 1 (hazard ratio [HR] 0.49, 95% confidence interval [CI] 0.37-0.67), 2 (HR 0.64 CI 0.54-0.76), and 3 (HR 0.64 CI 0.54-0.76), but not in CKD 4 (HR 0.86, CI 0.57-1.28) and 5 (HR 0.81, CI 0.47-1.40). Among patients with CKD, the benefit of anticoagulation therapy was only evident in those with a high risk of embolism (CHA 2 DS 2 -VASc score ≥ 4, HR 0.25, CI 0.08-0.80)., Conclusion: Advanced CKD is associated with a higher risk of NACE. The clinical benefit of anticoagulation therapy was reduced with the increasing CKD stage., (© 2023. The Author(s).)

Hypertension is an independent risk factor for thromboembolic events in patients with atrial fibrillation (AF). However, the association between blood pressure (BP) control and thromboembolic events remains under-evaluated in patients with AF. We aimed to identify the relation between BP control and the risk of ischemic stroke and systemic embolism in hypertensive patients with AF. Data on 13,712 consecutive patients with AF (9,505 with and 4,207 without hypertension) were retrospectively analyzed. The hypertensive group was divided into quartiles according to the initial BP, linearly interpolated mean BP, variability independent of the mean of the BP, and time in therapeutic range (&lt;130 mm Hg for systolic BP [SBP] and &lt;80 mm Hg for diastolic BP) during follow-up. The primary outcome was ischemic stroke and systemic embolism. The mean follow-up duration of the study population was median 2.7 years (interquartile range 1.1 to 4.9 years), and the median number of BP measurements was 14 (interquartile range 6 to 25) times. Strictly controlled initial and interpolated mean BP and low variability in controlled BP (variability independent of the mean) were associated with a lower risk of ischemic stroke and systemic embolism for both SBP and diastolic BP. A similar risk was observed in patients with strictly controlled SBP (time in therapeutic range under 130 mm Hg &gt;94%) and those without hypertension. In conclusion, continuous and strict maintenance of SBP under 130 mm Hg with low variability at outpatient clinic follow-up reduces the risk of ischemic stroke and systemic embolism in patients with hypertension and AF., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Sodium-glucose cotransporter 2 (SGLT2) inhibitors have been shown to lower cardiovascular morbidity and mortality in patients with type 2 diabetes mellitus (T2DM) and high cardiovascular risks. Here, we aimed to evaluate the effect of SGLT2 inhibitors on major adverse cardiovascular events (MACE), a composite of cardiovascular mortality, myocardial infarction, or ischemic stroke and hospitalization for heart failure in patients with T2DM and atrial fibrillation (AF). Using the Korean National Health Insurance Service database, we identified 40,268 patients with T2DM and AF who were newly prescribed oral hypoglycemic drugs (2,977 patients with SGLT2 inhibitors and 37,291 patients without SGLT2 inhibitors) between 2014 and 2018. After 1: 4 propensity score matching, patients who received SGLT2 inhibitors (n = 2,958) and those who did not receive SGLT2 inhibitors (n = 10,691) were enrolled, and followed up until December 31, 2018. During a mean follow-up duration of 2.1 ± 1.4 years, the risk of major adverse cardiovascular events was similar between the 2 groups (hazard ratio [HR] 0.96, 95% confidence interval [CI] 0.76 to 1.21). There were no significant differences between the 2 groups for cardiovascular mortality, myocardial infarction, or ischemic stroke. However, patients who received SGLT2 inhibitors had significantly lower risks of hospitalization for heart failure (HR 0.70, 95% CI 0.53 to 0.93) and all-cause mortality (HR 0.74, 95% CI 0.56 to 0.98) than those who did not receive SGLT2 inhibitors. In conclusion, in this real-world cohort of Asian patients with T2DM and AF, use of SGLT2 inhibitors was associated with a lower risk of hospitalization for heart failure., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Warfarin is the standard anticoagulation therapy for valvular atrial fibrillation (AF); however, new oral anticoagulants have emerged as an alternative. We compared the efficacy and safety of dabigatran with conventional treatment in AF associated with left-sided valvular heart disease (VHD), including mitral stenosis (MS). Patients with AF and left-sided VHD were randomly assigned to receive dabigatran or conventional treatment. The primary end point was the occurrence of clinical stroke or a new brain lesion (silent brain infarct and microbleed) on 1-year follow-up brain magnetic resonance imaging. Patients in the dabigatran group were switched from warfarin (n = 52), antiplatelets alone (n = 5), or no therapy (n = 2) to dabigatran. In the conventional group, 53 used warfarin (including 42 MS patients), and 7 used antiplatelets. No death or clinical stroke event occurred in either group during follow-up. Silent brain infarct and microbleed occurred in 20 and 2 patients in the dabigatran group and 20 and 4 patients in the conventional treatment group. The incidence rate of the primary end point did not significantly differ between groups (34% vs 40%, relative risk 0.87, 95% confidence interval 0.59 to 1.29, p = 0.491). The primary end point rate was similar between groups in 82 patients (40 in the dabigatran group and 42 in the conventional group) with MS (32% vs 34%, relative risk 0.93, 95% confidence interval: 0.57 to 1.50, p = 0.759). In conclusion, primary end point rates after treatment with dabigatran were similar to conventional treatment in patients with significant VHD and AF. New oral anticoagulants could be a reasonable alternative to warfarin in patients with AF and VHD, which should be confirmed in future large-scale studies., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Background: Anticoagulants are the standard therapy for patients with atrial fibrillation (AF) and antiplatelet therapy for those with coronary artery disease (CAD). However, compelling clinical evidence is still lacking regarding the long-term maintenance strategy with the combination of anticoagulant and antiplatelet drugs in patients with AF and stable CAD., Design: The EPIC-CAD trial is an investigator-initiated, multicenter, open-label randomized trial comparing the safety and efficacy of 2 antithrombotic strategies in patients with high-risk AF (CHA 2 DS 2 -VASc score ≥ 2 points) and stable CAD (≥6 months after revascularization for stable angina or ≥12 months for acute coronary syndrome; or medical therapy alone). Patients (approximately N = 1,038) will be randomly assigned at a 1:1 ratio to (1) monotherapy with edoxaban (a non-vitamin K antagonist oral anticoagulant) or (2) combination therapy with edoxaban plus a single antiplatelet agent. The primary endpoint is the net composite outcome of death from any cause, stroke, systemic embolism, myocardial infarction, unplanned revascularization, and major or clinically relevant nonmajor bleeding at 1 year after randomization., Results: As of December 2021, approximately 901 patients had been randomly enrolled over 2 years at 18 major cardiac centers across South Korea. The completed enrollment is expected at the mid-term of 2022, and the primary results will be available by 2023., Conclusions: EPIC-CAD is a large-scale, multicenter, pragmatic design trial, which will provide valuable clinical insight into edoxaban-based long-term antithrombotic therapy in patients with high-risk AF and stable CAD., (Copyright © 2022 Elsevier Inc. All rights reserved.)

We sought to evaluate the clinical implication of LAE based on left atrial anterior-posterior (LA AP) dimension or LA volume index (LAVI) in Korean patients with atrial fibrillation (AF). We enrolled 8159 AF patients from the CODE-AF registry. The primary outcome was rate of stroke or systemic embolism (SSE). The prevalence of mild, moderate, and severe LAE by LA AP dimension was 30.6%, 18.5%, and 21.4%, and by LAVI (available in 5808 patients) was 15.7%, 12.5% and 37.8%, respectively. Compared with no or mild LAE, patients with significant LAE (moderate to severe LAE, n = 3258, 39.9%) were associated with a higher rate of SSE (2.5% vs. 1.4%, P = 0.001). Multivariable analysis suggested presence of significant LAE by LA AP dimension was associated with a higher risk of SSE in the overall population (HR 1.57, 95% CI: 1.14-2.17, P = 0.005) and in patients using anticoagulants (n = 5836, HR 1.79, 95% CI: 1.23-2.63, P = 0.002). Patients with significant LAE by LAVI were also at higher risk of SSE (HR 1.58, 95% CI: 1.09-2.29, P = 0.017). In conclusion, significant LAE by LA dimension or LAVI was present in 39.9% and 50.2% of AF patients, respectively, and was associated with a higher rate of SSE., (© 2021. The Author(s).)

Background Postoperative atrial fibrillation (POAF) is common after cardiac surgery, but little is known about its incidence and natural course after noncardiac surgery. We evaluated the natural course and clinical impact of POAF and the long-term impact of anticoagulation therapy in patients without a history of atrial fibrillation (AF) undergoing noncardiac surgery. Methods and Results We retrospectively analyzed the database of Asan Medical Center (Seoul, Korea) to identify patients who developed new-onset POAF after undergoing noncardiac surgery between January 2006 and January 2016. The main outcomes were AF recurrence, thromboembolic event, and major bleeding during follow-up. Of 322 688 patients who underwent noncardiac surgery, 315 patients (mean age, 66.4 years; 64.4% male) had new-onset POAF with regular rhythm monitoring after discharge. AF recurred in 53 (16.8%) during 2 years of follow-up. Hypertension (hazard ratio, 2.12; P =0.02), moderate-to-severe left atrial enlargement (hazard ratio, 2.33; P =0.007) were independently associated with recurrence. Patients with recurrent AF had higher risks of thromboembolic events (11.2% versus 0.8%; P <0.001) and major bleeding (26.9% versus 4.1%; P <0.001) than those without recurrence. Patients with recurrent AF and without anticoagulation were especially predisposed to thromboembolic events ( P <0.001). Overall, anticoagulation therapy was not significantly associated with thromboembolic events (1.4% versus 2.5%, P =0.95). Conclusions AF recurred in 16.8% of patients with POAF after noncardiac surgery. AF recurrence was associated with higher risks of adverse clinical outcomes. Considering the high risk of anticoagulation-related bleeding, the benefits of routine anticoagulation should be carefully weighed in this population. Active surveillance for AF recurrence is warranted.

The current thromboembolic risk stratification of non-valvular atrial fibrillation (NVAF) does not include parameters from transthoracic echocardiography (TTE). We hypothesized that left atrial enlargement (LAE) on TTE could discriminate who require anticoagulation therapy among NVAF patients with low/borderline clinical embolic risk. This single-center cohort study included 6,602 patients with NVAF (median age, 56 years, 70.0% male) with a low to borderline clinical embolic risk (CHA 2 DS 2 -VASc score: 0 to 1 in males, 1 to 2 in females). LAE was classified as mild (≥41 mm in males; ≥39 mm in females) or moderate-severe (≥47 mm in males; ≥43 mm in females). The main study outcome was thromboembolic event (ischemic stroke and systemic embolism). Mild and moderate-severe LAE was diagnosed in 26.1% and 32.9% of the cohort, respectively. The patients with moderate-severe LAE showed a higher prevalence of baseline comorbidities and valvular heart disease and had a higher incidence of thromboembolic events than patients with mild or no LAE at 2 years of follow-up (2.5% vs 1.3% vs 1.1%, respectively, p < 0.001). After multivariable adjustment, patients with moderate-severe LAE were at a higher risk of thromboembolic event (hazard ratio, 2.54; 95% CI, 1.65 to 3.90; p < 0.001) compared to those with no LAE. This result persisted in a subgroup analysis of anticoagulant-naïve patients. The rate of thromboembolic events in patients with low clinical embolic risk and moderate-severe LAE was not different to those with high clinical embolic risk without LAE. In conclusion, Moderate-severe LAE on TTE was a significant predictor of thromboembolic events in NVAF patients at low/borderline clinical embolic risk., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background Severe conduction delay and inter/intra-atrial dissociation may occur in patients who undergo an extensive catheter ablation or a maze procedure for atrial tachyarrhythmia. We report a series of patients with inter/intra-atrial dissociation that mimicked complete atrioventricular block or ventricular tachycardia. Methods and Results We retrospectively reviewed the medical records of 7 patients who were referred for the evaluation of atrioventricular block (patients 1-6) or ventricular tachycardia (patient 7) that occurred after biatrial maze procedure and valvular surgery. During the electrophysiologic study, slow atrial or junctional escape rhythm dissociated from isolated atrial activity mimicked complete atrioventricular blocks. Intra-atrial dissociation of the right atrium or left atrium was observed. Atrioventricular nodal conduction from the nondissociated atrium to the ventricle was preserved in all patients, while the conduction from the dissociated atrium was blocked. In patient 7, the pacing of the ventricle by tracking of atrial tachycardia from the nondissociated left atrium/coronary sinus mimicked ventricular tachycardia during pacemaker interrogation. A total of 5 patients received new permanent pacemaker implantations during the index hospitalization for the surgery (n=2) or as a deferred procedure (n=3) according to the treatment for sick sinus syndrome. Conclusions Pseudo-atrioventricular block or pseudo-ventricular tachycardia may occur because of inter/intra-atrial dissociation after a maze procedure. The selection of patients for permanent pacemaker implantation should be determined based on the patient's symptoms and the status of the escape pacemaker and not on the apparent atrioventricular block. Proper diagnosis is important to avoid unnecessary implantation of a pacemaker or a defibrillator.

Background: The clinical implications of pericardial effusion (PE) after catheter ablation for atrial fibrillation (AF) are not well understood. We evaluated the association between newly developed PE after pulmonary vein isolation (PVI) for paroxysmal AF and arrhythmic recurrence., Methods: From a prospective AF ablation registry, 184 patients (mean age 59 ± 10 years, 65% male) who underwent first-time PV isolation using a smart touch surround flow catheter (Biosense Webster, Diamond Bar, CA) were analyzed. Postablation transthoracic echocardiography (TTE) was performed within 1-3 days after ablation, and the occurrence of PE was assessed., Results: PE developed in 91 patients (49.5%), and most were of minimal severity (minimal, 93.4%; mild, 6.6%). Patients with PE had significantly lower body mass index and underwent cavotricuspid isthmus ablation more frequently. Early arrhythmic recurrence (EAR) (within 3 months) was observed in 28.8% of patients and was not different according to the PE development (PE [+]: 29.7% vs PE [-]: 28.0%; P = .80). During a median follow-up of 696 days, the cumulative rate of the late arrhythmic recurrence (LAR) (after 3 months) was 36.4%, and there was no difference between groups (PE [+]: 36.7% vs PE [-]: 35.1%; P = .988). The only predictor of LAR was EAR, and no echocardiographic parameters showed a significant correlation with LAR., Conclusions: Minimal or mild PE after PVI for paroxysmal AF is a frequent echocardiographic finding, and it had no significant association with AF recurrence. Routine TTE after AF ablation has no clinical implication., (© 2020 Wiley Periodicals LLC.)

Background: This study investigated 12-lead electrocardiogram (ECG) predictors associated with atrial fibrillation (AF) or flutter (AFL), specifically whether ventricular repolarization abnormalities in surface ECG (i.e., non-specific ST-T abnormalities [NSSTTA], QT prolongation, early repolarization [ER]) were associated with the development of AF or AFL.Methods and Results:This study included 16,793 ambulatory Koreans (mean age 48.2 years, 62.3% male) who underwent medical check-ups at Asan Medical Center in 2002 (NSSTTA, n=1,037 [6.2%]; ER, n=1,493 [8.9%]). The primary outcome was the incidence of ECG-documented AF or AFL. During follow-up, new-onset AF or AFL was documented in 334 subjects (2.0%). The incidence of AF or AFL at the 10-year follow-up was higher in patients with than without NSSTTA (3.5% vs. 1.6%; hazard ratio [HR] 1.79, 95% confidence interval [CI] 1.28-2.50). The QT interval was associated with a higher risk of AF or AFL (HR 1.12 [95% CI 1.07-1.17] per 10 ms), and the risk was even higher in patients with multiple-region NSSTTA (HR 2.30; 95% CI 1.64-3.21) and NSSTTA with QT prolongation (HR 4.06; 95% CI 2.14-7.69). ER was not associated with a higher risk of AF or AFL (HR 1.02; 95% CI 0.71-1.46)., Conclusions: NSSTTA and QT prolongation, but not ER, were associated with a higher risk of future AF or AFL in a general ambulatory population after adjusting for parameters of atrial depolarization.

With safety concerns about increasing bleeding, off-label underdosing of non-vitamin K antagonist anticoagulants (NOACs) is common in East Asian patients with atrial fibrillation (AF). We tried to investigate the pattern of NOAC underdosing and associated clinical outcomes in patients with AF who are indicated for standard dosing. Using the Korean National Health Insurance Service database, we evaluated 16,568 patients with a new prescription of NOAC who are indicated for standard NOAC dosing and compared 4,536 patients with warfarin with respect to thromboembolic events (ischemic stroke or systemic embolization), all-cause mortality and major bleeding. Of the 16,568 patients indicated for standard NOAC dosing, 8,549 (51.9%) received off-label underdosing (50.6% rivaroxaban, 53.0% apixaban). During a median follow up of 15.0 months, as compared with warfarin, underdosing of rivaroxaban was associated with lower risks of major thromboembolic events (hazard ratio [HR]: 0.53; 95% confidence interval [CI]: 0.41 to 0.69) and all-cause mortality (HR 0.57, 95% CI: 0.41 to 0.82), and a similar risk of major bleeding (HR 1.10, 95% CI: 0.82 to 1.46). However, underdosing of apixaban was associated with similar risks of major thromboembolic events (HR: 0.90; 95% CI: 0.70 to 1.16), all-cause mortality (HR 0.94, 95 CI: 0.71 to 1.24) and major bleeding (HR 0.84, 95% CI: 0.61 to 1.17). In conclusion, in this Korean population with AF who are indicated for standard NOAC dosing, off-label underdosing is common and its clinical benefit over warfarin was inconsistent according to types of NOAC. Notably, apixaban underdosing provides no benefit in effectiveness compared with warfarin., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background: Fasciculoventricular (FV) bypass tracts (BTs) are the rarest form of ventricular preexcitation. Although they are not involved in clinically significant reentrant tachycardia, they may cause diagnostic and therapeutic confusion if not properly understood. This study aimed to assess the impact of FV BTs on the diagnosis and treatment of concomitant arrhythmias and cardiac diseases., Methods: Twenty-two patients with FV BTs who underwent electrophysiologic (EP) study were evaluated. The prevalence of concomitant arrhythmias and cardiac diseases in FV BTs was evaluated. The mechanisms of concomitant arrhythmias were determined by EP study and cardiac diseases were diagnosed by echocardiography., Results: One patient had FV BT with complete infra-Hisian atrioventricular (AV) block that mimicked a slow ventricular escape rhythm. Two patients had FV BT with atrial fibrillation or atrial flutter, which was misinterpreted as AV BT requiring emergency DC cardioversion. Eight patients had accompanying AV BTs. In 2 patients with AV BTs, unnecessary RF application was delivered after successful ablation of AV BT because conduction through a FV BT was mistaken for conduction through a residual AV BT. Five patients had no concomitant arrhythmia; however, two of them had hypertrophic cardiomyopathy with symptoms requiring beta-blocker. Patients had not been prescribed beta-blockers to avoid a proarrhythmic response before the EP study because the FV BTs mimicked AV BTs., Conclusion: FV BTs were frequently accompanied by AV BTs or other arrhythmias and cardiac diseases. They may cause misdiagnosis and inappropriate therapy and even unnecessary RF delivery when misinterpreted as AV BTs., (Copyright © 2019 Elsevier Inc. All rights reserved.)

The implication of coronary artery disease (CAD) without the clinical manifestation of myocardial infarction (non-MI-CAD) on thromboembolic events in patients with nonvalvular atrial fibrillation (NVAF) is not well evaluated. We hypothesized that non-MI-CAD would have a similar risk of future thromboembolism as MI-CAD. Clinical data for 17,073 consecutive patients (mean age, 64.3 years; males, 64.9%) diagnosed with NVAF at our center were analyzed. CAD was defined as stenosis of ≥50% stenosis of major coronary arteries identified using coronary artery angiography or coronary computed tomographic angiography. The main outcome of the present study was the rate of thromboembolic events (ischemic stroke and systemic embolism) during the follow-up period (3.1 ± 2.4 years). A total of 1,011 patients (5.9%) were diagnosed with CAD without clinical manifestation of MI (non-MI-CAD) and 708 (4.1%) had a history or diagnosis of MI-CAD. Thromboembolic events occurred in 1,007 patients (5.9%) during follow-up. The groups were at high risk of future thromboembolic events determined using univariate (hazard ratio [HR] 1.55; 95% confidence interval [CI] 1.25 to 1.91; p <0.001 for non-MI-CAD and HR 2.14; 95% CI 1.70 to 2.69; p <0.001 for MI-CAD) and multivariate analysis adjusted for CHA 2 DS 2 -VASc score components and relevant variables (HR 1.42; 95% CI 1.15 to 1.77; p = 0.001 for non-MI-CAD and HR 1.62; 95% CI 1.28 to 2.06; p <0.001 for MI-CAD); this trend was consistent in patients who did not receive anticoagulants during follow-up (n = 8,032, 47.0%). In conclusion, non-MI-CAD is an important predictor of thromboembolic events in patients with NVAF., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background To characterize the development of sick sinus syndrome ( SSS ) after the additive maze procedure ( MP ) during mitral valve surgery. Methods and Results Follow-up data (median, 3.6 years) of 750 patients with a prevalence of rheumatic cause of 57.6% were analyzed. SSS occurred in 35 patients with a time-dependent increase: the incidence rates at 1, 2, and 4 years after surgery were 2.9%, 3.7%, and 4.3%, respectively. The additive MP showed higher risks of SSS development (hazard ratio, 7.44; 95% confidence interval, 3.45-16.05; P<0.001) and pacemaker implantation (hazard ratio, 3.61; 95% confidence interval, 1.95-6.67; P<0.001). Patients who developed SSS showed higher 4-year rates of clinical events (death, stroke, and hospital admission) (67.5±8.5% versus 33.0±1.9%; P<0.001). After adjustment for age and preoperative peak systolic pulmonary artery pressure, the lesion extent (biatrial versus left atrial MP ), not the underlying cause (rheumatic versus nonrheumatic), was independently associated with SSS development (hazard ratio, 3.58; 95% confidence interval, 1.08-11.86; P=0.037). The adverse effect of the biatrial MP was confirmed in patients with trivial or mild preoperative tricuspid regurgitation showing higher SSS incidence (4.6±1.4% versus 1.0±0.7%; P=0.023), not in those with moderate-to-severe tricuspid regurgitation (6.8±1.7% versus 3.8±3.8%; P=0.337). Recurrence of atrial fibrillation was not associated with the lesion extent of the MP . Conclusions After the additive MP , the ongoing risk of SSS development should be acknowledged irrespective of the underlying cause. Considering additive risk of biatrial MP with similar atrial fibrillation recurrence rate, minimizing lesion extent is warranted.

Apixaban is effective and safe for preventing stroke, and its usage has increased exponentially in recent years. However, data concerning the therapeutic range of apixaban is limited. This study determined the trough and peak levels of apixaban-specific anti-factor Xa activity (AFXaA) in acute ischemic stroke patients with non-valvular atrial fibrillation (NVAF) in Korea. The study included 85 patients who received apixaban. Blood samples were taken to measure the trough and peak levels of AFXaA using a chromogenic anti-factor assay, as well as prothrombin time (PT) and activated partial thromboplastin time (aPTT). We also reviewed complications such as major bleeding of patients treated with apixaban. In patients given a 5.0-mg apixaban dose, the median trough and peak levels of AFXaA were 104.5 and 202.0 ng/mL. In patients given a 2.5-mg apixaban dose, the median trough and peak AFXaA levels were 76.0 and 151.0 ng/mL. The PT showed a positive correlation with increased AFXaA activity at both levels (Trough R = 0.486, Peak R = 0.592), but the aPTT had no relationship with AFXaA activity at both levels (Trough R = 0.181, Peak R = 0.129). Two cases with intracranial bleeding belonged to the highest AFXaA quartile (Trough, p = 0.176; Peak, p = 0.053). In conclusion, we determined the trough and peak levels of AFXaA in patients with NVAF while being treated with the apixaban in Korea. Our results could be used as a starting point when setting the reference ranges for laboratories using anti-Xa assay. Large-scale studies are needed to establish the reference range for AFXaA in patients with NVAF.

Persistent atrial fibrillation (PeAF) predictors after dual-chamber pacemaker (PM) implantation remain unclear. We sought to determine these predictors and establish an integrated scoring model. Data were retrospectively reviewed for 649 patients (63.8 ± 12.3 years, 48.6% male, mean CHA2DS2-VASC score 2.7 ± 2.0) undergoing dual-chamber PM implantation. PeAF was defined as documented AF on two consecutive electrocardiograms acquired ≥7 days apart. During a 7.1-year median follow-up (interquartile range 4.5-10.1 years), 67 (10.3%) patients had PeAF. Multivariable analysis showed the following independent predictors of future PeAF: ischemic stroke or transient ischemic accident history (hazard ratio [HR] 2.03, 95% confidence interval [CI] 1.03-3.50, p = 0.040), atrial fibrillation/flutter history (HR 1.80, 95% CI 1.01-3.20, p = 0.046), sinus node disease (HR 2.24, 95% CI 1.16-4.35, p = 0.016), left atrial enlargement (>45 mm, HR 2.14, 95% CI 1.26-3.63, p = 0.005), and time in automatic mode switching >1% at first follow-up interrogation (HR 2.58, 95% CI 1.51-4.42, p < 0.001). An integrated scoring model combining these predictors showed good discrimination performance at the seven-year follow-up. (C-statistic 0.716, 95% CI 0.629-0.802, p < 0.001). Significantly greater seven-year PeAF incidences were seen in patients with higher scores (2-5) than in those with lower scores (0-1) (22.8% ± 3.8% vs. 5.3% ± 1.7%, p < 0.001). In conclusion, an integrated scoring model combining clinical, echocardiographic, and electrocardiographic characteristics is useful for predicting future PeAF in patients with a dual-chamber PM.

Introduction: The incidence and predictors of tricuspid regurgitation (TR) after permanent pacemaker (PM) implantations have not been well evaluated. We attempted to determine TR's natural course and predictors, especially focusing on the influence of atrial fibrillation (AF). Methods: Data from 530 patients with dual‐chamber PMs were evaluated. The main study outcomes were moderate to severe TR and isolated TR (moderate to severe TR without other structural heart diseases [SHDs]) in follow‐up echocardiography. Results: Over a median follow‐up period of 7.6 years, moderate to severe TR developed in 14.5% patients. Of those, concomitant SHD was observed in 51.9% of patients, and 48.1% presented with isolated TR. A multivariable analysis identified the independent predictors of moderate to severe TR (diabetes mellitus [DM], chronic lung disease, preexisting mild TR, peripheral artery disease, moderate to severe aortic regurgitation, and persistent AF [PeAF]) and isolated TR (DM, preexisting mild TR, and PeAF). PeAF (n = 67, 12.6%) was an independent predictor of both moderate to severe TR (hazard ratio [HR] 2.59, 95% confidence interval [CI]: 1.22–5.51) and isolated TR (HR 4.54, 95% CI: 1.60–12.90). The patients with PeAF exhibited a higher incidence of moderate to severe TR (21.8% vs 12.9% vs 11.6% PeAF, paroxysmal AF, and without AF, respectively) and isolated TR (18.6% vs 6.6% vs 4.2%, respectively) during the follow‐up. Conclusion: Moderate to severe TR after PM implantations developed with or without the influence of concomitant SHD. Patients with PeAF exhibited a higher risk of moderate to severe TR after PM implantations. [ABSTRACT FROM AUTHOR]

Background Cryptogenic stroke can be subdivided into 3 distinct categories: stroke of no determined cause (CyNC), stroke due to multiple etiologies (Cy >1), and stroke etiology unclear due to incomplete evaluation. Although these subdivisions may be very different from one another with respect to baseline features and outcomes, they are often reported as a composite group in clinical trials. Methods Patients treated at our academic institution between July 2008 and June 2013 for acute ischemic stroke were retrospectively assessed in our prospective registry. CyNC and Cy >1 patients were compared to other Trial of Org 10172 in Acute Stroke Treatment (TOAST) stroke subtypes and to each other using univariate analyses and multivariate logistic regression. The primary outcome of interest was good functional outcome, defined as a discharge modified Rankin Scale score of 0-2. Results Of the 1311 included patients, 260 (19.8%) experienced a CyNC and 49 (3.7%) experienced a Cy >1. Cy >1 classification was associated with history of atrial fibrillation (odds ratio [OR], 3.17; 95% confidence interval [CI], 1.16-6.12; P = .001). In comparison to other TOAST classifications, CyNC strokes were more likely to have good functional outcome (OR, 1.97; 95% CI, 1.38-2.82; P < .001) after adjusting for baseline National Institutes of Health Stroke Scale, admission glucose, age, and intravenous tissue plasminogen activator (IV tPA). Conclusions Even after adjusting for higher IV tPA treatment rates, ischemic stroke patients with no identified cause had better outcomes than other TOAST groups. Conversely, patients coded as cryptogenic with more than 1 likely cause represent a different patient subpopulation. These data argue against the consolidation of cryptogenic stroke subcategories in future investigations. [ABSTRACT FROM AUTHOR]