Association between body mass index and results of cryoballoon ablation in Korean patients with atrial fibrillation: an analysis from Korean Heart Rhythm Society Cryoablation registry.

BACKGROUND: Pulmonary vein isolation using cryoablation is effective and safe in patients with atrial fibrillation (AF). Although both obesity and underweight are associated with a higher risk for incident AF, there is limited data on the efficacy and safety following cryoablation according to body mass index (BMI) especially in Asians. METHODS: Using the Korean Heart Rhythm Society Cryoablation registry, a multicenter registry of 12 tertiary hospitals, we analyzed AF recurrence and procedure-related complications after cryoablation by BMI (kg/m2) groups (BMI<18.5, underweight, UW; 18.5-23, normal, NW; 23-25, overweight, OW; 25-30, obese Ⅰ, OⅠ; ≥30, obese Ⅱ, OⅡ). RESULTS: A total of 2,648 patients were included (median age 62.0 years; 76.7% men; 55.6% non-paroxysmal AF). Patients were categorized by BMI groups; 0.9% UW, 18.7% NW, 24.8% OW, 46.1% OI, and 9.4% OII. UW patients were the oldest, and had least percentage of non-paroxysmal AF (33.3%). During a median follow-up of 1.7 years, atrial arrhythmia recurred in 874 (33.0%) patients (incidence rate, 18.9 per 100 person-year). After multivariable adjustment, the risk of AF recurrence was higher in UW group compared to NW group (adjusted hazard ratio, 95% confidence interval; 2.55, 1.18-5.50, p=0.02). Procedure-related complications occurred in 123 (4.7%) patients and the risk was higher for UW patients (odds ratio, 95% confidence interval; 2.90, 0.94-8.99, p=0.07), mainly due to transient phrenic nerve palsy. CONCLUSION: UW patients showed a higher risk of AF recurrence after cryoablation compared to NW patients. Also, careful attention is needed on the occurrence of phrenic nerve palsy in UW patients.

Comparison of Novel Telemonitoring System Using the Single-lead Electrocardiogram Patch With Conventional Telemetry System.

BACKGROUND AND OBJECTIVES: Although a single-lead electrocardiogram (ECG) patch may provide advantages for detecting arrhythmias in outpatient settings owing to user convenience, its comparative effectiveness for real-time telemonitoring in inpatient settings remains unclear. We aimed to compare a novel telemonitoring system using a single-lead ECG patch with a conventional telemonitoring system in an inpatient setting. METHODS: This was a single-center, prospective cohort study. Patients admitted to the cardiology unit for arrhythmia treatment who required a wireless ECG telemonitoring system were enrolled. A single-lead ECG patch and conventional telemetry were applied simultaneously in hospitalized patients for over 24 hours for real-time telemonitoring. The basic ECG parameters, arrhythmia episodes, and signal loss or noise were compared between the 2 systems. RESULTS: Eighty participants (mean age 62±10 years, 76.3% male) were enrolled. The three most common indications for ECG telemonitoring were atrial fibrillation (66.3%), sick sinus syndrome (12.5%), and atrioventricular block (10.0%). The intra-class correlation coefficients for detecting the number of total beats, atrial and ventricular premature complexes, maximal, average, and minimal heart rates, and pauses were all over 0.9 with p values for reliability <0.001. Compared to a conventional system, a novel system demonstrated significantly lower signal noise (median 0.3% [0.1-1.6%] vs. 2.4% [1.4-3.7%], p<0.001) and fewer episodes of signal loss (median 22 [2-53] vs. 64 [22-112] episodes, p=0.002). CONCLUSIONS: The novel telemonitoring system using a single-lead ECG patch offers performance comparable to that of a conventional system while significantly reducing signal loss and noise. TRIAL REGISTRATION: Clinical Research Information Service Identifier: KCT0008176.

The impact of early cryoballoon ablation on clinical outcome in patients with atrial fibrillation: From the Korean cryoballoon ablation registry.

INTRODUCTION: Influence of early atrial fibrillation (AF) ablation, particularly cryoballoon ablation (CBA), on clinical outcome during long-term follow-up has not been clarified. The objective was to determine whether an early CBA (diagnosis-to-ablation of ≤6 months) strategy could affect freedom from AF recurrence after index CBA. METHODS: The study included 2605 patients from Korean CBA registry data with follow-up >12 months after de novo CBA. The primary outcome was recurrence of atrial tachyarrhythmias (ATs) of ≥30-s after a 3-month blanking period. RESULTS: Compared to patients in early CBA group, patients in late CBA group had higher prevalence of diabetes, congestive heart failure, and chronic kidney disease, and higher mean CHA2 DS2 -VAS score. During mean follow-up of >21 months, ATs recurrence was detected in 839 (32.2%) patients. The early CBA group showed a significantly lower 2-year recurrence rate of ATs than the late CBA group (26.1% vs. 31.7%, p = 0.043). In subgroup analysis, the early CBA group showed significantly higher 1-year and 2-year freedom from ATs recurrence than the late CBA group only in paroxysmal atrial fibrillation (PAF) patients in overall and propensity score matched cohorts. Multivariate analysis showed that early CBA was an independent factor for preventing ATs recurrence in PAF (hazard ratio: 0.637; 95% confidence intervals: 0.412-0.984). CONCLUSION: Early CBA strategy, resulting in significantly lower ATs recurrence during 2-year follow-up after index CBA, might be considered as an initial rhythm control therapy in patients with paroxysmal AF.

Clinical Outcomes of Intracardiac Echocardiography-Guided Contrast Agent-Free Cryoballoon Ablation in Atrial Fibrillation Patients With Renal Insufficiency.

BACKGROUND AND OBJECTIVES: Previous studies have reported an association between impaired renal function and poor outcomes after radiofrequency catheter ablation in patients with atrial fibrillation (AF). However, outcomes of cryoballoon ablation (CBA) in patients with renal insufficiency are not fully elucidated. This study aimed to compare outcomes of CBA in AF patients with chronic kidney disease (CKD) versus those without CKD and to assess changes in renal function over 12 months following CBA. METHODS: A total of 839 patients (65.1% with non-paroxysmal AF [PAF]) who underwent de novo CBA were prospectively enrolled. We divided patients into two groups based on creatinine clearance rate (CCr) and performed intracardiac echocardiography (ICE)-guided contrast agent-free CBA. RESULTS: In comparison with patients without CKD (CCr >50, n=722), those with CKD (CCr ≤50, n=117) were older and predominantly female, had a lower body mass index, and showed a higher prevalence of heart failure and hypertension. Mean CHA2DS2-VAS score was significantly higher in CKD group than in non-CKD group. Procedure-related complications were not significantly different between two groups. During a mean follow-up period of 25.4±11.9 months, clinical recurrence occurred in 182 patients (21.7%) and not significantly different between two groups. In multivariate analysis, non-PAF and left atrial size were independent predictors of AF recurrence. CCr levels significantly improved over 12 months after CBA in CKD group. CONCLUSIONS: ICE-guided contrast-agent-free CBA showed comparable long-term clinical outcomes without increasing procedure-related complications and improvement of renal function over 12 months following CBA in AF patients with CKD.

Cryoballoon ablation of atrial fibrillation in octogenarians: one year outcomes from the cryo global registry.

BACKGROUND: Limited information is available on the safety and efficacy of cryoballoon ablation (CBA) in elderly patients with atrial fibrillation (AF). Moreover, global utilization of CBA in this population (≥ 80 years old) has not been reported. This study's objectives were to determine the use, efficacy, and safety of CBA to treat octogenarians suffering from AF. METHODS: In this sub-analysis of the Cryo Global Registry, 12-month outcomes of treating AF via CBA in octogenarians were compared to patients < 80 years old. Efficacy was evaluated as time to a ≥ 30 s atrial arrhythmia (AA) recurrence. Healthcare utilization was determined via repeat ablations and hospitalizations. Improvement upon disease burden was evaluated through patient reporting of symptoms and the EQ-5D-3L quality of life (QoL) survey. RESULTS: The octogenarian cohort (n = 101) had a higher prevalence of females (51.5% vs 35.7%) and CHA2DS2-VASc scores (4.2 ± 1.3 vs 2.0 ± 1.5) compared to the control cohort (n = 1573, both p < 0.01). Even when adjusting for baseline characteristics and antiarrhythmic drug usage, freedom from AA recurrence at 12 months (80.6% vs 78.9%, HRadj:0.97 [95% CI:0.59-1.58], p = 0.90) was comparable between octogenarians and control, respectively. Similar serious adverse event rates were observed between octogenarians (5.0%) and control (3.2%, p = 0.38). The groups did not differ in healthcare utilization nor reduction of AF-related symptoms from baseline to follow-up, but both experienced an improvement in QoL at 12 months. CONCLUSIONS: Despite more age-related comorbidities, CBA is a safe and effective treatment for AF in octogenarians, with efficacy and adverse events rates akin to ablations performed in younger patients. CLINICAL TRIAL REGISTRATION: https://clinicaltrials.gov/ct2/show/NCT02752737.

Safety and efficacy of intracardiac echocardiography-guided zero-fluoroscopic cryoballoon ablation for atrial fibrillation: a prospective randomized controlled trial.

AIMS: The development of intracardiac echocardiography (ICE) has enabled fluoroless atrial fibrillation (AF) ablation using three-dimensional electroanatomical mapping systems. However, fluoroless cryoballoon ablation (CBA) remains challenging, mainly because of the lack of a visual mapping system. Hence, this study aimed to investigate the safety and efficacy of fluoroless CBA for AF under ICE guidance. METHODS AND RESULTS: Patients (n = 100) who underwent CBA for paroxysmal AF were randomly assigned to zero-fluoroscopic (Zero-X) and conventional groups. Intracardiac echocardiography was used to guide the transseptal puncture and catheter and balloon manipulation in all enrolled patients. The patients were prospectively followed for 12 months after CBA. The mean age was 60.4 years, and the left atrial (LA) size was 39.4 mm. Pulmonary vein isolation (PVI) was achieved in all patients. In the Zero-X group, fluoroscopy was used in only one patient because of unstable phrenic nerve capture during right-sided PVI. The procedure time and LA indwelling time in the Zero-X group were not statistically different compared with that in the conventional group. Fluoroscopic time (9.0 vs. 0.008 min) and radiation exposure (29.4 vs. 0.02 mGy) were significantly shorter in the Zero-X group than in the conventional group (P < 0.001). The complication rate did not differ between the two groups. During a mean follow-up of 663.3 ± 172.3 days, the recurrence rate was similar (16.0 vs. 18.0%; P = 0.841) between the groups. Multivariate analysis revealed that LA size was the only independent predictor of clinical recurrence. CONCLUSION: Intracardiac echocardiography-guided fluoroless CBA for AF was a feasible strategy without compromising acute and long-term success or complication rates.

Safety of a single bolus administration of heparin without the measurement of activated clotting time during cryoballoon ablation: a prospective randomized controlled trial.

BACKGROUND: Single-shot ablation has emerged as an effective technique for index atrial fibrillation (AF) ablation, with an advantage of short procedure time. Although recent guidelines recommend peri-procedural uninterrupted oral anticoagulants (OACs), the intra-procedural anticoagulation strategy remains uncertain under non-vitamin K OACs (NOACs). We investigated procedural safety of a single bolus administration of heparin without activated clotting time (ACT) measurement during cryoballoon ablation (CBA). METHODS: Two hundred patients (64.2 ± 10.0 years, 70% with non-paroxysmal AF) who underwent CBA with uninterrupted NOACs were randomly assigned to No-ACT group and ACT group. A bolus of heparin (100 U/kg) was routinely administered immediately after transseptal puncture. In the ACT group, an additional injection of heparin (30 U/kg) was administered if ACT at 30 min after the initial bolus was < 300 s. RESULTS: There were no differences in baseline characteristics including CHA2DS2-VASc score between the two groups. The left atrium indwelling and procedure times were 60.4 ± 13.1 min and 78.9 ± 13.9 min, respectively, and not significantly different between the two groups. The mean ACT was 335.2 ± 59.9 s in the ACT group. Any bleeding rate was 3.2% in all patients and there was no statistically significant difference in bleeding complications between the two groups. In the ACT group, groin hematoma, laryngopharyngeal bleeding, and hemoptysis occurred in 3, 1, and 1 patient, respectively. Cardiac tamponade occurred in 1 patient in the No-ACT group. No thromboembolic events occurred during the 30-day follow-up after CBA. CONCLUSIONS: Single bolus administration of heparin without ACT measurement is a feasible anticoagulation strategy for CBA in patients with uninterrupted NOAC intake.

Association of typical atrial flutter and cavotricuspid isthmus ablation on clinical recurrence after cryoballoon ablation for atrial fibrillation.

Typical atrial flutter commonly occurs in patients with atrial fibrillation (AF). Limited information exists regarding the effects of concurrent atrial flutter on the long-term outcomes of rhythm control. This study investigated the association between concurrent typical atrial flutter and cavotricuspid isthmus (CTI) ablation and the recurrence of atrial arrhythmia. The data were obtained from a multicenter registry of cryoballoon ablation for AF (n = 2,689). Patients who were screened for typical atrial flutter were included in the analysis (n = 1,907). All the patients with typical atrial flutter underwent CTI ablation. The primary endpoint was the late recurrence of atrial arrhythmia, including AF, atrial flutter, and atrial tachycardia. Among the 1,907 patients, typical atrial flutter was detected in 493 patients (25.9%). Patients with concurrent atrial flutter had a lower incidence of persistent AF and a smaller size of the left atrium. Patients with atrial flutter had a significantly lower recurrence rate of atrial arrhythmia (19.7% vs. 29.9%, p < 0.001). In patients with atrial flutter, the recurrence rate of atrial tachycardia or atrial flutter was more frequent (7.3% vs. 4.7%, p = 0.028), but the recurrence rate of AF was significantly lower (17.0% vs. 29.4%, p < 0.001). Atrial flutter has been identified as an independent predictor of the primary endpoint (adjusted hazard ratio, 0.704; 95% confidence interval, 0.548-0.906; p = 0.006). Typical atrial flutter in patients with AF may serve as a positive marker of the recurrence of atrial arrhythmia, and performing CTI ablation in this population is associated with a reduced likelihood of AF recurrence. Performing routine screening and ablation procedures for coexisting atrial flutter may improve the clinical outcomes of AF.

Outcomes of On-Label Reduced-Dose Edoxaban in Patients With Atrial Fibrillation: The LEDIOS Registry.

BACKGROUND: Non-vitamin K antagonist oral anticoagulants (NOACs) are effective in preventing thromboembolisms and reduce the risk of bleeding compared with warfarin. There are few reports on the outcomes of on-label reduced-dose NOACs. The aim of this study was to assess the safety and efficacy of on-label reduced-dose edoxaban in patients with atrial fibrillation (AF). METHODS: This study is a multi-center, prospective, non-interventional study to evaluate the safety and efficacy of on-label reduced-dose edoxaban in patients with AF. We evaluated outcomes of major bleeding, stroke or systemic embolism, all-cause death, and composite clinical outcomes. RESULTS: A total of 2,448 patients (mean age 75.0 ± 8.3 years, 801 [32.7%] males) was included in the present study. The mean CHA2DS2-VASc score was 3.7 ± 1.5. Major bleeding events occurred at a rate of 1.34%/yr. The event rate of strokes and systemic embolisms was 1.13%/yr. The overall net clinical outcomes occurred at a rate of 3.19%/yr. There were no significant differences according to the number of dose reduction criteria, renal dysfunction, or body weight. Higher HAS-BLED score and higher combination of CHA2DS2-VASc and HAS-BLED score was associated with an increased risk of composite clinical outcomes compared to the lower score groups. CONCLUSIONS: This study was the largest prospective real-world study to investigate the safety and efficacy of on-label low-dose edoxaban in an Asian population. Reduced-dose edoxaban can be used safely in patients with severe renal dysfunction or extremely low body weight. Our observation suggests that physicians should consider bleeding risk even in a low-dose regimen. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03554837.

Prevalence of Isolated Nocturnal Hypertension and Development of Arterial Stiffness, Left Ventricular Hypertrophy, and Silent Cerebrovascular Lesions: The KoGES (Korean Genome and Epidemiology Study).

Background Apart from nondippers' impact on cardiovascular events, the prevalence of isolated nocturnal hypertension (INH) and its consequences on both the heart and brain were not clearly investigated in the general population. Methods and Results The participants underwent ambulatory blood pressure monitoring evaluations for arterial stiffness, echocardiography, and brain magnetic resonance imaging. They were grouped into normotension, INH, and overt diurnal hypertension, based on ambulatory blood pressure monitoring and history of antihypertensive treatment. White matter hyperintensity, arterial stiffness, and echocardiographic parameters were compared. Of the 1734 participants, there were 475 (27.4%) subjects with normotension, 314 with INH (18.1%), and 945 with overt diurnal hypertension (54.5%). Prevalence of INH was not different between sex or age. Of INH, 71.3% (n=224) was caused by elevated diastolic blood pressure. After multivariable adjustment, INH showed higher pulse wave velocity (P<0.001) and central systolic blood pressure (P<0.001), left ventricular mass index (P=0.026), and worse left ventricular diastolic function (early diastolic mitral annular velocity) (P<0.001) than normotension. Mean white matter hyperintensity scores of INH were not different from normotension (P=0.321), but the odds for white matter hyperintensity presence were higher in INH than normotension (odds ratio, 1.504 [95% CI, 1.097-2.062]; P=0.011). Conclusions INH was common in the general population and associated with increased arterial stiffness, left ventricular hypertrophy, and diastolic dysfunction. White matter hyperintensity was more likely to be present in the INH group than in the normotension group. The use of ambulatory blood pressure monitoring should be encouraged to identify masked INH and prevent the occurrence of cardiovascular events.

Cryoballoon Catheter Ablation in Korean Patients With Paroxysmal and Persistent Atrial Fibrillation: One Year Outcome From the Cryo Global Registry.

BACKGROUND AND OBJECTIVES: Cryoballoon catheter ablation for the treatment of patients with symptomatic atrial fibrillation (AF) has been adopted globally, but there are limited multicenter reports of 12-month outcomes in the Korean patient population. This analysis evaluated the clinical performance and safety of cryoballoon ablation (CBA) according to standard-of-care practices in Korea. METHODS: This evaluation of Korean patients with AF was conducted within the larger Cryo Global Registry, which is a prospective, multicenter, post-market registry. Freedom from a ≥30-second recurrence of atrial arrhythmias (after a 90-day blanking period until 12 months) and procedural safety were examined in subjects treated with CBA at 3 Korean centers. RESULTS: Overall, 299 patients with AF (60±11 years old, 24.7% female, 50.5% paroxysmal AF) underwent CBA using the Arctic Front Advance cryoballoon. Of those, 298 were followed-up for at least 12 months. Mean procedure-, left atrial dwell- and fluoroscopy time was 76±21 minutes, 56±23 minutes, and 27±23 minutes, respectively. Freedom from AF recurrence at 12 months was 83.9% (95% confidence interval [CI], 76.9-88.9%) in the paroxysmal and 61.6% (95% CI, 53.1-69.0%) in the persistent AF cohort. Rhythm monitoring was performed on average 4.7±1.4 times during the follow-up period. Serious device- or procedure-related adverse events occurred in 2 patients (0.7%). The 12-month Kaplan-Meier estimate of freedom from repeat ablation and cardiovascular-related hospitalization was 93.8% (95% CI, 90.4-96.1%) and 89.7% (95% CI, 85.6-92.7%), respectively. CONCLUSIONS: CBA is an efficient, effective, and safe procedure for the treatment of AF patients when used according to real-world practices in Korea. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02752737.

Does isolation of the left atrial posterior wall using cryoballoon ablation improve clinical outcomes in patients with persistent atrial fibrillation? A prospective randomized controlled trial.

AIMS: Posterior wall isolation (PWI) of the left atrium (LA) adjunct to pulmonary vein isolation (PVI) by radiofrequency catheter ablation has shown favourable outcomes in patients with persistent atrial fibrillation (PeAF). This study was sought to investigate the efficacy and safety of additional PWI by cryoballoon ablation (CBA) alone in patients with PeAF. METHODS AND RESULTS: Patients who underwent de novo CBA for PeAF (n = 100) were randomly assigned (1 : 1) to the PVI only group and PVI combined with PWI (PVI+PWI) group. Procedural and clinical outcomes were prospectively compared over a 12-month follow-up.Baseline characteristics, including mean AF duration (56.2 ± 43.2 months) and LA size (48.2 ± 7.7 mm), were well-balanced between the groups. Successful PVI was achieved in all patients. In the PVI+PWI group, complete PWI by CBA was achieved in 31 (62%) patients. The LA indwelling and procedure times were significantly longer in the PVI+PWI group. The complication rates were not different between groups. During a mean follow-up of 457.9 ± 61.8 days, the recurrence rate of atrial tachyarrhythmia was significantly lower in the PVI+PWI group than in the PVI only group (24% vs. 46%; P = 0.035). The recurrence-free survival rate was significantly higher in the PVI+PWI group compared with the PVI only group, irrespective of complete PWI (log-rank P = 0.013). Multivariate analysis showed that adjunctive PWI [hazard ratio (HR) 0.255; P = 0.003] and LA size (HR 1.079; P = 0.014) were independent predictors of clinical recurrence. CONCLUSION: Compared with PVI only, adjunctive PWI achieved exclusively by CBA resulted in better clinical outcomes without increasing complications in patients with PeAF.

Genome-wide association study-based prediction of atrial fibrillation using artificial intelligence.

OBJECTIVE: We previously reported early-onset atrial fibrillation (AF) associated genetic loci among a Korean population. We explored whether the AF-associated single-nucleotide polymorphisms (SNPs) selected from the Genome-Wide Association Study (GWAS) of an external large cohort has a prediction power for AF in Korean population through a convolutional neural network (CNN). METHODS: This study included 6358 subjects (872 cases, 5486 controls) from the Korean population GWAS data. We extracted the lists of SNPs at each p value threshold of the association statistics from three different previously reported ethnical-specific GWASs. The Korean GWAS data were divided into training (64%), validation (16%) and test (20%) sets, and a stratified K-fold cross-validation was performed and repeated five times after data shuffling. RESULTS: The CNN-GWAS predictive power for AF had an area under the curve (AUC) of 0.78±0.01 based on the Japanese GWAS, AUC of 0.79±0.01 based on the European GWAS, and AUC of 0.82±0.01 based on the multiethnic GWAS, respectively. Gradient-weighted class activation mapping assigned high saliency scores for AF associated SNPs, and the PITX2 obtained the highest saliency score. The CNN-GWAS did not show AF prediction power by SNPs with non-significant p value subset (AUC 0.56±0.01) despite larger numbers of SNPs. The CNN-GWAS had no prediction power for odd-even registration numbers (AUC 0.51±0.01). CONCLUSIONS: AF can be predicted by genetic information alone with moderate accuracy. The CNN-GWAS can be a robust and useful tool for detecting polygenic diseases by capturing the cumulative effects and genetic interactions of moderately associated but statistically significant SNPs. TRIAL REGISTRATION NUMBER: NCT02138695.

Left Atrial Appendage Occlusion Device Embolization (The LAAODE Study): Understanding the Timing and Clinical Consequences from a Worldwide Experience.

BACKGROUND: Left atrial appendage occlusion device embolization (LAAODE) is rare but can have substantial implications on patient morbidity and mortality. Hence, we sought to perform an analysis to understand the timing and clinical consequences of LAAODE. METHODS: A comprehensive search of PubMed and Web of Science databases for LAAODE cases was performed from October 2nd, 2014 to November 1st, 2017. Prior to that, we included published LAAODE cases until October 1st, 2014 reported in the systematic review by Aminian et al. RESULTS: 103 LAAODE cases including Amplatzer cardiac plug (N=59), Watchman (N=31), Amulet (N=11), LAmbre (N=1) and Watchman FLX (N=1) were included. The estimated incidence of device embolization was 2% (103/5,000). LAAODE occurred more commonly in the postoperative period compared with intraoperative (61% vs. 39%). The most common location for embolization was the descending aorta 30% (31/103) and left atrium 24% (25/103) followed by left ventricle 20% (21/103). Majority of cases 75% (77/103) were retrieved percutaneously. Surgical retrieval occurred most commonly for devices embolized to the left ventricle, mitral apparatus and descending aorta. Major complications were significantly higher with postoperative LAAODE compared with intraoperative (44.4% vs. 22.5%, p=0.03). CONCLUSIONS: LAAODE is common with a reported incidence of 2% in our study. Post-operative device embolization occurred more frequently and was associated with a higher rate of complications than intraoperative device embolizations. Understanding the timings and clinical sequelae of DE can aid physicians with post procedural follow-up and also in the selection of patients for these procedures.

Does merged three-dimensional mapping improve contact force and long-term procedure outcome in atrial fibrillation ablation? (MICRO-AF study): a prospective randomized controlled study.

Integration of electroanatomical map (EAM) with preacquired three-dimensional (3D) cardiac images provides detailed appreciation of the complex anatomy of the left atrium (LA) and pulmonary vein (PV). High-density (HD) multi-electrode mapping catheters have enabled creating more accurate EAM reflecting real-time volume-rendered LA-PV geometry during atrial fibrillation (AF) ablation. However, no study has compared the outcomes of AF ablation using HD-EAM versus 3D-merged map. We aimed to investigate the procedural and clinical outcomes of AF ablation with HD-EAM (HD-EAM group) versus 3D-merged map (Merge group). One hundred patients (59.5 ± 11.5 years, 53% with paroxysmal AF [PAF]) were randomly assigned (1:1) to HD-EAM or Merged group. HD multi-electrode mapping and contact force (CF)-sensing catheters were used to create virtual LA-PV chamber and to perform wide antral circumferential ablation (WACA), respectively. The two groups showed no significant differences in baseline characteristics and procedural data including ablation time, fluoroscopy time, LA voltage, and CF. PV isolation with a single WACA line was achieved in 21 (42%) and 27 (54%) patients in the Merge and HD-EAM groups, respectively (P = NS). CF was significantly lower in lesions with gap than lesions without gap after a single WACA (7.3 ± 7.3 g vs. 16.0 ± 8.3, respectively, P < 0.001). During the 12-month follow-up, no significant difference in AF recurrence was observed between two groups, irrespective of AF type. In multivariate analysis, non-PAF was an independent risk factor for AF recurrence. Integration of 3D cardiac imaging did not improve procedural and clinical outcomes. HD-EAM provides an accurate real-time LA geometry.

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

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

Association of pericardial adipose tissue with left ventricular structure and function: a region-specific effect?

BACKGROUND: The independent role of pericardial adipose tissue (PAT) as an ectopic fat associated with cardiovascular disease (CVD) remains controversial. This study aimed to determine whether PAT is associated with left ventricular (LV) structure and function independent of other markers of general obesity. METHODS: We studied 2471 participants (50.9 % women) without known CVD from the Korean Genome Epidemiology Study, who underwent 2D-echocardiography with tissue Doppler imaging (TDI) and computed tomography measurement for PAT. RESULTS: Study participants with more PAT were more likely to be men and had higher cardiometabolic indices, including blood pressure, glucose, and cholesterol levels (all P < 0.001). Greater pericardial fat levels across quartiles of PAT were associated with increased LV mass index and left atrial volume index (all P < 0.001) and decreased systolic (P = 0.015) and early diastolic (P < 0.001) TDI velocities, except for LV ejection fraction. These associations remained after a multivariable-adjusted model for traditional CV risk factors and persisted even after additional adjustment for general adiposity measures, such as waist circumference and body mass index. PAT was also the only obesity index independently associated with systolic TDI velocity (P < 0.001). CONCLUSIONS: PAT was associated with subclinical LV structural and functional deterioration, and these associations were independent of and stronger than with general and abdominal obesity measures.

Impact of Catheter Ablation on Sleep Quality and Relationship Between Sleep Stability and Recurrence of Paroxysmal Atrial Fibrillation After Successful Ablation: 24-Hour Holter-Based Cardiopulmonary Coupling Analysis.

Background Sleep fragmentation and sleep apnea are common in patients with atrial fibrillation (AF). We investigated the impact of radio-frequency catheter ablation (RFCA) on sleep quality in patients with paroxysmal AF and the effect of a change in sleep quality on recurrence of AF. Methods and Results Of 445 patients who underwent RFCA for paroxysmal AF between October 2007 and January 2017, we analyzed 225 patients who had a 24-hour Holter test within 6 months before RFCA. Sleep quality was assessed by cardiopulmonary coupling analysis using 24-hour Holter data. We compared cardiopulmonary coupling parameters (high-frequency coupling, low-frequency coupling, very-low-frequency coupling) before and after RFCA. Six months after RFCA, the high-frequency coupling (marker of stable sleep) and very-low-frequency coupling (rapid eye movement/wake marker) was significantly increased (29.84%-36.15%; P<0.001; and 26.20%-28.76%; P=0.002, respectively) while low-frequency coupling (unstable sleep marker) was decreased (41.25%-32.13%; P<0.001). We divided patients into 3 tertiles according to sleep quality before RFCA, and the risk of AF recurrence in each group was compared. The second tertile was used as a reference; patients with unstable sleep (Tertile 3) had a significantly lower risk of AF recurrence (hazard ratio [HR], 0.32; 95% CI, 0.12-0.83 for high-frequency coupling; and HR, 0.22; 95% CI, 0.09-0.58 for low-frequency coupling). Conclusions Sleep quality improved after RFCA in patients with paroxysmal AF. The recurrence rate was significantly lower in patients who had unstable sleep before RFCA. These results suggest that RFCA can influence sleep quality, and sleep quality assessment before RFCA may provide a risk marker for recurrence after RFCA in patients with paroxysmal AF.

Efficacy of high-power and short-duration ablation in patients with atrial fibrillation: a prospective randomized controlled trial.

AIMS: The formation of radiofrequency lesions depends on the power and duration of ablation, and the contact force (CF). Although high power (HP) creates continuous and transmural lesions, most centres still use 25-30 W for 30-40 s for safety reasons. We evaluated the clinical efficacy and safety of a HP and short-duration (HPSD) strategy for atrial fibrillation (AF) ablation. METHODS AND RESULTS: One hundred and fifty patients [58.2 ± 10.0 years, 48% with paroxysmal AF (PAF)] scheduled for index AF ablation using a CF-sensing catheter were randomly assigned to three groups [30 W, 40 W, and 50 W at ablation sites of anterior, roof, and inferior segments of pulmonary vein (PV) antra and roof line between each upper PV]. In 25-30 W for ≤20 s was applied at posterior wall ablation site in all subjects. Compared with the 30 W and 40 W groups, procedure (P < 0.001) and ablation times (P < 0.001) were shorter and ablation number for PV isolation (P < 0.001) was smaller in the 50 W group. There were no significant differences in the CF and ablation index (AI) among the three groups. There were no significant differences in the procedure-related complication rates. During the 12-month follow-up, AF recurred in 24 (16%) patients with no significant difference among the groups (P = 0.769). In the multivariate analysis, non-PAF [hazard ratio (HR) 2.836, P = 0.045] and AI (HR 0.983, P = 0.001) were independent risk factors for AF recurrence. CONCLUSION: Radiofrequency ablation with HPSD is a safe and effective strategy with reduced ablation number and shortened procedure time compared to conventional ablation.