Atrial fibrillation: current knowledge and recommendations for management. Working Group on Arrhythmias of the European Society of Cardiology

Oral anticoagulation therapy initiation in patients with atrial fibrillation in relation to world region of origin: a register-based nationwide study

BACKGROUND

Atrial fibrillation (AF) is the most common sustained arrhythmia and results in a high risk of stroke. The number of immigrants is increasing globally, but little is known about potential differences in AF care across migrant populations.

AIM

To investigate if initiation of oral anticoagulation therapy (OAC) differs for patients with incident AF in relation to country of origin.

METHODS

A nationwide register-based study covering 1999-2017. AF was defined as a first-time diagnosis of AF and a high risk of stroke. Stroke risk was defined according to guidelines from the European Society of Cardiology (ESC). Poisson regression adjusted for sex, age, socioeconomic position and comorbidity was made to compute incidence rate ratios (IRR) for initiation of OAC.

RESULTS

The AF population included 254 586 individuals of Danish origin, 6673 of Western origin and 3757 of non-Western origin. Overall, OAC was initiated within -30/+90 days relative to the AF diagnosis in 50.3% of individuals of Danish origin initiated OAC, 49.6% of Western origin and 44.5% of non-Western origin. Immigrants from non-Western countries had significantly lower adjusted IRR of initiating OAC according to all ESC guidelines compared with patients of Danish origin. The adjusted IRRs ranged from 0.73 (95% CI: 0.66 to 0.80) following the launch of the 2010 ESC guideline to 0.89 (95% CI: 0.82 to 0.97) following the launch of the 2001 ESC guideline.

CONCLUSION

Patients with AF with a high risk of stroke of non-Western origin have persistently experienced a lower chance of initiating OAC compared with patients of Danish origin during the last decades.

Standardized 2D atrial mapping and its clinical applications

The visualization and comparison of electrophysiological information in the atrium among different patients could be facilitated by a standardized 2D atrial mapping. However, due to the complexity of the atrial anatomy, unfolding the 3D geometry into a 2D atrial mapping is challenging. In this study, we aim to develop a standardized approach to achieve a 2D atrial mapping that connects the left and right atria, while maintaining fixed positions and sizes of atrial segments across individuals. Atrial segmentation is a prerequisite for the process. Segmentation includes 19 different segments with 12 segments from the left atrium, 5 segments from the right atrium, and two segments for the atrial septum. To ensure consistent and physiologically meaningful segment connections, an automated procedure is applied to open up the atrial surfaces and project the 3D information into 2D. The corresponding 2D atrial mapping can then be utilized to visualize different electrophysiological information of a patient, such as activation time patterns or phase maps. This can in turn provide useful information for guiding catheter ablation. The proposed standardized 2D maps can also be used to compare more easily structural information like fibrosis distribution with rotor presence and location. We show several examples of visualization of different electrophysiological properties for both healthy subjects and patients affected by atrial fibrillation. These examples show that the proposed maps provide an easy way to visualize and interpret intra-subject information and perform inter-subject comparison, which may provide a reference framework for the analysis of the atrial fibrillation substrate before treatment, and during a catheter ablation procedure.

Clinical factors distinguishing renal infarction from acute pyelonephritis: A randomly matched retrospective case-control study

INTRODUCTION

Renal infarction (RI) is rare but clinically important because the appropriate treatment depends on the time of diagnosis. RI is often misdiagnosed as acute pyelonephritis (APN) because both diseases have nonspecific symptoms such as flank pain and abdominal pain. We identified predictors for distinguishing RI from APN.

METHODS

The data of patients visited the emergency department and diagnosed with RI or APN from March 2016 to May 2020 were prospectively collected and retrospectively analyzed. Patients aged under 18 years, with a history of trauma, or incomplete medical records were excluded. Using a matching ratio of 1:5, RI patients were randomly matched to APN patients. Multivariable logistic regression analysis was performed to identify factors that could distinguish RI from APN. In addition, we constructed a decision tree to identify patterns of risk factors and develop prediction algorithms.

RESULTS

The RI and APN groups included 55 and 275 patients, respectively. Multivariable logistic regression analysis showed that male sex (OR, 6.161; p = 0.009), atrial fibrillation (AF) (OR, 14.303; p = 0.021), costovertebral angle tenderness (CVAT) (OR, 0.106; p < 0.001), aspartate transaminase (AST) level > 21.50 U/L (OR, 19.820; p < 0.001), C-reactive protein (CRP) level < 19.75 mg/L (OR, 10.167; p < 0.001), and pyuria (OR, 0.037; p < 0.001) were significantly associated with RI distinguishing from APN.

CONCLUSION

Male sex, AF, no CVAT, AST level > 21.50 U/L, CRP level < 19.75 mg/L, and no pyuria were significant factors that could distinguish RI from APN.

Application of smart devices in investigating the effects of air pollution on atrial fibrillation onset

Few studies have examined the link between short-term exposure to air pollutants and atrial fibrillation (AF) episodes. This study aims to examine the association of hourly criteria air pollutants with AF episodes. We employ a smart device-based photoplethysmography technology to screen AF from 2018 to 2021. Hourly concentrations of six criteria air pollutants are matched to the onset hour of AF for each participant. We adopt a time-stratified case-crossover design to capture the acute effects of air pollutants on AF episodes, using conditional logistic regression models. Subgroup analyses are conducted by age, gender, and season. A total of 11,906 episodes of AF are identified in 2976 participants from 288 Chinese cities. Generally, the strongest associations of air pollutants are present at lag 18-24 h, with positive and linear exposure-response relationships. For an interquartile range increase in inhalable particles, fine particles, nitrogen dioxide, and carbon monoxide, the odds ratio (OR) of AF is 1.19 [95% confidential interval (CI): 1.03, 1.37], 1.38 (95%CI: 1.14, 1.67), 1.60 (95%CI: 1.16, 2.20) and 1.48 (95%CI: 1.19, 1.84), respectively. The estimates are robust to the adjustment of co-pollutants, and they are larger in females, older people, and in cold seasons. There are insignificant associations for sulfur dioxide and ozone. This nationwide case-crossover study demonstrates robust evidence of significant associations between hourly exposure to air pollutants and the onset of AF episodes, which underscores the importance of ongoing efforts to further improve air quality as an effective target for AF prevention.

Prognostic impact of heart rate during atrial fibrillation on clinical outcomes in elderly non-valvular atrial fibrillation patients: ANAFIE Registry sub-cohort study

BACKGROUND

Elderly patients with atrial fibrillation (AF) are at a higher risk for all-cause mortality and heart failure. Rate control is an essential component in AF management. This exploratory study assessed the relationship between resting heart rate during AF at baseline and clinical outcomes in Japanese elderly non-valvular AF (NVAF) patients, using the All Nippon AF In the Elderly Registry (ANAFIE) dataset.

METHODS

This sub-cohort included patients who agreed to participate and presented with AF at enrollment in the ANAFIE study. They were categorized into six groups according to the resting heart rate during AF. Outcomes included 2-year cumulative incidences of stroke/systemic embolic events (SEE), ischemic stroke, major bleeding, cardiovascular (CV) events, CV death, all-cause death, and net clinical outcome, a composite of stroke/SEE, major bleeding, and all-cause death.

RESULTS

Of the 8292 patients included in this sub-cohort (paroxysmal, 1496; non-paroxysmal, 6796), 90 % of patients were using anticoagulants. Higher heart rate was more frequently reported in women and in patients with paroxysmal AF and was associated with increased use of direct oral anticoagulants (DOACs) and antiarrhythmic drugs. Heart rate ≥110 beats per minute (bpm) was associated with a significantly higher incidence of cardiac events and numerically higher incidences of CV death and all-cause death compared with a heart rate of 60 to <80 bpm, all of which were driven by an increased risk in patients with non-paroxysmal AF. Hazard ratios by the type of anticoagulant for each clinical outcome were comparable across all heart rate categories, indicating no significant interactions.

CONCLUSIONS

Elderly Japanese patients with non-paroxysmal NVAF and a heart rate ≥110 bpm have an increased risk of cardiac events. There was no interaction between heart rate category and the relative risk of adverse clinical events in patients taking DOACs compared with those taking warfarin.

Usefulness of systemic immune-inflammation index in predicting atrial fibrillation recurrence after direct current cardioversion

Background: We aimed to determine whether there is a relationship between the systemic immune-inflammation (SII) index and the recurrence of atrial fibrillation (AF) after successful direct current cardioversion (DCCV). Methods: The study included 99 patients with persistent AF who underwent successful cardioversion between 2015 and 2020. Results: In multiple regression analyses, the SII index was found to be a better independent predictor of AF recurrence after successful DCCV (p < 0.001). The cut-off value of SII (563) was associated with 96.9% sensitivity and 55.2% specificity to predict AF recurrence after DCCV. Conclusion: As a simple biomarker, SII index is an independent parameter for predicting AF recurrence after successful DCCV in patients with persistent AF. Also, SII levels can predict AF recurrence better than neutrophil-to-lymphocyte ratio.

Management of atrial fibrillation: two decades of progress - a scientific statement from the European Cardiac Arrhythmia Society

BACKGROUND

Atrial fibrillation (AF) is the most common sustained arrhythmia encountered in clinical practice. The aim of this review was to evaluate the progress made in the management of AF over the two last decades.

RESULTS

Clinical classification of AF is usually based on the presence of symptoms, the duration of AF episodes and their possible recurrence over time, although incidental diagnosis is not uncommon. The majority of patients with AF have associated cardiovascular diseases and more recently the recognition of modifiable risk factors both cardiovascular and non-cardiovascular which should be considered in its management. Among AF-related complications, stroke and transient ischaemic accidents (TIAs) carry considerable morbidity and mortality risk. The use of implantable devices such as pacemakers and defibrillators, wearable garments and subcutaneous cardiac monitors with recording capabilities has enabled to access the burden of "subclinical AF". The recent introduction of non-vitamin K antagonists has led to improve the prevention of stroke and peripheral embolism. Agents capable of reversing non-vitamin K antagonists have also become available in case of clinically relevant major bleeding. Transcatheter closure of left atrial appendage represents an option for patients unable to take oral anticoagulation. When treating patients with AF, clinicians need to select the most suitable strategy, i.e. control of heart rate and/or restoration and maintenance of sinus rhythm. The studies comparing these two strategies have not shown differences in terms of mortality. If an AF episode is poorly tolerated from a haemodynamic standpoint, electrical cardioversion is indicated. Otherwise, restoration of sinus rhythm can be obtained using intravenous pharmacological cardioversion and oral class I or class III antiarrhythmic is used to prevent recurrences. During the last two decades after its introduction in daily practice, catheter ablation has gained considerable escalation in popularity. Progress has also been made in AF associated with heart failure with reduced or preserved ejection fraction.

CONCLUSIONS

Significant progress has been made within the past 2 decades both in the pharmacological and non-pharmacological managements of this cardiac arrhythmia.

Incidence and predictors of left atrial appendage thrombus on transesophageal echocardiography before elective cardioversion

Guidelines recommend transesophageal echocardiography (TEE) before cardioversion in thrombogenic arrhythmias when the requirement of ≥ 3 weeks of anticoagulation is not met. Current data to support this approach, especially with direct oral anticoagulants (DOAC), are scarce. We analyzed consecutive elective pre-cardioversion TEE in a high-volume electrophysiology center for the occurrence of left atrial appendage (LAA) thrombi or reduced LAA flow velocity. Possible predictors were recorded and compared in a multivariate logistic regression analysis. Consecutive pre-cardioversion TEE in 512 patients (148 female, median age 69 years) were included. In all patients, indication for TEE was either intake of anticoagulation < 3 weeks before cardioversion or uncertain adherence to the prescribed anticoagulation regimen. Of the 512 TEE, 19 (3.7%) depicted a LAA thrombus. An additional 41 patients (8.0%) showed either a reduced LAA flow velocity (≤ 20 cm/s), LAA sludge, or both. In a multivariate logistic regression analysis, QRS width on admission 12-lead ECG emerged as a possible predictor of LAA thrombus and reduced LAA flow (p = 0.008). Noteworthy, a high CHA2DS2-VASc score was not associated with an increased risk of reduced LAA emptying velocity and LAA thrombi were even found in patients with a CHA2DS2-VASc score of 0 (n = 1) and 1 (n = 1). The presence of LAA thrombus before an elective cardioversion is a rare event in the age of direct oral anticoagulants. However, LAA thrombi occurred even in supposed low-risk individuals according to the CHA2DS2-VASc score. QRS width may aid in identifying patients at risk of reduced LAA flow velocity.

The association of galectin-3 level with ventricular arrhythmias and left ventricular strain in heart failure patients with implantable cardioverter defibrillator

BACKGROUND

Ventricular arrhythmias are life-threatening complications of heart failure (HF). Galectin-3, an indicator of fibrosis, is associated with incident HF and was found to be related to poor prognosis in these patients. We aimed to investigate the association of galectin-3 level with left ventricular (LV) arrhythmias in HF.

METHODS

A total of 92 non-ischaemic HF patients who had implantable cardioverter-defibrillator were included in this study. Patients were divided into two groups based on the galectin-3 level. Ventricular arrhythmic events and LV strain indices were compared between the two groups. Negative binomial regression was used to detect the independent predictors of total arrhythmic events in HF patients.

RESULTS

The median age was 65 (54-71) in the high galectin-3 group (HGAL) and 62 (52-68) in the low galectin-3 group (LGAL). Ventricular arrhythmic events were more frequent in HGAL than in LGAL, including non-sustained ventricular tachycardia (VTnon), sustained-VT (VTs), and ventricular fibrillation (VF) (p < 0.0001, p = 0.002, and p = 0.026, respectively). There were no statistically significant differences between HGAL and LGAL in terms of LV strain measurements. Galectin-3 level was positively significantly correlated with total arrhythmic events (r = 0.58, p < 0.001), but no correlation was found between galectin-3 and LV global longitudinal strain (r = 0.15, p = 0.16). Galectin-3 was an independent predictor of total ventricular arrhythmic events in HF patients (p < 0.0001).

CONCLUSION

VTnon, VTs, and VF events were higher in HGAL compared to LGAL. Galectin-3 was an independent predictor of total ventricular arrhythmic events in HF patients and might be used to detect high-risk HF patients for arrhythmic events.

Socioeconomic inequality in oral anticoagulation therapy initiation in patients with atrial fibrillation with high risk of stroke: a register-based observational study

OBJECTIVE

The study aimed to examine the association between socioeconomic factors (SEFs) and oral anticoagulation (OAC) therapy and whether it was influenced by changing guidelines. We hypothesised that inequities in initiation of OAC reduced over time as more detailed and explicit clinical guidelines were issued.

DESIGN

Register-based observational study.

SETTINGS

All Danish patients with an incident hospital diagnosis of atrial fibrillation (AF), aged ≥30 years old and with high risk of stroke from 1 May 1999 to 2 October 2015 were included. Absolute risk differences (RD) (95% CI) were used to measure the association.

PARTICIPANTS

154 448 patients (mean age 78.2 years, men 47.3%).

EXPOSURE

Education, family income and cohabiting status were the SEFs used as exposure.

OUTCOME

A prescription of OAC within -30 to +90 days of baseline (incident AF).

RESULTS

During 2002-2007, the crude RD of initiation of OAC for men with high education was 14.9% (12.8 to 16.9). Inequality reduced when new guidelines were published, and in 2013-2016 the crude RD was 5.6% (3.5 to 7.7). After adjusting for age, the RD substantially reduced. The same pattern was seen for cohabiting status, while inequality was smaller and more constant for income.

CONCLUSION

Patients with low income, low education and living alone were associated with lower chance of being initiated with OAC. For education and cohabiting status, the crude difference reduced around 2011, when more detailed clinical guidelines were implemented in Denmark. Our results indicate that new guidelines might reduce inequality in OAC initiation and that new, high-cost drugs increase inequality.

Natural Course of New-Onset Postoperative Atrial Fibrillation after Noncardiac Surgery

Background

Postoperative atrial fibrillation (POAF) is common after cardiac surgery, but little is known about its incidence and natural course after noncardiac surgery. We evaluated the natural course and clinical impact of POAF and the long‐term impact of anticoagulation therapy in patients without a history of atrial fibrillation (AF) undergoing noncardiac surgery.

Methods and Results

We retrospectively analyzed the database of Asan Medical Center (Seoul, Korea) to identify patients who developed new‐onset POAF after undergoing noncardiac surgery between January 2006 and January 2016. The main outcomes were AF recurrence, thromboembolic event, and major bleeding during follow‐up. Of 322 688 patients who underwent noncardiac surgery, 315 patients (mean age, 66.4 years; 64.4% male) had new‐onset POAF with regular rhythm monitoring after discharge. AF recurred in 53 (16.8%) during 2 years of follow‐up. Hypertension (hazard ratio, 2.12; P=0.02), moderate‐to‐severe left atrial enlargement (hazard ratio, 2.33; P=0.007) were independently associated with recurrence. Patients with recurrent AF had higher risks of thromboembolic events (11.2% versus 0.8%; P<0.001) and major bleeding (26.9% versus 4.1%; P<0.001) than those without recurrence. Patients with recurrent AF and without anticoagulation were especially predisposed to thromboembolic events (P<0.001). Overall, anticoagulation therapy was not significantly associated with thromboembolic events (1.4% versus 2.5%, P=0.95).

Conclusions

AF recurred in 16.8% of patients with POAF after noncardiac surgery. AF recurrence was associated with higher risks of adverse clinical outcomes. Considering the high risk of anticoagulation‐related bleeding, the benefits of routine anticoagulation should be carefully weighed in this population. Active surveillance for AF recurrence is warranted.

The 4S-AF Scheme (Stroke Risk; Symptoms; Severity of Burden; Substrate): A Novel Approach to In-Depth Characterization (Rather than Classification) of Atrial Fibrillation

Atrial fibrillation (AF) is a complex condition requiring holistic management with multiple treatment decisions about optimal thromboprophylaxis, symptom control (and prevention of AF progression), and identification and management of concomitant cardiovascular risk factors and comorbidity. Sometimes the information needed for treatment decisions is incomplete, as available classifications of AF mostly address a single domain of AF (or patient)-related characteristics. The most widely used classification of AF based on AF episode duration and temporal patterns (that is, the classification to first-diagnosed, paroxysmal, persistent/long-standing persistent, and permanent AF) has contributed to a better understanding of AF prevention and treatment but its limitations and the need for a multidimensional AF classification have been recognized as more complex treatment options became available. We propose a paradigm shift from classification toward a structured characterization of AF, addressing specific domains having treatment and prognostic implications to become a standard in clinical practice, thus aiming to streamline the assessment of AF patients at all health care levels facilitating communication among physicians, treatment decision-making, and optimal risk evaluation and management of AF patients. Specifically, we propose the 4S-AF structured pathophysiology-based characterization (rather than classification) scheme that includes four AF- and patient-related domains-Stroke risk, Symptoms, Severity of AF burden, and Substrate severity-and provide a hypothetical model for the use of 4S-AF characterization scheme to aid treatment decision making concerning the management of patients with AF in clinical practice.

Clinical classification and the subclinical atrial fibrillation challenge: a position paper of the European Cardiac Arrhythmia Society

Symptomatic atrial fibrillation (AF) or clinical AF is associated with impaired quality of life, higher risk of stroke, heart failure, and increased mortality. Current clinical classification of AF is based on the duration of AF episodes and the recurrence over time. Appropriate management strategy should follow guidelines of Scientific Societies. The last decades have been marked by the advances in mechanism comprehension, better management of symptomatic AF, particularly regarding stroke prevention with the use of direct oral anticoagulants and a wider use of AF catheter or surgical ablations. The advent of new tools for detection of asymptomatic AF including continuous monitoring with implanted electronic devices and the use of implantable cardiac monitors and recently wearable devices or garments have identified what is called "subclinical AF" encompassing atrial high-rate episodes (AHREs). New concepts such as "AF burden" have resulted in new management challenges. Oral anticoagulation has proven to reduce substantially stroke risk in patients with symptomatic clinical AF but carries the risk of bleeding. Management of detected asymptomatic atrial arrhythmias and their relation to clinical AF and stroke risk is currently under evaluation. Based on a review of recent literature, the validity of current clinical classification has been reassessed and appropriate updates are proposed. Current evidence supporting the inclusion of subclinical AF within current clinical classification is discussed as well as the need for controlled trials which may provide responses to current therapeutic challenges particularly regarding the subsets of asymptomatic AF patients that might benefit from oral anticoagulation.

Artificial Neural Network for Atrial Fibrillation Identification in Portable Devices

Atrial fibrillation (AF) is a common cardiac disorder that can cause severe complications. AF diagnosis is typically based on the electrocardiogram (ECG) evaluation in hospitals or in clinical facilities. The aim of the present work is to propose a new artificial neural network for reliable AF identification in ECGs acquired through portable devices. A supervised fully connected artificial neural network (RSL_ANN), receiving 19 ECG features (11 morphological, 4 on F waves and 4 on heart-rate variability (HRV)) in input and discriminating between AF and non-AF classes in output, was created using the repeated structuring and learning (RSL) procedure. RSL_ANN was created and tested on 8028 (training: 4493; validation: 1125; testing: 2410) annotated ECGs belonging to the "AF Classification from a Short Single Lead ECG Recording" database and acquired with the portable KARDIA device by AliveCor. RSL_ANN performance was evaluated in terms of area under the curve (AUC) and confidence intervals (CIs) of the received operating characteristic. RSL_ANN performance was very good and very similar in training, validation and testing datasets. AUC was 91.1% (CI: 89.1-93.0%), 90.2% (CI: 86.2-94.3%) and 90.8% (CI: 88.1-93.5%) for the training, validation and testing datasets, respectively. Thus, RSL_ANN is a promising tool for reliable identification of AF in ECGs acquired by portable devices.

Catheter ablation of atrial fibrillation after pericardiectomy: multi-center experience in China

Background

To study the effectiveness and safety of atrial fibrillation (AF) catheter ablation after pericardiectomy.

Methods

Data of 24 consecutive AF patients after pericardiectomy underwent catheter ablation from five centers were collected and analyzed retrospectively. All patients were followed up at 1, 3, and 12 months after catheter ablation. Results of a repeated blood test, electrocardiogram, and echocardiography during follow-up were also collected. Adverse events such as recurrence of AF, heart failure, stroke/transient ischemic attack (TIA) and minor, and major bleeding were recorded. All patients underwent brain magnetic resonance imaging (MRI) at the end of 12 months follow-up.

Results

Patients were young (20-73 years old, 48.1±11.0). Fifteen (62.5%) patients were male. CHA2DS2-VASc score (0-3, 0.21±0.41) was low in these 24 patients. Among these patients, 11 (45.8%) were paroxysmal AF, 8 (33.3%) were persistent AF, and 5 (20.8%) were long-lasting persistent AF. Left atrium diameter over 45 mm was detected in 17 (70.8%) patients. All patients underwent catheter ablation successfully. No peri-ablation procedure-related complication happened. Oral anticoagulant therapy was stopped 3 months after the final ablation. Anti-arrhythmia drugs were continued for all patients after ablation. For 12 months follow-up, AF recurred in 10 (41.7%) patients 3-7 months after the first ablation. MRI detected silent cerebral infarction (SCI) in 2 (8.3%) patients. No other adverse events occurred during follow-up.

Conclusions

It is safe for AF patients to undergo catheter ablation after pericardiectomy, but the rate of recurrence of AF is high.

Treatment strategies and subsequent changes in the patient-reported quality-of-life among elderly patients with atrial fibrillation

BACKGROUND

Rhythm-control strategy, including catheter ablation (CA) application, constitutes an integral part of atrial fibrillation (AF) management. However, elderly patients are underrepresented in clinical trials, and reports on patient-reported outcome of various rhythm-control treatments remain limited. Therefore, we aimed to investigate the application of a rhythm-control strategy for elderly patients with AF.

METHODS

Using a prospective, multicenter Japanese registry, we analyzed 733 patients with AF aged ≥70 years who completed the Atrial Fibrillation Effect on Quality-of-Life (AFEQT) questionnaire at baseline and 1-year visit. Improvement in patient-reported quality-of-life (QOL) was assessed according to their initial treatment strategy.

RESULTS

A total of 321 patients (43.8%) were managed with rhythm-control strategy, of which 125 (17.1%) received treatment with antiarrhythmic drugs (AADs) alone and 196 (26.7%) underwent CA. Compared with the rate-control group, the rhythm-control group was younger and less likely to have comorbid conditions but had lower baseline AFEQT-overall summary (OS) scores (71.8 [standard deviation 20.3] vs. 80.0 [standard deviation 16.1]; P < .001). After the first year, AFEQT-OS scores improved regardless of treatment strategies (ie, rate- or rhythm-control). After adjusting for confounders, CA implementation and a lower baseline AFEQT score were associated with meaningful improvement in QOL (changes in AFEQT-OS score ≥5). QOL improvement among subgroups of rhythm-control patients with AADs alone was not clinically meaningful.

CONCLUSIONS

In contemporary Japanese clinical practice, rhythm-control strategy is widely implemented in elderly patients with AF, and CA use is associated with improvement in QOL in carefully selected patients.

How the Deuteration of Dronedarone Can Modify Its Cardiovascular Profile: In Vivo Characterization of Electropharmacological Effects of Poyendarone, a Deuterated Analogue of Dronedarone

Since deuterium replacement has a potential to modulate pharmacodynamics, pharmacokinetics and toxicity, we developed deuterated dronedarone; poyendarone, and assessed its cardiovascular effects. Poyendarone hydrochloride in doses of 0.3 and 3 mg/kg over 30 s was intravenously administered to the halothane-anesthetized dogs (n = 4), which provided peak plasma concentrations of 108 ± 10 and 1120 ± 285 ng/mL, respectively. The 0.3 mg/kg shortened the ventricular repolarization period. The 3 mg/kg transiently increased the heart rate at 5 min but decreased at 45 min, and elevated the total peripheral vascular resistance and left ventricular preload, whereas it reduced the mean blood pressure at 5 min, left ventricular contractility and cardiac output. The transient tachycardic action is considered to be induced by the hypotension-induced, reflex-mediated increase of sympathetic tone. The 3 mg/kg delayed both intra-atrial and intra-ventricular conductions, indicating Na⁺ channel inhibitory action. Moreover, the 3 mg/kg transiently shortened the ventricular repolarization period at 5 min. No significant change was detected in the late repolarization by poyendarone, indicating it might not hardly significantly alter rapidly activating delayed-rectifier K⁺ current (I_Kr). Poyendarone prolonged the atrial effective refractory period greater than the ventricular parameter. When compared with dronedarone, poyendarone showed similar pharmacokinetics of dronedarone, but reduced β-adrenoceptor blocking activity as well as the cardio-suppressive effect. Poyendarone failed to inhibit I_Kr and showed higher atrial selectivity in prolonging the effective refractory period of atrium versus ventricle. Thus, the deuteration may be an effective way to improve the cardiovascular profile of dronedarone. Poyendarone is a promising anti-atrial fibrillatory drug candidate.

Presence and function of stress granules in atrial fibrillation

AIMS

Stress granules (SGs) are transient cytoplasmic mRNA and protein complexes that form in eukaryotic cells under stress. SGs are related to multiple diseases, but there are no reports of the existence of SGs in atrial fibrillation (AF).

METHODS AND RESULTS

Cell models of AF were established by field stimulation at 600 times per minute. HL-1 cells, cardiomyocytes and cardiac fibroblasts were transfected with G3BP1-cDNA plasmid by Lipofectamine 2000. The presence of SGs was detected by immunofluorescence analysis against GTPase-activating protein SH3 domain binding protein 1 (G3BP1) and poly(A)-binding protein 1 (PABP-1) and electron microscopy. Stable HL-1 cell lines transfected with lentivirus overexpressing G3BP1were constructed to further induce the formation of SGs in AF. Reactive oxygen species (ROS) and calcium overload in tachypaced HL-1 cells were studied by flow cytometry. The effects of G3BP1 overexpression on cardiac fibroblast proliferation and the protein expression level of collagen I/III and fibronectin-1 were also studied. Additionally, we detected protein synthesis in general and in single cells by puromycin incorporation in paced HL-1 cells. Here, we first showed that SGs are present in both tachypaced mouse cardiomyocytes and HL-1 atrial cells, although the presence is partial and at a low level. G3BP1 overexpression promoted SG formation, inhibited the rapid pacing-induced increase in ROS level, and attenuated calcium overload in HL-1 cells (all P<0.05). Furthermore, G3BP1 overexpression inhibited cardiac fibroblast proliferation (P<0.05) and decreased the protein expression level of collagen I and fibronectin-1 in cardiac fibroblasts stimulated by angiotensin II (all P<0.05). The bulk puromycin incorporation analyzed by Western blot did not show a global reduction in protein synthesis. However, puromycin incorporation in single cells detected by immunofluorescence analysis showed that protein synthesis in SG-containing cells significantly reduced (P<0.01).

CONCLUSIONS

SGs are rapidly induced and present partially in AF, and G3BP1 overexpression promotes SG formation and confers cytoprotection against oxidative stress, calcium overload and atrial fibrosis in AF.

Relation of Neutrophil to Lymphocyte Ratio to Risk of Incident Atrial Fibrillation

Clinical and experimental data support a critical role for inflammation in cardiovascular disease. The purpose of the current study was to examine the relation between an inflammatory marker, neutrophil-to-lymphocyte ratio (NLR), and incident atrial fibrillation (AF) in asymptomatic adults. We investigated 21,118 self-referred men and women who were annually screened in a tertiary medical center. All subjects were free of AF at baseline and had their serum NLR calculated at the first annual visit. Subjects were divided into 2 groups based on their baseline NLR: Low (<2.83; n = 17,524) and high (≥2.83; n = 3,594; Upper Sextile). The primary endpoint was new onset AF during follow-up. Mean age of study population was 48 ± 10 years and 72% were men. A total of 563 (2.7%) incident events occurred during an average follow-up of 7.5 ± 5 years. Unadjusted Cox regression analysis demonstrated that each 1 unit increase in NLR was associated with a significant 14% increase in risk of occurrence of a first AF event (95% confidence interval 1.06 to 1.23, p < 0.001) and 20% increased risk of death. Kaplan-Meier's survival analysis showed that the cumulative probability of incident AF was significantly higher among subjects with high NLR compared with low NLR group (p = 0.006). Interaction analysis with adjustment to clinical parameters showed that NLR-related risk was age-dependent, such that in the younger age-group (< =50 years) high NLR group had two folds increased risk for AF event compared with low NLR group (95% confidence interval 1.08 to 3.51; p = 0.027) whereas among older subjects the rate of events was similar between both NLR groups (p = NS; p for interaction = 0.024). In conclusion, our findings suggest that high NLR is associated with increased risk of new onset AF. This finding is more pronounced among young adults.

Exploring the Quality of Anticoagulant Prescribed for Patients With Atrial Fibrillation at the St John of God Hawkesbury District Health Centre, New South Wales, Australia

BACKGROUND

Limited data are available on the clinical management of atrial fibrillation (AF) and its outcomes from an Australian perspective.

OBJECTIVE

To describe the appropriateness of antithrombotic prescribing for patients who presented with a diagnosis of AF to the Hawkesbury St John of God Hospital, New South Wales, Australia.

METHODS

This retrospective observational study reviewed patients admitted to St John of God Hawkesbury Hospital with AF between June 2016 and June 2017. We calculated stroke risk using the CHA2DS2-VASc score based on medical records and reviewed the appropriateness of oral anticoagulant (OAC) prescribing compared to the 2016 European Society of Cardiology guidelines. Patients were excluded if they had only 1 episode of AF that reverted either spontaneously or upon cardioversion without any documented recurrences.

RESULTS

A total of 200 patients (18 years) were included, with 180 (90%) deemed eligible for anticoagulation. Of these 72.8% (n = 131) were prescribed an OAC. A total of 40.0% of patients at low risk of stroke and 68.4% at intermediate risk were prescribed an OAC, respectively. Apixaban was the direct OAC of choice with 36.6% of patients prescribed an OAC receiving apixaban. Warfarin was prescribed for 25.1% of the patients who were prescribed an OAC.

CONCLUSIONS

The underutilization of anticoagulant medication in high-risk groups and over utilization in low-risk groups remains an ongoing issue in contemporary AF management, and it highlights the need to improve AF-related stroke prevention in our jurisdiction.

Analysis of cardiovascular mortality, bleeding, vascular and cerebrovascular events in patients with atrial fibrillation vs. sinus rhythm undergoing transfemoral Transcatheter Aortic Valve Implantation (TAVR)

Background

Transcatheter aortic valve replacement (TAVR) has been demonstrated to be an established therapy for high-risk, inoperable patients with severe symptomatic aortic valve stenosis. For patients with moderate surgical risk, TAVR is equivalent to conventional aortic valve surgery. However, atrial fibrillation (AF) is also present in many of these patients, thus requiring post-implantation oral anticoagulation therapy in addition to the inhibition of thrombocyte aggregation, which poses the risk of bleeding complications. The aim of our work was to investigate the influence of AF on mortality and the occurrence of bleeding, vascular and cerebrovascular complications related to TAVR according to the VARC-2 criteria.

Methods

Two hundred eighty-three patients who underwent TAVR between March 2010 and April 2016 were retrospectively examined. In total, 257 patients who underwent transfemoral access were included in this study. The mean patient age was 81 ± 6 years, 54.1% of the patients were women, and 42.4% had pre-interventional AF.

Results

Compared to patients with sinus rhythm (SR, n = 148), patients with AF (n = 109) had an almost three-fold higher incidence of major vascular complications (AF 14.7% vs. SR 5.4%, p = 0.016) and life-threatening bleeding (AF 11.9% vs. SR 4.1%, p = 0.028) during the first 30 post-procedural days. However, the rate of cerebrovascular complications (AF 3.7% vs. SR 2.7%, p = 0.726) did not significantly differ between the two groups. Overall mortality was significantly higher in patients with AF during the first month (AF 8.3% vs. SR 2.0%, p = 0.032) and the first year (AF 28.4% vs. SR 15.3%; p = 0.020) following TAVR.

Conclusion

Patients with AF had significantly more severe bleeding complications after TAVR, which were significantly related to mortality. Future prospective randomized studies must clarify the optimal anticoagulation therapy for patients with AF after TAVR.

Trial registration

DRKS00011798 on DRKS (Date 17.03.2017).

Timing of Susceptibility to Mortality and Heart Failure in Patients With Preexisting Atrial Fibrillation After Transcatheter Aortic Valve Implantation

The relationship between cardiac rhythm and adverse events after transcatheter aortic valve implantation (TAVI) remains unclear. To compare the prognostic impact of preexisting atrial fibrillation (AF) and new-onset AF (NOAF) after TAVI, we assessed 1,124 patients (846 with sinus rhythm [SR], 49 with NOAF, and 229 with preexisting AF) who underwent TAVI with a balloon-expandable valve from October 2013 to April 2016. The incidences of all-cause death and rehospitalization for heart failure (HF) were retrospectively evaluated. The median follow-up period was 370 days (range 188 to 613). In the Kaplan-Meier analysis, the incidences of all-cause death and rehospitalization for HF were significantly higher in patients with preexisting AF than those in patients with NOAF and SR. The multivariable analysis showed that preexisting AF was significantly associated with increased all-cause death (hazard ratio [HR] 1.54; 95% confidence interval [CI] 1.02 to 2.34) and rehospitalization for HF (HR 2.94; 95% CI 1.75 to 4.93). The landmark analysis demonstrated that patients with preexisting AF had a significantly higher incidence of rehospitalization for HF within the first 6 months after TAVI (HR 4.04; 95% CI 2.23 to 7.32), and a higher incidence of all-cause death from 6 months to 2 years after TAVI (HR 2.12; 95% CI 1.15 to 3.90). Our study demonstrated that preexisting AF increased the risk of all-cause death and rehospitalization for HF after TAVI in comparison with NOAF or SR. Moreover, there was a specific timing of susceptibility to all-cause death and rehospitalization for HF after TAVI.

Contemporary Atrial Fibrillation Management: A Comparison of the Current AHA/ACC/HRS, CCS, and ESC Guidelines

In this article we compare and contrast the current recommendations, and highlight the important differences, in the American College of Cardiology/American Heart Association/Heart Rhythm Society, European Society of Cardiology, and Canadian Cardiovascular Society atrial fibrillation (AF) guidelines. Although many of the recommendations of the various societies are similar, there are important differences in the methodologies underlying their development and the specific content. Specifically, key differences can be observed in: (1) the definition of nonvalvular AF, which subsequently affects anticoagulation choices and candidacy for non-vitamin K antagonist oral anticoagulants; (2) the symptom score used to guide management decisions and longitudinal patient profiling; (3) the stroke risk stratification algorithm used to determine indications for oral anticoagulant therapy; (4) the role of acetylsalicylic acid in stroke prevention in AF; (5) the antithrombotic regimens used in the context of coronary artery disease, acute coronary syndromes, and percutaneous coronary intervention; (6) the rate control target and medications recommended to achieve the target; and (7) the role of "first-line" catheter ablation, open surgical ablation, and left atrial appendage exclusion.

Impact of atrial fibrillation on the clinical course of apical hypertrophic cardiomyopathy

BACKGROUND

Apical hypertrophic cardiomyopathy (ApHCM) is considered a 'benign' form of hypertrophic cardiomyopathy, with limited data on the long-term outcome. However, the clinical impact of atrial fibrillation (AF) in ApHCM is largely unknown. The hypothesis was that AF is common and has a prognostic implication in ApHCM.

METHODS

The occurrence of AF and outcome was assessed in 306 consecutive patients with ApHCM (68% male, 62±11 years).

RESULTS

AF occurred in 77 patients with ApHCM (prevalence, 25.2%; annual incidence, 4.6%/year) and was independently predicted by old age and large left atrium (>45 mm). Among 70 AF patients indicated with anticoagulation, 53 patients (76%) received warfarin. During a follow-up of 5.5±2.0 years, the patients with AF had a higher incidence of all-cause death, cardiovascular death and strokes (11.7% vs 1.3%, 6.5% vs 0.9% and 19.5% vs 2.6%, respectively, all p<0.05) than those without AF. When adjusted by the age and gender, those with AF still had an increased risk for all-cause death (HR 6.58; 95% CI 1.65-26.16, p=0.007) and strokes (HR 5.13; 95% CI 1.85 to 14.18, p=0.002). AF was detected before the time of stroke in 8 (53%) out of 15 patients with both AF and stroke. In addition, six out of eight patients were on anticoagulation at the time of stroke. The cause of death was a stroke in three (33%) out of nine patients with AF.

CONCLUSION

In patients with ApHCM, AF was common and was associated with a substantial risk for strokes and mortality suggesting that AF should be carefully managed in ApHCM.

Right Ventricular and Right Atrial Involvement Can Predict Atrial Fibrillation in Patients with Hypertrophic Cardiomyopathy?

OBJECTIVES AND BACKGROUND

Atrial fibrillation (AF) is associated with clinical deterioration, stroke and disability in patients with hypertrophic cardiomyopathy (HCM). Therefore, the objective of this study was to evaluated cardiac magnetic resonance (CMR)-derived determinants for the occurrence of AF in patients with HCM.

METHODS

98 Patients with HCM and 30 healthy controls underwent CMR and were followed-up for 6 ± 3 years.

RESULTS

19 (19.4%) patients presented with AF at initial diagnosis, 19 (19.4%) developed AF during follow-up and 60 (61.2%) remained in sinus rhythm (SR). Compared to healthy controls, patients with HCM who remained in SR presented with significantly increased left ventricular mass, an elevated left ventricular remodeling index, enlarged left atrial volumes and reduced septal mitral annular plane systolic excursion (MAPSE) compared to healthy controls. Whereas HCM patients who presented with AF at initial diagnosis and those who developed AF during follow-up additionally presented with reduced tricuspid annular plane systolic excursion (TAPSE) and right atrial (RA) dilatation. Receiver-operator curve analysis indicated good predictive performance of TAPSE, RA diameter and septal MAPSE (AUC 0.73, 0.69 and 0.71, respectively) to detect patients at risk of developing AF.

CONCLUSION

Reduced MAPSE measurements and enlarged LA volumes seems to be a common feature in patients with HCM, whereas reduced TAPSE and RA dilatation only seem to be altered in patients with history of AF and those developing AF. Therefore, they could serve as easy determinable markers of AF in patients with HCM.

Impaired quality of life in patients with intermittent atrial fibrillation

Objective:

The quality of life (QoL) is impaired in patients with atrial fibrillation (AF). However, the data on the perceived QoL of patients with different types of AF is limited. In this study, we investigated the QoL of patients with intermittent and chronic AF.

Methods:

The study was designed as an observational cross-sectional study, and 135 consecutive patients with documented AF admitted to the cardiology outpatient clinic in a tertiary hospital were recruited. The pattern of AF was classified as intermittent or chronic AF. The European Heart Rhythm Association (EHRA) classification and symptom severity score were used to quantify the symptoms related to AF. The QoL was assessed by the Short Form-36 and the Canadian Cardiovascular Society Severity in Atrial Fibrillation (SAF) scale.

Results:

Thirty-nine percent of the patients (n=52) had intermittent AF and 61% (n=83) had chronic AF. In the overall patient population, 92% reported having at least one of the symptoms that can be attributable to AF. Although the prevalence of symptoms were similar in patients with intermittent or chronic AF, the patients with intermittent AF perceived more severe palpitations (symptom severity score 2.4±1.7 vs. 1.5±1.5, p=0.003). Patients with intermittent AF had higher EHRA and SAF scores than the patients with chronic AF (2.6±0.9 vs. 1.9±0.8, p<0.001; 2.5±1.3 vs. 1.7±1.2, p<0.001, respectively).

Conclusion:

Outpatients with AF have a high prevalence of symptoms and impaired QoL. The impairment of subjective health-related QoL is worse in patients with intermittent AF.

Clinical implications of conduction abnormalities and arrhythmias after transcatheter aortic valve implantation

Transcatheter aortic valve implantation (TAVI) has become an established treatment option for patients with aortic stenosis at prohibitive risk to undergo surgical aortic valve replacement. Despite conveying obvious clinical benefits and a decreasing frequency of complications, the occurrence of new conduction abnormalities and arrhythmias remains an important issue. Generally considered a minor complication, they may have a profound impact on prognosis and quality of life after TAVI. Therefore the purpose of this review is to assess and discuss the available information on clinical implications of both new conduction abnormalities and arrhythmias after TAVI.

Effect of hyperthyroidism on the hypercoagulable state and thromboembolic events in patients with atrial fibrillation

OBJECTIVE

To clarify whether hyperthyroidism (HT) itself confers an additional effect on the hypercoagulable state and the risk of ischemic stroke among patients with hyperthyroid atrial fibrillation (AF).

METHODS

We prospectively evaluated plasma D-dimer levels and thromboembolic events among three groups of patients (hyperthyroid AF, n = 62; nonthyroid AF, n = 107, and HT without AF, n = 100). Plasma D-dimer levels were used to evaluate the hypercoagulable state.

RESULTS

The D-dimer level was significantly higher in patients with hyperthyroid AF than in nonthyroid AF (0.66 ± 0.06 vs. 0.34 ± 0.02 mg/l, p < 0.001) and HT without AF (0.66 ± 0.06 vs. 0.27 ± 0.02 mg/l, p < 0.001). During a 3-year follow-up, patients with hyperthyroid AF had a significantly higher incidence of ischemic stroke compared with patients with nonthyroid AF (hazard ratio, HR: 3.2, 95% confidence interval, CI: 1.01-5.59, p = 0.04). Cox regression analysis revealed that age (HR: 2.5, 95% CI: 1.01-1.21, p = 0.05), CHADS2-VAS score (HR: 5.5, 95% CI: 1.51-7.43, p = 0.01) and anticoagulation (HR: 0.45, 95% CI: 0.07-0.54, p = 0.01) were independent predictors of risk for the occurrence of ischemic stroke.

CONCLUSIONS

The present study suggests that HT may enhance the hypercoagulable state and the risk of ischemic stroke in patients with AF.

Evidence-based study on antithrombotic therapy in patients at risk of a stroke with paroxysmal atrial fibrillation

The aim of the present study was to determine the optimal intensity of anticoagulation therapy in elderly patients with paroxysmal atrial fibrillation (PAF), using aspirin and varied concentrations of warfarin. Elderly patients with PAF (n=1,162) who met the inclusion criteria of the study and were at middle or high-risk of a stroke were investigated. Patients were divided into six groups (four high-risk groups and two middle-risk groups). Patients were treated with aspirin or varied concentrations of warfarin. The primary endpoint events, secondary endpoint events, major bleeding events and minor bleeding events were observed and compared. In high-risk elderly patients, warfarin significantly reduced primary and secondary endpoint events, total primary events and total events compared with aspirin. In middle-risk elderly patients, for all the events warfarin demonstrated no significant difference compared with aspirin. In high-risk patients with PAF, when the concentration of warfarin was adjusted to target international normalized ratio (INR) range 1.7–2.5, the primary and secondary endpoint events, total primary events and total events were significantly lower (P<0.05), compared with aspirin and warfarin at INR 1.2–1.6. When the intensity of warfarin was adjusted to the target INR 2.6–3.0, the primary and secondary endpoint events were significantly lower (P<0.05) compared with aspirin and warfarin INR at 1.2–1.6. This study determined that in high-risk elderly patients with PAF, warfarin is recommended for anticoagulation with an optimal INR range of 1.7–2.5. In patients at a middle-risk of a stroke, aspirin is the recommended treatment as an antithrombotic as results have indicated that there is limited benefit in the use of warfarin.

Atrial Fibrillation in the Intensive Care Setting

Atrial fibrillation (AF) is the commonest cardiac arrhythmia both in the general population and in the intensive care unit (ICU) setting. Its incidence continues to rise, affecting up to 10% of patients admitted to a general ICU and up to 50% of those admitted to a cardiac ICU. Uncontrolled AF has detrimental effects on the cardiovascular system, including heart failure, thromboembolic events, reduced quality of life and prolonged hospital stay. This article reviews the risk factors for developing AF, possible underlying mechanisms, clinical features and diagnosis, and focuses particularly on its management according to the latest guidelines with a specific focus on the ICU patient. We also discuss novel anticoagulants that will revolutionise the management of antithrombotic therapy in AF patients by replacing warfarin.

High accuracy in automatic detection of atrial fibrillation for Holter monitoring

Atrial fibrillation (AF) has been considered as a growing epidemiological problem in the world, with a substantial impact on morbidity and mortality. Ambulatory electrocardiography (e.g., Holter) monitoring is commonly used for AF diagnosis and therapy and the automated detection of AF is of great significance due to the vast amount of information provided. This study presents a combined method to achieve high accuracy in AF detection. Firstly, we detected the suspected transitions between AF and sinus rhythm using the delta RR interval distribution difference curve, which were then classified by a combination analysis of P wave and RR interval. The MIT-BIH AF database was used for algorithm validation and a high sensitivity and a high specificity (98.2% and 97.5%, respectively) were achieved. Further, we developed a dataset of 24-h paroxysmal AF Holter recordings (n=45) to evaluate the performance in clinical practice, which yielded satisfactory accuracy (sensitivity=96.3%, specificity=96.8%).

Atrial fibrillation and aortic stenosis: impact on clinical outcomes among patients undergoing transcatheter aortic valve implantation

BACKGROUND

Atrial fibrillation (AF) is an important risk factor for stroke and is common among elderly patients undergoing transcatheter aortic valve implantation. The aim of this study was to assess the impact of AF on clinical outcomes among patients undergoing transcatheter aortic valve implantation.

METHODS AND RESULTS

Between August 2007 and October 2011, a total of 389 high-risk patients undergoing transcatheter aortic valve implantation were included into a prospective registry. AF was recorded in 131 patients (33.7%) with a mean CHA(2)DS(2)-VASC score of 4.5±1.2 and was paroxysmal in 26 (25.0%), persistent in 8 (7.7%), and permanent in 70 patients (67.3%). Patients with and without AF had similar baseline characteristics except for fewer revascularization procedures (coronary artery bypass grafting: 12% versus 22%; P=0.03) among AF patients. At 1 year, all-cause mortality was higher among patients with AF (30.9%) compared with those without AF (13.9%; hazard ratio [HR], 2.36; 95% confidence interval [CI], 1.43-3.90; P=0.0008). This was observed irrespective of the type of AF (permanent, HR, 2.47; 95% CI, 1.40-4.38; persistent, HR, 3.60; 95% CI, 1.10-11.78; paroxysmal, HR, 2.88; 95% CI, 1.37-6.05). Mortality gradually increased with higher CHA(2)DS(2)-VASC scores (score 1-3: HR, 2.20; 95% CI, 0.92-5.27; score 6-8: HR, 4.12; 95% CI, 2.07-8.20). The risks of stroke (3.9% versus 5.1%; HR, 0.76; 95% CI, 0.23-1.96; P=0.47) and life-threatening bleeding (19.8% versus 14.7%; HR, 1.37; 95% CI, 0.86-2.19; P=0.19) were similar among patients with and without AF.

CONCLUSIONS

AF is common among high-risk patients with severe aortic stenosis undergoing transcatheter aortic valve implantation and is associated with a >2-fold increased risk of all-cause and cardiovascular mortality, irrespective of the type of AF. The gradient of risk directly correlates with the CHA(2)DS(2)-VASC score.

Dehydroepiandrosterone sulfate levels and risk of atrial fibrillation: the Rotterdam Study

BACKGROUND

High plasma dehydroepiandrosterone sulfate (DHEAS) levels have been associated with a reduced risk of cardiovascular disease and atherosclerosis. To our knowledge, no previous follow-up study has investigated the association between DHEAS and the development of atrial fibrillation. Our objective was to investigate the association between DHEAS levels and incident atrial fibrillation.

METHODS AND RESULTS

The study was based on a random sample within the prospective population-based Rotterdam Study. The study population comprised 1180 participants without atrial fibrillation at baseline for whom baseline levels of DHEAS were measured in plasma. Atrial fibrillation was ascertained from centre visit electrocardiogram (ECG) assessments as well as medical records. During a mean follow-up period of 12.3 years, 129 participants developed atrial fibrillation. DHEAS levels were inversely associated with the risk of atrial fibrillation (hazard ratio (HR) per standard deviation (SD): 0.74, 95% confidence interval (CI): 0.58-0.94). Subjects in the highest DHEAS quartile had an almost three times lower risk of atrial fibrillation during follow-up, compared to those in the lowest DHEAS quartile (HR: 0.34, 95% CI: 0.18-0.64) adjusted for age, sex and cardiovascular risk factors.

CONCLUSION

DHEAS can be regarded as an important indicator of future atrial fibrillation in both men and women, independent of known cardiovascular risk factors.

Intravenous amiodarone for acute pharmacological conversion of atrial fibrillation in the emergency department

Atrial fibrillation (AF) is the most common arrhythmia seen in patients presenting to the emergency department (ED). Pharmacological conversion of atrial fibrillation to normal sinus rhythm (NSR) may be a feasible management strategy in selected patients. Recent guidelines have recommended intravenous amiodarone, a class III antiarrhythmic agent, for the conversion of AF to NSR. The purpose of this review is to examine the published evidence for the efficacy of IV amiodarone for the acute conversion of AF to NSR in the ED. Currently available data from 11 randomized, controlled trials and 3 meta analyses do not support the use of conventional doses of IV amiodarone for acute conversion in the ED. High dose IV or combined IV and oral administration may be effective as early as 8 hours in patients with recent-onset AF of <48 hour duration in patients without contraindications to these high dose regimens. There are no data to support the use of IV amiodarone for acute conversion in patients with an ejection fraction of <40% or clinical heart failure, so its use in these scenarios should be limited to symptomatic patients who are refractory to electrical conversion. More well-designed studies are required to determine the role of IV amiodarone for the acute conversion of AF in the ED.

Twenty-five years in the making: flecainide is safe and effective for the management of atrial fibrillation

Atrial fibrillation (AF) is the most common arrhythmia in clinical practise and its prevalence is increasing. Over the last 25 years, flecainide has been used extensively worldwide, and its capacity to reduce AF symptoms and provide long-term restoration of sinus rhythm (SR) has been well documented. The increased mortality seen in patients treated with flecainide in the Cardiac Arrhythmia Suppression Trial (CAST) study, published in 1991, still deters many clinicians from using flecainide, denying many new AF patients a valuable treatment option. There is now a body of evidence that clearly demonstrates that flecainide has a favourable safety profile in AF patients without significant left ventricular disease or coronary heart disease. As a result of this evidence, flecainide is now recommended as one of the first-line treatment options for restoring and maintaining SR in patients with AF under current treatment guidelines. The objective of this article is to review the literature pertaining to the pharmacological characteristics, safety and efficacy of flecainide, and to place this drug in the context of current therapeutic management strategies for AF.

Is structural remodeling of fibrillated atria the consequence of tissue hypoxia?

BACKGROUND

Matrix metalloproteinases (MMPs) play an important role in degradation of the extracellular matrix of injured tissue. MMP-9 expression increases in fibrillating atrial tissue; however, the mechanism for this increase has not been clarified.

METHODS AND RESULTS

Changes in the expression of vascular endothelial growth factor (VEGF), VEGF receptors, and hypoxia-induced transcription factor-1alpha (HIF-1alpha) in fibrillating atrial tissue were investigated. Atrial tissue samples were obtained from 13 patients with atrial fibrillation (AF) and 25 patients without a history of AF (regular sinus rhythm, RSR) undergoing cardiac operations. Western blot, real-time polymerase chain reaction, and immunofluorescence analyses of the expression of VEGF, VEGF receptors, and HIF-1alpha were performed. The VEGF mRNA and protein levels increased significantly in the AF group compared with the RSR group (P<0.05), and the expression of HIF-1alpha protein was also significantly higher in the AF group. VEGF receptor-1 mRNA, a high-affinity receptor for VEGF, but not VEGF receptor-2 mRNA, was upregulated in the atria of the AF group (P<0.05). Immunofluorescence staining revealed excess production and co-localization of HIF-1alpha, VEGF and MMP-9 in the endothelium of the atrial arteries in the AF group.

CONCLUSIONS

It is possible that upregulation of HIF-1/VEGF is involved in the enhancement of MMP-9 expression under hypoxic conditions.

Challenges in the classification of atrial fibrillation

The incidence and prevalence of atrial fibrillation (AF) are increasing worldwide. AF is of public health importance because it accounts for substantial morbidity, mortality, and health-care costs. AF may be transient initially, but many patients have progressive disease marked by increasing frequency and duration of episodes. Various classification schemes for AF have been proposed, although current guidelines are based on temporal rhythm-based patterns. We discuss existing schemes for the classification of AF, focusing on the advantages and limitations of the pattern-based scheme, in the context of new knowledge about AF pathophysiology, AF patterns, and clinical outcomes. Furthermore, we address gaps in knowledge that present opportunities to re-examine the current pattern-based classification of AF. A future classification scheme should ideally combine elements such as the risk of stroke, an assessment of symptoms, and the degree of impairment of the atrial substrate.

Angiotensin II receptor blockers in the prevention of atrial fibrillation

Atrial fibrillation (AF) is the most common sustained arrhythmia. While antiarrhythmic agents and electrical cardioversion are highly effective in restoring sinus rhythm, the results obtained in prevention of recurrences are disappointing. Recently, angiotensin II has been recognized as a key factor in atrial structural and electrical remodeling associated with AF. So there are several potential mechanisms by which inhibition of the renin-angiotensin-aldosterone system may reduce AF. In this review, we report the results of studies evaluating the effect of angiotensin II receptor blockers (ARBs) in various clinical settings (i.e., lone AF, hypertension, high-risk patients, congestive heart failure, secondary prevention). However, many of these studies are small and retrospective and have a limited follow-up; moreover, since AF is related to several causes, chiefly heart diseases, patients with different characteristics have often been enrolled. Thus, it is not surprising that the results obtained are frequently conflicting. With these limitations and considering only the results of larger studies with longer follow-up, ARBs are effective in preventing AF in patients with congestive heart failure or hypertension with left ventricular hypertrophy or coronary artery/cerebrovascular disease. In any case, the use of ARBs is not recommended at present in clinical practice to prevent AF.