Predicting impaired cardiopulmonary exercise capacity in patients with atrial fibrillation using a simple echocardiographic marker.

BACKGROUND: Exercise intolerance is a common symptom associated with atrial fibrillation (AF). However, echocardiographic markers that can predict impaired exercise capacity are lacking. OBJECTIVE: This study aimed to investigate the association between echocardiographic parameters and exercise capacity assessed by cardiopulmonary exercise testing in patients with AF. METHODS: This single-center prospective study enrolled patients with AF who underwent echocardiography and cardiopulmonary exercise testing to evaluate exercise capacity at a tertiary center for AF management from 2020 to 2022. Patients with valvular heart disease, reduced left ventricular ejection fraction, or documented cardiomyopathy were excluded. RESULTS: Of the 188 patients, 134 (71.2%) exhibited impaired exercise capacity (peak oxygen consumption ≤85%), including 4 (2.1%) having poor exercise capacity (peak oxygen consumption <50%). Echocardiographic findings revealed that these patients had an enlarged left atrial end-systolic diameter (LA); smaller left ventricular end-diastolic diameter (LVEDD); and increased relative wall thickness, tricuspid regurgitation velocity, and LA/LVEDD and E/e' ratios. In addition, they exhibited lower peak systolic velocity of the mitral annulus and LA reservoir strain. In the multivariate regression model, LA/LVEDD remained the only significant echocardiographic parameter after adjustment for age, sex, and body mass index (P = .020). This significance persisted even after incorporation of heart rate reserve, N-terminal pro-B-type natriuretic peptide level, and beta-blocker use into the model. CONCLUSION: In patients with AF, LA/LVEDD is strongly associated with exercise capacity. Further follow-up and validation are necessary to clarify its clinical implications in patient care.

Sex-based differences in obstructive sleep apnea and atrial fibrillation: Implication of atrial fibrillation burden.

Background: Obstructive sleep apnea (OSA) is a risk factor for atrial fibrillation (AF); however, it is unclear whether AF increases the risk of OSA. Furthermore, sex differences among patients with both AF and OSA remain unclear. We aimed to determine the association between an increased AF burden and OSA and investigate the differences in clinical characteristics between women and men with AF and OSA. Methods: This was a descriptive, cross-sectional analysis from a prospective cohort study. Patients with non-valvular AF were recruited from the cardiac electrophysiology clinic of a tertiary center; they underwent a home sleep apnea test and 14-day ambulatory electrocardiography. Moderate-to-severe OSA was defined as an apnea-hypopnea index of ≥15. Results: Of 320 patients with AF, 53.4% had moderate-to-severe OSA, and the mean body mass index (BMI) was 25.6 kg/m2. Less women (38.2%) had moderate-to-severe OSA than men (59.3%) (p < 0.001). In the multivariate analysis, age, being a man, and BMI were significantly associated with moderate-to-severe OSA. AF burden was associated with moderate-to-severe OSA only in men (odds ratio: 1.008; 95% confidence interval: 1.001-1.014). Women and men with OSA had similar BMI (p = 0.526) and OSA severity (p = 0.754), but women were older than men (70.1 ± 1.3 vs. 63.1 ± 0.9 years, p < 0.001). Women with moderate-to-severe OSA had a lower AF burden than men did (27.6 ± 7.1 vs. 49.5 ± 3.9%, p = 0.009). Conclusions: AF burden is a sex-specific risk factor for OSA and is limited to men. In contrast, women with both AF and OSA have a lower AF burden than men, despite being older and having similar OSA severity and body habitus. Thus, AF may develop later in women with OSA than in men.

Novel scoring system derived from meta-analysis and validated in cohort population for predicting 1-year atrial fibrillation recurrence after cryoballoon catheter ablation: The HeLPS-Cryo score.

BACKGROUND: Atrial fibrillation (AF) recurrence rates in 1 year after cryoballoon ablation catheter (CBCA) are still high. We purposed to identify strong predictors for AF recurrence after the successful CBCA procedure and develop a new scoring system based only on pre-procedural parameters. METHODS: In the derivation phase, a systematic review and meta-analysis identified the strong predictors of AF recurrence after the CBCA. The pooled hazard ratio (HR) was used to create the new scoring system. The second phase validated the new scoring system in the cohort population. RESULTS: A meta-analysis including 29 cohort studies with 16196 participants confirmed that persistent AF, stroke, heart failure, and left atrial diameter (LAD) >40 mm were powerful predictors for AF recurrence after the CBCA procedure. The HeLPS-Cryo (heart failure [1], left atrial dilatation [1], persistent AF [2], and stroke [2]) was developed based on those pre-procedural predictors. It was validated in 140 patients receiving CBCA procedures and revealed excellent predictive performance for 1-year AF recurrence (AUC = 0.8877; 95% CI = 0.8208 to 0.9546). The HeLPS-Cryo score of ≥3 could predict 1-year AF recurrence with sensitivity and specificity of 78.9% and 87.9%, respectively. The positive predictive value was 66.7%, and the negative predictive value was 93.1%. CONCLUSION: The HeLPS-Cryo score can help the physician estimate the probability of 1-year AF recurrence after the successful CBCA procedure. Patients with HeLPS-Cryo score <3 are good candidates for the CBCA procedure.

Prognostic implication of heart failure stage and left ventricular ejection fraction for patients with in-hospital cardiac arrest: a 16-year retrospective cohort study.

BACKGROUND: The 2022 AHA/ACC/HFSA guidelines for the management of heart failure (HF) makes therapeutic recommendations based on HF status. We investigated whether the prognosis of in-hospital cardiac arrest (IHCA) could be stratified by HF stage and left ventricular ejection fraction (LVEF). METHODS: This single-center retrospective study analyzed the data of patients who experienced IHCA between 2005 and 2020. Based on admission diagnosis, past medical records, and pre-arrest echocardiography, patients were classified into general IHCA, at-risk for HF, pre-HF, HF with preserved ejection fraction (HFpEF), and HF with mildly reduced ejection fraction or HF with reduced ejection fraction (HFmrEF-or-HFrEF) groups. RESULTS: This study included 2,466 patients, including 485 (19.7%), 546 (22.1%), 863 (35.0%), 342 (13.9%), and 230 (9.3%) patients with general IHCA, at-risk for HF, pre-HF, HFpEF, and HFmrEF-or-HFrEF, respectively. A total of 405 (16.4%) patients survived to hospital discharge, with 228 (9.2%) patients achieving favorable neurological recovery. Multivariable logistic regression analysis indicated that pre-HF and HFpEF were associated with better neurological (pre-HF, OR: 2.11, 95% confidence interval [CI]: 1.23-3.61, p = 0.006; HFpEF, OR: 1.90, 95% CI: 1.00-3.61, p = 0.05) and survival outcomes (pre-HF, OR: 2.00, 95% CI: 1.34-2.97, p < 0.001; HFpEF, OR: 1.91, 95% CI: 1.20-3.05, p = 0.007), compared with general IHCA. CONCLUSION: HF stage and LVEF could stratify patients with IHCA into different prognoses. Pre-HF and HFpEF were significantly associated with favorable neurological and survival outcomes after IHCA. Further studies are warranted to investigate whether HF status-directed management could improve IHCA outcomes.

Long-term outcomes of left atrial appendage occlusion in patients with atrial fibrillation and end stage renal disease.

OBJECTIVE: In patients with atrial fibrillation (AF) and end-stage renal disease (ESRD), oral anticoagulants are contraindicated, and left atrial appendage occlusion (LAAO) is an alternative treatment. However, the efficacy of thromboembolic prevention using LAAO in these patients has rarely been reported in Asian populations. To our knowledge, this is the first long-term LAAO study in patients with AF undergoing dialysis in Asia. METHODS: In this study, 310 patients (179 men) with a mean age of 71.3 ± 9.6 years and mean CHA2DS2-VASc 4.2 ± 1.8 were consecutively enrolled at multiple centers in Taiwan. The outcomes of 29 patients with AF and ESRD undergoing dialysis who underwent LAAO were compared to those without ESRD. The primary composite outcomes were stroke, systemic embolization, or death. RESULTS: No difference in mean CHADS-VASc score was noted between patients with versus without ESRD (4.1 ± 1.8 vs. 4.6 ± 1.9, p = 0.453). After a mean follow-up of 38 ± 16 months, the composite endpoint was significantly higher in patients with ESRD (hazard ratio, 5.12 [1.4-18.6]; p = 0.013) than in those without ESRD after LAAO therapy. Mortality was also higher in patients with ESRD (hazard ratio, 6.6 [1.1-39.7]; p = 0.038). The stroke rate was numerically higher in patients with versus without ESRD, but the difference was not statistically significant (hazard ratio, 3.2 [0.6-17.7]; p = 0.183). Additionally, ESRD was associated with device-related thrombosis (odds ratio, 6.15; p = 0.047). CONCLUSION: Long-term outcomes of LAAO therapy may be less favorable in patients with AF undergoing dialysis, possibly because of the poor condition of patients with ESRD.

Predictors of Left Ventricular Ejection Fraction Improvement in Patients with Early-Stage Heart Failure with Reduced Ejection Fraction.

Objectives: To identify the predictors of left ventricular ejection fraction (LVEF) recovery in patients with heart failure with reduced ejection fraction (HFrEF) and compare the mortality rate between patients with HFrEF and heart failure with improved ejection fraction (HFimpEF). Methods: Patients in a post-acute care program from 2018 to 2021 were enrolled. A series of echocardiograms were arranged during follow-up. Mortality, cardiovascular death and sudden cardiac death events were recorded. A total of 259 patients were enrolled and followed for at least 1 year; 158 (61%) patients fulfilled the criteria of HFimpEF, 87 (33.6%) were defined as having persistent HFrEF, and 14 (5.4%) were defined as having heart failure with mildly reduced ejection fraction. The patients with HFimpEF and persistent HFrEF were included for analysis. Results: The mean follow-up duration was 1090 ± 414 days, and the median time to LVEF recovery was 159 days (IQR 112-289 days). Multivariate logistic regression analysis showed that beta-blocker prescription was the only independent predictor of HFimpEF [odds ratio (OR) 2.11, 95% confidence interval (CI) 1.10-4.08, p = 0.03]. Diagnosis of ischemic cardiomyopathy (ICM) and QRS duration ≥ 110 ms were negative predictors of HFimpEF (OR 0.49, 95% CI 0.27-0.88, p = 0.02, and OR 0.4, 95% CI 0.21-0.77, p = 0.005, respectively). The patients with HfimpEF had a significantly better prognosis with lower mortality (hazard ratio 0.2, 95% CI 0.08-0.50, log-rank p < 0.001) than the patients with persistent HFrEF. Conclusions: Beta-blocker prescription was an independent predictor of HFimpEF, while the diagnosis of ICM and QRS duration ≥ 110 ms were negative predictors of HFimpEF. Patients with HfimpEF had a significantly lower mortality rate compared to those with persistent HFrEF.

Noninvasive cardiac radioablation for ventricular tachycardia: dosimetric comparison between linear accelerator- and robotic CyberKnife-based radiosurgery systems.

BACKGROUND: Few dosimetric comparisons have been published between linear accelerator (LA)-based systems and CyberKnife (CK)-based robotic radiosurgery systems for cardiac radio-ablation in ventricular tachycardia. This study aimed to compare the dosimetry of noninvasive cardiac radio-ablation deliverable on LA with that on CK. METHODS: Thirteen patients who underwent noninvasive cardiac radio-ablation by LA were included. The prescribed dose was 25 Gy in 1 fraction, and the average planning target volume was 49.8 ± 31.0 cm3 (range, 14.4-93.7 cm3). CK plans were generated for comparison. RESULTS: Both the CK and LA plans accomplished appropriate dose coverage and normal tissue sparing. Compared with the LA plans, the CK plans achieved significantly lower gradient indices (3.12 ± 0.71 vs. 3.48 ± 0.55, p = 0.031) and gradient measures (1.00 ± 0.29 cm vs. 1.17 ± 0.29 cm, p < 0.001). They had similar equivalent conformity indices (CK vs. LA: 0.84 ± 0.08 vs. 0.87 ± 0.07, p = 0.093) and maximum doses 2 cm from the planning target volume (PTV) in any direction (CK vs. LA: 50.8 ± 9.9% vs. 53.1 ± 5.3%, p = 0.423). The dosimetric advantages of CK were more prominent in patients with a PTV of ≤ 50 cm3 or a spherical PTV. In patients with a PTV of > 50 cm3 or a non-spherical PTV, the LA and CK plans were similar regarding dosimetric parameters. CK plans involved more beams (232.2 ± 110.8 beams vs. 10.0 ± 1.7 arcs) and longer treatment times (119.2 ± 43.3 min vs. 22.4 ± 1.6 min, p = 0.007). CONCLUSIONS: Both CK and LA are ideal modalities for noninvasive cardiac radio-ablation. Upfront treatment should be considered based on clinical intent.

Minimal Fluoroscopic Catheter Ablation for Adult Patients with Paroxysmal Supraventricular Tachycardia without the Assistance of Intracardiac Echocardiography.

Background: Radiation exposure during fluoroscopic procedures increases the risk of cancer for both patients and operators. Objectives: The aim of this study was to investigate the safety and efficacy of adopting a three-dimensional electroanatomical mapping (3D EAM) system during ablation for paroxysmal supraventricular tachycardia (PSVT), without the assistance of intracardiac echocardiography (ICE), for both right- and left-chamber cardiac procedures. Methods: We retrospectively enrolled all patients with PSVT from September 2018 to December 2020. The patients were grouped according to the use of the 3D EAM system (3D-guided group, n = 102 vs. conventional group, n = 226). Results: The acute success rates were high in both groups (100% vs. 99.1%). The fluoroscopy time was significantly lower in the 3D-guided group than in the conventional group (2.4 ± 4.4 vs. 19.0 ± 10.8 min); the procedure time was significantly increased in the 3D-guided group (104.5 ± 29.9 vs. 94.0 ± 31.9 min), and this was associated with the post-electrophysiology test diagnosis after adjustment for multiple variables [standardized B coefficient (ß) 0.188]. There was no learning curve for each electrophysiologist in terms of fluoroscopy and procedure times. Conclusions: The 3D EAM system, without the assistance of ICE, was safe and effective in guiding PSVT ablation in both left- and right-chamber ablation.

Impact of Direct Oral Anticoagulant Concentration on Clinical Outcomes in Asian Patients with Atrial Fibrillation.

A real-world association between direct oral anticoagulant (DOAC) concentration and clinical outcomes among Asian patients with atrial fibrillation (AF) is reported herein. Patients with AF aged ≥ 20 years who used DOAC for ≥ 3 days were enrolled. Trough and peak DOAC concentrations were measured and compared with the expected range reported in clinical trials. The Cox proportional hazard model was used to investigate the association between concentration and outcomes. From January 2016 to July 2022, a total of 859 patients were enrolled. Among them, 22.5%, 24.7%, 36.4%, and 16.4% were on dabigatran, rivaroxaban, apixaban, and edoxaban, respectively. Compared with clinical trials, the proportion of DOAC concentrations higher or lower than the expected range were 9.0% and 14.6% for trough, respectively, and 20.9% and 12.1% for peak, respectively. The average follow-up duration was 2.4 ± 1.6 years. The incidence of stroke and systemic thromboembolism (SSE) was 1.31 per 100-person years, and low trough concentration predicted SSE (hazard ratio (HR) = 2.78 (1.20, 6.46)). The incidence of major bleeding was 1.64 per 100-person years, and high trough was associated with major bleeding (HR = 2.63 (1.09, 6.39)). The association between peak concentration and SSE or major bleeding was nonsignificant. Off-label underdosing (odds ratio (OR) = 2.69 (1.70, 4.26)), once daily DOAC dosing (OR = 3.22 (2.07, 5.01)), and high creatinine clearance (OR = 1.02 (1.01, 1.03)) caused low trough concentration. Contrarily, congestive heart failure was significantly associated with high trough concentration (OR = 1.71 (1.01, 2.92)). In conclusion, trough DOAC concentration measurements should be considered among patients at risk of out-of-expected range DOAC concentrations.

Impact of amiodarone on plasma concentration of direct oral anticoagulant in patients with atrial fibrillation.

BACKGROUND/PURPOSE: Amiodarone increases exposure of direct oral anticoagulants (DOACs). We aimed to analyze the effects of concurrent amiodarone use on DOAC concentrations and clinical outcomes. METHODS: Patients who were ≥20 years of age, had atrial fibrillation, and took DOAC were enrolled to provide trough and peak samples for DOAC concentration measurements using ultra-high-performance liquid chromatography-tandem mass spectrometry. The results were compared with concentrations reported in clinical trials to define above, within, or under the expected range. The outcomes of interest were major bleeding and any gastrointestinal bleeding. Multivariate logistic regression and Cox proportional hazards model were used to determine the impact of amiodarone on above-range concentration and clinical outcomes, respectively. RESULTS: A total of 722 participants (420 men, 58.2%) were enrolled to provide 691 trough samples and 689 peak samples. Among them, 21.3% concurrently used amiodarone. The proportion of patients with above-range trough and peak concentrations was 16.4% and 30.2%, respectively, for amiodarone users, in contrast to 9.4% and 19.8% for amiodarone non-users. The use of amiodarone was associated with above-range trough and peak concentrations (odds ratio [OR] = 2.00 [1.16, 3.47] and 1.82 [1.19, 2.79], respectively). However, amiodarone was not a significant predictor of major bleeding or any gastrointestinal bleeding. CONCLUSION: Concurrent amiodarone use led to increased DOAC concentration but was not associated with a higher risk of major bleeding or any gastrointestinal bleeding. Therapeutic monitoring of DOAC users concurrently taking amiodarone may be recommended for patients with an additional risk of increased DOAC exposure.

Association between atrial fibrillation burden and cognitive function in patients with atrial fibrillation.

BACKGROUND: Accumulating evidence has demonstrated an association between clinical atrial fibrillation (AF) and cognitive impairment. This study aimed to further clarify the impact of AF burden on cognitive function based on detailed electrophysiological recordings and standardized assessments of cognitive function. METHODS: This prospective cohort study, conducted at the Cardiac Electrophysiology Clinic of a tertiary center, included patients with non-valvular AF. AF burden was evaluated using 14-day patch-based electrocardiography. Cognitive function was assessed using the Montreal Cognitive Assessment (MoCA). RESULTS: Enrolled patients (n = 253) were grouped according to the median AF burden (13.52%). Patients with higher AF burden were significantly older and had larger left atrium size, a worse ejection fraction, and a lower MoCA score than those with lower AF burden. Predictors of MoCA score included age, CHA2DS2-VASc score, AF burden, and Center for Epidemiologic Studies Depression Scale scores. The association between MoCA scores and AF burden remained significant after adjustment for demographic characteristics, underlying diseases, and echocardiographic parameters (standardized beta coefficient: -0.159, 95% confidence interval: -0.020 to -0.004, p = 0.004). CONCLUSION: AF burden is associated with cognitive function in patients with AF. Further studies are required to determine whether reducing AF burden can preserve cognitive function in these patients.

2022 Taiwan lipid guidelines for primary prevention.

Elevated circulating low-density lipoprotein cholesterol (LDL-C) is a major risk factor of atherosclerotic cardiovascular disease (ASCVD). Early control of LDL-C to prevent ASCVD later in life is important. The Taiwan Society of Lipids and Atherosclerosis in association with the other seven societies developed this new lipid guideline focusing on subjects without clinically significant ASCVD. In this guideline for primary prevention, the recommended LDL-C target is based on risk stratification. A healthy lifestyle with recommendations for foods, dietary supplements and alcohol drinking are described. The pharmacological therapies for LDL-C reduction are recommended. The aim of this guideline is to decrease the risk of ASCVD through adequate control of dyslipidemia in Taiwan.

Preserved Electroencephalogram Power and Global Synchronization Predict Better Neurological Outcome in Sudden Cardiac Arrest Survivors.

Quantitative EEG (qEEG) delineates complex brain activities. Global field synchronization (GFS) is one multichannel EEG analysis that measures global functional connectivity through quantification of synchronization between signals. We hypothesized that preservation of global functional connectivity of brain activity might be a surrogate marker for good outcome in sudden cardiac arrest (SCA) survivors. In addition, we examined the relation of phase coherence and GFS in a mathematical approach. We retrospectively collected EEG data of SCA survivors in one academic medical center. We included 75 comatose patients who were resuscitated following in-hospital or out-of-hospital nontraumatic cardiac arrest between 2013 and 2017 in the intensive care unit (ICU) of National Taiwan University Hospital (NTUH). Twelve patients (16%) were defined as good outcome (GO) (CPC 1-2). The mean age in the GO group was low (51.6 ± 15.7 vs. 68.1 ± 12.9, p < 0.001). We analyzed standard EEG power, computed EEG GFS, and assessed the cerebral performance category (CPC) score 3 months after discharge. The alpha band showed the highest discrimination ability (area under curve [AUC] = 0.78) to predict GO using power. The alpha band of GFS showed the highest AUC value (0.8) to predict GO in GFS. Furthermore, by combining EEG power + GFS, the alpha band showed the best prediction value (AUC 0.86) in predicting GO. The sensitivity of EEG power + GFS was 73%, specificity was 93%, PPV was 0.67%, and NPV was 0.94%. In conclusion, by combining GFS and EEG power analysis, the neurological outcome of the nontraumatic cardiac arrest survivor can be well-predicted. Furthermore, we proved from a mathematical point of view that although both amplitude and phase contribute to obtaining GFS, the interference in phase variation drastically changes the possibility of generating a good GFS score.

Efficacy and Safety of Proprotein Convertase Subtilisin/Kexin Type 9 Inhibitors as Adjuvant Treatments for Patients with Hypercholesterolemia Treated with Statin: A Systematic Review and Network Meta-analysis.

Background: The proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors are potent LDL-C lowering agents. However, few head-to-head studies evaluated the efficacy on the lowering in other atherogenic apolipoproteins and safety of PCSK9 inhibitors at different dosages as an add-on statins therapy in hypercholesterolemia patients. Methods: This study is a systematic review and network meta-analysis of randomized control trials to compare the efficacy of lipid reduction and adverse events of PCSK9 inhibitors in statin-treated hypercholesterolemia patients. PubMed, EMBASE, and Cochrane Library databases were searched till April 20, 2021, for randomized controlled trials. Random-effect network meta-analyses were undertaken to compare the differences in the percent reduction in low-density lipoprotein cholesterol (LDL-C), apolipoprotein B (ApoB), and lipoprotein (a) [Lp(a)] levels and the risk of AEs among different PCSK9 inhibitors. Results: A total of 22 articles with 42,786 patients were included. The lipid reductions in LDL-C, ApoB, and Lp(a) with add-on PCSK9 inhibitors vs. placebo in statin-treated patients across all trials were 50-63%, 43-52%, and 23-31%, respectively. Evolocumab 140 mg Q2W was ranked the best among all treatment strategies for lowering LDL-C, ApoB, and Lp(a) levels, and the treatment difference was 68.05% (95% confidence interval (CI), 62.43% to 73.67) in LDL-C reduction, 54.95% (95% CI, 49.55% to 60.35%) in ApoB reduction, and 34.25% (95% CI, 27.59% to 40.91%) in Lp(a) reduction compared with the placebo. No significant risk difference of adverse events between PCSK9 inhibitors and placebo was found. Conclusion: PCSK9 inhibitors showed a significant effect on the reduction in LDL-C, ApoB, and Lp(a) levels in statin-treated patients. Evolocumab 140 mg Q2W showed significantly larger degrees of LDL-C, ApoB, and Lp(a) reduction.

Factors Associated With Edoxaban Concentration Among Patients With Atrial Fibrillation.

Background and Purpose: Edoxaban exposure varies across different ethnicities. The purpose of our study was to examine the risk factors associated with high or low edoxaban concentrations in Asian populations. Methods: Participants with atrial fibrillation who were undergoing edoxaban therapy were enrolled. Peak (1-4 h after edoxaban administration) and trough (24 ± 4 h from the last edoxaban dose) blood samples were collected to measure edoxaban concentrations using ultrahigh-performance liquid chromatography with tandem mass spectrometry. The edoxaban concentrations were compared to those observed in clinical trials to define a higher- or lower-than-expected range. Multivariate logistic regression was used to analyze the risk factors associated with high or low edoxaban concentrations. Results: Eighty participants (49 men, 61.3%) were enrolled and provided 78 trough and 76 peak samples. Twenty participants (25.6%) were determined to have low trough concentrations, which was associated with higher creatinine clearance and the use of the 30 mg regimen (odds ratio [OR] and 95% confidence interval [CI], 1.06 [1.01, 1.11], p = 0.01 and 5.77 [1.34, 24.75], p = 0.02, respectively). In contrast, 21 participants (27.6%) had high peak concentrations, which was associated with an off-label overdosing regimen (OR = 4.68 [1.23, 17.70], p = 0.02). Conclusion: Our study identified factors associated with increased or decreased edoxaban exposure. The measurement of edoxaban concentration may be recommended for patients with selected characteristics.

First Asian population study of stereotactic body radiation therapy for ventricular arrhythmias.

We report the first Asian series on stereotactic body radiation (SBRT) for refractory ventricular arrhythmia (VA) in Taiwanese patients. Three-dimensional electroanatomic maps, delayed-enhancement magnetic resonance imaging (DE-MRI), and dual-energy computed tomography (CT) were used to identify scar substrates. The main target volume was treated with a single radiation dose of 25 Gy and the margin volume received 20 Gy using simultaneous integrated boost delivered by the Varian TrueBeam system. Efficacy was assessed according to VA events recorded by an implantable cardioverter-defibrillator (ICD) or a 24-h Holter recorder. Pre- and post-radiation therapy imaging studies were performed. From February 2019 to December 2019, seven patients (six men, one woman; mean age, 55 years) were enrolled and treated. One patient died of hepatic failure. In the remaining six patients, at a median follow-up of 14.5 months, the VA burden and ICD shocks significantly decreased (only one patient with one ICD shock after treatment). Increased intensity on DE-MRI might be associated with a lower risk for VA recurrence, whereas dual-energy CT had lower detection sensitivity. No acute or minimal late adverse events occurred. In patients with refractory VA, SBRT is associated with a marked reduction in VA burden and ICD shocks, and DE-MRI might be useful for monitoring treatment effects.

GSTM3 variant is a novel genetic modifier in Brugada syndrome, a disease with risk of sudden cardiac death.

BACKGROUND: Brugada syndrome (BrS) is a rare inherited disease causing sudden cardiac death (SCD). Copy number variants (CNVs) can contribute to disease susceptibility, but their role in Brugada syndrome (BrS) is unknown. We aimed to identify a CNV associated with BrS and elucidated its clinical implications. METHODS: We enrolled 335 unrelated BrS patients from 2000 to 2018 in the Taiwanese population. Microarray and exome sequencing were used for discovery phase whereas Sanger sequencing was used for the validation phase. HEK cells and zebrafish were used to characterize the function of the CNV variant. FINDINGS: A copy number deletion of GSTM3 (chr1:109737011-109737301, hg38) containing the eighth exon and the transcription stop codon was observed in 23.9% of BrS patients versus 0.8% of 15,829 controls in Taiwan Biobank (P < 0.001), and 0% in gnomAD. Co-segregation analysis showed that the co-segregation rate was 20%. Patch clamp experiments showed that in an oxidative stress environment, GSTM3 down-regulation leads to a significant decrease of cardiac sodium channel current amplitude. Ventricular arrhythmia incidence was significantly greater in gstm3 knockout zebrafish at baseline and after flecainide, but was reduced after quinidine, consistent with clinical observations. BrS patients carrying the GSTM3 deletion had higher rates of sudden cardiac arrest and syncope compared to those without (OR: 3.18 (1.77-5.74), P<0.001; OR: 1.76 (1.02-3.05), P = 0.04, respectively). INTERPRETATION: This GSTM3 deletion is frequently observed in BrS patients and is associated with reduced INa, pointing to this as a novel potential genetic modifier/risk predictor for the development of the electrocardiographic and arrhythmic manifestations of BrS. FUNDING: This work was supported by the Ministry of Science and Technology (107-2314-B-002-261-MY3 to J.M.J. Juang), and by grants HL47678, HL138103 and HL152201 from the National Institutes of Health to CA.

Validation and Disease Risk Assessment of Previously Reported Genome-Wide Genetic Variants Associated With Brugada Syndrome: SADS-TW BrS Registry.

BACKGROUND: Brugada syndrome (BrS) is an oligogenic arrhythmic disease with increased risk of sudden cardiac arrest. Several BrS or ECG traits-related single-nucleotide polymorphisms (SNPs) were identified through previous genome-wide association studies in white patients. We aimed to validate these SNPs in BrS patients in the Taiwanese population, assessing the cumulative effect of risk alleles and the BrS-polygenic risk score in predicting cardiac events. METHODS: We genotyped 190 unrelated BrS patients using the TWB Array, and Taiwan Biobank was used as controls. SNPs not included in the array were imputed by IMPUTE2. Cox proportional hazards model was used to evaluate the associations between each particular SNP, the collective BrS-polygenic risk score, and clinical outcomes. RESULTS: Of the 88 previously reported SNPs, 22 were validated in Taiwanese BrS patients (P<0.05). Of the 22 SNPs, 2 (rs10428132 and rs9388451) were linked with susceptibility to BrS, 10 were SNPs previously reaching genome-wide significance, and 10 were SNPs associated with ECG traits. For the 3 most commonly reported SNPs, disease risk increased consistently with the number of risk alleles (odds ratio, 3.54; Ptrend=1.38×10-9 for 5 risk alleles versus 1). Similar patterns were observed in both SCN5A mutation+ (odds ratio, 3.66; Ptrend=0.049) and SCN5A mutation- (odds ratio, 3.75; Ptrend=8.54×10-9) subgroups. Furthermore, BrS patients without SCN5A mutations had more risk alleles than BrS patients with SCN5A mutations regardless of the range of polygenic risk scores. Three SNPs (rs4687718, rs7784776, and rs2968863) showed significant associations with the composite outcome (sudden cardiac arrest plus syncope, hazard ratio, 2.13, 1.48, and 0.41; P=0.02, 0.006, and 0.008, respectively). CONCLUSIONS: Our findings suggested that some SNPs associated with BrS or ECG traits exist across multiple populations. The cumulative risk of the BrS-related SNPs is similar to that in white BrS patients, but it appears to correlate with the absence of SCN5A mutations.