Yu-Feng Hu

National Yang Ming University, T’ai-pei, Taipei, Taiwan

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Publications (142)518.17 Total impact

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    ABSTRACT: Catheter ablation of atrial fibrillation (AF) has evolved over the past 20 years from being a novel, unproven procedure to a commonly performed procedure. Triggers are important for the initiation of AF and a suitable substrate is important for perpetuation of AF. Remodeling, including electrical and structural remodeling, is common in patients with persistent AF. Therefore, targeting the remodeled atrium is a critical issue during persistent AF ablation. However, ablation outcomes remain suboptimal despite aggressive substrate modification. Empirical linear ablation is not recommended because of the difficulty in achieving complete linear block and it is recommended only if macroreentry tachycardia develops during the procedure. Complex fractionated atrial electrogram (CFAE) ablation is recommended in the Heart Rhythm Society Consensus Document but efficacy has been limited in long-term follow-up studies. Rotor ablation is controversial. A combined approach using CFAE, similarity and phase mappings with rotor identification may be helpful in searching for AF sources and subsequent substrate ablation. Nevertheless, more prospective randomized studies are required to validate efficacy and safety.
    Preview · Article · Jan 2016 · Circulation Journal
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    ABSTRACT: Background: Atrial fibrillation (AF) can be associated with an increased risk of developing coronary artery disease (CAD) due to mechanisms of inflammation, endothelial dysfunction and adverse atrial remodelling. It is unclear if adverse coronary events can be further reduced after successful catheter ablation of AF. We hypothesise that AF ablation and sinus maintenance could reduce future adverse cardiac events in patients with underlying CAD. Methods: A total of 310 patients with drug-refractory paroxysmal AF and prior history of percutaneous coronary intervention (PCI) for underlying CAD were recruited in the retrospective case control study. Of these, 155 patients underwent AF ablation (the Ablation Group), while 155 patients received medical treatment (the Medical Group). All patients were followed up for major adverse cardiac events, including acute coronary syndrome requiring hospitalisation, stroke, pulmonary embolism and mortality. Results: The clinical characteristics were comparable between the two groups, except for higher antiarrhythmic drug use in the Medical Group. During a follow-up duration of 61±32 months, all-cause mortality (8.4% vs. 1.3%, p=0.004) and the overall major adverse events (47.7% vs. 12.3%, p<0.001) were significantly higher in the Medical Group than the Ablation Group. There were also more instances of stroke (10.3% vs. 3.2%, p=0.013) and acute coronary syndrome requiring hospitalisation (29% vs. 7.1%, p<0.001) in the Medical Group than the Ablation Group. Multivariate analysis confirmed that non-ablation was an independent risk factor for major adverse events (p<0.001, HR 3.4, 95% confidence interval 1.9-5.9). Conclusion: In PAF patients with established CAD who underwent PCI, catheter ablation could lead to fewer major adverse cardiac events compared to medical therapy.
    No preview · Article · Jan 2016 · Heart, Lung and Circulation
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    ABSTRACT: Background: The aim of this study was to investigate the different substrate characteristics of repetitive premature ventricular complexed (PVC) trigger sites by the non-contact mapping (NCM). Methods: Thirty-five consecutive patients, including 14 with arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC) and 21 with idiopathic right ventricular outflow tract tachycardia (RVOT VT), were enrolled for electrophysiological study and catheter ablation guided by the NCM. Substrate and electrogram (Eg) characteristics of the earliest activation (EA) and breakout (BO) sites of PVCs were investigated, and these were confirmed by successful PVC elimination. Results: Overall 35 dominant focal PVCs were identified. PVCs arose from the focal origins with preferential conduction, breakout, and spread to the whole right ventricle. The conduction time and distance from EA to BO site were both longer in the ARVC than the RVOT group. The conduction velocity was similar between the 2 groups. The negative deflection of local unipolar Eg at the EA site (EA slope3,5,10ms values) was steeper in the RVOT, compared to ARVC patients. The PVCs of ARVC occurred in the diseased substrate in the ARVC patients. More radiofrequency applications were required to eliminate the triggers in ARVC patients. Conclusions/interpretation: The substrate characteristics of PVC trigger may help to differentiate between idiopathic RVOT VT and ARVC. The slowing and slurred QS unipolar electrograms and longer distance from EA to BO in RVOT endocardium suggest that the triggers of ARVC may originate from mid- or sub-epicardial myocardium. More extensive ablation to the trigger site was required in order to create deeper lesions for a successful outcome.
    Full-text · Article · Oct 2015 · PLoS ONE
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    ABSTRACT: The clinical characteristics and prognostic value of early repolarization (ER) in patients with arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) and symptomatic ventricular arrhythmias remain unclear. We investigated the prevalence, clinical features, and cardiovascular outcomes of patients with symptomatic ARVD/C and ER. A total of 59 consecutive ARVD/C patients hospitalized for catheter ablation, presenting with and without J-point elevations of ≥0.1mV in at least 2 inferior leads or lateral leads were enrolled. Clinical characteristics, electrophysiological study, substrate mapping, catheter ablation, and future clinical outcomes in a prospective patient registry were investigated. ER was observed in 38 patients (64.4%). Among these patients, ER was found in the inferior leads in 18 patients (47.4%), in the lateral leads in 2 patients (5.3%), and in both inferior and lateral leads in 18 patients (47.4%). Patients exhibiting ER were commonly men, had lower right ventricular ejection fraction, had higher incidence of clinical ventricular fibrillation or aborted sudden cardiac death, had more defibrillator implantations, had higher the need of epicardial ablation, and had more major criteria according to the task force criteria. Significant higher incidence of induced ventricular fibrillation and shorter tachycardia cycle length of induced ventricular tachycardia were found during procedure. The recurrence rate of ventricular arrhythmias did not differ between patients with and without ER after catheter ablation. A high prevalence of electrocardiographic ER was found among symptomatic ARVD/C patients undergoing catheter ablation. ER in 12-lead ECG is associated with an increased risk of clinical fatal ventricular arrhythmias. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
    No preview · Article · Oct 2015 · International journal of cardiology
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    ABSTRACT: Atrial fibrillation (AF) is associated with cognitive decline and may contribute to an increased risk of dementia. The goal of the present study was to investigate whether statin use prevented non-vascular dementia in subjects with AF. Data from the National Health Insurance Research Database of Taiwan were used in this study. The study group comprised 51,253 AF subjects aged ≥60years who had received statin treatment. For each study patient, four age- and sex-matched AF subjects without statin exposure were selected as the control group (n=205,012). The risk of non-vascular dementia was compared between the statin and control groups. During the follow-up period, 17,201 patients experienced non-vascular dementia. The annual incidence of non-vascular dementia was lower in the statin group than in the control group (1.89% vs. 2.20%; p<0.001). Statin use exhibited a protective effect on the occurrence of non-vascular dementia, with an adjusted hazard ratio (HR) of 0.832 (95% confidence interval=0.801-0.864). Among statin types, the use of rosuvastatin was associated with the largest risk reduction (adjusted HR=0.661). Statin exposure duration was related inversely to the risk of non-vascular dementia. In this large-scale nationwide cohort study, statin use was associated with a lower risk of non-vascular dementia in AF. Use of more potent statin and longer exposure time may be associated with greater benefits. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
    No preview · Article · Oct 2015 · International journal of cardiology
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    ABSTRACT: Background: Recent studies from Asia have suggested that the risk of ischemic stroke for patients with atrial fibrillation (AF) with a "low-risk" congestive heart failure, hypertension, age ≥75, diabetes mellitus, prior stroke or transient ischemic attack, vascular disease, age 65 to 74, female (CHA2DS2-VASc) score of 0 (for males) or 1 (for females) might be higher than that for non-Asians. Objectives: This study hypothesized that the age threshold (65 years) used in the CHA2DS2-VASc system for initiating oral anticoagulants (OACs) might be lower in Taiwanese AF patients than in non-Asians. Methods: We used the National Health Insurance Research Database in Taiwan to study 186,570 nonanticoagulated AF patients. There were 9,416 males with a CHA2DS2-VASc score of 0 and 6,390 females with a CHA2DS2-VASc score of 1. Their risk of ischemic stroke was analyzed with stratification on the basis of age. Results: The annual risks of ischemic stroke for males (score 0) and females (score 1) were 1.15% and 1.12%, respectively, and continuously increased from younger to older age groups, with an increment in stroke risk evident for patients >50 years of age. At a cutoff of 50 years, patients could be further stratified into 2 subgroups with different stroke risks (>50 years of age: 1.78%/year; vs. <50 years of age: 0.53%/year). This observation was consistent for males (1.95%/year vs. 0.46%/year, respectively) and females (1.58%/year vs. 0.64%/year, respectively) with AF. In a subgroup analysis, the annual risks of ischemic stroke for males and females with AF 50 to 54 years of age were 1.47% and 1.07%, respectively. Conclusions: For Taiwanese patients 50 to 64 years of age, the annual stroke risk was 1.78%, which may exceed the threshold for OAC use for stroke prevention. The annual risk of ischemic stroke for AF patients <50 years of age was 0.53%, which was truly low-risk, and OACs could be omitted. Whether resetting the age threshold to 50 years could refine current clinical risk stratification for Asian AF patients deserves further study.
    No preview · Article · Sep 2015 · Journal of the American College of Cardiology
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    ABSTRACT: Background: -Current American and European guidelines emphasized the importance of rate control treatments in treating atrial fibrillation (AF) with a Class I recommendation, although data about the survival benefits of rate control are lacking. The goal of the present study was to investigate whether patients receiving rate control drugs had a better prognosis compared to those without rate-control treatment. Methods and results: -This study used the "National Health Insurance Research Database" in Taiwan. There were 43,879, 18,466 and 38,898 AF patients enrolled in the groups of beta-blockers (BBs), calcium channel blockers (CCBs) and digoxin, respectively. The reference group consisted of 168,678 subjects who did not receive any rate-control drug. The clinical endpoint was all-cause mortality. During a follow-up of 4.9±3.7 years, mortality occurred in 88,263 patients (32.7%). After the adjustment for the baseline differences, the risk of mortality was lower in patients receiving BBs (adjusted hazard ratio [HR] = 0.76, 95% confidence interval [CI] = 0.74-0.78) and CCBs (adjusted HR = 0.93, 95% CI = 0.90-0.96) compared to those who did not receive rate-control medications. On the contrary, the digoxin group had a higher risk of mortality with an adjusted HR of 1.12 (95% CI = 1.10-1.14). The results were consistently observed in subgroup analyses and among the cohorts after propensity matching. Conclusions: -In this nationwide AF cohort, the risk of mortality was lower for patients receiving rate-control treatments with BBs or CCBs, and the use of BBs was associated with a largest risk reduction. Digoxin use was associated with greater mortality. Prospective randomized trials are necessary to confirm these findings.
    No preview · Article · Sep 2015 · Circulation
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    ABSTRACT: The prognostic significance of premature atrial complex (PAC) burden is not fully elucidated. We aimed to investigate the relationship between the burden of PACs and long-term outcome. We investigated the clinical characteristics of 5371 consecutive patients without atrial fibrillation (AF) or a permanent pacemaker (PPM) at baseline who underwent 24-hour electrocardiography monitoring between January 1, 2002, and December 31, 2004. Clinical event data were retrieved from the Bureau of National Health Insurance of Taiwan. During a mean follow-up duration of 10±1 years, there were 1209 deaths, 1166 cardiovascular-related hospitalizations, 3104 hospitalizations for any reason, 418 cases of new-onset AF, and 132 PPM implantations. The optimal cut-off of PAC burden for predicting mortality was 76 beats per day, with a sensitivity of 63.1% and a specificity of 63.5%. In multivariate analysis, a PAC burden >76 beats per day was an independent predictor of mortality (hazard ratio: 1.384, 95% CI: 1.230 to 1.558), cardiovascular hospitalization (hazard ratio: 1.284, 95% CI: 1.137 to 1.451), new-onset AF (hazard ratio: 1.757, 95% CI: 1.427 to 2.163), and PPM implantation (hazard ratio: 2.821, 95% CI: 1.898 to 4.192). Patients with frequent PAC had increased risk of mortality attributable to myocardial infarction, heart failure, and sudden cardiac death. Frequent PACs increased risk of PPM implantation owing to sick sinus syndrome, high-degree atrioventricular block, and/or AF. The burden of PACs is independently associated with mortality, cardiovascular hospitalization, new-onset AF, and PPM implantation in the long term. © 2015 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.
    Preview · Article · Aug 2015 · Journal of the American Heart Association
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    ABSTRACT: Radiofrequency ablation of ventricular arrhythmias (VAs) originating from the continuum between the aortic sinus of Valsalva (ASV) and the left ventricular (LV) summit is a challenge. To investigate the electrocardiographic, electrophysiological, and anatomical characteristics of VAs and develop an algorithm for predicting the successful ablation site. We recruited 66 patients (mean age of 47±15 years old; 42 male patients) with symptomatic VAs originating from the continuum between the ASV and LV summit who underwent radiofrequency ablation. Patients were classified into 4 groups (group 1: ASV, n=20; group 2: subvalvular region, n=15; group 3: great cardiac vein/anterior interventricular vein [GCV/AIV], n=16; group 4: epicardium requiring pericardial access, n=15). The QRS morphological characteristics of the VAs were compared among the 4 groups. ECG analysis revealed that the aVL/aVR Q-wave ratio is useful in the prediction of successful ablation sites in the ASV, subvalvular area, GCV/AIV, and epicardium requiring pericardial access at cut-off values of ≤1.415, 1.416-1.535, 1.536-1.740, and >1.740, respectively. The aVL/aVR Q-wave ratio was well correlated to the distance between the successful ablation site and the LV summit tip. A distance of >18.9 mm and LV myocardial thickness of >9.1 mm predicted the need for the epicardial or GCV/AIV approaches. There were no major procedural complications. Eight (12.1%) patients developed VA recurrence during a mean follow-up of 15.9 months (9-24). The aVL/aVR Q-wave ratio is a useful parameter for predicting the successful ablation sites of VAs originating from the continuum between the ASV and LV summit. Copyright © 2015. Published by Elsevier Inc.
    No preview · Article · Aug 2015 · Heart rhythm: the official journal of the Heart Rhythm Society
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    ABSTRACT: Both American and European guidelines recommended the use of CHA2DS2-VASc score, rather than CHADS2, for stroke risk stratification in atrial fibrillation (AF). However, the CHA2DS2-VASc score has not been proved to be better than CHADS2 for Asians in a large-scale study. We aimed to compare the accuracies of CHADS2 and CHA2DS2-VASc scores in predicting ischemic stroke in Chinese. This study used the "National Health Insurance Research Database" in Taiwan. A total of 186,570 AF patients without antithrombotic therapies were selected as the study cohort. The clinical endpoint was occurrence of ischemic stroke. During the follow-up of 3.4+3.7 years, 23,723 patients (12.7%) experienced ischemic stroke. The CHA2DS2-VASc score performed better than CHADS2 score in predicting ischemic stroke assessed by c-indexes (0.698 versus 0.659, p<0.0001). Among 25,286 patients with a CHADS2 score of 0, the CHA2DS2-VASc score ranged from 0-3 and the annual stroke rate ranged from 1.15% to 4.47%. Compared to patients with a CHA2DS2-VASc score of 0, the hazard ratio of ischemic stroke for patients with a CHA2DS2-VASc score of 3 was 3.998. Patients with a CHADS2 score of 0 were not necessarily 'low risk', and the annual stroke rate can be as high as 4.47% when they were further stratified by the CHA2DS2-VASc score. In contrast, patients with a CHA2DS2-VASc score of 0 had a truly low risk of ischemic stroke, with an annual stroke rate around 1.15%. The same as Caucasians, the CHA2DS2-VASc score should be used for stroke risk stratification in Asians. Copyright © 2015. Published by Elsevier Inc.
    No preview · Article · Aug 2015 · Heart rhythm: the official journal of the Heart Rhythm Society
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    ABSTRACT: The recurrence of atrial fibrillation (AF) is not uncommon in the era of catheter ablation. This study aimed to evaluate the characteristics of AF patients who underwent multiple (>2) ablation procedures. Of 666 consecutive patients (53 ± 11 y/o, 484 men) who underwent catheter ablation of AF (paroxysmal AF, n = 530), 144 (22%) underwent 2 procedures and 52 (8%) underwent more than 2 procedures due to symptomatic recurrences refractory to medication during 48 ± 23 months of follow-up. Baseline and procedural characteristics at the index procedure were investigated to determine their impact on the necessity of multiple procedures. After 2 procedures, 48 (92%) of 52 patients had pulmonary vein (PV) ectopic beats initiating AF. Coexisting PV and non-PV triggers were found in 23 of 48 patients. In a multivariate analysis, the presence of non-PV triggers (p = 0.004; odds ratio 2.69, 95% CI 1.37 to 5.28) at the index procedure was the only independent predictor of necessary multiple procedures. Among patients with non-PV ectopic beats initiating AF at the index procedure, the presence of ligament of Marshall triggers (p = 0.001, odds ratio 6.74, 95% CI 2.13 to 21.32) could predict the necessity of multiple procedures. The need for multiple catheter ablation procedures can be predicted by the presence of non-PV ectopic beats initiating AF at the index procedure. However, PV-initiated AF remains the major cause of AF recurrence despite multiple catheter ablation procedures. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
    No preview · Article · Jul 2015 · Journal of Cardiovascular Electrophysiology
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    ABSTRACT: Atrial fibrillation (AF) is associated with an increased risk of cognitive impairment and functional decline, and may contribute to development of dementia. Data from a nationwide large-scale population-based cohort study are lacking. Besides, how best to predict the occurrence of incident dementia among AF subjects remains uncertain. A total of 332,665 AF subjects without dementia were identified as the study group from the "National Health Insurance Research Database" in Taiwan. For each study patient, one age- and sex-matched subject without AF and dementia was selected as the control group. The study end point was occurrence of dementia, and the usefulness of CHADS2 and CHA2DS2-VASc scores in predicting dementia was analyzed. During the follow-up, 29,012 AF patients experienced dementia with an annual incidence of 2.12%, higher than non-AF subjects (1.50%). Patients with AF possessed a higher risk of dementia with a hazard ratio (HR) of 1.420 after adjustments for age, gender, baseline differences and medication use. Among AF patients, the CHADS2 and CHA2DS2-VASc scores were significant predictors of dementia with an adjusted HR of 1.520 and 1.497 per 1 increment of the CHADS2 and CHA2DS2-VASc scores, respectively. The c-index for CHA2DS2-VASc in predicting dementia (0.611, 95% confidence interval [CI]=0.608-0.614) was significantly higher than the CHADS2 score (0.589, 95% CI=0.586-0.592) (DeLong test p<0.001). In this nationwide cohort study, AF was independently associated with a higher risk of dementia. The CHA2DS2-VASc score can be used to estimate the risk of dementia in AF patients. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
    No preview · Article · Jul 2015 · International journal of cardiology
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    ABSTRACT: Hyperthyroidism is a known reversible cause of atrial fibrillation (AF). However, some patients remain in AF despite restoration of euthyroid status. This study compared electrophysiological characteristics and long-term ablation outcome in AF patients with and without history of hyperthyroidism. The study enrolled 717 consecutive patients with AF who underwent first AF ablation, which involved pulmonary vein isolation (PVI) in paroxysmal AF and additional substrate modification in non-paroxysmal AF patients. Eighty-four patients (12%) with hyperthyroidism history were compared to those without. Euthyroid status was achieved for ≥3 months before ablation in hyperthyroid patients. Patients with hyperthyroid history were associated with older age, more female gender, lower mean right atrial voltage, higher number of PV ectopic foci (1.3±0.4 vs. 1.0±0.2, P<0.01) and higher prevalence of non-PV foci (42% vs. 23%, P<0.01). Ectopic foci from ligament of Marshall (LOM) were demonstrated more often in hyperthyroid patients (7.1% vs. 1.6%, P<0.01) in whom alcohol ablations were required. After propensity score matching for potential covariates, history of hyperthyroidism was an independent predictor of AF recurrence after single procedure (hazard ratio=2.07, 95% confidence interval=1.27-3.38). AF recurrence rates after multiple procedures were not different between patients with and without hyperthyroid history. Patients with hyperthyroid history had significantly higher number of PV ectopies and higher prevalence of non-PV ectopic foci comparing to euthyroid patients which resulted in the higher AF recurrence rate after single procedure. Copyright © 2015. Published by Elsevier Inc.
    No preview · Article · Jun 2015 · Heart rhythm: the official journal of the Heart Rhythm Society
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    ABSTRACT: Ventricular arrhythmia (VA) can occur during propafenone therapy in atrial fibrillation (AF) patients with structurally normal heart. This study was designed to evaluate the incidence and characteristics of propafenone associated VAs in AF patients with structurally normal heart. First, we studied and compared the risk of new-onset VAs between AF patients with structurally normal heart taking and not taking propafenone in a nationwide longitudinal cohort in Taiwan (n = 127197, since 2000). Then, we investigated the association between propafenone and VA in AF patients with structurally normal heart in a single-center database (n = 396). In the nationwide cohort, 102 patients (0.008% per patient-year) developed ventricular tachycardia (VT)/ ventricular fibrillation (VF) during a follow-up period of 9.8 ± 3.5 years. After multivariate Cox regression analysis, propafenone treatment was a significant risk factor for new-onset VT/VF with a hazard ratio (HR) of 3.59 (95% confidence interval (CI)= 1.30-9.89, p value = 0.0136). Propafenone treatment offered protection against ischemic stroke with HR 0.649 (95% CI =0.55-0.77, p value <0.001).In the single center study using ECG and medical records, presence of inferior J wave, wider QRS, and old age were independent risk factors for VA after adjustment of clinical, biochemical and echocardiographic variables. Albeit low incidence, propafenone therapy for AF was associated new-onset VA in the nationwide longitudinal cohort study in Taiwan. Old age, presence of inferior lead J wave, and wider QRS in ECG were significant risk factors in our single center study. Copyright © 2015. Published by Elsevier Inc.
    No preview · Article · Apr 2015 · Heart rhythm: the official journal of the Heart Rhythm Society
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    ABSTRACT: Arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) is an inherited genetic disease caused by defective desmosomal proteins, and it has typical histopathological features characterized by predominantly progressive fibro-fatty infiltration of the right ventricle. Clinical presentations of ARVD/C vary from syncope, progressive heart failure (HF), ventricular tachyarrhythmias, and sudden cardiac death (SCD). The 2010 modified Task Force criteria were established to facilitate the recognition and diagnosis of ARVD/C. An implantable cardiac defibrillator (ICD) remains to be the cornerstone in prevention of SCD in patients fulfilling the diagnosis of definite ARVD/C, especially among ARVD/C patients with syncope, hemodynamically unstable ventricular tachycardia (VT), ventricular fibrillation, and aborted SCD. Further risk stratification is clinically valuable in the management of patients with borderline or possible ARVD/C and mutation carriers of family members. However, given the entity of heterogeneous penetrance and non-uniform phenotypes, the standardization of clinical practice guidelines for at-risk individuals will be the next frontier to breakthrough.
    No preview · Article · Mar 2015 · Journal of Cardiology
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    ABSTRACT: Although the CHA2DS2-VASc (congestive heart failure, hypertension, age 75 years or older, diabetes mellitus, previous stroke or transient ischemic attack, vascular disease, age 65 to 74 years, female) score is recommended by both American and European guidelines for stroke risk stratification in atrial fibrillation (AF), the treatment recommendations for a CHA2DS2-VASc score of 1 are less clear. This study aimed to investigate the risk of ischemic stroke in patients with a single additional stroke risk factor (i.e., CHA2DS2-VASc score = 1 [males] or 2 [females]) and the impact of different component risk factors. We used the National Health Insurance Research Database in Taiwan. Among 186,570 AF patients not on antiplatelet or anticoagulant therapy, we evaluated males with a CHA2DS2-VASc score of 1 and females with a CHA2DS2-VASc score of 2. The clinical endpoint was the occurrence of ischemic stroke. Among 12,935 male AF patients with a CHA2DS2-VASc score of 1, 1,858 patients (14.4%) experienced ischemic stroke during follow-up (5.2 ± 4.3 years), with an annual stroke rate of 2.75%. Ischemic stroke risk ranged from 1.96%/year for men with vascular disease to 3.50%/year for those 65 to 74 years of age. For 7,900 females with AF and a CHA2DS2-VASc score of 2, 14.9% experienced ischemic stroke for an annual stroke rate of 2.55%. Ischemic stroke risk increased from 1.91%/year for women with hypertension to 3.34%/year for those 65 to 74 years of age. Not all risk factors in CHA2DS2-VASc score carry an equal risk, with age 65 to 74 years associated with the highest stroke rate. Oral anticoagulation should be considered for AF patients with 1 additional stroke risk factor given their high risk of ischemic stroke. Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.
    No preview · Article · Feb 2015 · Journal of the American College of Cardiology
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    ABSTRACT: Ablations of atrial fibrillation (AF) have become more widely performed, and the strategy about long-term usage of oral anticoagulants (OACs) after catheter ablation is an important issue, especially for patients without obvious evidences of recurrences. The annual rate of thromboembolic (TE) event after catheter ablation was less than 1%. CHADS2 and CHA2DS2-VASc scores could be used to identify patients at the risk of TE events after ablations who should continue OACs regardless of the status of recurrence. Despite the improvement in understanding of AF and advancement of technology in catheter ablation, the long-term successful rates of paroxysmal and non-paroxysmal AF are around 50% and 30%, respectively. Patients with a high CHADS2 score are at a high risk of recurrence which could continuously occur after the catheter ablation without reaching a plateau. Among the patients with a CHADS2 score of ≥3, 26.9% of the recurrences happened 2 years post catheter ablation. Compared to the episodes of AF before catheter ablation, the AF episodes after ablation procedures are less symptomatic and shorter in duration. Therefore, it may not be safe to stop OACs for patients with a high risk score since the AF episodes are difficult to be detected after ablation procedures, but remain dangerous. In conclusion, the decision about the long-term strategy of OACs should be based on patients' baseline clinical risk scores, such as CHADS2 and CHA2DS2-VASc scores, rather than the status of recurrence.
    No preview · Article · Feb 2015 · Journal of Thoracic Disease
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    ABSTRACT: Atrial fibrillation (AF) is the most common cardiac arrhythmia. However, the development of preventative therapies for AF has been disappointing. The infiltration of immune cells and proteins that mediate the inflammatory response in cardiac tissue and circulatory processes is associated with AF. Furthermore, the presence of inflammation in the heart or systemic circulation can predict the onset of AF and recurrence in the general population, as well as in patients after cardiac surgery, cardioversion, and catheter ablation. Mediators of the inflammatory response can alter atrial electrophysiology and structural substrates, thereby leading to increased vulnerability to AF. Inflammation also modulates calcium homeostasis and connexins, which are associated with triggers of AF and heterogeneous atrial conduction. Myolysis, cardiomyocyte apoptosis, and the activation of fibrotic pathways via fibroblasts, transforming growth factor-β and matrix metalloproteases are also mediated by inflammatory pathways, which can all contribute to structural remodelling of the atria. The development of thromboembolism, a detrimental complication of AF, is also associated with inflammatory activity. Understanding the complex pathophysiological processes and dynamic changes of AF-associated inflammation might help to identify specific anti-inflammatory strategies for the prevention of AF.
    No preview · Article · Jan 2015 · Nature Reviews Cardiology
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    ABSTRACT: Noncompliant patients might be at risk of thromboembolism because of the short half-life and rapid offset of dabigatran etexilate. The assessment and management of dabigatran noncompliance should be optimized. A total of 150 nonvalvular atrial fibrillation patients receiving dabigatran were prospectively enrolled and followed for drug compliance and persistence. Noncompliance was identified by questionnaires and interviews. The hemoclot thrombin inhibitor (HTI) assay was used for monitoring the plasma dabigatran levels. Sixteen patients were noncompliant (10.7%). None of the clinical characteristics were significantly relevant to noncompliance after multivariate analysis. The dabigatran plasma level based on HTI was the only independent predictor of noncompliance (odds ratio: 0.97 per ng/mL, P = 0.003). The prothrombin time (PT), international normalized ratio of PT (INR [PT]), and activated partial thromboplastin time did not differ between compliant and noncompliant patients. During the follow-up, the persistent prescription of dabigatran was noted in 75% of noncompliant patients without improvement in compliance. The drug discontinuation rate was higher in the noncompliant than compliant patients (6.7% vs. 25%, P = 0.035). None of the patients in either group received warfarin after discontinuing dabigatran. The assessment and management of dabigatran noncompliance is generally ignored in clinical practice. The measurement of dabigatran plasma levels by HTI could be a reliable and simple method to identify noncompliant patients. ©2015 Wiley Periodicals, Inc.
    No preview · Article · Jan 2015 · Pacing and Clinical Electrophysiology
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    ABSTRACT: Atrial fibrillation (AF) is prevalent in end-stage renal disease (ESRD) patients and negatively impacts patient outcomes. We explored the incidence and risk factors for new-onset AF among patients with ESRD undergoing renal replacement therapy, without a prior history of AF, retrieved from Taiwan's National Health Insurance Research Database (NHIRD). For each of 134,901 patients with ESRD, one age- and gender-matched control and one similarly matched patient with chronic kidney disease (CKD), a total of 404,703 patients, were selected from the NHIRD. The study endpoint was the occurrence of new-onset AF and patients were followed an average of 5.1 years. The incidence rates of AF were 12.1, 7.3, and 5.0 per 1000 person-years for ESRD, CKD, and control patients, respectively. Among patients with ESRD, age, hypertension, heart failure, coronary artery disease, peripheral arterial occlusive disease, and chronic obstructive pulmonary disease were significant risk factors for new-onset AF. Thus, patients with ESRD had a significantly higher risk of new-onset AF. The presence of multiple risk factors was associated with a higher possibility of AF occurrence.Kidney International advance online publication, 14 January 2015; doi:10.1038/ki.2014.393.
    Preview · Article · Jan 2015 · Kidney International

Publication Stats

2k Citations
518.17 Total Impact Points

Institutions

  • 2007-2016
    • National Yang Ming University
      • • School of Medicine
      • • Institute of Clinical Medicine
      T’ai-pei, Taipei, Taiwan
    • Taipei Veterans General Hospital
      • Cardiology Division
      T’ai-pei, Taipei, Taiwan
  • 2009
    • Taipei Medical University Hospital
      T’ai-pei, Taipei, Taiwan
    • University of the Ryukyus
      • Faculty of Medicine
      Okinawa, Okinawa, Japan
    • Chung Shan Medical University
      • Institute of Medicine
      臺中市, Taiwan, Taiwan