Current Anticoagulant Usage Patterns and Determinants in Korean Patients with Nonvalvular Atrial Fibrillation

PURPOSE: Stroke prevention in patients with atrial fibrillation (AF) is influenced by many factors. Using a contemporary registry, we evaluated variables associated with the use of warfarin or direct oral anticoagulants (OACs). MATERIALS AND METHODS: In the prospective multicenter CODE-AF registry, 10529 patients with AF were evaluated. Multivariate analyses were performed to identify variables associated with the use of anticoagulants. RESULTS: The mean age of the patients was 66.9±14.4 years, and 64.9% were men. The mean CHA₂DS₂-VASc and HAS-BLED scores were 2.6±1.7 and 1.8±1.1, respectively. In patients with high stroke risk (CHA₂DS₂-VASc ≥2), OACs were used in 83.2%, including direct OAC in 68.8%. The most important factors for non-OAC treatment were end-stage renal disease [odds ratio (OR) 0.27; 95% confidence interval (CI): 0.19-0.40], myocardial infarct (OR 0.53; 95% CI: 0.40-0.72), and major bleeding (OR 0.57; 95% CI: 0.39-0.84). Female sex (OR 1.40; 95% CI: 1.21-1.61), cancer (OR 1.78; 95% CI: 1.38-2.29), and smoking (OR 1.60; 95% CI: 1.15-2.24) were factors favoring direct OAC use over warfarin. Among patients receiving OACs, the rate of combined antiplatelet agents was 7.8%. However, 73.6% of patients did not have any indication for a combination of antiplatelet agents. CONCLUSION: Renal disease and history of valvular heart disease were associated with warfarin use, while cancer and smoking status were associated with direct OAC use in high stroke risk patients. The combination of antiplatelet agents with OAC was prescribed in 73.6% of patients without definite indications recommended by guidelines.ope

Adult Dilated Cardiomyopathy Patient with Wolff-Parkinson-White Syndrome

We report on catheter ablation and clinical results in an adult with Wolff-Parkinson-White (WPW) syndrome for dyssynchrony-related dilated cardiomyopathy in the absence of supraventricular tachycardia (SVT). This patient did not have sustained SVT, but developed rapid progression of ventricular dysfunction that was not responsive to heart failure medication. Ventricular preexcitation could not be medically suppressed, but was successfully ablated. This was followed by complete resolution of ventricular dysfunction within six months.ope

Physical Activity and Risk of Atrial Fibrillation: A Nationwide Cohort Study in General Population

Although exercise prevents cardiovascular disease and mortality, vigorous exercise and endurance athletics can cause atrial fibrillation (AF). However, no large cohort study has assessed the relationship between physical activity and AF in the general population. We assessed the effect of physical activity at different energy expenditures on the incidence of AF. We studied 501,690 individuals without pre-existing AF (mean age, 47.6 ± 14.3 years; 250,664 women [50.0%]) included in the Korean National Health Insurance Service database. The physical activity level was assessed using a standardized self-reported questionnaire at baseline. During a median follow-up of 4 years, 3,443 participants (1,432 women [41.6%]) developed AF. The overall incidence of AF at follow-up was 1.79 per 1,000 person-years. The subjects who met the recommended physical activity level (500-1,000 metabolic equivalent task [MET] minutes/week) had a 12% decreased AF risk (adjusted hazard ratio [HR]: 0.88, 95% confidence interval [CI]: 0.80-0.97), but not the insufficiently (1-500 MET-minutes/week; HR: 0.94, 95% CI: 0.86-1.03) and highly active subjects (≥1,000 MET-minutes/week; HR: 0.93, 95% CI: 0.85-1.03). The recommended minimum key target range of physical activity level was associated with the maximum benefit for reduced AF risk in the general population. The dose-response relationship between physical activity level and AF risk showed a U-shaped pattern. Although exceeding the key target range attenuated this benefit, it did not increase the AF risk beyond that during inactivity.ope

Conduit Puncture for Electrophysiological Procedures in Patients with Fontan Circulation

Background: Electrophysiological procedures are challenging in patients who have undergone lateral tunnel or extracardiac conduit Fontan operation because the caval veins are not connected to the cardiac atria and ventricles. This study describes our experience in managing a series of patients with Fontan circulation requiring catheter ablation for arrhythmias. Methods: This study included eight consecutive patients with Fontan circulation who underwent catheter ablation or pacemaker implantation via Fontan conduit puncture [median age (interquartile range), 21.5 (16.0-25.8) years; 5 men]. Lateral tunnel and extracardiac conduit were equally distributed among the eight patients. A standard technique for conduit puncture and subsequent electrophysiologic procedure was used. The time taken for conduit puncture was compared for different types of conduits. Results: The median age of patients in this series was 21.5 years (interquartile range: 16.0-25.8 years). Fontan conduit puncture via right femoral vein under intracardiac echocardiographic guidance was successfully performed without complications in seven of the eight patients. Conduit puncture failed in one patient with extracardiac conduit made of the pericardium due to interruption of both femoral veins. In three patients with Fontan conduit made of pericardium, a Bronckenbrough transseptal needle or a radiofrequency transseptal needle with a snare was used. In four patients with Fontan conduit made of Gore-tex, a radiofrequency transseptal needle with a snare, and percutaneous transluminal angioplasty balloon were used. Fontan conduit puncture time was significantly longer in patients with conduit made of Gore-tex (median time, 91 min; interquartile range, 59.8-130.5 min) than in patients with conduit made of the pericardium (median time, 11.5 min; interquartile range, 10.0-18.3 min), respectively (p=0.020). Conclusions: Conduit puncture is feasible and safe in patients with lateral tunnel and extracardiac Fontan circulation. Puncture of the Gore-tex conduit is more difficult and time consuming than puncture of the pericardium conduit.ope

Rare and Elusive Arrhythmia: Atrial Tachycardia From Noncoronary Aortic Cusp During Catheter Ablation for Atrial Fibrillation

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Comparison of Clinical and Imaging Characteristics and Outcomes between Provoked and Unprovoked Acute Pulmonary Embolism in Koreans

This study was performed to compare clinical and imaging parameters and prognosis of unprovoked pulmonary embolism (PE), provoked PE with reversible risk factors (provoked-rRF), and provoked PE with irreversible risk factors (provoked-iRF) in Koreans. Three hundred consecutive patients (mean age, 63.6 ± 15.0 yr; 42.8% male) diagnosed with acute PE were included. The patients were classified into 3 groups; unprovoked PE, provoked-rRF, and provoked-iRF; 43.7%, 14.7%, and 41.7%, respectively. We followed up the patients for 25.4 ± 33.7 months. Composite endpoint was all-cause mortality and recurrent PE. The provoked-iRF group had significantly higher all-cause mortality, mortality from PE and recurrent PE than the unprovoked and provoked-rRF groups (P 1.2 mg/dL; P 5 mg/L; P = 0.002; HR, 5.308; 95% CI, 1.824-15.447) and computed tomography (CT) obstruction index (P = 0.034; HR, 1.090; 95% CI, 1.006-1.181). In conclusion, provoked-iRF has a poorer prognosis than unprovoked PE and provoked-rRF. Renal insufficiency, high CRP, and CT obstruction index are poor prognostic factors in unprovoked PE.ope

Comparison of Rhythm and Rate Control Strategies for Stroke Occurrence in a Prospective Cohort of Atrial Fibrillation Patients

PURPOSE: Comparisons of rhythm and rate control strategies for stroke prevention in patients with atrial fibrillation (AF) are still inconclusive. We compared differences in clinical outcomes between the rhythm and rate control strategies. MATERIALS AND METHODS: The COmparison study of Drugs for symptom control and complication prEvention of Atrial Fibrillation (CODE-AF) registry prospectively enrolled 6000 patients who were treated for AF using real-world guideline adherence at multiple referral centers. In total, 2508 (41.8%) patients were clinically followed up for over six months. Of these, 1134 (45.2 %) patients treated by rhythm control and 1374 (54.8 %) patients treated by rate control were analyzed for clinical outcomes, including stroke and cardiovascular outcomes. RESULTS: Among all patients (age, 68+/-10 years; male, 62.4%), those treated with the rhythm control strategy were significantly younger, had more symptomatic paroxysmal AF, and a shorter AF duration, and were less likely to have diabetes, renal dysfunction, and heart failure, compared to those treated with the rate control strategy (CHA(2)DS(2)-VASc score 2.4+/-1.5 vs. 3.1+/-1.7, p<0.001). Even though oral anticoagulation was similarly prescribed in both groups, occurrence of stroke was less likely to occur in the rhythm control strategy group (0.0% vs. 0.7%, p=0.015). Multivariate Cox hazard regression showed that only age, especially more than 75 years old, were significantly correlated with the occurrence of stroke, regardless of the strategy used for treatment. CONCLUSION: In this prospective AF cohort, compared with the rate control strategy, the rhythm control strategy was associated with fewer cardiovascular events and strokes in a short-term period.ope

Label Adherence for Non-Vitamin K Antagonist Oral Anticoagulants in a Prospective Cohort of Asian Patients with Atrial Fibrillation

PURPOSE: Label adherence for non-vitamin K antagonist oral anticoagulants (NOACs) has not been well evaluated in Asian patients with non-valvular atrial fibrillation (AF). The present study aimed to assess label adherence for NOACs in a Korean AF population and to determine risk factors of off-label prescriptions of NOACs. MATERIALS AND METHODS: In this COmparison study of Drugs for symptom control and complication prEvention of AF (CODE-AF) registry, patients with AF who were prescribed NOACs between June 2016 and May 2017 were included. Four NOAC doses were categorized as on- or off-label use according to Korea Food and Drug Regulations. RESULTS: We evaluated 3080 AF patients treated with NOACs (dabigatran 27.2%, rivaroxaban 23.9%, apixaban 36.9%, and edoxaban 12.0%). The mean age was 70.5±9.2 years; 56.0% were men; and the mean CHA₂DS₂-VASc score was 3.3±1.4. Only one-third of the patients (32.7%) was prescribed a standard dose of NOAC. More than one-third of the study population (n=1122, 36.4%) was prescribed an off-label reduced dose of NOAC. Compared to those with an on-label standard dosing, patients with an off-label reduced dose of NOAC were older (≥75 years), women, and had a lower body weight (≤60 kg), renal dysfunction (creatinine clearance ≤50 mL/min), previous stroke, previous bleeding, hypertension, concomitant dronedarone use, and anti-platelet use. CONCLUSION: In real-world practice, more than one-third of patients with NOAC prescriptions received an off-label reduced dose, which could result in an increased risk of stroke. Considering the high risk of stroke in these patients, on-label use of NOAC is recommended.ope

Focal Atrial Tachycardia Arising from the Inferior Vena Cava.

The inferior vena cava (IVC) is a rare site of focal atrial tachycardia (AT). Here, we report a 20-year-old woman who underwent catheter ablation for anti-arrhythmic drug-resistant AT originating from the IVC. She had undergone open-heart surgery for patch closure of an atrial septal defect 17 years previously and permanent pacemaker implantation for sinus node dysfunction 6 years previously. The AT focus was at the anterolateral aspect of the IVC-right atrial junction, and it was successfully ablated under three-dimensional electroanatomical-mapping guidance. We suspect that the mechanism of this tachycardia was associated with previous IVC cannulation for open-heart surgery.ope

Transvascular Implantation of an Implantable Cardioverter-Defibrillator in a Patient Who has Undergone One-and-a-Half Ventricle Repair

Implantable cardioverter-defibrillator (ICD) therapy is acknowledged as a valid treatment method for the effective prevention of sudden cardiac death, which is a major cause of mortality in adult congenital heart disease patients. But ICD implantation by the conventional transvascular approach is not always possible in patients who have undergone palliative surgery due to congenital and structural heart disease. Here, we report a case in which an ICD was transvascularly implanted in an arrhythmogenic right ventricular cardiomyopathy patient who had undergone a one-and-a-half ventricle repair.ope