Atrial Fibrillation Pattern Research Articles

Atrial Fibrillation, Anticoagulation, and Major Bleeding Episodes in Geriatric Patients at the Risk of Falling

Background: Geriatric patients are at risk for atrial fibrillation (AF), stroke, and the risk of anticoagulation (OAC) related bleeding is presumed to be higher. Detailed knowledge about the prevalence of AF and bleeding pattern in this population is scarce. This study sought to assess the prevalence of AF, use of OAC and rate of major bleeding in geriatric patients who frequently fall. Methods: Observational cohort study at a Fall and Syncope Clinic. Patients of 65 years and older, that underwent both an electrocardiogram (ECG) and holter registration were included. Use and reasons to withhold OAC, and rate of major bleeding were retrieved from the medical files. Results: n=428, mean age 79.8 years. Mean CHA2DS2VASc and HAS-BLED score was 4.0 and 2.9 respectively. AF was known in 98 (23%) patients, first diagnosed in 10 (2%). First diagnosed AF was identified on all Holters, and on the ECG in half of the new cases. AF was paroxysmal in 45 patients (45%). 84% of patients known with AF used OAC. The rate of major bleeding was 1.1 per 100 treatment years. Major bleeding was not different between patients using antiplatelet agents (APA), OAC or no antithrombotic medication. Conclusions: The rate of AF in geriatric patients is high and almost 50% is paroxysmal. Compared to previous studies the use of OAC has substantially increased to 84% and in this geriatric cohort no differences were found in the rate of major bleeding between those with APA, OAC or without antithrombotic medication.

Assessment of Sex Differences in the Initial Symptom Burden, Applied Treatment Strategy, and Quality of Life in Japanese Patients With Atrial Fibrillation

The clinical characteristics and outcomes of women and men with atrial fibrillation (AF) are reported to be different. However, whether sex-related differences extend to patients' symptom burden and perceived quality of life (QOL) or the management pattern of AF has been rarely studied, particularly in Asian countries. To assess the differences in symptoms, treatment, and QOL between Japanese female and male patients with AF. Retrospective cohort study using data from the multicenter outpatient registry Keio Interhospital Cardiovascular Studies-Atrial Fibrillation (KiCS-AF), which collects information regarding health status and the treatment of patients with newly diagnosed or referred AF. One-year follow-up data were available for 1534 patients at 11 referral centers in the Tokyo, Japan, area who were enrolled between September 2012 and December 2015. All data available up to the 1-year follow-up examination through July 31, 2017, were included. Sex, symptoms, AF treatment, and QOL as determined by Atrial Fibrillation Effect on Quality of Life (AFEQT) questionnaires at their initial visit and 1 year later. Of 1534 patients, 1076 (70.1%) were men. Compared with men, women were more likely to be older (median age, 73 years [interquartile range {IQR}, 65-78 years] vs 65 years [IQR, 57-73 years], P < .001) and have higher median brain-type natriuretic peptide levels (102.8 pg/mL [IQR, 47.3-235.5 pg/mL] vs 74.1 pg/mL [IQR, 28.5-150.5 pg/mL], P < .001). Women also had lower median AFEQT overall summary scores than men (75 [IQR, 61-85] vs 80 [IQR, 69-90]; P < .001) but similar treatment satisfaction at baseline. During follow-up, women were less likely to be treated with a rhythm control strategy (48.1% [n = 214] vs 58.0% [n = 621], P < .001), including catheter ablation of AF (adjusted hazard ratio, 0.77 [95% CI, 0.62-0.95]; P = .02). At 1-year follow-up, women and men had improved QOL scores, regardless of their baseline characteristics (eg, age or brain-type natriuretic peptide levels) or treatment strategies, yet the sex gap persisted and grew (adjusted change in AFEQT overall summary score during 12 months, 5.89 [95% CI, 2.24-9.54] in women vs 8.94 [95% CI, 5.59-12.30] in men; P = .02). In contemporary Japanese clinical practice among unselected patients with AF, women were initially seen with greater QOL impairment, and the sex gap grew 1 year after presentation. The present study underscores the need for focused efforts to better understand and close this observed sex gap over the initial year of treatment for patients with AF.

Sex disparities on psychological responses among implantable cardioverter defibrillator patients with underlying heart diseases

The potential utility of entropy (En) for atrial fibrillation (AF) mapping has been demonstrated in previous studies by multiple groups, where an association between high bipolar electrogram (EGM) entropy and the pivot of rotors has been shown. Though En is potentially attractive new approach to ablation, no studies have examined its temporal stability and specificity, which are critical to the application of entropy to clinical ablation. In the current study, we sought to objectively measure the temporal stability and specificity of bipolar EGM entropy in medium to long term recordings using three studies: i) a human basket catheter AF study, ii) a tachypaced sheep AF study and iii) a computer simulation study.To characterize the temporal dynamics and specificity of Approximate, Sample and Shannon entropy (ApEn/SampEn/ShEn) in human (H), sheep (S), and computer simulated AF.64-electrode basket bi-atria sustained AF recordings (H:15 min; S:40 min) were separated into 5 s segments. ShEn/ApEn/SampEn were computed, and co-registered with NavX 3D maps. Temporal stability was determined in terms of: (i) global pattern stability of En and (ii) the relative stability the top 10% of En regions. To provide mechanistic insights into underlying mechanisms, stability characteristics were compared to models depicting various propagation patterns. To verify these results, cross-validation was performed across multiple En algorithms, across species, and compared with dominant frequency (DF) temporal characteristics. The specificity of En was also determined by looking at the association of En to rotors and areas of wave cross propagation.Episodes of AF were analysed (H:26 epochs, 6040 s; S:15 epochs, 14,160 s). The global pattern of En was temporally unstable (CV- H:13.42% ± 4.58%; S:14.13% ± 8.13%; Friedman- H: p > 0.001; S: p > 0.001). However, within this dynamic flux, the top 10% of ApEn/SampEn/ShEn regions were relatively temporally stable (Kappa >0.6) whilst the top 10% of DF regions were unstable (Kappa <0.06). In simulated AF scenarios, the experimental data were optimally reproduced in the context of an AF pattern with stable rotating waves surrounded by wavelet breakup (Kappa: 0.610; p < 0.0001).En shows global temporal instability, however within this dynamic flux, the top 10% regions exhibited relative temporal stability. This suggests that high En regions may be an appealing ablation target. Despite this, high En was associated with not just the pivot of rotors but also with areas of cross propagation, which suggests the need for future work before clinical application is possible.

The combined evaluation of ambulatory-based late potentials and heart rate turbulence to predict ventricular arrhythmias in patients with postmyocardial infarction

The potential utility of entropy (En) for atrial fibrillation (AF) mapping has been demonstrated in previous studies by multiple groups, where an association between high bipolar electrogram (EGM) entropy and the pivot of rotors has been shown. Though En is potentially attractive new approach to ablation, no studies have examined its temporal stability and specificity, which are critical to the application of entropy to clinical ablation. In the current study, we sought to objectively measure the temporal stability and specificity of bipolar EGM entropy in medium to long term recordings using three studies: i) a human basket catheter AF study, ii) a tachypaced sheep AF study and iii) a computer simulation study.To characterize the temporal dynamics and specificity of Approximate, Sample and Shannon entropy (ApEn/SampEn/ShEn) in human (H), sheep (S), and computer simulated AF.64-electrode basket bi-atria sustained AF recordings (H:15 min; S:40 min) were separated into 5 s segments. ShEn/ApEn/SampEn were computed, and co-registered with NavX 3D maps. Temporal stability was determined in terms of: (i) global pattern stability of En and (ii) the relative stability the top 10% of En regions. To provide mechanistic insights into underlying mechanisms, stability characteristics were compared to models depicting various propagation patterns. To verify these results, cross-validation was performed across multiple En algorithms, across species, and compared with dominant frequency (DF) temporal characteristics. The specificity of En was also determined by looking at the association of En to rotors and areas of wave cross propagation.Episodes of AF were analysed (H:26 epochs, 6040 s; S:15 epochs, 14,160 s). The global pattern of En was temporally unstable (CV- H:13.42% ± 4.58%; S:14.13% ± 8.13%; Friedman- H: p > 0.001; S: p > 0.001). However, within this dynamic flux, the top 10% of ApEn/SampEn/ShEn regions were relatively temporally stable (Kappa >0.6) whilst the top 10% of DF regions were unstable (Kappa <0.06). In simulated AF scenarios, the experimental data were optimally reproduced in the context of an AF pattern with stable rotating waves surrounded by wavelet breakup (Kappa: 0.610; p < 0.0001).En shows global temporal instability, however within this dynamic flux, the top 10% regions exhibited relative temporal stability. This suggests that high En regions may be an appealing ablation target. Despite this, high En was associated with not just the pivot of rotors but also with areas of cross propagation, which suggests the need for future work before clinical application is possible.

Signal-averaged Electrocardiograph Can Evaluate Citrate Response and Vasovagal Reflex During Apheresis Donation

The potential utility of entropy (En) for atrial fibrillation (AF) mapping has been demonstrated in previous studies by multiple groups, where an association between high bipolar electrogram (EGM) entropy and the pivot of rotors has been shown. Though En is potentially attractive new approach to ablation, no studies have examined its temporal stability and specificity, which are critical to the application of entropy to clinical ablation. In the current study, we sought to objectively measure the temporal stability and specificity of bipolar EGM entropy in medium to long term recordings using three studies: i) a human basket catheter AF study, ii) a tachypaced sheep AF study and iii) a computer simulation study.To characterize the temporal dynamics and specificity of Approximate, Sample and Shannon entropy (ApEn/SampEn/ShEn) in human (H), sheep (S), and computer simulated AF.64-electrode basket bi-atria sustained AF recordings (H:15 min; S:40 min) were separated into 5 s segments. ShEn/ApEn/SampEn were computed, and co-registered with NavX 3D maps. Temporal stability was determined in terms of: (i) global pattern stability of En and (ii) the relative stability the top 10% of En regions. To provide mechanistic insights into underlying mechanisms, stability characteristics were compared to models depicting various propagation patterns. To verify these results, cross-validation was performed across multiple En algorithms, across species, and compared with dominant frequency (DF) temporal characteristics. The specificity of En was also determined by looking at the association of En to rotors and areas of wave cross propagation.Episodes of AF were analysed (H:26 epochs, 6040 s; S:15 epochs, 14,160 s). The global pattern of En was temporally unstable (CV- H:13.42% ± 4.58%; S:14.13% ± 8.13%; Friedman- H: p > 0.001; S: p > 0.001). However, within this dynamic flux, the top 10% of ApEn/SampEn/ShEn regions were relatively temporally stable (Kappa >0.6) whilst the top 10% of DF regions were unstable (Kappa <0.06). In simulated AF scenarios, the experimental data were optimally reproduced in the context of an AF pattern with stable rotating waves surrounded by wavelet breakup (Kappa: 0.610; p < 0.0001).En shows global temporal instability, however within this dynamic flux, the top 10% regions exhibited relative temporal stability. This suggests that high En regions may be an appealing ablation target. Despite this, high En was associated with not just the pivot of rotors but also with areas of cross propagation, which suggests the need for future work before clinical application is possible.

Treatment strategies in geriatric patients with atrial fibrillation: Results from the NATURE AF registry

Distinct differences in clinical presentation and management of atrial fibrillation (AF) were observed in geriatric versus younger patients from several registries. However, there is a lack of information about age-related AF profile in our population. To raise, according of age, therapeutic particularities of patients recruited from the prospective NATURE AF registry (NAtional TUnisian REgistry of Atrial Fibrillation). Between March and June 2017, we prospectively registered information of 912 patients with a recently diagnosed AF. Rhythm management and anticoagulation strategies were compared between two groups of geriatric (> 75 years old) and younger (< 75 years old) populations. Twenty-three percents of patients had more than 75 years old. Underlying cardiopathy was similar between the two groups ( P = 0.181). However, there was age difference concerning the pattern of AF ( P = < 0.001). In fact, permanent AF was predominant in geriatric population (36%) in contrast to predominant paroxystic AF in younger population (40%). Rate control strategy was significantly more adopted in older patients ( P < 0.001). Concerning the rate control therapies, digoxin was more prescribed in this population P = 0.007) in contrast to the similar use of B-blockers ( P = 0.251). When rhythm control strategy was adopted, there was no significant difference in the use of the majority of antiarrythmic drugs, however, only flecaine was less prescribed in geriatric than younger population ( P < 0.001).). There was no age difference in percent of prescribed anticoagulation medications for both vitamin K antagonists ( P = 0.125) and novel oral anticoagulants ( P = 0.165). NATURE AF registry showed that geriatric patients differ from youngs in term of rhythm management strategy. However, both groups shared, unexpectedly, similar anticoagulation therapy use.

Gender differences in presentation and treatment of patients with atrial fibrillation: Results from the Nature AF registry

Distinct differences in clinical presentation and management of atrial fibrillation (AF) were observed in men versus women from several registries. However, there is a lack of information about gender-related AF profile in our population. To raise, according of gender, the demographic, clinical and therapeutic particularities of patients recruited from the prospective NATURE AF registry (National Tunisian Registry of Atrial Fibrillation). Between March and June 2017, we prospectively registered information of 912 patients with a recently diagnosed AF. According to gender, demographics, clinical and etiological characteristics as well as arrhythmia management strategies were compared. Fifty two percent of patients were female. Women were older ( P = 0.012). Valvular etiology was more diagnosed in women ( P < 0.001), mainly mitral valvuolpathy ( P < 0.001). However, there was no gender difference concerning the patterns of AF ( P = 0.365). There was no gender difference in percent of prescribed anticoagulation medications for both vitamin K antagonists ( P = 0.76) and novel oral anticoagulants ( P = 0.839). Rate control strategy was significantly more adopted in women then in men ( P = 0.005). Concerning the rate control therapies, digoxin was more prescribed in women ( P = 0.005) in contrast to the similar use of B-blockers ( P = 0.912). NATURE AF registry showed that women presenting with AF differ from men in term of age, underlying cardiopathy and rhythm management strategy. Despite these differences, both groups shared similar AF pattern and anticoagulation therapy.

Temporal stability and specificity of high bipolar electrogram entropy regions in sustained atrial fibrillation: Implications for mapping

BackgroundThe potential utility of entropy (En) for atrial fibrillation (AF) mapping has been demonstrated in previous studies by multiple groups, where an association between high bipolar electrogram (EGM) entropy and the pivot of rotors has been shown. Though En is potentially attractive new approach to ablation, no studies have examined its temporal stability and specificity, which are critical to the application of entropy to clinical ablation. In the current study, we sought to objectively measure the temporal stability and specificity of bipolar EGM entropy in medium to long term recordings using three studies: i) a human basket catheter AF study, ii) a tachypaced sheep AF study and iii) a computer simulation study. ObjectiveTo characterize the temporal dynamics and specificity of Approximate, Sample and Shannon entropy (ApEn/SampEn/ShEn) in human (H), sheep (S), and computer simulated AF. Methods64-electrode basket bi-atria sustained AF recordings (H:15 min; S:40 min) were separated into 5 s segments. ShEn/ApEn/SampEn were computed, and co-registered with NavX 3D maps. Temporal stability was determined in terms of: (i) global pattern stability of En and (ii) the relative stability the top 10% of En regions. To provide mechanistic insights into underlying mechanisms, stability characteristics were compared to models depicting various propagation patterns. To verify these results, cross-validation was performed across multiple En algorithms, across species, and compared with dominant frequency (DF) temporal characteristics. The specificity of En was also determined by looking at the association of En to rotors and areas of wave cross propagation. ResultsEpisodes of AF were analysed (H:26 epochs, 6040 s; S:15 epochs, 14,160 s). The global pattern of En was temporally unstable (CV- H:13.42% ± 4.58%; S:14.13% ± 8.13%; Friedman- H: p > 0.001; S: p > 0.001). However, within this dynamic flux, the top 10% of ApEn/SampEn/ShEn regions were relatively temporally stable (Kappa >0.6) whilst the top 10% of DF regions were unstable (Kappa <0.06). In simulated AF scenarios, the experimental data were optimally reproduced in the context of an AF pattern with stable rotating waves surrounded by wavelet breakup (Kappa: 0.610; p < 0.0001). ConclusionEn shows global temporal instability, however within this dynamic flux, the top 10% regions exhibited relative temporal stability. This suggests that high En regions may be an appealing ablation target. Despite this, high En was associated with not just the pivot of rotors but also with areas of cross propagation, which suggests the need for future work before clinical application is possible.

Long-term suppression of atrial fibrillation by botulinum toxin injection into epicardial fat pads in patients undergoing cardiac surgery: Three-year follow-up of a randomized study

Botulinum toxin (BTX) injections into epicardial fat pads in patients undergoing coronary artery bypass grafting (CABG) has resulted in suppression of atrial fibrillation (AF) during the early postoperative period through 1-year of follow-up in a pilot program. The purpose of this study was to report 3-year AF patterns by the use of implantable cardiac monitors (ICMs). Sixty patients with a history of paroxysmal AF and indications for CABG were randomized 1:1 to either BTX or placebo injections into 4 posterior epicardial fat pads. All patients received an ICM with regular follow-up for 3 years after surgery. The primary end point of the extended follow-up period was incidence of any atrial tachyarrhythmia after 30 days of procedure until 36 months on no antiarrhythmic drugs. The secondary end points included clinical events and AF burden. At the end of 36 months, the incidence of any atrial tachyarrhythmia was 23.3% in the BTX group vs 50% in the placebo group (hazard ratio 0.36; 95% confidence interval 0.14-0.88; P = .02). AF burden at 12, 24, and 36 months was significantly lower in the BTX group than in the placebo group: 0.22% vs 1.88% (P = .003), 1.6% vs 9.5% (P < .001), and 1.3% vs 6.9% (P = .007), respectively. In the BTX group, 2 patients (7%) were hospitalized during follow-up compared with 10 (33%) in the placebo group (P = .02). Injection of BTX into epicardial fat pads in patients undergoing CABG resulted in a sustained and substantial reduction in atrial tachyarrhythmia incidence and burden during 3-year follow-up, accompanied by reduction in hospitalizations.

Lifetime Pattern of Atrial Fibrillation and the Risks of Stroke and Death in a Population-based Cohort of Men (from The Manitoba Follow-Up Study)

Atrial fibrillation (AF) is associated with stroke and mortality. The arrhythmia can be sustained or intermittent. Previous studies that have used fixed covariates and short-time horizons to examine the relation between the pattern of AF and the occurrence of events have produced conflicting results. The Manitoba Follow-Up Study includes 3,983 originally healthy men who have been followed with routine examinations since 1948. AF status during each visit was classified into the following patterns: free of AF, newly diagnosed; intermittent AF-in sinus;intermittent AF-in AF; sustained AF. We created adjusted Cox proportional hazards models with time-dependent covariates to estimate risks for stroke and death according to AF pattern. After 167,982 person-years of follow-up and 66,297 electrocardiograms (ECGs), 548 men had at least 1 ECG documenting AF, 799 had a stroke, and 3173 died. Relative to men free of AF, sustained and newly diagnosed AF were associated with stroke (hazard ratio [HR] 1.85, 95% confidence interval [CI] 1.33 to 2.59 and HR 1.71, 95% CI 1.10 to 2.66, respectively) and death (HR 2.48, 95% CI 2.11 to 2.92 and HR 2.03, 95% CI 1.64 to 2.52, respectively). Intermittent AF was associated with death (HR 2.41 95% CI 1.58 to 3.68 in AF and HR 1.71 95% CI 1.44 to 2.03 in sinus), but not with stroke (HR 0.68, 95% CI 0.22 to 2.13 in AF and HR 1.02 95% CI 0.72 to 1.45 in sinus). Antithrombotic therapy was associated with a reduced risk of the outcomes. In conclusion, longitudinal analysis of patterns of AF evolving over time provided evidence that the associated risks of stroke and death vary considerably with rhythm classification on serial ECGs.

Conservative Management of Atrial Fibrillation in Heart Failure Patients in a Tertiary Care Medical Center

Introduction Several recent studies support a salutary effect of atrial fibrillation (AF) ablation in patients with heart failure with reduced ejection fraction (HFrEF), with ablation reducing mortality and heart failure hospitalization compared to strategies of rate control or anti-arrhythmic medication. The current patterns of AF management in the HFrEF population in tertiary care centers are not well understood. Objective To determine the primary approach to AF treatment in patients with HFrEF in a large tertiary care center with access to all modalities of CHF and AF management. Methods Consecutive patients undergoing ICD interrogation were assessed for history of AF and HFrEF and AF management strategy. Strategies were categorized as rate control, anti-arrhythmic medication rhythm control, or curative ablation (RFA). Use of anticoagulation was also assessed along with patient co-morbidities. Results Sixty-seven patients (76% men, mean age 70) with LVEF ≤35% and AF were assessed over a six month period in ICD clinic. A strategy of rate control was pursued in 34.3%, rhythm control in 35.8%, and RFA in 28.4% (remainder were untreated). Anticoagulation was employed in 82.1%. The most commonly used antiarrhythmic medication was amiodarone and most common anticoagulant was warfarin. Conclusions These findings portray a conservative approach to AF in the HFrEF population, with fewer than 30% of patients undergoing RFA. These data suggest that further large trials with positive outcomes for RFA in HFrEF population will likely be required to overcome conflicting data and current treatment patterns of AF in this population, given the patients’ co-morbidities.

Stationary Atrial Fibrillation Properties in the Goat Do Not Entail Stable or Recurrent Conduction Patterns.

Introduction: Electro-anatomical mapping of the atria is used to identify the substrate of atrial fibrillation (AF). Targeting this substrate by ablation in addition to pulmonary vein ablation did not consistently improve outcome in clinical trials. Generally, the assessment of the substrate is based on short recordings (≤10 s, often even shorter). Thus, targeting the AF substrate assumes spatiotemporal stationarity but little is known about the variability of electrophysiological properties of AF over time.Methods: Atrial fibrillation (AF) was maintained for 3–4 weeks after pericardial electrode implantation in 12 goats. Within a single AF episode 10 consecutive minutes were mapped on the left atrial free wall using a 249-electrode array (2.25 mm inter-electrode spacing). AF cycle length, fractionation index (FI), lateral dissociation, conduction velocity, breakthroughs, and preferentiality of conduction (Pref) were assessed per electrode and AF property maps were constructed. The Pearson correlation coefficient (PCC) between the 10 AF-property maps was calculated to quantify the degree spatiotemporal stationarity of AF properties. Furthermore, the number of waves and presence of re-entrant circuits were analyzed in the first 60-s file. Comparing conduction patterns over time identified recurrent patterns of AF with the use of recurrence plots.Results: The averages of AF property maps were highly stable throughout the ten 60-s-recordings. Spatiotemporal stationarity was high for all 6 property maps, PCC ranged from 0.66 ± 0.11 for Pref to 0.98 ± 0.01 for FI. High stationarity was lost when AF was interrupted for about 1 h. However, the time delay between the recorded files within one episode did not affect PCC. Yet, multiple waves (7.7 ± 2.3) were present simultaneously within the recording area and during 9.2 ± 11% of the analyzed period a re-entrant circuit was observed. Recurrent patterns occurred rarely and were observed in only 3 out of 12 goats.Conclusions: During non-self-terminating AF in the goat, AF properties were stationary. Since this could not be attributed to stable recurrent conduction patterns during AF, it is suggested that AF properties are determined by anatomical and structural properties of the atria even when the conduction patterns are very variable.

Thirty-Second Gold Standard Definition of Atrial Fibrillation and Its Relationship With Subsequent Arrhythmia Patterns: Analysis of a Large Prospective Device Database.

The Heart Rhythm Society consensus statement arbitrarily defines atrial fibrillation (AF) ablation failure as any episode ≥30 seconds. However, if brief AF events are not correlated to longer events, the rationale for this end point is questionable. We determined the impact of AF episode duration threshold on AF incidence and burden. Patients with a pacemaker in a prospective registry with device-detected AF and follow-up >30 days were analyzed. AF patterns were calculated for various AF duration thresholds (30 s; 2 and 6 minutes; 3.8, 5.5, and 24 hours) selected based on published consensus statements, established evidence of stroke risk, and device capabilities. Freedom from AF postdevice implant at each AF episode duration threshold was assessed, as was overall AF burden. Among 615 patients with pacemaker (aged 72.0±11.8 years, 54.2% male, follow-up 3.7±2.2 years) with device-detected AF, 599 had ≥1 AF episode of ≥30 seconds duration (median, 22 episodes). At 12 months, freedom from AF was 25.5%, 30.1%, 34.6%, 52.6%, 56.5%, and 73.1% for duration thresholds of 30 seconds, 2 minutes, 6 minutes, 3.8 hours, 5.5 hours, and 24 hours, respectively. Of patients with a first episode of 30 seconds to 2 minutes, 35.8% were free from subsequent episode >2 minutes at 180 days. Median AF burden was significantly less for patients with first episodes between 30 seconds and 3.8 hours versus >3.8 hours (0.2% versus 9.5%, respectively; P<0.0001). Small differences in AF episode duration definition can significantly affect the perceived incidence of AF and impact reported outcomes, including AF ablation success. An initial AF episode of 30 seconds does not predict clinically meaningful AF patterns.

Atrial Fibrillation Burden: Moving Beyond Atrial Fibrillation as a Binary Entity: A Scientific Statement From the American Heart Association

Our understanding of the risk factors and complications of atrial fibrillation (AF) is based mostly on studies that have evaluated AF in a binary fashion (present or absent) and have not investigated AF burden. This scientific statement discusses the published literature and knowledge gaps related to methods of defining and measuring AF burden, the relationship of AF burden to cardiovascular and neurological outcomes, and the effect of lifestyle and risk factor modification on AF burden. Many studies examine outcomes by AF burden classified by AF type (paroxysmal versus nonparoxysmal); however, quantitatively, AF burden can be defined by longest duration, number of AF episodes during a monitoring period, and the proportion of time an individual is in AF during a monitoring period (expressed as a percentage). Current guidelines make identical recommendations for anticoagulation regardless of AF pattern or burden; however, a review of recent evidence suggests that higher AF burden is associated with higher risk of stroke. It is unclear whether the risk increases continuously or whether a threshold exists; if a threshold exists, it has not been defined. Higher burden of AF is also associated with higher prevalence and incidence of heart failure and higher risk of mortality, but not necessarily lower quality of life. A structured and comprehensive risk factor management program targeting risk factors, weight loss, and maintenance of a healthy weight appears to be effective in reducing AF burden. Despite this growing understanding of AF burden, research is needed into validation of definitions and measures of AF burden, determination of the threshold of AF burden that results in an increased risk of stroke that warrants anticoagulation, and discovery of the mechanisms underlying the weak temporal correlations of AF and stroke. Moreover, developments in monitoring technologies will likely change the landscape of long-term AF monitoring and could allow better definition of the significance of changes in AF burden over time.

Abstract 1: Early Recurrence in Paroxysmal Versus Sustained Atrial Fibrillation in Patients With Acute Ischemic Stroke

Background and purpose: To date, there have been no thorough investigations on the possible role of atrial fibrillation (AF) pattern in stroke recurrence during early-phase post stroke. We investigated for differences in ischemic outcome between patients with paroxysmal AF (PAF) and those with sustained AF (SAF), within 90 days from acute ischemic stroke (AIS). Methods: Patients from the RAF and RAF-DOAC study databases were categorized into 2 groups: PAF and SAF (persistent + permanent AF). Early recurrence was defined as the composite of ischemic stroke, transient ischemic attack and symptomatic systemic embolism within 90 days from AIS. Results: A total of 2,150 patients (1,155 females, 53.7%) were enrolled: 930 (43.3%) had PAF and 1220 (56.7%) SAF. Patients with SAF were on average older, were more likely to have: diabetes mellitus, hypertension, a history of stroke/TIA, congestive heart failure, atrial enlargement, pacemaker and a high NIHSS. During the 90-day follow-up, 107 recurrent ischemic events were recorded from index stroke. Multivariate analysis for predictive factors of early ischemic recurrence indicated that SAF was associated with a non-significant increase in ischemic events at 90 days, compared to PAF (HR 1.23; 95% CI 0.74-2.04; p = 0.418) (Figure). Conclusions: PAF and SAF patients with acute stroke resulted having similar risks of ischemic recurrence within 90 days from index event. Therein, these findings suggest that AF pattern should not influence decision making concerning the timing of anticoagulant administration after an acute stroke.

Atrial fibrillation type matters: greater infarct volume and worse neurological defects seen in acute cardiogenic cerebral embolism due to persistent or permanent rather than paroxysmal atrial fibrillation.

Some studies have shown that the type of atrial fibrillation (AF), whether paroxysmal AF (PAF) or persistent or permanent AF (PeAF), affects the incidence of ischaemic stroke. This study sought to determine the relationship between the AF pattern and the severity and brain volume of infarction in an AF population including transient ischaemic attack (TIA) patients. This was a retrospective observational study. We studied 161 consecutive patients who were admitted to our stroke care unit with cardiogenic embolism or TIA related to non-valvular AF (age 79 ± 9.5, 78 females, and 87 PAF patients). We evaluated the differences in severity and infarct volume between the types of AF. Additionally, we divided the patients into three groups according to severe stroke (n = 38), TIA (n = 28), and those who were neither (stroke, n = 95) for the assessment of the predictors of severe stroke and TIA. Persistent or permanent atrial fibrillation patients with acute cardiogenic stroke or TIA had worse peak National Institute of Health Stroke Scale (NIHSS) scores [PAF median 4 (range 3-14), PeAF 17 (5.8-25); P < 0.0001] and worse NIHSS scores at discharge [PAF 2.0 (1-7), PeAF 11 (3-22); P < 0.0001]. Their infarct brain volume assessed by computed tomography or magnetic resonance imaging was also larger [PAF 4.4 (1.1-32) mL, PeAF 64 (6.9-170) mL; P < 0.0001]. Multivariate analysis of severe stroke vs. non-severe stroke patients showed that having PeAF was the only independent predictor of severe stroke [odds ratio (OR) 4.27, 95% confidence interval (CI) 1.91-10.2; P = 0.0003]. Comparison of TIA vs. non-TIA patients showed that PeAF (OR 0.120, 95% CI 0.0230-0.444; P = 0.0008) and anticoagulant use (OR 8.24, 95% CI 2.15-40.8; P = 0.0018) were independent predictors of TIA. Cardiogenic emboli due to non-valvular PeAF are associated with a worse acute clinical course and greater volume of infarction than those due to PAF.

Left ventricular torsional parameters before and after atrial fibrillation ablation: a velocity vector imaging study

Background and aimEffects of atrial fibrillation (AF) and its ablative treatment on LV torsion have not yet been fully investigated. This study aimed to examine whether AF patterns of LV contraction and its ablative correction can exert a significant impact on LV torsion by velocity vector imaging (VVI).MethodsThis case-control study conducted in Rajaie Cardiovascular, Medical and Research Center between October 2012 and June 2013. Study participants were 30 consecutive patients with symptomatic paroxysmal AF who met the inclusion criteria. The control group included 24 healthy participants with no history of cardiovascular disease. All individuals were in sinus rhythm at the time of echocardiography before and after the ablation procedure. Two-dimensional (2D) and Doppler echocardiography on a commercially available ultrasound system was performed for all the patients. Scanning was done by a wide-band ultrasound transducer with the frequency range between 2.5–3.5 MHz. The two short-axis views at basal and apical levels were subsequently processed off-line by VVI XStrain software. In order for data analysis, SPSS 16 utilized using paired and independent t-test. p-value ≤0.05 was considered significant.ResultsLV torsion (°/cm) mean ± SD was significantly lower in paroxysmal AF patients before ablation (0.8±0.3) than the control group (1.5±0.4) (p<0.001) and increased significantly after ablation (1.1±0.5) compared with before ablation (p=0.004), but still significantly lower than the control group (p=0.003). LV Twist, twist rate and untwist rate mean ± SD were significantly lower in paroxysmal AF patients before ablation than the control group and increased significantly after ablation compared with before ablation, but still significantly lower than the control group.ConclusionSubclinical LV dysfunction may be detected in paroxysmal AF rhythm by measuring torsional parameters through VVI which improves after AF ablation.

Decreased Mortality With Beta-Blockers in Patients With Heart Failure and Coexisting Atrial Fibrillation: An AF-CHF Substudy

ObjectivesThe impact of beta-blockers on mortality and hospitalizations was assessed in the largest randomized trial of patients with both atrial fibrillation (AF) and heart failure with a reduced ejection fraction (HFrEF): the Atrial Fibrillation-Congestive Heart Failure trial. BackgroundAlthough beta-blockers are the cornerstone of therapy for HFrEF, a recent patient-level meta-analysis cast doubt on their efficacy in patients with coexisting AF. MethodsFrom a total of 1,376 subjects randomized in the AF-CHF trial, those without beta-blockers at baseline were propensity matched to a maximum of 2 exposed patients. All absolute standardized differences after matching were ≤10%. Primary analyses respected the intention-to-treat principle. In on-treatment sensitivity analyses, beta-blocker status was modeled as a time-dependent covariate. ResultsBaseline characteristics were comparable among the matched cohorts (mean age 70 ± 11 years, 81% male, and mean left ventricular ejection fraction 27 ± 6%). During a median follow-up of 37 months, beta-blockers were associated with significantly lower all-cause mortality (hazard ratio [HR]: 0.721, 95% confidence interval [CI]: 0.549 to 0.945; p = 0.0180) but not hospitalizations (HR: 0.886; 95% CI: 0.715 to 1.100; p = 0.2232). Similar results were obtained in sensitivity analyses that modeled beta-blockers as a time-dependent variable (HR: 0.668 for all-cause mortality; 95% CI: 0.511 to 0.874; p = 0.0032; HR: 0.814 for hospitalizations; 95% CI: 0.653 to 1.014; p = 0.0658). There were no significant interactions between beta-blockers and patterns (i.e., persistent vs. paroxysmal) or burden of AF with respect to mortality or hospitalizations. ConclusionsIn propensity-matched analyses, beta-blockers were associated with significantly lower mortality but not hospitalizations in patients with HFrEF and AF, irrespective of the pattern or burden of AF. These results support current evidence-based recommendations for beta-blockers in patients with HFrEF, whether or not they have associated AF.

Stroke and Mortality Risk in Patients With Various Patterns of Atrial Fibrillation: Results From the ENGAGE AF-TIMI 48 Trial (Effective Anticoagulation With Factor Xa Next Generation in Atrial Fibrillation-Thrombolysis in Myocardial Infarction 48).

Whether the pattern of atrial fibrillation (AF) modifies the risk/benefit of anticoagulation is controversial. In ENGAGE AF-TIMI 48 trial (Effective Anticoagulation with Factor Xa Next Generation in Atrial Fibrillation-Thrombolysis in Myocardial Infarction 48), the factor Xa inhibitor edoxaban was noninferior to warfarin in preventing stroke or systemic embolic events and significantly reduced bleeding and cardiovascular mortality. However, detailed analyses by AF pattern have not been reported. The 21 105 patients were categorized as having paroxysmal (<7 days duration), persistent (≥7 days but <1 year), or permanent (≥1 year or failed cardioversion) AF patterns at randomization. Efficacy and safety outcomes were evaluated during the 2.8 years median follow-up and compared by AF pattern. The primary end point of stroke/systemic embolic event was lower in those patients with paroxysmal AF (1.49%/year), compared with persistent (1.83%/year; P-adj =0.015) and permanent AF (1.95%/year; P-adj =0.004). Overall, all-cause mortality also was lower with paroxysmal (3.0%/year) compared with persistent (4.4%/year; P-adj <0.001) and permanent AF (4.4%/year; P-adj <0.001). Annualized major bleeding rates were similar across AF patterns (2.86% versus 2.65% versus 2.73%). There was no effect modification by treatment assignment. In ENGAGE AF-TIMI 48 trial, patients with paroxysmal AF suffered fewer thromboembolic events and deaths compared with those with persistent and permanent AF. The efficacy and safety profile of edoxaban as compared with warfarin was consistent across the 3 patterns of AF. URL: http://www.clinicaltrials.gov. Unique identifier: NCT00781391.

Stroke Prevention for Patients with Atrial Fibrillation: Beyond the Guidelines.

Atrial fibrillation (AF) is the most common serious heart rhythm disorder, with a lifetime incidence of 1 in 4 for patients >40 years of age[1]. AF is a major cause of death and disability, as it is associated with a 4-5 fold increase in the risk of ischemic stroke[2]. In patients with AF, oral anticoagulation (OAC) therapy can reduce the risk of stroke by about two-thirds and the risk of all-cause mortality by approximately one-quarter, but is associated with an increased risk of bleeding[3], [4]. Atrial fibrillation (AF) is the most common serious heart rhythm disorder and is associated with an increased risk of ischemic stroke. This risk can be moderated with oral anticoagulation therapy, but the decision to do so must be balanced against the risks of bleeding. Herein, we discuss three emerging areas where more high-quality evidence is required to guide risk stratification: 1) the relationships between the pattern and burden of AF and stroke 2) the risk conferred by short episodes of device-detected "sub-clinical" atrial fibrillation (SCAF) and 3) the significance of AF that occurs transiently with stress (AFOTS), as is often detected during medical illness or after surgery. Risk stratification is important to identify patients with AF who can benefit from OAC therapy. There are, however, several common clinical scenarios where guidelines do not yet provide direction for stroke prevention; or do so based on limited high-quality evidence.