Ta-Chuan Tuan

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

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Publications (102)418.28 Total impact

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    ABSTRACT: Background: Influenza infection could activate systemic inflammatory responses and increase the sympathetic tone which play an important role in the pathogenesis of atrial fibrillation (AF). Objective: The goal of the present study was to investigate whether influenza infection was a risk factor of AF. We also aimed to study whether influenza vaccination could decrease the AF risk. Methods: From 2000-2010, a total of 11,374 patients with newly diagnosed AF were identified from the Taiwan National Health Insurance Research Database. On the same date of enrollment, 4 control patients (without AF) with matched age and sex were selected to be the control group for each study patient. The relationship between AF and influenza infection/ vaccination 1 year before the enrollment was analyzed. Results: Compared to patients without influenza infection nor vaccination (reference group, n=38,353), patients with influenza infection without vaccination (n=1,369) were associated with a significant higher risk of AF with an odds ratio of 1.182 (p=0.032) after the adjustment for baseline differences. The risk of AF was lower among patients receiving influenza vaccination without influenza infection (n=16,452) with an odds ratio of 0.881 (p<0.001). For patients who have received influenza vaccination and experienced influenza infection (n=696), the risk of AF was similar to that of the reference group (odds ratio=1.136, p=0.214). The lower risk of AF with vaccination was consistently observed in subgroup analyses. Conclusions: Influenza infection was significantly associated with the development of AF, with an 18% increase in the risk, which could be reduced through influenza vaccination.
    No preview · Article · Feb 2016 · Heart rhythm: the official journal of the Heart Rhythm Society
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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: 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: 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: Orthostatic hypotension (OH) is a common condition encountered in the elderly. The present study aimed to examine the relationship between OH and adverse events in Asians. We used the "National Health Insurance Research Database" in Taiwan. A total of 1226 patients with OH and without previous history of ischemic stroke and myocardial infarction were identified as the study group. For each study patient, ten age-, sex- and comorbidity-matched subjects without OH were selected to constitute the control group (n=12,260). The clinical endpoints were ischemic stroke, myocardial infarction and all-cause mortality. The mean age of the study population was 54.8±19.0years and males accounted for 47% of the patients. During the follow-up of 4.5±2.9years, 704 (5.2%) patients developed ischemic stroke, 190 (1.4%) patients developed myocardial infarction, and 733 (5.4%) patients died. In the multivariable Cox regression analyses which were adjusted for age, gender and differences in medication usages, OH was significantly associated with an increased risk of ischemic stroke (hazard ratio [HR]=1.40, 95% confidence interval (CI)=1.09-1.81, p=0.009), all-cause mortality (HR=1.35; 95% CI=1.05-1.73, p=0.018) and adverse events (ischemic stroke, myocardial infarction or mortality) (HR=1.41; 95% CI=1.18-1.68, p<0.001). OH is an independent factor associated with ischemic stroke and mortality in Asians. Whether aggressive managements for stroke prevention could improve the outcome for OH patients deserves further study. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
    No preview · Article · May 2015 · International Journal of Cardiology
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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: 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
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    ABSTRACT: Multiform premature ventricular complexes (PVCs) are common electrocardiographic abnormalities in patients with structurally normal hearts. However, the prognostic value of these complexes remains unclear. This study aimed to clarify the role of PVC polymorphism in predicting adverse outcomes. We examined the database for 24-hour electrocardiography monitoring between January 1, 2002 and December 31, 2004. We analyzed 3351 individuals with apparently normal hearts. Kaplan-Meier curves and multivariate Cox proportional hazards models were employed to estimate the effect of multiform PVC and uniform PVC on the number of incident adverse events. Average follow-up time was 10±1years. Patients with multiform PVC were older and had a higher prevalence of comorbidities. In multivariate analysis, patients with multiform PVC had an increased incidence of mortality (hazard ratio [HR]: 1.642, 95% confidence interval [CI]: 1.327-2.031), hospitalization (HR: 1.196, 95% CI: 1.059-1.350), cardiovascular hospitalization (HR: 1.289, 95% CI: 1.030-1.613), new-onset heart failure (HF; HR: 1.456, 95% CI: 1.062-1.997), transient ischemic accident (HR: 1.411, 95% CI 1.063-1.873), and new-onset atrial fibrillation (AF; HR: 1.546, 95% CI: 1.058-2.258) compared to the group without PVC. Patients with multiform PVC had a higher rate of mortality (HR: 1.231, 95% CI: 1.033-1.468) and all cause-hospitalization (HR: 1.147, 95% CI: 1.025-1.283) compared with patients with uniform PVC. The presence of multiform PVC was associated with a higher incidence of mortality, hospitalization, transient ischemic attack, new-onset AF, and new-onset HF independent of other clinical risk factors. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.
    No preview · Article · Nov 2014 · International Journal of Cardiology
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    ABSTRACT: Background: A new scoring system, the anticoagulation and risk factors in atrial fibrillation (ATRIA) score, was proposed for risk stratification in patients with atrial fibrillation (AF). Whether the ATRIA scheme can adequately identify patients who are at low risk of ischemic stroke remains unknown. Objectives: The goal of the present study was to compare the performance of ATRIA to that of CHA2DS2-VASc (congestive heart failure, hypertension, age ≥75, diabetes mellitus, prior stroke or transient ischemic attack, vascular disease, age 65 to 74, female) scores for stroke prediction. Methods: This study used the National Health Insurance research database in Taiwan. A total of 186,570 AF patients without antithrombotic therapy were selected as the study cohort. The clinical endpoint was the occurrence of ischemic stroke. Results: 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 ATRIA score in predicting ischemic stroke as assessed by c-indexes (0.698 vs. 0.627, respectively; p < 0.0001). The CHA2DS2-VASc score also improved the net reclassification index by 11.7% compared with ATRIA score (p < 0.0001). Among 73,242 patients categorized as low-risk on the basis of an ATRIA score of 0 to 5, the CHA2DS2-VASc scores ranged from 0 to 7, and annual stroke rates ranged from 1.06% to 13.33% at 1-year follow-up and from 1.15% to 8.00% at 15-year follow-up. The c-index of CHA2DS2-VASc score (0.629) was significantly higher than that of the ATRIA score (0.593) in this "low-risk" category (p < 0.0001). Conclusions: Patients categorized as low-risk by use of the ATRIA score were not necessarily low-risk, and the annual stroke rates can be as high as 2.95% at 1-year follow-up and 2.84% at 15-year follow-up. In contrast, patients with a CHA2DS2-VASc score of 0 had a truly low risk of ischemic stroke, with an annual stroke rate of approximately 1%.
    No preview · Article · Oct 2014 · Journal of the American College of Cardiology
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    ABSTRACT: Background The implantation of permanent pacemaker (PPM) is life-saving for patients with life-threatening bradycardia. However, the effectiveness and prognosis of PPM implantations for extremely old patients (> 90 years old) have not been investigated before. Methods From 2001-2012, a total of 108 patients older than 90 years were identified from 2,630 consecutive patients receiving PPM implantations in our hospital as the study group. For each study patient, four age-, gender- and comorbidity-matched subjects who did not have the diagnoses of bradyarrhythmias indicated for PPM implantations were selected from the “Taiwan National Health Research Database” to constitute the control group (n = 432). The study endpoint was all-cause mortality. Results The median age of the study population was 91 (inter-quartile range = 90-93) years. Among the PPM group, 45 patients died during the follow-up with an annual mortality rate of 18.7%. The risk of mortality did not differ significantly between the study and control groups with a hazard ratio of 1.020 (95% confidence interval = 0.724-1.437, p value = 0.912) after the adjustment for age and gender. Procedure-related complications occurred in 7.4% of the patients receiving PPM implants, and pocket hematoma was the most common one. The pre-implantation history of heart failure and cerebrovascular accident, rather than age, were significant predictors of mortality among PPM recipients. Conclusions Nonagenarians with severe bradyarrhythmias could retain the same life expectancies as those without bradyarrhythmias through PPM implantations. Extremely old age (> 90 years) should not be a barrier for PPM implants when indications were present.
    No preview · Article · Oct 2014 · The Canadian journal of cardiology
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    ABSTRACT: Background Digoxin and related cardiac glycoside have been used for almost 100 years in atrial fibrillation (AF). However, recent 2 analyses of the “AFFIRM” trial showed non-consistent results about the risk of mortality associated with digoxin use. The goal of the present study is to investigate the relationship between digoxin and the risk of ischemic stroke and mortality in Asians. Methods This study used the “National Health Insurance Research Database” in Taiwan. A total of 4,781 AF patients who did not receive any antithrombotic therapy were selected as the study population. Among the study population, 829 subjects (17.3%) received the digoxin treatment. The risks of ischemic stroke and mortality of patients with or without digoxin use were compared. Results The use of digoxin was associated with an increased risk of clinical events with an adjusted hazard ratio of 1.41 (95% CI =1.17-1.70) for ischemic stroke and 1.21 (95% CI =1.01-1.44) for all-cause mortality. In the subgroup analysis based on the coexistence with heart failure or not, digoxin was a risk factor of adverse events for patients without heart failure, but not for those with heart failure (interaction p<0.001 for either endpoint). Among AF patients without heart failure, the use of beta-blockers was associated with better survival with an adjusted hazard ratio of 0.48 (95% CI = 0.34-0.68). Conclusions Digoxin should be avoided for AF patients without heart failure since it was associated with an increased risk of clinical events. Beta-blockers may be a better choice for controlling ventricular rate.
    No preview · Article · Oct 2014 · The Canadian journal of cardiology
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    ABSTRACT: BACKGROUND The risk of acute myocardial infarction (AMI) in patients with atrial fibrillation (AF) with a CHA(2)DS(2)-VASc score of 0 (for men) or 1 (for women) has not been previously investigated. OBJECTIVE The objective of the present study was to compare the risk of AMI in AF and non-AF subjects with a Low (0 or 1) CHA(2)DS(2)VASc score. METHODS By using the National Health Insurance Research Database in Taiwan, we identified 7254 men with AF (with a CHA(2)DS(2)VASc score of 0) and 4860 women with AF (with a CHA(2)DS(2)-VASc score of 1). For each study patient, 1 age-, sex-, and CHA(2)DS(2)-VASc score-matched subject without AF was randomly selected to constitute the control group (n = 12,114). The clinical end point was the occurrence of AMI. RESULTS During a mean follow-up period of 5.7 L- 3.6 years, 258 patients (1.1%) suffered an AMI, with an annual incidence of 0.29% and 0.100/0 for patients with and without AF. AF was an independent risk factor of AMI, with an adjusted hazard ratio (HR) of 2.93 (95% confidence interval 2.21-3.87; P <.001). The risk of AMI was higher in men with AF than in women with AF, with a hazard ratio of 2.24 (95% confidence interval 1.61-3.11; P <.001) after adjustment for age and other comorbidities. CONCLUSION In patients with a CHA(2)DS(2)-VASc score of 0 or 1, AF was an independent risk factor of AMI. The risk of AMI was higher in men with AF than in women with AF. Cardiovascular risk prevention should be performed as part of the holistic management of AF to minimize the risks of AMI associated with AF.
    No preview · Article · Aug 2014 · Heart rhythm: the official journal of the Heart Rhythm Society
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    ABSTRACT: Introduction: The characteristics of endocardial electrograms needed to detect the overlying abnormal epicardial substrates in arrhythmogenic right ventricular cardiomyopathy with epicardial ventricular tachycardia (VT) remain unclear. This study investigated which of the endocardial electrogram characteristics could predict the overlying abnormal epicardial substrates. Methods and results: In 20 consecutive patients (median age: 46 years, 11 men) undergoing epicardial VT ablation, detailed endocardial and epicardial mappings were obtained by using the CARTO 3 system. The endocardial electrographic characteristics (unipolar peak-to-peak voltage, unipolar peak-negative-voltage, bipolar voltage, and bipolar electrogram duration) of the opposite endocardium and epicardium in RV were retrospectively investigated (N = 1,697 paired points, 84 ± 60 pairs/patient). Endocardial predictors of the presence of epicardial dense scar (<0.5 mV), low voltage zones (LVZ; ≤1.5 mV), and ablation targets (by using activation mapping, entrainment mapping, and pace mapping) were analyzed. Results: In the multivariable analysis, (1) unipolar peak-negative voltage independently predicted the presence of epicardial LVZ, epicardial dense scar, and ablation targets; (2) bipolar voltage could not predict epicardial lesions; and (3) bipolar electrogram duration predicted epicardial LVZ, but not dense scar or ablation targets. The endocardial unipolar peak-negative voltage of <1.66 mV (89% sensitivity and 53% specificity) was the optimal cutoff point for predicting epicardial dense scar. Conclusions: In patients with RV epicardial VT, the presence of unipolar peak-negative voltage of <1.66 mV in the endocardium predicted the presence of epicardial dense scar (<0.5 mV) and potential ablation targets in the overlying epicardium.
    No preview · Article · Jul 2014 · Journal of Cardiovascular Electrophysiology

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1k Citations
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Institutions

  • 2003-2016
    • National Yang Ming University
      • • School of Medicine
      • • Institute of Clinical Medicine
      T’ai-pei, Taipei, Taiwan
  • 2005-2014
    • Taipei Veterans General Hospital
      • Cardiology Division
      T’ai-pei, Taipei, Taiwan
  • 2009
    • University of the Ryukyus
      • Faculty of Medicine
      Okinawa, Okinawa, Japan