Comparison between catheter ablation versus permanent pacemaker implantation as an initial treatment for tachycardia-bradycardia syndrome patients: a prospective, randomized trial.

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.

Incidence and predictors of left atrial thrombus in patients with atrial fibrillation under anticoagulation therapy.

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]), CHA2DS2-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.

Reduction of moderate to severe tricuspid regurgitation after catheter ablation for atrial fibrillation.

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.

Upper turnaround point in a reentry circuit of the idiopathic left posterior fascicular ventricular tachycardia.

BACKGROUND: The anatomic extent of the reentry circuit in idiopathic left posterior fascicular ventricular tachycardia (LPF-VT) is yet to be fully elucidated. We hypothesized that entrainment mapping could be used to delineate the reentry circuit of an LPF-VT, especially including the upper turnaround point. METHODS: Twenty-three consecutive LPF-VT patients (mean age, 29 ± 9 years, 18 males) were included. We performed overdrive pacing with entrainment attempts at the left bundle branch (LBB) and the left His bundle (HB) region. RESULTS: Overdrive pacing from the LBB region showed concealed fusion in all 23 patients (post-pacing interval [PPI], 322.1 ± 64.3 ms; tachycardia cycle length [TCL], 319.0 ± 61.6 ms; PPI-TCL, 3.1 ± 4.6 ms) with a long stimulus-to-QRS interval (287.9 ± 58.0 ms, approximately 90% of the TCL). Pacing from the same LBB region at a slightly faster pacing rate showed manifest fusion with antidromic conduction to the LBB and minimal in-and-out time to the LBB potential (PPI-TCL, 21.3 ± 13.7 ms). Overdrive pacing from the left HB region showed manifest fusion with a long PPI-TCL (53.9 ± 22.5 ms). CONCLUSIONS: Our pacing study results suggest that the upper turnaround point in a reentry circuit of the LPF-VT may extend to the proximal His-Purkinje conduction system near the LBB region but below the left HB region. The LPF may constitute the retrograde limb of the reentry circuit.

Incidence and Predictors of Severe Tricuspid Regurgitation in Atrial Fibrillation Patients Without Structural Heart Disease.

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.

Clinical benefits and risks of anticoagulation therapy according to the degree of chronic kidney disease in patients with atrial fibrillation.

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 CHA2DS2-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 (CHA2DS2-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.

Oral anticoagulants and concurrent rifampin administration in tuberculosis patients with non-valvular atrial fibrillation.

BACKGROUND: Evidence and guidelines for Non-vitamin K antagonist oral anticoagulants (NOACs) use when prescribing concurrent rifampin for tuberculosis treatment in patients with non-valvular atrial fibrillation (NVAF) are limited. METHODS: Using the Korean National Health Insurance Service database from January 2009 to December 2018, we performed a population-based retrospective cohort study to assess the net adverse clinical events (NACE), a composite of ischemic stroke or systemic embolism and major bleeding, of NOACs compared with warfarin among NVAF patients taking concurrent rifampin administration for tuberculosis treatment. After a propensity matching score (PSM) analysis, Cox proportional hazards regression was performed in matched cohorts to investigate the clinical outcomes. RESULTS: Of the 735 consecutive patients selected, 465 (63.3%) received warfarin and 270 (36.7%) received NOACs. Among 254 pairs of patients after PSM, the crude incidence rate of NACE was 25.6 in NOAC group and 32.8 per 100 person-years in warfarin group. There was no significant difference between NOAC and warfarin use in NACE (hazard ratio [HR], 0.74; 95% confidence interval [CI], 0.48-1.14; P = 0.172). Major bleeding was the main driver of NACE, and NOAC use was associated with a statistically significantly lower risk of major bleeding than that with warfarin use (HR, 0.63; 95% CI, 0.40-1.00; P = 0.0499). CONCLUSIONS: In our population-based study, there was no statically significant difference in the occurrence of NACE between NOAC and warfarin use. NOAC use may be associated with a lower risk of major bleeding than that with warfarin use.

Controlled Level and Variability of Systolic Blood Pressure on the Risk of Thromboembolic Events in Atrial Fibrillation and Hypertension.

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 (<130 mm Hg for systolic BP [SBP] and <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 >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.

Effect of Sodium-Glucose Cotransporter Inhibitors on Major Adverse Cardiovascular Events and Hospitalization for Heart Failure in Patients With Type 2 Diabetes Mellitus and Atrial Fibrillation.

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.

Comparison of Dabigatran Versus Warfarin Treatment for Prevention of New Cerebral Lesions in Valvular Atrial Fibrillation.

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.

Prevalence and Characteristics of Atrial Tachycardia From Noncoronary Aortic Cusp During Atrial Fibrillation Catheter Ablation.

BACKGROUND AND OBJECTIVES: Atrial tachycardias (ATs) from noncoronary aortic cusp (NCC) uncovered after radiofrequency ablation for atrial fibrillation (AF) are rarely reported. This study was conducted to investigate the prevalence and clinical characteristics of NCC ATs detected during AF ablation and compare their characteristics with de novo NCC ATs without AF. METHODS: Consecutive patients who underwent radiofrequency catheter ablation for AF were reviewed from the multicenter AF ablation registry of 11 tertiary hospitals. The clinical and electrophysiological characteristics of NCC AT newly detected during AF ablation were compared with its comparators (de novo NCC AT ablation cases without AF). RESULTS: Among 10,178 AF cases, including 1,301 redo ablation cases, 8 (0.08%) NCC AT cases were discovered after pulmonary vein isolation (PVI; 0.07% in first ablation and 0.15% in redo ablation cases). All ATs were reproducibly inducible spontaneously or with programmed atrial stimulation without isoproterenol infusion. The P-wave morphological features of tachycardia were variable depending on the case, and most cases exhibited 1:1 atrioventricular conduction. AF recurrence rate after PVI and NCC AT successful ablation was 12.5% (1 of 8). Tachycardia cycle length was shorter than that of 17 de novo ATs from NCC (303 versus 378, p=0.012). No AV block occurred during and after successful AT ablation. CONCLUSIONS: Uncommon NCC ATs (0.08% in AF ablation cases) uncovered after PVI, showing different characteristics compared to de-novo NCC ATs, should be suspected irrespective of P-wave morphologies when AT shows broad propagation from the anterior interatrial septum.

Usefulness of cardiac magnetic resonance images for prediction of sudden cardiac arrest in patients with mitral valve prolapse: a multicenter retrospective cohort study.

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.

Pacemaker dependency after transcatheter aortic valve replacement compared to surgical aortic valve replacement.

ABSTRACT: Transcatheter aortic valve replacement (TAVR) is a standard treatment indicated for severe aortic stenosis in high-risk patients. The objective of this study was to evaluate the incidence of pacemaker dependency after permanent pacemaker implantation (PPI) following TAVR or surgical aortic valve replacement (SAVR) and the risk of mortality at a tertiary center in Korea.In this retrospective study conducted at a single tertiary center, clinical outcomes related to pacemaker dependency were evaluated for patients implanted with pacemakers after TAVR from January 2012 to November 2018 and post-SAVR from January 2005 to May 2015. Investigators reviewed patients' electrocardiograms and baseline rhythms as well as conduction abnormalities. Pacemaker dependency was defined as a ventricular pacing rate > 90% with an intrinsic rate of <40 bpm during interrogation.Of 511 patients who underwent TAVR for severe AS, 37(7.3%) underwent PPI after a median duration of 6 (3-7) days, whereas pacemakers were implanted after a median interval of 13 (8-28) days post-SAVR in 10 of 663 patients (P < .001). Pacemaker dependency was observed in 36 (97.3%) patients during 7 days immediately post-TAVR and in 25 (64.9%) patients between 8 and 180 days post-TAVR. Pacemaker dependency occurred after 180 days in 17 (50%) patients with TAVR and in 4 (44.4%) patients with SAVR. Twelve (41.4%) patients were pacemaker-dependent after 365 days post-TAVR.Pacemaker dependency did not differ at 6 months after TAVR vs SAVR. In patients undergoing post-TAVR PPI, 58.6% were not pacemaker-dependent at 1 year after the TAVR procedure.

Natural Course of New-Onset Postoperative Atrial Fibrillation after Noncardiac Surgery.

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.

Esophageal Thermal Injury after Catheter Ablation for Atrial Fibrillation with High-Power (50 Watts) Radiofrequency Energy.

BACKGROUND AND OBJECTIVES: Data regarding the safety of atrial fibrillation (AF) ablation using high-power (50 W) radiofrequency (RF) energy in Asian populations are limited. This study was conducted to evaluate the incidence and pattern of esophageal injury after high-power AF ablation in an Asian cohort. METHODS: We searched the prospective AF ablation registry to identify patients who underwent AF ablation with 50 W RF energy using the smart touch surround flow catheter (Biosense Webster, Diamond Bar, CA, USA). Visitag™ (Biosense Webster) was used for lesion annotation with predefined settings of catheter stability (3 mm for 5 seconds) and minimum contact force (50% of time >5 g). All patients underwent upper gastrointestinal endoscopy at 1 or 3 days after the ablation. RESULTS: A total of 159 patients (mean age: 63±9 years, male: 69%, paroxysmal AF: 45.3%, persistent AF: 27.7%, long-standing persistent AF: 27.0%) were analyzed. Initially, 26 patients underwent pulmonary vein isolation with 50 W for 5 seconds at each point. The remaining 133 patients underwent prolonged RF duration (anterior 10 seconds and posterior 6 seconds). The incidence rates of esophageal erythema/erosion and superficial ulceration were 1.3% for each type of the lesion. Food stasis, a suggestive finding of gastroparesis, was observed in 25 (15.7%) patients. There were no cases of cardiac tamponade, stroke, or death. CONCLUSIONS: In Asian patients, AF ablations using 50 W resulted in very low rates of mild esophageal complications.

The shape of the left lateral ridge as a predictor of long-term outcome of catheter ablation for atrial fibrillation based on clinical and experimental data.

BACKGROUND: The left lateral ridge (LLR) is an important structure for ablation of atrial fibrillation (AF). This study assessed how the LLR shape is associated with the long-term outcomes of AF ablation and investigated the relationship with radiofrequency (RF) lesion formation. METHODS AND RESULTS: Clinical study - we assessed multi-detector computed tomography (MDCT) images in 247 patients who underwent AF ablation. Patients were classified into two groups according to the shape of the LLR: Narrow LLR group (n = 116; 47%) and Wide LLR group (n = 131; 53%). After a follow-up period 475 ± 245 days, the AF-free rate was significantly higher in the wide LLR than Narrow LLR group (83.2% vs. 62.9%, p = 0.0004). A multivariate analysis showed that the shape of the LLR was an independent predictor of AF recurrence after ablation (hazard ratio 2.58; 95% confidential interval = 1.48-4.51, p = 0.001). Experimental study - Two types of the ridge models were made with porcine atrial tissues: "Narrow ridge(4.2 ± 0.9 mm)" and "Wide ridge(9.7 ± 1.8 mm)" RF ablation was performed on each ridge model using a contact force (CF)-sensing catheter. The mean CF and the RF lesion volume of the narrow ridge were significantly less than those of the wide ridge model (5.42 ± 3.13 g vs. 10.37 ± 3.98 g, p = 0.001; 19.8 ± 9.9 mm3 vs. 44.2 ± 13.6 mm3, p < 0.001, respectively). CONCLUSIONS: AF recurrence after ablation was more frequent in patients with a narrow LLR. LLR shape as assessed using MDCT is associated with long-term outcomes after AF ablation. CF and lesion formation data using the porcine atrial tissue model support our clinical results.

Relation of Left Atrial Enlargement to Subsequent Thromboembolic Events in Nonvalvular Atrial Fibrillation Patients With Low to Borderline Embolic Risk.

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 (CHA2DS2-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.