2011 ACCF/AHA/HRS Focused Updates Incorporated Into the ACC/AHA/ESC 2006 Guidelines for the Management of Patients With Atrial Fibrillation

How to estimate heart rate from pulse rate reported by oscillometric method in atrial fibrillation: The value of pulse rate variation

OBJECTIVES

To evaluate whether the mean pulse rate (PR) from three oscillometric blood pressure (BP) measurements provides an accurate estimation of electrocardiogram ventricular rate (HR) in patients with permanent atrial fibrillation (AF).

METHODS

BP and PR were measured with an oscillometric BP device for three times with one-minute interval. Simultaneously, one-minute electrocardiogram was also recorded for three times. The first PR and HR values were recorded as PR1 and HR1, and the averages of three PR and HR values as mean PR (mPR) and mean HR (mHR). Meanwhile, the differences between the highest and lowest values among the three PR and HR were calculated as ΔPR and ΔHR. Furthermore, the patients were stratified on ΔPR into the 0-15 and >15 subgroups.

RESULTS

A moderate positive correlation existed between PR1 and HR1 or mPR and mHR, and Bland-Altman plot also showed quite wide 95% limits between them. Meanwhile, ΔPR was significantly higher than ΔHR (12.1±8.6 vs 3.6±2.5bpm, P<0.001). However, in the 0-15 subgroup, the correlation between mPR and mHR was high (R2=0.800), and the 95% limits were only from -11.3 to 14.2bpm with a difference of 1.4bpm. The coincidence (mPR-mHR<10bpm) rate was 93.9% when PR≤80bpm, 96.3% when PR 81-100bpm, and 88.9% when PR over 100bpm.

CONCLUSION

The average of three PR values reported by an oscillometric BP device could provide a clinically accepted estimation of mean HR of 3min in AF patients with ΔPR 0-15bpm and mean PR ≤100bpm.

Safety of The Direct Oral Anticoagulant Edoxaban for Atrial Fibrillation After Cardiac Surgery: Pilot Study

Direct oral anticoagulants have recently been recommended for non-valvular atrial fibrillation, but have rarely been studied in the field of cardiac surgery. We prospectively investigated the safety of edoxaban, a novel oral anticoagulant, for use in cardiac surgery patients with postoperative atrial fibrillation (POAF), which is the most common complication of cardiac surgery and can lead to stroke. The subjects were adult cardiac surgery patients with POAF who received oral edoxaban for 2 months in an open-label pilot study. The primary endpoint was cerebrovascular/bleeding events up to 2 months, while the secondary endpoints were hemoglobin, prothrombin time, and activated partial thromboplastin time. There were no cerebrovascular or bleeding events during edoxaban treatment and the test drug was not discontinued by any patient. There was no macroscopic hematuria and hemoglobin did not decrease, being significantly higher than the baseline level after 2 months. The prothrombin time was significantly prolonged from 1 week to 2 months and the activated partial thromboplastin time was significantly prolonged from 1 day to 2 months. Echocardiography detected pericardial effusion in 1 patient, but hemoglobin did not decrease and the effusion improved with diuretic therapy. In conclusion, despite the limited sample size of this pilot study, it was demonstrated that edoxaban does not induce bleeding in patients with POAF after cardiac surgery, suggesting that it is safe to perform a large-scale efficacy study of edoxaban as anticoagulant therapy for POAF.

Guidelines for the Use of Echocardiography in the Evaluation of a Cardiac Source of Embolism

Embolism from the heart or the thoracic aorta often leads to clinically significant morbidity and mortality due to transient ischemic attack, stroke or occlusion of peripheral arteries. Transthoracic and transesophageal echocardiography are the key diagnostic modalities for evaluation, diagnosis, and management of stroke, systemic and pulmonary embolism. This document provides comprehensive American Society of Echocardiography guidelines on the use of echocardiography for evaluation of cardiac sources of embolism. It describes general mechanisms of stroke and systemic embolism; the specific role of cardiac and aortic sources in stroke, and systemic and pulmonary embolism; the role of echocardiography in evaluation, diagnosis, and management of cardiac and aortic sources of emboli including the incremental value of contrast and 3D echocardiography; and a brief description of alternative imaging techniques and their role in the evaluation of cardiac sources of emboli. Specific guidelines are provided for each category of embolic sources including the left atrium and left atrial appendage, left ventricle, heart valves, cardiac tumors, and thoracic aorta. In addition, there are recommendation regarding pulmonary embolism, and embolism related to cardiovascular surgery and percutaneous procedures. The guidelines also include a dedicated section on cardiac sources of embolism in pediatric populations.

Reproducibility and Reliability of the Quality of Life Questionnaire in Patients With Atrial Fibrillation

BACKGROUND

Studies have shown the impact of atrial fibrillation (AF) on the patients' quality of life. Specific questionnaires enable the evaluation of relevant events. We previously developed a questionnaire to assess the quality of life of patients with AF (AFQLQ version 1), which was reviewed in this study, and new domains were added.

OBJECTIVE

To demonstrate the reproducibility of the AFQLQ version 2 (AFQLQ v.2), which included the domains of fatigue, illness perception and well-being.

METHODS

We applied 160 questionnaires (AFQLQ v.2 and SF-36) to 40 patients, at baseline and 15 days after, to measure inter- and intraobserver reproducibility. The analysis of quality of life stability was determined by test-retest, applying the Bartko intraclass correlation coefficient (ICC). Internal consistency was assessed by Cronbach's alpha test.

RESULTS

The total score of the test-retest (n = 40) had an ICC of 0.98 in the AFQLQ v.2, and of 0.94 in the SF36. In assessing the intra- and interobserver reproducibility of the AFQLQ v.2, the ICC reliability was 0.98 and 0.97, respectively. The internal consistency had a Cronbach's alpha coefficient of 0.82, compatible with good agreement of the AFQLQ v.2.

CONCLUSION

The AFQLQ v.2 performed better than its previous version. Similarly, the domains added contributed to make it more comprehensive and robust to assess the quality of life of patients with AF.

The rs6771157 C/G polymorphism in SCN10A is associated with the risk of atrial fibrillation in a Chinese Han population

A recent genome wide associated study in European descent population identified the association of Atrial fibrillation (AF) risk with a single nucleotide polymorphism (SNP) in SCN10A. The aim of this study was to evaluate whether SCN10A polymorphisms are associated with AF risk in the Chinese Han population. A total of 2,300 individuals of Chinese Han origin were recruited and three potentially functional SNPs were genotyped. Logistic regression models were utilized to calculate odds ratios (ORs) at a 95% confidence intervals (CIs). Logistic regression analysis in an additive genetic model revealed that one SNP in SCN10A (rs6771157) was associated with an increased risk of AF (adjusted OR = 1.20, 95% CI: 1.06 - 1.36, P = 0.003). Stratification analysis of several main AF risk factors indicated that the risk associations with rs6771157 were not statistically different among different subgroups. In summary, our study suggests the possible involvement of the SCN10A variant in AF development in Chinese Han populations. Further biological function analyses are required to confirm our finding.

Serum Galectin-3 Levels Predict Recurrences after Ablation of Atrial Fibrillation

Galectin-3 is a biomarker of fibrosis and atrial remodeling, involved in the mechanisms of initiation and maintenance of atrial fibrillation (AF). We sought to study the accuracy of galectin-3 level in predicting recurrences of AF after ablation. Serum concentrations of galectin-3 were determined in a consecutive series of patients addressed for AF ablation in our center. After a 3-month blanking period, recurrences of atrial arrhythmias were collected during the first year in all patients, using Holter monitoring at 3, 6 months and 12 months. A total of 160 patients were included, with a mean galectin-3 rate was 14.4 ± 5.6 ng/mL. At 12-month, 55 patients (34%) had reexperienced sustained atrial arrhythmia. Only higher galectin-3 level (HR = 1.07 [1.01–1.12], p = 0.02) and larger left atrial diameter (HR = 1.07 [1.03–1.12], p = 0.001) independently predicted recurrence. Patients with both galectin-3 level <15 ng/mL and left atrial diameter <40 millimeters had a 1-year arrhythmia-free survival rate − after a single procedure without anti-arrhythmic drug − of 91%, as compared with 41% in patients with galectin-3 ≥ 15 and left trial diameter ≥40 (p < 0.0001), whether AF was paroxysmal or persistent. Galectin-3 and left atrial diameters, rather than clinical presentation of AF, predict recurrences after ablation.

Has the aetiology of ischaemic stroke changed in the past decades? Analysis and comparison of data from current and historical stroke databases

OBJECTIVES

We aimed to determine whether the aetiology of ischaemic stroke has changed in recent years and, if so, to ascertain the possible reasons for these changes.

PATIENTS AND METHODS

We analysed the epidemiological history and vascular risk factors of all patients diagnosed with ischaemic stroke at Complejo Hospitalario Universitario de Albacete (CHUA) from 2009 to 2014. Ischaemic stroke subtypes were established using the TOAST criteria. Our results were compared to data from the classic Stroke Data Bank (SDB); in addition, both series were compared to those of other hospital databases covering the period between the two.

RESULTS

We analysed 1664 patients (58% were men) with a mean age of 74 years. Stroke aetiology in both series (CHUA, SDB) was as follows: atherosclerosis (12%, 9%), small-vessel occlusion (13%, 25%), cardioembolism (32%, 19%), stroke of other determined aetiology (3%, 4%), and stroke of undetermined aetiology (40%, 44%). Sixty-three percent of the patients from the CHUA and 42% of the patients from the SDB were older than 70 years. Cardioembolic strokes were more prevalent in patients older than 70 years in both series. Untreated hypertension was more frequent in the SDB (SDB = 31% vs CHUA = 10%). The analysis of other databases shows that the prevalence of cardioembolic stroke is increasing worldwide.

CONCLUSIONS

Our data show that the prevalence of lacunar strokes is decreasing worldwide whereas cardioembolic strokes are increasingly more frequent in both our hospital and other series compared to the SDB. These differences may be explained by population ageing and the improvements in management of hypertension and detection of cardioembolic arrhythmias in stroke units.

Predictors of significant coronary artery disease in atrial fibrillation: Are cardiac troponins a useful measure

BACKGROUND

Cardiac Troponin I (cTnI) is frequently measured in patients presenting with symptomatic atrial fibrillation (AF). The significance of elevated cTnI levels in this patient cohort is unclear. We investigated the value of cTnI elevation in this setting and whether it is predictive for significant coronary artery disease (sCAD).

METHODS

We conducted a retrospective, single-center, case-control study of 231 patients who presented with symptomatic AF to The Prince Charles Hospital emergency department, Brisbane, Australia between 2006 and 2014. Patients who underwent serial cTnI testing and assessment for CAD were included. Clinical variables that are known to predict CAD and could potentially predict cTnI elevation were collected. Binary logistic regression was performed to identify predictors of sCAD and cTnI elevation.

RESULTS

Cardiac Troponin I elevation above standard cut off was not predictive for sCAD after adjustment for other predictors (OR 1.62, 95% CI 0.79-3.32. p=0.19). However, the highest cTnI concentration value (cTnI peak) was predictive for sCAD (OR 2.02, 95% CI 1.02-3.97, p=0.04). Dyspnea on presentation (OR 4.52, 95% CI 1.87-10.91, p=0.001), known coronary artery disease (OR 3.44, 95% CI 1.42-8.32, p=0.006), and ST depression on the initial electrocardiogram (OR 2.57, 95% CI 1.11-5.97, p=0.028) predicted sCAD in our cohort, while heart rate on initial presentation was inversely correlated with sCAD (OR 0.99, 95% CI 0.971-1.00, p=0.034).

CONCLUSION

Troponin elevation is common in patients presenting to hospital with acute symptomatic AF and it is not a reliable indicator for underlying sCAD in this patient cohort. However, cTnI peak was a predictor of significant coronary artery disease.

Value of Implantable Loop Recorders in Monitoring Efficacy of Radiofrequency Catheter Ablation in Atrial Fibrillation

BACKGROUND The aim of this study was to evaluate the value of the implantable loop recorder (ILR) in diagnosing atrial fibrillation (AF) and assessing the postoperative efficacy of radiofrequency catheter ablation (RFCA). MATERIAL AND METHODS A total of 32 patients who successfully underwent RFCA were selected. These patients discontinued antiarrhythmic medication with no AF recurrence for more than 3 months after RFCA, and underwent ILR placement by a conventional method. The clinical manifestations and information on arrhythmias recorded by the ILR were followed up to assess the efficacy of AF RFCA. RESULTS The mean follow-up period was 24.7±12.5 months. Of 32 patients with ILR information, 27 had successful RFCA and 5 had recurrent AF. The follow-up results obtained by traditional methods showed 29 patients with successful RFCA and 3 with recurrent AF (P<0.05). Among the 18 patients with clinical symptoms, 13 had recorded cardiac arrhythmic events (72.2%) and 5 showed sinus rhythm (27.8%). The ILRs recorded 18 patients with arrhythmic events (56.3%), including 12 cases of atrial arrhythmias, among whom 5 recurred at 9, 12, 16, 17, and 32 months after AF RFCA; there were also 2 patients with ventricular tachycardia (VT) and 4 with bradycardia. CONCLUSIONS The value of ILR in assessing the efficacy of AF RFCA was superior to that of traditional methods. ILR can promptly detect asymptomatic AF, and can monitor electrocardiogram features after RFCA, thus providing objective evidence of efficacy.

The rs6817105 polymorphism on chromosome 4q25 is associated with the risk of atrial fibrillation in the Chinese Han population

OBJECTIVE

Previous genome-wide association studies (GWASs) have identified rs6817105-a single nucleotide polymorphism (SNP) on chromosome 4q25-to be associated with the risk of atrial fibrillation (AF) in a European-descent population. We recently demonstrated this association in a large cohort of Japanese ancestry. Our present study was designed to determine this association in the Chinese Han population.

METHODS

This case-control study included 597 AF cases and 996 AF-free controls, and rs6817105 SNPs were genotyped using the TaqMan allelic discrimination assay. Odds ratios (ORs) and 95% confidence intervals (95%CIs) were calculated in logistic regression models.

RESULTS

The genotype distribution of rs6817105-CC was significantly more frequent in the AF patients than in the controls (p=3.24×10-32). In our study, logistic regression analysis showed a strong association between rs6817105 and the risk of AF (additive model: OR=2.22, 95%CI=1.89-2.61, p=2.33×10-22; dominant model: OR=2.96, 95%CI: 2.16-4.07, p=2.03×10-11; recessive model: OR=2.83, 95%CI=2.27-3.54, p=4.00×10-20). Stratification analyses showed a borderline statistical difference between subgroups of age for the association of rs6817105 with AF risk (p=0.049). However, further interactive analysis indicated no significant interaction between genotype of rs6817105 and age (p=0.178).

CONCLUSION

Our finding suggested that SNP rs6817105 may be associated with a high significant risk of AF in the Chinese Han population, although more replicative studies of larger sample size are needed to confirm this finding.

A single-center randomized, controlled trial investigating the efficacy of a mHealth ECG technology intervention to improve the detection of atrial fibrillation: the iHEART study protocol

Background

Atrial fibrillation is a major public health problem and is the most common cardiac arrhythmia, affecting an estimated 2.7 million Americans. The true prevalence of atrial fibrillation is likely underestimated because episodes are often sporadic; therefore, it is challenging to detect and record an occurrence in a “real world” setting. To date, mobile health tools that promote earlier detection and treatment of atrial fibrillation and improvement in self-management behaviors and knowledge have not been evaluated. This study will be the first to address the epidemic problem of atrial fibrillation with a novel approach utilizing advancements in mobile health electrocardiogram technology to empower patients to actively engage in their healthcare and to evaluate impact on quality of life and quality-adjusted life years. Furthermore, sending a daily electrocardiogram transmission, coupled with receiving educational and motivational text messages aimed at promoting self-management and a healthy lifestyle may improve the management of chronic cardiovascular conditions (e.g., hypertension, diabetes, heart failure, etc.). Therefore, we are currently conducting a randomized controlled trial to assess the efficacy of a mobile health intervention, iPhone® Helping Evaluate Atrial fibrillation Rhythm through Technology (iHEART) versus usual cardiac care.

Methods

The iHEART study is a single center, prospective, randomized controlled trial. A total of 300 participants with a recent history of atrial fibrillation will be enrolled. Participants will be randomized 1:1 to receive the iHEART intervention, receiving an iPhone® equipped with an AliveCor® Mobile ECG and accompanying Kardia application and behavioral altering motivational text messages or usual cardiac care for 6 months.

Discussion

This will be the first study to investigate the utility of a mobile health intervention in a “real world” setting. We will evaluate the ability of the iHEART intervention to improve the detection and treatment of recurrent atrial fibrillation and assess the intervention's impact on improving clinical outcomes, quality of life, quality-adjusted life-years and disease-specific knowledge.

Trial registration

NCT02731326; Verified April 2016

Prevalence and Course of Atrial Fibrillation in Critically Ill Trauma Patients

Atrial fibrillation (AF) is the most common cardiac dysrhythmia. Its prevalence, risk factors, course, and complications are not well described in critically ill trauma patients. This was a retrospective, single-center, cohort study at an academic, level 1 trauma center. Trauma patients >18 years, identified from the trauma registry and admitted to the intensive care unit (ICU), were sequentially screened for AF. A matched cohort was created by selecting patients consecutively admitted before and after the patients who experienced AF. Of 2591 patients screened, 191 experienced AF, resulting in a prevalence of 7.4%. There was no difference in injury severity score (ISS) between those with and without AF, but patients with AF had higher observed mortality (15.5% vs 6.7%, P < .001). Patients with a history of AF (n = 75) differed from new-onset AF (n = 106) in their mean age, 78.9 ± 8.4 versus 69.2 ± 17.9 years; mean time to AF onset, 1.1 ± 2.3 versus 5.2 ± 10.2 days; median duration of AF, 29.8 (1-745.2) versus 5.9 (0-757) hours; and rate of AF resolution, 28% versus 82.1%, respectively. Despite a higher ISS, Sequential Organ Failure Assessment and length of stay, the new-onset AF group experienced a similar rate of mortality compared to the history of AF group (14.7% vs 16.0%). Patients with AF had a higher mortality when compared to those in sinus rhythm. The course of AF in the new-onset AF group occurred later was shorter and was more likely to convert; however, these patients had a longer ICU stay when compared to those who had a history of AF.

Effect of a Multidisciplinary Approach for the Management of Patients With Atrial Fibrillation in the Emergency Department on Hospital Admission Rate and Length of Stay

Management of atrial fibrillation (AF) in the emergency department (ED) is variable because of the absence of universally adopted treatment guidelines. To address potentially preventable hospital admissions and prolonged length of stay, an AF treatment pathway was co-developed by physicians from the cardiac electrophysiology service and the department of emergency medicine at our institution. The impact of this AF pathway on patient outcomes was evaluated with a prospective, observational study conducted in a single tertiary care center from July 1, 2013, to June 30, 2014. The primary study outcome was the rate of hospital admission. The secondary outcomes were duration of ED visit and inpatient length of stay. The 94 patients treated according to the AF pathway during the study period were less likely to be admitted than the 265 patients who received routine care (16% vs 80%, p <0.001). For admitted patients, the mean length of stay was shorter for patients treated according to the AF pathway (32 vs 85 hours, p = 0.002). The time spent in the ED was longer for patients in the AF pathway (16 vs 85 hours, p <0.001). Utilization of a multidisciplinary pathway for management of AF in the ED led to a significant reduction in the rate of hospital admission. Patients who were admitted after receiving care according to the AF pathway had a shorter length of stay. In conclusion, utilization of a multidisciplinary AF pathway resulted in a 5-fold reduction in admission rate and >2-fold reduction length of stay for admitted patients.

Dual-chamber implantable cardioverter-defibrillator. Is it useful in patient with permanent atrial fibrillation?

In patients with permanent atrial fibrillation (AF) and implantable cardioverter–defibrillator (ICD) implant indication, a single‐chamber device is the choice because AF does not provide interesting information for the treatment. It is very unusual to find patients with permanent AF that coexist with atrial tachycardia with various degree of Atrioventricular block.

Effects of atorvastatin on atrial remodeling in a rabbit model of atrial fibrillation produced by rapid atrial pacing

Background

Accumulating evidence suggests that myeloperoxidase (MPO) is involved in atrial remodeling of atrial fibrillation (AF). Statins could reduce the MPO levels in patients with cardiovascular diseases. This study evaluated the effects of atorvastatin on MPO level and atrial remodeling in a rabbit model of pacing-induced AF.

Methods

Eighteen rabbits were randomly divided into sham, control and atorvastatin groups. Rabbits in the control and atorvastatin groups were subjected to rapid atrial pacing (RAP) at 600 bpm for 3 weeks, and treated with placebo or atorvastatin (2.5 mg/kg/d), respectively. Rabbits in the sham group did not receive RAP. After 3 weeks of pacing, atrial structural and functional changes were assessed by echocardiography, atrial effective refractory period (AERP) and AF inducibility were measured by atrial electrophysiological examination, and histological changes were evaluated by Masson trichrome-staining. The L-type calcium channel α1c (Cav1.2), collagen I and III, MPO, matrix metalloproteinase (MMP)-2 and MMP-9 were analyzed by real time polymerase chain reaction and/or western blot.

Results

All rabbits were found to have maintained sinus rhythm after 3 weeks of RAP. Atrial burst stimulation induced sustained AF (>30 min) in 5, 4, and no rabbits in the control, atorvastatin, and sham groups, respectively. The AERP shortened and Cav1.2 mRNA level decreased in the control group, but these changes were suppressed in the atorvastatin group. Obvious left atrial enlargement and dysfunction was found in both control and atorvastatin groups. Compared with the control group, these echocardiograhic indices of left atrium did not differ in the atorvastatin group. Prominent atrial fibrosis and increased levels of collagen I and III were observed in the control group but not in the atorvastatin group. The mRNA and protein levels of MPO, MMP-2 and MMP-9 significantly increased in the control group, but these changes were prevented in the atorvastatin group.

Conclusion

Treatment with atorvastatin prevented atrial remodeling in a rabbit model of RAP-induced AF. The reduction of levels of atrial MPO, MMP-2 and MMP-9 may contribute to the prevention of atorvastatin on atrial remodeling.

Prevention and Treatment of Lower Limb Deep Vein Thrombosis after Radiofrequency Catheter Ablation: Results of a Prospective active controlled Study

We conducted a prospective, single-center, active controlled study from July 2013 to January 2015, in Chinese patients with rapid ventricular arrhythmia who had received radiofrequency catheter ablation (RFCA) treatment to determine formation of lower extremity deep vein thrombosis (LDVT) post RFCA procedure, and evaluated the effect of rivaroxaban on LDVT. Patients with asymptomatic pulmonary thromboembolism who had not received any other anticoagulant and had received no more than 36 hours of treatment with unfractionated heparin were included. Post RFCA procedure, patients received either rivaroxaban (10 mg/d for 14 days beginning 2–3 hours post-operation; n = 86) or aspirin (100 mg/d for 3 months beginning 2–3 hours post-operation; n = 90). The primary outcome was a composite of LDVT occurrence, change in diameter of femoral veins, and safety outcomes that were analyzed based on major or minor bleeding events. In addition, blood flow velocity was determined. No complete occlusive thrombus or bleeding events were reported with either of the group. The lower incidence rate of non-occluded thrombus in rivaroxaban (5.8%) compared to the aspirin group (16.7%) indicates rivaroxaban may be administered post-RFCA to prevent and treat femoral venous thrombosis in a secure and effective way with a faster inset of action than standard aspirin therapy.

Results from a multicentre comparison of cryoballoon vs. radiofrequency ablation for paroxysmal atrial fibrillation: is cryoablation more reproducible?

AIM

Cryoballoon ablation (Cryoballoon) has emerged as a new alternative for the treatment of symptomatic drug-refractory atrial fibrillation (AF). Whether the results of Cryoballoon are more reproducible than those of radiofrequency (RF) ablation remains to be proved.

METHODS AND RESULTS

A total of 860 consecutive patients undergoing a first ablation procedure for paroxysmal AF (467 treated with RF and 393 treated with Cryoballoon) were selected from a prospective multicentre survey of AF ablation (FrenchAF). Radiofrequency and Cryoballoon were compared regarding mid-term efficacy and safety. During a median follow-up of 14 months (interquartile range 8-23), patients treated with Cryoballoon displayed similar rates of freedom from atrial arrhythmia relapse in centres performing this technique (68-80% at 18 months). However, in centres performing RF, a greater heterogeneity in procedural results was observed (46-79% were free from atrial arrhythmia relapse at 18 months). On multivariate analysis, Cryoballoon (HR = 0.47, 95% CI 0.35-0.65, P < 0.001) and annual AF ablation caseload (HR = 0.87 per every 100 AF ablation procedures per year; 95% CI 0.80-0.96, P = 0.003) were independent predictors of procedural success. However, on sensitivity analysis, according to the ablation method, annual AF ablation caseload predicted only sinus rhythm maintenance in the subgroup of patients treated with RF. Analysis of interoperator results with Cryoballoon and RF confirmed lower reproducibility of RF, but suggested that besides caseload, other operator-related factors may play a role.

CONCLUSION

Cryoballoon seems to be less operator-dependent and more reproducible than RF in the setting of paroxysmal AF ablation.

A clustered randomized trial to IMProve treatment with AntiCoagulanTs in patients with Atrial Fibrillation (IMPACT-AF): design and rationale

Atrial fibrillation (AF) is common, increasing as the population ages, and a major cause of embolic stroke. While oral anticoagulation (OAC) is highly effective at preventing stroke in patients with AF, it continues to be underused in eligible patients worldwide. The objective of this prospective, cluster randomized controlled trial (IMPACT-AF; ClinicalTrials.gov #NCT02082548) is to determine whether a comprehensive customized intervention will increase the rate and persistence of use of OAC in patients with AF. IMPACT-AF will be conducted in approximately 50 centers in 5 low- to middle-income countries. Before randomization, sites within countries will be paired to match in size, practice type and baseline rate of OAC use. Site pairs will be randomized to intervention versus control. In total, 40 to 70 patients with AF and at least 2 CHA2DS2-VASc risk factors will be enrolled at each site using a consecutive enrollment strategy, with the goal of capturing actual practice patterns. We aim for patients with a new diagnosis of AF to comprise at least 30% of the study cohort. Assuming an average baseline OAC use of 60% and a post-intervention use of 70% with a post-control rate of 60%, there will be roughly 94-98% power with 25 clusters per group (intracluster correlation coefficient of 0.02). While this trial focuses on improving treatment use and reducing preventable strokes, we also aim to better understand the reasons for OAC underuse. This will improve the intervention with the goal of creating educational recommendations to improve care for patients with AF.

Elevated plasma levels of Th17-related cytokines are associated with increased risk of atrial fibrillation

We performed a matched case-control study using a propensity score matching, to assess the association of Th17-related cytokines, including interleukin (IL) 17A (IL-17A), IL-17F, IL-21, IL-22 and IL-6, along with interferon-γ (IFN-γ), IL-10, IL-9, and IL-4, with the risk of AF. A total of 336 patients with AF were matched 1:1 with patients without AF. Plasma levels of cytokines were measured using Luminex xMAP assays. The plasma levels of all examined cytokines were significantly higher in AF patients than controls (P < 0.05), and these cytokines were highly correlated with each other (P < 0.01). A multivariate conditional logistic regression analysis showed that elevated plasma levels of IL-17A, IL-17F, IL-21, IL-22, IFN-γ, IL-10, IL-9 and IL-6 were significantly associated with AF risk independently of potential confounders. There were no significant differences in plasma levels of examined cytokines between paroxysmal and chronic AF patients. IL-17A, IL-21, IL-10 and IL-6 levels were positively correlated with left atrial diameter; IL-17F level was negatively correlated with left ventricle ejection fraction among AF patients (P < 0.05). Elevated plasma levels of Th17-related cytokines were independently associated with increased an risk of AF; hence, Th17-related cytokines may be involved in the pathogenesis of AF.

North American Thrombosis Forum, AF Action Initiative Consensus Document

The North American Thrombosis Forum Atrial Fibrillation Action Initiative consensus document is a comprehensive yet practical briefing document focusing on stroke and bleeding risk assessment in patients with atrial fibrillation, as well as recommendations regarding anticoagulation options and management. Despite the breadth of clinical trial data and guideline recommendation updates, many clinicians continue to struggle to synthesize the disparate information available. This problem slows the uptake and utilization of updated risk prediction tools and adoption of new oral anticoagulants. This document serves as a practical and educational reference for the entire medical community involved in the care of patients with atrial fibrillation.

Changes in left ventricular filling parameters following catheter ablation of atrial fibrillation

BACKGROUND

Atrial fibrillation (AF) is common in the setting of abnormal ventricular relaxation. We evaluated the association between ventricular relaxation grade and atrial fibrosis and examined the change in left ventricular filling parameters following catheter ablation.

METHODS AND RESULTS

AF patients undergoing catheter ablation who had cardiac late gadolinium enhancement MRI (LGE-MRI) and echocardiographic examinations were included in the study. Left atrial (LA) tissue fibrosis and volume were quantified using LGE-MRI. Echocardiograms were performed at baseline and 3 months following catheter ablation to assess left ventricular (LV) filling. Two hundred and ninety three patients (60.8 % male) met the inclusion criteria. In patients in sinus rhythm at baseline (n = 115), ventricular relaxation pattern was identified as normal in 54 patients (47.0 %), impaired in 35 (30.4 %), pseudo-normal in 18 (15.7 %), and restrictive in 8 (7.0 %). Restrictive LV filling was associated with higher LA volume index (61.2 ± 30.5 vs 46.0 ± 18.5 ml/m²; p < 0.01) and LA fibrosis (21.8 ± 10.9 % vs 15.5 ± 9.4 %; p = 0.036) compared to non-restrictive filling. In patients in sinus rhythm on both pre- and post-ablation echocardiograms (n = 104), A waves decreased from 0.70 ± 0.23 at baseline to 0.60 ± 0.20 (p < 0.01) and E/E' decreased from 9.6 ± 4.0 at baseline to 8.6 ± 3.5 (p = 0.03). Thirty-two patients (27.2 %) had an improvement, and 24 patients (23.1 %) had a worsening in diastolic grade. Clinical heart failure and diabetes were associated with worse diastolic grade post-ablation.

CONCLUSIONS

Restrictive LV filling is associated with higher LA fibrosis. A change in echocardiographic LV filling pattern was noted in over 50 % of patients post-ablation.

Anticoagulant Use in Patients With Nonvalvular Atrial Fibrillation: Has Prescribing Improved?

Discordance between international guideline recommendations and anticoagulant prescribing patterns among patients with nonvalvular atrial fibrillation (NVAF) has been frequently reported. This study was designed to compare the anticoagulant utilization pattern to earlier data in the same population and identify predictors of anticoagulant prescribing among patients with NVAF. We reviewed patients with NVAF admitted to Tasmania’s 3 major hospitals between January 2011 and June 2012 and compared the anticoagulant utilization pattern to earlier data. Patients were excluded if they had only 1 episode of NVAF that reverted spontaneously or upon cardioversion. Multivariate logistic regression analysis was used to identify predictors of anticoagulant prescribing. Overall, 53.8% of patients received anticoagulant treatment compared to 40.4% 15 years ago. Among eligible patients at high-risk of stroke, 52.5% were receiving anticoagulant therapy (vs 42.1% 15 years ago). Approximately 10% of patients with a CHADS2 score ≥2 were not receiving any antithrombotic treatment, reduced from 18.2% in the earlier cohort, whereas anticoagulant use increased among those at low risk (score 0) to 48.5% from 14.2%. Younger age (odds ratio [OR] 0.99, 95% confidence interval [CI] 0.97-1.0; P = .04); CHADS2 = 1, relative to 0 (OR 1.68, 95% CI 1.07-2.63; P = .02); CHF (OR 1.56, 95% CI 1.12-2.15; P = .008); and embolic disease history (OR 1.77, 95% CI 1.09-2.86; P = .02) were significant predictors of anticoagulant prescribing. While there has been improvement over the past 15 years, suboptimal use of anticoagulant therapy among high-risk patients with NVAF remains common. There is significant potential for improvement in the quality of stroke prophylaxis in patients with NVAF.

Does left atrial appendage (LAA) occlusion device alter the echocardiography and electrocardiogram parameters in patients with atrial fibrillation?

BACKGROUND

The alterations of echocardiography and electrocardiogram (ECG) in patients received left atrial appendage LAA occlusion therapy are still unclear. The present study was to evaluate the influence of LAA occlusion device on echocardiography and ECG changes in patients with atrial fibrillation (AF).

METHODS

Seventy-three patients who had undergone Watchman, LAmbre and Lefort were enrolled in this study. Echocardiography and ECG results at pre- and post-operation were collected. Besides, echocardiography was also performed during follow-up visits at 1, 6 and 12months after discharge.

RESULTS

After LAA occlusion, a slight and measureable movement of QRS electric axis was observed in most patients. The significant differences were also observed in heart rate (HR) and the mean-mean QT interval between pre- and post-operation for all patients. There existed no significant difference in echocardiographic parameters between before and after device implantation. However, a larger left atrial (LA) diameter was detected by echocardiography during follow-up visit at 6months when compared with pre-operation parameters. Similarly, aortic root diameter (ARD) was also larger during follow-up at 12months than the baseline dimension in pre-operation.

CONCLUSIONS

LAA occlusion device resulted in a slightly movement in QRS axis, reduced HR and increased the mean-mean QT interval duration. In addition, LA diameter and ARD seemed to be larger after device implantation.

Variable use of amiodarone is associated with a greater risk of recurrence of atrial fibrillation in the critically ill

Background

Atrial fibrillation is a common rhythm disturbance in the general medical-surgical intensive care unit. Amiodarone is a popular drug in this setting but evidence to inform clinical practice remains scarce. We aimed to identify whether variation in the clinical use of amiodarone was associated with recurrent atrial fibrillation.

Methods

This was a retrospective audit of 177 critically ill patients who developed new-onset atrial fibrillation after admission to a tertiary level medical-surgical trauma intensive care unit. Patterns of amiodarone prescription (including dosage schedule and duration) were assessed in relation to recurrence of atrial fibrillation during the intensive care unit stay. Known recurrence risk factors, such as inotrope administration, cardiac disease indices, Charlson Comorbidity Index, magnesium concentrations, fluid balance, and potassium concentrations, were also included in adjusted analysis using forward stepwise logistic regression modelling.

Results

The cohort had a median (interquartile range) age of 69 years (60–75), Acute Physiology and Chronic Health Evalution II score of 22 (17–28) and Charlson Comorbidity Index of 2 (1–4). A bolus dose of amiodarone followed by infusion (P = 0.02), in addition to continuing amiodarone infusion through to discharge from the intensive care unit (P < 0.001), were associated with less recurrent dysrhythmia. Recurrence after successful treatment was associated with ceasing amiodarone while an inotrope infusion continued (P < 0.001), and was more common in patients with a prior history of congestive cardiac failure (P = 0.04), and a diagnosis of systemic inflammatory response syndrome (P = 0.02).

Conclusions

Amiodarone should be administered as a bolus dose followed immediately with an infusion when treating atrial fibrillation in the medical-surgical intensive care unit. Consideration should be given to continuing amiodarone infusions in patients on inotropes until they are ceased.

Atrial Fibrillation Increases the Risk of Peripheral Arterial Disease With Relative Complications and Mortality: A Population-Based Cohort Study

Atrial fibrillation (AF), an increasing prevalent cardiac arrhythmia due to aging general population, has many common risk factors with peripheral arterial disease (PAD). However, it is unclear whether AF is associated with a risk of PAD. We investigated the prevalence of AF and PAD in the general population and the risk of PAD among the AF population. This longitudinal, nationwide, population-based cohort study was conducted using data from the Taiwan National Health Insurance Research Database recorded during 2000 to 2011. In total, 3814 and 15,364 patients were included in the AF and non-AF cohorts, respectively. Univariate and multivariate Cox proportional hazard regression models were used for examining the effects of AF on the risk of outcomes. The average follow-up periods of PAD were 4.96 ± 3.28 and 5.29 ± 3.35 years for the AF and non-AF cohorts, respectively. Overall, the risk of PAD showed a significantly higher risk in the AF cohort (adjusted HR=1.31, 95% CI=1.19-1.45) compared with the non-AF cohort. Similar results were observed for heart failure and stroke, where the AF cohort had a 1.83-fold and 2.53-fold higher risk of developing heart failure and stroke. The AF cohort also had a significant increased risk for mortality (adjusted HR=1.66, 95% CI=1.49-1.84). The present study indicated that the incidence of PAD, heart failure, stroke, and overall mortality is higher in patients with AF than in those without it.

Impact of an Emergency Department Observation Unit Management Algorithm for Atrial Fibrillation

Background

Atrial fibrillation (AF) is a common, growing, and costly medical condition. We aimed to evaluate the impact of a management algorithm for symptomatic AF that used an emergency department observation unit on hospital admission rates and patient outcomes.

Methods and Results

This retrospective cohort study compared 563 patients who presented consecutively in the year after implementation of the algorithm, from July 2013 through June 2014 (intervention group), with 627 patients in a historical cohort (preintervention group) who presented consecutively from July 2011 through June 2012. All patients who consented to have their records used for chart review were included if they had a primary final emergency department diagnosis of AF. We observed no significant differences in age, sex, vital signs, body mass index, or CHADS2 (congestive heart failure, hypertension, age, diabetes mellitus, and prior stroke or transient ischemic attack) score between the preintervention and intervention groups. The rate of inpatient admission was significantly lower in the intervention group (from 45% to 36%; P<0.001). The groups were not significantly different with regard to rates of return emergency department visits (19% versus 17%; P=0.48), hospitalization (18% versus 16%; P=0.22), or adverse events (2% versus 2%; P=0.95) within 30 days. Emergency department observation unit admissions were 40% (P<0.001) less costly than inpatient hospital admissions of ≤1 day's duration.

Conclusions

Implementation of an emergency department observation unit AF algorithm was associated with significantly decreased hospital admissions without increasing the rates of return emergency department visits, hospitalization, or adverse events within 30 days.

Warfarin Use and Risk of Stroke in Patients With Atrial Fibrillation Undergoing Hemodialysis: A Meta-Analysis

In spite of the substantial burden of atrial fibrillation and associated elevated ischemic stroke risk in patients undergoing hemodialysis, the role of warfarin in these high-risk patients remains uncertain. Our objective was to clarify the association between warfarin use and risk of stroke for patients with atrial fibrillation undergoing dialysis.PubMed and Embase from January 1966 to January 2015 were searched to identify relevant studies. Inclusion criteria were cohort studies, patients with atrial fibrillation undergoing hemodialysis, and reported quantitative estimates of the multivariate adjusted relative risk (RR) and 95% confidence interval (CI) for future stroke associated with warfarin use. We identified 8 studies, with a total of 9539 participants and 706 stroke events. Three studies reported total stroke as primary endpoint and other studies reported ischemic stroke as primary endpoint. Pooling the results showed that warfarin use was associated with higher risk of any stroke (RR 1.50, 95% CI: 1.13-1.99). By stroke type, warfarin was not significantly linked to risk of ischemic stroke (RR 1.01, 95% CI: 0.65-1.57, P = 0.97), but was related to greater hemorrhagic stroke risk (RR 2.30, 95% CI: 1.62-3.27). Warfarin heightened overall bleeding risk (RR 1.27, 95% CI: 1.03-1.56), but not death (RR 0.67, 95% CI: 0.37-1.21).Among patients with atrial fibrillation undergoing hemodialysis, use of warfarin is associated with a higher risk of hemorrhagic stroke, but did not increase overall mortality.

Atrial fibrillation: mechanisms, therapeutics, and future directions

Atrial fibrillation (AF) is the most prevalent cardiac arrhythmia, affecting 1% to 2% of the general population. It is characterized by rapid and disorganized atrial activation leading to impaired atrial function, which can be diagnosed on an EKG by lack of a P-wave and irregular QRS complexes. AF is associated with increased morbidity and mortality and is a risk factor for embolic stroke and worsening heart failure. Current research on AF support and explore the hypothesis that initiation and maintenance of AF require pathophysiological remodeling of the atria, either specifically as in lone AF or secondary to other heart disease as in heart failure-associated AF. Remodeling in AF can be grouped into three categories that include: (i) electrical remodeling, which includes modulation of L-type Ca(2+) current, various K(+) currents and gap junction function; (ii) structural remodeling, which includes changes in tissues properties, size, and ultrastructure; and (iii) autonomic remodeling, including altered sympathovagal activity and hyperinnervation. Electrical, structural, and autonomic remodeling all contribute to creating an AF-prone substrate which is able to produce AF-associated electrical phenomena including a rapidly firing focus, complex multiple reentrant circuit or rotors. Although various remodeling events occur in AF, current AF therapies focus on ventricular rate and rhythm control strategies using pharmacotherapy and surgical interventions. Recent progress in the field has started to focus on the underlying substrate that drives and maintains AF (termed upstream therapies); however, much work is needed in this area. Here, we review current knowledge of AF mechanisms, therapies, and new areas of investigation.

Repeat Catheter Ablation of Long-standing Persistent Atrial Fibrillation in Patients with a Total Atrial Fibrillation Duration of More Than 2 Years: Effects of the CHA2DS2-VASc Score and Estimated Glomerular Filtration Rate on the Outcomes

Objective Little is known about the outcome of repeat catheter ablation of long-standing persistent atrial fibrillation (AF) in patients with a total AF duration of more than 2 years. The main objective of this study was to explore the results and factors affecting the clinical success rate of these repeat procedures. Methods We enrolled 99 patients with a total AF duration of more than 2 years and recurrent atrial arrhythmias after the initial catheter ablation of long-standing persistent AF. The enrolled patients were divided into two groups named the AF-recurrence group (50 patients) and the atrial tachycardia (AT)-recurrence group (49 patients) and all underwent a strict follow-up. The quality of life (QOL) and AF-related symptom classification were assessed at baseline and at 24 months post re-ablation. Results After a mean follow-up of 31 months, 30 (30.3%) patients were free from arrhythmia recurrence, and the success rate in the AT-recurrence group was higher than that in the AF-recurrence group (32.7% vs. 28.0%, p=0.614). A Cox regression analysis revealed a CHA2DS2-VASc score ≥3 to be a predictor of recurrence. AF recurrent patients with an abnormal renal function were more prone to undergo a failed procedure. However, an abnormal renal function had no effect on the outcome of the repeat procedure for patients with AT recurrence. At the 24-month follow-up, patients maintaining sinus rhythm (SR) had a significantly improved QOL and AF-related symptoms. Conclusion The success rate of repeat procedures for long-standing persistent AF and a total AF duration of more than 2 years is poor for patients with a CHA2DS2-VASc score ≥3. An impaired renal function has an unfavorable effect on the outcome for patients with AF recurrence. For patients maintaining SR, both the QOL and AF symptomatology improve significantly.

Reduced Incidence of Thromboembolic Events after Surgical Closure of Left Atrial Appendage in Patients with Atrial Fibrillation

Objective

Most of the detected thrombi in patients with atrial fibrillation (AF) can be found in the left atrial appendage (LAA). Interventional LAA closure recently proved to be noninferior to warfarin therapy. Whether these results can be fully translated into surgical LAA closure remains unclear. Corresponding data are still lacking. The present observational study evaluated the impact of surgical LAA closure in patients with AF undergoing cardiac surgery on postoperative thromboembolic events.

Methods

A prospective registry enrolled 398 patients with permanent AF undergoing cardiac surgery. Concomitant procedures were isolated surgical ablation (group I, n = 71), isolated LAA closure (group II, n = 44), and combined surgical ablation and LAA closure (group III, n = 196). The control group consisted of 87 patients without concomitant surgical ablation or LAA closure. One-year follow-up was completed in all patients. End points were thromboembolic events and death from any cause.

Results

Clinical baseline characteristics were comparable among the groups. General hospital mortality was 5.5% and likewise differed not significantly. Postoperatively, mean (SD) CHAD2S2-VASc score of 3.5 (1.3) differed not significantly among the groups, indicating comparable thromboembolic risk. Follow-up referred to all hospital survivors (n = 376). Herein, overall incidence of thromboembolic events was 9.8% (n = 37), with an associated mortality of 41.0%. Patients with LAA closure alone or in combination with surgical ablation had a significantly reduced incidence of thromboembolic events (6.6% vs 20.5%, P < 0.01) and consecutively improved survival after 1 year of follow-up (7.0% vs 17.1%, P < 0.01).

Conclusions

Left atrial appendage closure alone or in combination with surgical ablation was associated with a significantly reduced rate of thromboembolic events and consecutively improved survival after 1 year of follow-up.

Efficacy and safety of apixaban compared with aspirin in the elderly: a subgroup analysis from the AVERROES trial

BACKGROUND

increasing age is associated with a higher prevalence of atrial fibrillation (AF), and higher risks of stroke and bleeding. We report the effects of apixaban versus acetylsalicylic acid (ASA) in older patients (≥75 years and ≥85 years) compared with younger patients with AF unsuitable for vitamin K antagonists.

METHODS

AVERROES (Apixaban Versus ASA to Prevent Stroke In AF Patients Who Have Failed or Are Unsuitable for Vitamin K Antagonist Treatment) trial (n = 5,599) included 1,898 patients ≥75 years and 366 patients ≥85 years. We compared the baseline characteristics and effects of apixaban compared with aspirin on clinical outcomes by age.

RESULTS

compared with aspirin, apixaban was more efficacious for preventing strokes and systemic embolism in patients ≥85 years (absolute rate [AR] 1%/year on apixaban versus 7.5%/year on aspirin; hazard ratio [HR] 0.14, 95% confidence interval [CI] 0.02-0.48) compared with younger patients (AR 1.7%/year on apixaban versus 3.4%/year on aspirin; HR 0.50, 95% CI 0.35-0.69) (P-value for interaction = 0.05). Major haemorrhage was higher in patients ≥85 years compared with younger patients but similar with apixaban versus aspirin in both young and older individuals (4.9%/year versus 1.0%/year on aspirin and 4.7%/year versus 1.2%/year on apixaban) with no significant treatment-by-age interaction (P-value = 0.65).

CONCLUSIONS

older patients with AF are at particularly high risk of stroke if given aspirin and have substantially greater relative and absolute benefits from apixaban compared with younger patients with no greater risk of haemorrhage.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov number: NCT00496769. URL: https://clinicaltrials.gov/ct2/show/NCT00496769.

Patient Characteristics and Antithrombotic Prescribing Patterns in Patients With Atrial Fibrillation in Tasmania

Limited data are available on atrial fibrillation (AF) and its clinical management and outcomes from an Australian perspective. This study was designed to examine the patient characteristics and antithrombotic treatment patterns among patients with AF in Tasmania, Australia. This retrospective observational study reviewed and followed patients with AF admitted to Tasmania’s 3 major hospitals between January 2011 and June 2012. Patients were excluded if they had only 1 episode of AF that reverted spontaneously or upon cardioversion without any documented recurrences. We reviewed the records of 2502 patients (≥18 years), and1469 were subsequently included in the study. The mean (±standard deviation [SD]) age of the patients was 76 (±12.3) years. The mean (± SD) CHADS2 score was 2.1 (±1.3), and 65.7% had a score ≥2. In total, only 55.6% of patients with CHADS2 score ≥2 were receiving anticoagulation and 9.9% were not receiving any antithrombotic treatment, whereas 85.4% of those at low risk (score 0) were on antithrombotic therapy. Hospitalization was associated with a significant increase in the rate of combination (antiplatelet plus anticoagulant) therapy ( P < .001). Suboptimal use of antithrombotic therapy highlights the need to improve AF management in our jurisdiction.

Long-Term Overexpression of Hsp70 Does Not Protect against Cardiac Dysfunction and Adverse Remodeling in a MURC Transgenic Mouse Model with Chronic Heart Failure and Atrial Fibrillation

Previous animal studies had shown that increasing heat shock protein 70 (Hsp70) using a transgenic, gene therapy or pharmacological approach provided cardiac protection in models of acute cardiac stress. Furthermore, clinical studies had reported associations between Hsp70 levels and protection against atrial fibrillation (AF). AF is the most common cardiac arrhythmia presenting in cardiology clinics and is associated with increased rates of heart failure and stroke. Improved therapies for AF and heart failure are urgently required. Despite promising observations in animal studies which targeted Hsp70, we recently reported that increasing Hsp70 was unable to attenuate cardiac dysfunction and pathology in a mouse model which develops heart failure and intermittent AF. Given our somewhat unexpected finding and the extensive literature suggesting Hsp70 provides cardiac protection, it was considered important to assess whether Hsp70 could provide protection in another mouse model of heart failure and AF. The aim of the current study was to determine whether increasing Hsp70 could attenuate adverse cardiac remodeling, cardiac dysfunction and episodes of arrhythmia in a mouse model of heart failure and AF due to overexpression of Muscle-Restricted Coiled-Coil (MURC). Cardiac function and pathology were assessed in mice at approximately 12 months of age. We report here, that chronic overexpression of Hsp70 was unable to provide protection against cardiac dysfunction, conduction abnormalities, fibrosis or characteristic molecular markers of the failing heart. In summary, elevated Hsp70 may provide protection in acute cardiac stress settings, but appears insufficient to protect the heart under chronic cardiac disease conditions.

Role of insertable cardiac monitors in anticoagulation therapy in patients with atrial fibrillation at high risk of bleeding

AIMS

We aimed to ascertain whether an insertable cardiac monitor (ICM)-guided rhythm-control strategy and assessment of atrial fibrillation (AF) burden may allow safe withdrawal and obviate long-term use of oral anticoagulants (OACs) in AF patients at high bleeding risk.

METHODS AND RESULTS

We implanted ICMs in 70 patients with AF with high risk of stroke (CHADS2 ≥2, CHA2DS2-VASc score ≥2) and bleeding (HAS-BLED score ≥3) after restoration of normal sinus rhythm (NSR) for continuous rhythm monitoring and optimization of antiarrhythmic drugs (AADs) when necessary. Patients were categorized into: (i) Group A (NSR/low AF burden, <1%), (ii) Group B (moderate/variable AF burden), and (iii) Group C (high AF burden, always AF). At patients' insistence, OACs were discontinued after proper counselling only if they maintained NSR/low AF burden for ≥3 consecutive months. All patients (age 73.3 ± 11.7 years; 53% male) were followed clinically and with ICM monitoring for 23.5 ± 10.5 months for outcomes including stroke, bleeding, death, device malfunction or infection, and AADs' adverse effects. Patients in Group A (n = 43), Group B (n = 20), and Group C (n = 7) had similar CHADS2 (2.09 ± 0.65, 2.05 ± 0.51, and 2.14 ± 0.38, respectively), CHA2DS2-VASc (3.05 ± 1.05, 2.85 ± 0.99, and 2.42 ± 0.53, respectively), and HAS-BLED (3.02 ± 1.01, 3.40 ± 0.68, and 3.00 ± 0.58, respectively) scores (P > 0.05). In 53 (76%) patients (Group A = 41 and Group B = 12) who maintained NSR/low AF burden, OACs were discontinued without adverse events. Severe bleeding occurred in 4 of 17 (24%) patients who remained on OACs.

CONCLUSION

In AF patients with high bleeding risk, ICM-guided rhythm control with AADs and assessment of AF burden may allow safe discontinuation of OACs.