Atrial flutter and the risk of thromboembolism: a systematic review and meta-analysis

Comprehensive Analysis of Anticoagulant Therapy in Patients with Isolated Atrial Flutter

Limited comparative data exist regarding the risk of cardiogenic emboli in patients with isolated atrial flutter (AFL). Some studies suggest a lower complication risk in AFL compared to atrial fibrillation (AFib), but methodological limitations and conflicting reports necessitate a comprehensive investigation. Our analysis proposes that isolated AFL carries a lower risk of ischemic events and left atrial thrombus formation than AFib. Importantly, we caution against applying stroke risk assessment approaches designed for AFib to AFL patients, as it may lead to harmful overestimations and unnecessary anticoagulant prescriptions. Furthermore, we highlight the current lack of sufficient data to determine the overall clinical benefit of prolonged anticoagulant therapy in patients with isolated AFL, especially when CHA2DS2-VASc index values are below 4. This review challenges existing perceptions, offering insights into the nuanced risk profiles of the transitional nature of isolated AFL due to the high incidence of AFib development within a year of AFL diagnosis. In conclusion, tailored risk assessments and further research are essential for precise clinical decision-making in this dynamic landscape.

The Risk of Left Atrial Appendage Thrombus in Patients With Atrial Flutter Versus Atrial Fibrillation

Objective

Patients with atrial fibrillation (AF) are at increased risk of thromboembolic events originating mainly from left atrial appendage thrombus (LAAT). Patients with atrial flutter (AFL) are treated with anticoagulation based on the same criteria as patients with AF. However, whether patients with AFL have similar thromboembolic risk as AF is unclear. In the current study we aimed to estimate the prevalence of LAAT in patients with AFL undergoing trans-esophageal echocardiography (TEE).

Methods/results

We included 438 patients (404 with AF and 34 with AFL) scheduled for TEE to rule out LAAT before cardioversion (patients who reported no or inadequate anticoagulation before cardioversion). Demographic and echocardiographic data were compared between patients with and without LAAT. Despite a similar CHA2DS2-VASC score (3.8 ± 1.3 vs 3.4 ± 1.5 in the AF and AFL groups, respectively, P = .09), LAAT was documented in 12 (2.8%) in the AF group and in no patient in the AFL group (P < .0001).

Conclusion

Based on our results and previous studies, it seems reasonable to re-evaluate the need for oral anticoagulation in specific populations with AFL such as those with solitary AFL (without a history of AF episodes) undergoing successful ablation and in those with low CHA2DS2-VASC score.

Ablation index-guided cavotricuspid isthmus ablation with contiguous lesions using fluoroscopy integrated 3D mapping in atrial flutter

PURPOSE

The feasibility and safety of cavotricuspid isthmus (CTI) ablation with contiguous lesions using ablation index (AI) under the guidance of fluoroscopy integrated 3D mapping (CARTO UNIVU/CU) in typical atrial flutter (AFL) remains uncertain. This study aimed to determine the efficacy of AI-guided CTI ablation with contiguous lesions in patients with AFL.

METHODS

In this single-center, prospective, non-randomized, single-arm, observational study, procedural outcomes were determined in 151 patients undergoing AI-guided CTI ablation (AI group) with a target AI value of 450 and an interlesion distance of ≤ 4 mm under CU guidance. These outcomes were compared with those of 30 patients undergoing non-AI-guided ablation (non-AI group).

RESULTS

Among 151 patients, first-pass conduction block was achieved in 120 (80%) patients in the AI group (67% in the non-AI group, P = 0.152) with a shorter fluoroscopy time of 0.2 ± 0.4 min (1.7 ± 2.0 min in the non-AI group, P < 0.001). Conduction gaps were located at the atrial aspects near the inferior vena cava in 24 of 31 (78%) patients without first-pass conduction block. The AI group received 11 ± 5 (12 ± 4 in the non-AI group, P = 0.098) radiofrequency (RF) applications, and the RF time was 4.2 ± 2.4 (5.1 ± 2.5 min in the non-AI group, P = 0.011). Despite the occurrence of steam pop in 3 (2%) patients, none of them developed cardiac tamponade. No patients had recurrence within 6 months of follow-up.

CONCLUSIONS

AI-guided CTI ablation in combination with CU was feasible and effective in reducing radiation exposure in patients with AFL.

Long-term mortality and cardiovascular outcomes in patients with atrial flutter after catheter ablation

AIMS

For patients with typical and atypical atrial flutter (AFL) but without history of atrial fibrillation (AF), the long-term cardiovascular (CV) outcomes after catheter ablation for AFL remain unclear. We compared the long-term all-cause mortality and CV outcomes in patients with AFL receiving catheter ablation compared with the results with medical therapy.

METHODS AND RESULTS

Atrial flutter patients receiving catheter ablation for typical AFL were identified using the Health Insurance Database, and constituted the 'AFL ablation group'. Patients with typical and atypical AFL but without ablation (AFL without ablation group) were propensity matched to the AFL ablation group. Patients with prior AF diagnosis were excluded. Primary outcomes included all-cause and CV mortality, heart failure (HF) hospitalization, and stroke. The multivariable cox hazards regression model was used to evaluate the hazard ratio (HR) for study outcomes. A total of 3784 AFL patients (1892 patients in each group) was studied. Their mean follow-up durations were 7.85 ± 2.57 years (AFL without ablation group) and 8.31 ± 4.53 years (AFL ablation group). Atrial flutter with ablation patients had lower risks of all-cause mortality (HR: 0.68, P < 0.001), CV deaths (HR: 0.78, P = 0.001), HF hospitalization (HR: 0.84, P = 0.01), and stroke (HR: 0.80, P = 0.01).

CONCLUSIONS

Catheter ablation for AFL in patients without prior AF was associated with lower risks of all-cause mortality and CV events compared with AFL patients without ablation during long-term follow-ups.

Heart failure and atrial flutter: a systematic review of current knowledge and practices

While the interplay between heart failure (HF) and atrial fibrillation (AF) has been extensively studied, little is known regarding HF and atrial flutter (AFL), which may be managed differently. We reviewed the incidence, prevalence, and predictors of HF in AFL and vice versa, and the outcomes of treatment of AFL in HF. A systematic literature review of PubMed/Medline and EMBASE yielded 65 studies for inclusion and qualitative synthesis. No study described the incidence or prevalence of AFL in unselected patients with HF. Most cohorts enrolled patients with AF/AFL as interchangeable diagnoses, or highly selected patients with tachycardia‐induced cardiomyopathy. The prevalence of HF in AFL ranged from 6% to 56%. However, the phenotype of HF was never defined by left ventricular ejection fraction (LVEF). No studies reported the predictors, phenotype, and prognostic implications of AFL in HF. There was significant variation in treatments studied, including the proportion that underwent ablation. When systolic dysfunction was tachycardia‐mediated, catheter ablation demonstrated LVEF normalization in up to 88%, as well as reduced cardiovascular mortality. In summary, AFL and HF often coexist but are understudied, with no randomized trial data to inform care. Further research is warranted to define the epidemiology and establish optimal management.

Thromboembolic events following cardioversion of acute atrial fibrillation and flutter: a systematic review and meta-analysis

BACKGROUND

Recent studies have presented concerning data on the safety of cardioversion for acute atrial fibrillation and flutter. We conducted this meta-analysis to evaluate the effect of oral anticoagulation use on thromboembolic events post-cardioversion of low-risk acute atrial fibrillation and flutter patients of < 48 h in duration.

METHODS

We searched MEDLINE, Embase, and Cochrane from inception through February 6, 2020 for studies reporting thromboembolic events post-cardioversion of acute atrial fibrillation and flutter. Main outcome was thromboembolic events within 30 days post-cardioversion. Primary analysis compared thromboembolic events based on oral anticoagulation use versus no oral anticoagulation use. Secondary analysis was based on baseline thromboembolic risk. We performed meta-analyses where 2 or more studies were available, by applying the DerSimonian-Laird random-effects model. Risk of bias was assessed with the Quality in Prognostic Studies tool.

RESULTS

Of 717 titles screened, 20 studies met inclusion criteria. Primary analysis of seven studies with low risk of bias demonstrated insufficient evidence regarding the risk of thromboembolic events associated with oral anticoagulation use (RR = 0.82 where RR < 1 suggests decreased risk with oral anticoagulation use; 95% CI 0.27 to 2.47; I² = 0%). Secondary analysis of 13 studies revealed increased risk of thromboembolic events with high baseline thromboembolic risk (RR = 2.25 where RR > 1 indicates increased risk with higher CHADS₂ or CHA₂DS₂-VASc scores; 95% CI 1.25 to 4.04; I² = 0%).

CONCLUSION

Primary analysis revealed insufficient evidence regarding the effect of oral anticoagulation use on thromboembolic events post-cardioversion of low-risk acute atrial fibrillation and flutter, though the event rate is low in contemporary practice. Our findings can better inform patient-centered decision-making when considering 4-week oral anticoagulation use for acute atrial fibrillation and flutter patients.

Impact of catheter ablation in patients with atrial flutter and concurrent heart failure

Background

No studies assessed impact of atrial flutter (AFL) ablation on outcomes in patients with AFL and concurrent heart failure (HF).

Objectives

To assess the effect of AFL ablation on mortality and HF readmissions in patients with AFL and HF.

Methods

This retrospective cohort study identified 15,952 patients with AFL and HF from the 2016–17 Nationwide Readmissions Database. The primary outcome was a composite of all-cause mortality and/or HF readmission at 1 year. Secondary outcomes included HF readmission, all-cause mortality, and atrial fibrillation (AF) readmission at 1 year. Propensity score match (1:2) algorithm was used to adjust for confounders. Cox proportional hazard regression was used to generate hazard ratios.

Results

Of the 15,952 patients, 9889 had heart failure with reduced ejection fraction (HFrEF) and 6063 had heart failure with preserved ejection fraction (HFpEF). In the matched HFrEF cohort (n = 5421), the primary outcome was significantly lower in patients undergoing ablation (HR 0.72, 95% CI 0.61–0.85, P < .001). HF readmission (HR 0.73, 95% CI 0.61–0.89, P = .001), all-cause mortality (HR 0.62, 95% CI 0.46–0.85, P = .003), and AF readmission (HR 0.63, 95% CI 0.48–0.82, P = .001) were also significantly reduced. In the matched HFpEF cohort (n = 2439), the primary outcome was lower in the group receiving ablation but was not statistically significant (HR 0.80, 95% CI 0.63–1.01, P = .065).

Conclusion

In patients with AFL and HFrEF, AFL ablation was associated with lower mortality and HF readmissions at 1 year. Patients with AFL and HFpEF did not show a similar significant reduction in the primary outcome.

Modern treatment of supraventricular tachycardia

Supraventricular tachycardia (SVT) is one of the most common arrhythmias. The prevalence of SVT varies widely in different countries and is 2,25 per 1,000 people in the general population. SVT reduce the quality of life of patients, and in some cases can worsen the prognosis. In patients with cardiovascular disease, the risk of SVT increases. Therapy of SVT is selected depending on the stability of hemodynamic and the QRS width. Until now, the treatment of SVT remains an urgent issue of modern cardiology, since despite the high effectiveness of catheter ablation, antiarrhythmic therapy plays an important role.

The 2020 Canadian Cardiovascular Society/Canadian Heart Rhythm Society Comprehensive Guidelines for the Management of Atrial Fibrillation

The Canadian Cardiovascular Society (CCS) atrial fibrillation (AF) guidelines program was developed to aid clinicians in the management of these complex patients, as well as to provide direction to policy makers and health care systems regarding related issues. The most recent comprehensive CCS AF guidelines update was published in 2010. Since then, periodic updates were published dealing with rapidly changing areas. However, since 2010 a large number of developments had accumulated in a wide range of areas, motivating the committee to complete a thorough guideline review. The 2020 iteration of the CCS AF guidelines represents a comprehensive renewal that integrates, updates, and replaces the past decade of guidelines, recommendations, and practical tips. It is intended to be used by practicing clinicians across all disciplines who care for patients with AF. The Grading of Recommendations, Assessment, Development and Evaluations (GRADE) system was used to evaluate recommendation strength and the quality of evidence. Areas of focus include: AF classification and definitions, epidemiology, pathophysiology, clinical evaluation, screening and opportunistic AF detection, detection and management of modifiable risk factors, integrated approach to AF management, stroke prevention, arrhythmia management, sex differences, and AF in special populations. Extensive use is made of tables and figures to synthesize important material and present key concepts. This document should be an important aid for knowledge translation and a tool to help improve clinical management of this important and challenging arrhythmia.

The implications of catheter ablation for solitary atrial flutter in preventing stroke risk: a nationwide population-based cohort study

AIMS

The implications of ablation for atrial fibrillation in preventing stroke are controversial, and no studies have investigated whether ablation prevents ischaemic stroke (IS) in atrial flutter (AFL).

METHODS AND RESULTS

This study analysed data contained in the Taiwan National Health Insurance Research Database for 16 765 patients with a first diagnosis of solitary AFL during 2001-2013. Eligible patients were divided into two groups according to whether or not they had received ablation. Propensity score matching (PSM) was performed to mitigate the effects of potential confounding factors. The primary outcome was occurrence of IS during follow-up. After 1:2 PSM, the analysis included 1037 patients in the ablation group and 2074 patients in the non-ablation group. The incidence of IS was lower in the ablation group compared to the non-ablation group [subdistribution hazard ratio (SHR) 0.61, 95% confidence interval (CI) 0.41-0.90] during the 2-year follow-up period but not thereafter (SHR 1.03, 95% CI 0.72-1.48). When grouping by stroke history, it revealed that ablation affected the incidence of stroke in patients without history of stroke (SHR 0.59, 95% CI 0.38-0.91) but not in patients with history of stroke. When each group was stratified by CHA2DS2-VASc score, ablation lowered the incidence of stroke in patients with CHA2DS2-VASc ≤3 (SHR 0.31, 95% CI 0.16-0.60) but not in patients with CHA2DS2-VASc ≥4 in the initial 2-year follow-up.

CONCLUSION

The different incidence of IS in patients with/without ablation indicates that ablation reduces the risk of IS in AFL patients.

CHA2DS2-VASc and readmission with new-onset atrial fibrillation, atrial flutter, or acute cerebrovascular accident

BACKGROUND

Although risk factors for atrial fibrillation (AF) and atrial flutter (AFL) are known, identifying patients who will develop AF/AFL within the near future remains challenging. We sought to evaluate if the CHA₂DS₂-VASc risk score (CVRS) can identify hospital readmissions with AF, AFL, or acute cerebrovascular accident (CVA) among hospitalized patients without prior history of AF/AFL.

METHODS

Using the Nationwide Readmission Database, a study cohort included patients without prior AF/AFL or new diagnosis of AF/AFL at the index hospitalization from 2012 to 2014. Patients were stratified based on the CVRS into three groups: Low (CVRS ≤1), Intermediate (CVRS 2-5), and High (CVRS ≥6).The primary outcome of interest was 180-day readmission rate with a primary or secondary diagnosis of AF/AFL. Secondary outcomes of interest were acute CVA and 6-month mortality rate.

RESULTS

A total of 17,820,640 patients were included in our study. Over a 6-month follow up duration from the index hospitalization, the overall re-admission rate for new onset atrial arrhythmias (AF/AFL) was 3.48% (n = 620,986), acute CVA 0.13% (n = 22,522), and all-cause mortality 0.31% (n = 55,632). When compared to other groups, patients with a higher CVRS were readmitted more frequently for AF/AFL [odds ratio (OR) 2.43; 95% confidence interval (CI) 2.41-2.45, P < .0001), acute CVA (OR 3.96; 95%CI 3.85-4.08, P < .0001), and all-cause mortality (OR 2.19; 95%CI 2.14-2.24, P < .0001).

CONCLUSION

In this large contemporary cohort, a CHADS2VA2SC score ≥ 6 identified patients without known prior atrial arrhythmias at an elevated risk of developing AF/AFL or acute CVA within 6 months of hospitalization.

Atrial Tachyarrhythmias and Atrial Flutter: the Basics of Diagnostics and Modern Opportunities of Therapy

The article is devoted to the description of all types of atrial tachyarrhythmias, including inappropriate sinus tachycardia, which, as a rule, is not paid enough attention in the domestic literature, sinoatrial node reentrant tachycardia, focal and multifocal atrial tachycardia, atrial flutter, and atrial fibrillation. The electrophysiological mechanisms of development and electrocardiographic criteria for the diagnosis of these cardiac rhythm disturbances are presented. Along with this, the article discusses the modern view of the strategy and tactics of pharmacological cardioversion and preventive therapy in patients with the main types of atrial tachyarrhythmias and atrial flutter. It is noted that the prognosis for inappropriate sinus tachycardia, as a rule, is favorable, and therefore, aim of treatment is to reduce the symptoms, and in their absence medical treatment is not necessary. Much attention is paid to drug and interventional treatment of atrial flutter. It is emphasized that catheter ablation of isthmus-dependent atrial flutter in most cases is preferred over long-term pharmacotherapy. However, in prolonged observation (more than 3 years), nearly 1/3 of patients may develop paroxysmal atrial fibrillation. At the same time, catheter ablation of atypical atrial flutter is, in most cases, substantially less effective. The indications and side effects of catheter ablation of the sinus node are also discussed. The authors provide a critical analysis of traditional approaches to the treatment of atrial tachyarrhythmias and analyze new recommendations for the management of these patients presented in Europe and the USA. Based on these recommendations, clear algorithms for the management of patients with atrial tachyarrhythmias are given. The need to prevent thromboembolic complications in some types of atrial tachyarrhythmias is emphasized.

Atrial Appendage Thrombosis Risk Is Lower for Atrial Flutter Compared with Atrial Fibrillation

BACKGROUND

The risk of stroke and thromboembolism in atrial fibrillation is established. However, the evidence surrounding the risk of thromboembolism in patients with atrial flutter is not as clear. We hypothesized that atrial flutter would have indicators of less risk for thromboembolism compared with atrial fibrillation on transesophageal echocardiography, thereby possibly leading to a lower stroke risk.

METHODS

A retrospective review of 2225 patients undergoing transesophageal echocardiography was performed. Those with atrial fibrillation or atrial flutter were screened. Exclusion criteria were patients being treated with chronic anticoagulation, the presence of a prosthetic valve, moderate to severe mitral regurgitation or stenosis, congenital heart disease, or a history of heart transplantation. A total of 114 patients with atrial fibrillation and 55 patients with atrial flutter met the criteria and were included in the analysis.

RESULTS

Twelve patients (11%) in the atrial fibrillation group had left atrial appendage thrombus versus zero patients in the atrial flutter group (P < .05). The prevalence of spontaneous echocardiography contrast was significantly higher and left atrial appendage emptying velocity was significantly lower in the atrial fibrillation group compared with the atrial flutter group (P < .001). No spontaneous contrast was seen when the left atrial appendage emptying velocity was >60 cm/sec.

CONCLUSIONS

Patients with atrial flutter have a lower incidence of left atrial appendage thrombi, higher left atrial appendage emptying velocity, and less left atrial spontaneous contrast compared with patients with atrial fibrillation, suggesting a lower risk for potential arterial thromboembolism.

Different Implications of Heart Failure, Ischemic Stroke, and Mortality Between Nonvalvular Atrial Fibrillation and Atrial Flutter-a View From a National Cohort Study

BACKGROUND

Atrial flutter (AFL) has been identified to be equivalent to atrial fibrillation (AF) in terms of preventing ischemic stroke, although differences exist in atrial rate, substrate, and electrophysiological mechanisms. This study aimed to investigate differences in clinical outcomes between nonvalvular AF and AFL.

METHODS AND RESULTS

AF and AFL patients without any prescribed anticoagulation were enrolled from a 13-year national cohort database. Under series exclusion criteria, ischemic stroke, heart failure hospitalization, and all-cause mortality were compared between the groups in real-world conditions and after propensity score matching. We identified 175 420 patients in the AF cohort and 6239 patients in the AFL cohort, and the prevalence of most comorbidities and frequency of medications were significantly higher in the AF group than the AFL group. In the real-world setting the AF patients had higher incidence rates of ischemic stroke, heart failure hospitalization, and all-cause mortality than the AFL patients (all P<0.001). After propensity score matching, the incidence rate of ischemic stroke in the AF cohort was 1.63-fold higher than in the AFL cohort (P<0.001), the incidence rate of heart failure hospitalization in the AF cohort was 1.70-fold higher than in the AFL cohort (P<0.001), and the incidence rate of all-cause mortality in the AF cohort was 1.08-fold higher than in the AFL cohort (P=0.002).

CONCLUSIONS

There were differences between AF and AFL in comorbidities and prognosis with regard to ischemic stroke, heart failure hospitalization, and all-cause mortality.

Supraventricular Arrhythmias in Patients with Adult Congenital Heart Disease

An increasing number of patients with congenital heart disease survive to adulthood; such prolonged survival is related to a rapid evolution of successful surgical repairs and modern diagnostic techniques. Despite these improvements, corrective atrial incisions performed at surgery still lead to subsequent myocardial scarring harbouring a potential substrate for macro-reentrant atrial tachycardia. Macroreentrant atrial tachycardias are the most common (75 %) type of supraventricular tachycardia (SVT) in patients with adult congenital heart disease (ACHD). Patients with ACHD, atrial tachycardias and impaired ventricular function - important risk factors for sudden cardiac death (SCD) - have a 2-9 % SCD risk per decade. Moreover, ACHD imposes certain considerations when choosing antiarrhythmic drugs from a safety aspect and also when considering catheter ablation procedures related to the inherent cardiac anatomical barriers and required expertise. Expert recommendations for physicians managing these patients are therefore mandatory. This review summarises current evidence-based developments in the field, focusing on advances in and general recommendations for the management of ACHD, including the recently published recommendations on management of SVT by the European Heart Rhythm Association.

Prevalence and outcome of thrombotic and embolic complications in adults after Fontan operation

There are limited studies of thrombotic and embolic complications (TEC) in the adult Fontan population. The purpose of the study was to determine the prevalence, risk factors, and outcomes of TECs in this population.

METHODS

Retrospective review of adults with a previous Fontan operation, with follow-up at Mayo Clinic, 1994-2014. Systemic TEC was defined as intracardiac thrombus, ischemic stroke, or systemic arterial embolus. Nonsystemic TEC was defined as Fontan conduit/right atrial thrombus or pulmonary embolus.

RESULTS

We identified 387 patients with a mean (SD) age of 28 (7) years and a mean follow-up of 8 (2) years. An atriopulmonary connection (APC) was done for 286 patients (74%). Atrial arrhythmias were present in 278 (72%). There were 121 TECs (systemic n=36, nonsystemic n=85) in 98 patients (25%). Risk factors for systemic TEC were atrial arrhythmia (hazard ratio 2.28, P=.001) and APC (hazard ratio 1.98, P=.02); nonsystemic TEC also had similar risk factors. All 98 patients received warfarin. Warfarin was discontinued in 10 of 98 because of bleeding, and 8 of these 10 subsequently had a second TEC. Among the 82 patients who had follow-up imaging, 16 (20%) had resolution of thrombus. In total, 24 of 98 patients had a second TEC, most of whom had inadequate anticoagulation.

CONCLUSIONS

Thrombotic and embolic complication was not uncommon; risk factors for TEC were APC and atrial arrhythmias. Most patients were treated successfully with warfarin alone. A second TEC occurred in most patients whose anticoagulation was discontinued because of bleeding events.

Stroke and Systemic Embolism After Successful Ablation of Typical Atrial Flutter

BACKGROUND

Following successful cavotricuspid isthmus (CTI) ablation during typical atrial flutter (AFL), anticoagulation therapy is usually withdrawn. However, potential subsequent atrial fibrillation (AF) in these patients may increase embolic risk in the long term. Embolic rates in this setting have not been clearly established. Our aim was to determine the incidence of stroke/systemic embolism following radiofrequency ablation of AFL, particularly in those without a prior history of AF.

HYPOTHESIS

After succesful AFL ablation, patients may suffer embolic complications in the long-term follow-up, mainly due to asymptomatic AF episodes.

METHODS

We conducted a retrospective analysis of all patients who underwent CTI ablation due to AFL in our center between 2006 and 2009.

RESULTS

During the study period, 188 patients (mean age, 62.9 ± 8.6 years) underwent CTI ablation; 120 without prior AF were included in the study. At the end of the follow-up period (mean, 5.0 ± 2.4 years), 56.7% of patients (68/120) remained in sinus rhythm, 7/120 experienced a recurrence of AFL, and 45/120 (38%) developed AF. Ischemic stroke occurred in 11 patients and systemic embolism in 1. Of these patients, 5 had documented AF following AFL ablation. In the remaining 7 cases, previously undiagnosed AF was subsequently diagnosed at the time of stroke/embolism.

CONCLUSIONS

Patients with AFL who undergo successful ablation are by no means free from embolic complications during long-term follow-up, mainly due to a high rate of AF development. Given the difficulties in detecting AF and the uncertainty about the temporal relation of AF and stroke, oral anticoagulation may need to be continued in those patients with underlying stroke risk factors.

Atrial flutter: Clinical risk factors and adverse outcomes in the Framingham Heart Study

BACKGROUND

Few epidemiologic cohort studies have evaluated atrial flutter (flutter) as an arrhythmia distinct from atrial fibrillation (AF).

OBJECTIVE

The purpose of this study was to examine the clinical correlates of flutter and its associated outcomes to distinguish them from those associated with AF in the Framingham Heart Study.

METHODS

We reviewed and adjudicated electrocardiograms (ECGs) previously classified as flutter or AF/flutter and another 100 ECGs randomly selected from AF cases. We examined the clinical correlates of flutter by matching up to 5 AF and 5 referents to each flutter case using a nested case referent design. We determined the 10-year outcomes associated with flutter with Cox models.

RESULTS

During mean follow-up of 33.0 ± 12.2 years, 112 participants (mean age 72 ± 10 years, 30% women) developed flutter. In multivariable analyses, smoking (odds ratio [OR] 2.84, 95% confidence interval [CI] 1.54-5.23), increased PR interval (OR 1.28 per SD, 95% CI 1.03-1.60), myocardial infarction (OR 2.25, 95% CI 1.05-4.80) and heart failure (OR 5.22, 95% CI 1.26-21.64) were associated with incident flutter. In age- and sex-adjusted models, flutter (vs referents) was associated with 10-year increased risk of AF (hazard ratio [HR] 5.01, 95% CI 3.14-7.99), myocardial infarction (HR 3.05, 95% CI 1.42-6.59), heart failure (HR 4.14, 95% CI 1.90-8.99), stroke (HR 2.17, 95% CI 1.13-4.17), and mortality (HR 2.00, 95% CI 1.44-2.79).

CONCLUSION

We identified the clinical correlates associated with flutter and observed that flutter was associated with multiple adverse outcomes.

Executive Summary: European Heart Rhythm Association Consensus Document on the Management of Supraventricular Arrhythmias: Endorsed by Heart Rhythm Society (HRS), Asia-Pacific Heart Rhythm Society (APHRS), and Sociedad Latinoamericana de Estimulación Cardiaca y Electrofisiologia (SOLAECE)

This paper is an executive summary of the full European Heart Rhythm Association (EHRA) consensus document on the management of supraventricular arrhythmias, published in Europace. It summarises developments in the field and provides recommendations for patient management, with particular emphasis on new advances since the previous European Society of Cardiology guidelines. The EHRA consensus document is available to read in full at http://europace.oxfordjournals.org.

New oral anticoagulants in patients undergoing atrial flutter radiofrequency catheter ablation: an observational study

AIM

Atrial flutter (AFL) ablation requires optimal periprocedural anticoagulation in order to minimize thromboembolic events/bleeding risk. This study describes the characteristics of patients receiving new oral anticoagulants before AFL ablation and assesses complications.

METHODS

This multicenter, retrospective study reports ischemic and hemorrhagic predischarge, postprocedural complications.

RESULTS

We evaluated 60 patients (62.3% male; mean age: 69.2 ± 9.7 years; CHA2DS2-VASc score: 2.44 ± 1.46, HAS-BLED score: 1.14 ± 0.7). Twenty-one (35.0%) and 23 patients (38.3%) received twice-daily dabigatran 110 or 150 mg; 16 patients (26.6%) received once-daily rivaroxaban (15 mg [n = 5] or 20 mg [n = 11]). Four cases of postprocedural minor bleeding were reported.

CONCLUSION

This is the first study assessing new oral anticoagulants for periprocedural anticoagulation, specifically in patients undergoing AFL ablation. No major bleeding was reported. Further prospective investigation is warranted.

Outcomes after ablation for typical atrial flutter (from the Loire Valley Atrial Fibrillation Project)

Similar predisposing factors are found in most types of atrial arrhythmias. The incidence of atrial fibrillation (AF) among patients with atrial flutter is high, suggesting similar outcomes in patients with those arrhythmias. We sought to investigate the long-term outcomes and prognostic factors of patients with AF and/or atrial flutter with contemporary management using radiofrequency ablation. In an academic institution, we retrospectively examined the clinical course of 8,962 consecutive patients admitted to our department with a diagnosis of AF and/or atrial flutter. After a median follow-up of 934 ± 1,134 days, 1,155 deaths and 715 stroke and/thromboembolic (TE) events were recorded. Patients with atrial flutter undergoing cavotricuspid isthmus ablation (n = 875, 37% with a history of AF) had a better survival rate than other patients (hazard ratio [HR] 0.35, 95% confidence interval [CI] 0.25 to 0.49, p <0.0001). Using Cox proportional hazards model and propensity score model, after adjustment for main other confounders, ablation for atrial flutter was significantly associated with a lower risk of all-cause mortality (HR 0.55, 95% CI 0.36 to 0.84, p = 0.006) and stroke and/or TE events (HR 0.53, 95% CI 0.30 to 0.92, p = 0.02). After ablation, there was no significant difference in the risk of TE between patients with a history of AF and those with atrial flutter alone (HR 0.83, 95% CI 0.41 to 1.67, p = 0.59). In conclusion, in patients with atrial tachyarrhythmias, those with atrial flutter with contemporary management who undergo cavotricuspid isthmus radiofrequency ablation independently have a lower risk of stroke and/or TE events and death of any cause, whether a history of AF is present or not.

Transesophageal echocardiography of intracardiac thrombus in congenital heart disease and atrial flutter: the importance of thorough examination of the Fontan

Transesophageal echocardiography (TEE) is used in atrial flutter or fibrillation (AFF) before electric cardioversion to detect intracardiac thrombi. Previous studies have described the use of TEE to diagnose intracardiac thrombi in the left atrium and left atrial appendage, which has an incidence of 8 % among patients without congenital heart disease (CHD). In their practice the authors have noted a significant incidence of intracardiac thrombi in other structures of patients with CHD and AFF. This study aimed to determine the incidence and location of intracardiac thrombi using TEE in patients with CHD requiring electric cardioversion of AFF and to compare the use of TEE and transthoracic echo (TTE) to detect intracardiac thrombus in this population. A retrospective chart review of TEE and TTE findings for all patients with CHD who had electric cardioversion of AFF at our institution from 2005 to 2013 was conducted. The diagnosis, presence, and location of intracardiac thrombus were determined. The TEE and TTE results were compared. The study identified 27 patients with CHD who met the study entry criteria at our institution between 2005 and 2013. Seven of these patients had a single ventricle with Fontan palliation. All the patients presented with AFF and had TEE before electric cardioversion. No patients were excluded from the study. The patients ranged in age from 2 to 72 years (median, 21 years) and weighed 17-100 kg (median, 65 kg). The duration of AFF before TEE and attempted cardioversion ranged from 1 day to 3 weeks (median, 3.5 days). Intracardiac thrombus was present in 18 % (5/27) of the patients and in 57 % (4/7) of the Fontan patients with AFF. No embolic events were reported acutely or during a 6-month follow-up period. Among patients with CHD who present with AFF, a particularly high incidence of intracardiac thrombi is present in the Fontan patients that may be difficult to detect by TTE. Thorough TEE examination of the Fontan and related structures is indicated before electric cardioversion of AFF. The incidence of intracardiac thrombus in CHD patients is more than double that reported in non-CHD patients.

Current treatment options for atrial flutter and results with cryocatheter ablation

Rhythm disturbances arising in the upper chambers of the heart are not uncommon. They are associated with a heavy burden of illness for the affected individual, as well as society in general. Atrial flutter, a re-entrant atrial tachycardia, is one such rhythm disturbance. The objective of this review article is twofold: first, to provide a brief insight into atrial flutter and the typical treatments for this arrhythmia in clinical practice; and second, to give an in-depth account of cryocatheter ablation as a relatively new treatment option for this potentially debilitating condition. The many recent clinical studies documenting the use of cryocatheter ablation for treatment of atrial flutter are presented, and their results briefly discussed. Overall, as cryocatheter ablation embeds itself among the arsenal of treatments for atrial flutter, the promising results from clinical studies appear destined to elevate cryocatheter ablation to a premier position among the treatment options for atrial flutter.

Predictors of the atrial fibrillation following catheter ablation of typical atrial flutter

Background:

Despite technical refinements and improved long-term efficacy of the ablation procedure for treating AFL (AFL), the subsequent occurrence of AF (AF) following this procedure remains a significant clinical problem.

Objectives:

To determine long-term incidence and predictors of AF after catheter ablation of typical AFL.

Material and Methods:

Between March 2005 and February 2010, a total of 84 consecutive patients who underwent catheter ablation of documented typical AFL were enrolled.

Results:

Cavotricuspid isthmus ablation was successful in terminating and preventing the re-induction of AFL in all 84 patients (100%). The mean follow-up duration for study was 26± 22 months. During the follow-up period, early AF occurred in 5% after successful catheter ablation of AFL and late AF in 11% of the patients. The clinical variables associated with the occurrence of AF after catheter ablation of AFL were female, a history of AF before AFL ablation, body mass index (BMI), and left atrial abnormality. However, logistic multivariate analysis demonstrated that only BMI was independently associated with the late AF (OR 1.36, 95% CI 1.11-1.70, P = 0.004).

Conclusions:

Catheter ablation of flutter circuit will not prevent later manifestation of AF in 16% of the patients undergoing catheter ablation of the typical AFL. BMI was the only independent predictor of AF following catheter ablation of the typical AFL.

Effect of atrial fibrillation on atrial thrombogenesis in humans: impact of rate and rhythm

OBJECTIVES

We sought to assess the effect of atrial fibrillation (AF) on atrial thrombogenesis in humans by determining the impact of rate and rhythm.

BACKGROUND

Although AF is known to increase the risk of thromboembolic stroke from the left atrium (LA), the exact mechanisms remain poorly understood.

METHODS

We studied 55 patients with AF who underwent catheter ablation while in sinus rhythm; 20 patients were induced into AF, 20 patients were atrial paced at 150 beats/min, and 15 were control patients. Blood samples were taken from the LA, right atrium, and femoral vein at baseline and at 15 min in all 3 groups. Platelet activation (P-selectin) was measured by flow cytometry. Thrombin generation (thrombin-antithrombin [TAT] complex), endothelial dysfunction (asymmetric dimethylarginine [ADMA]), and platelet-derived inflammation (soluble CD40 ligand [sCD40L]) were measured using enzyme-linked immunosorbent assay.

RESULTS

Platelet activation increased significantly in both the AF (p < 0.001) and pacing (p < 0.05) groups, but decreased in control patients (p < 0.001). Thrombin generation increased specifically in the LA compared with the periphery in both the AF (p < 0.01) and pacing (p < 0.01) groups, but decreased in control patients (p < 0.001). With AF, ADMA (p < 0.01) and sCD40L (p < 0.001) levels increased significantly at all sites, but were unchanged with pacing (ADMA, p = 0.5; sCD40L, p = 0.8) or in control patients (ADMA, p = 0.6; sCD40L, p = 0.9).

CONCLUSIONS

Rapid atrial rates and AF in humans both result in increased platelet activation and thrombin generation. Prothrombotic activation occurs to a greater extent in the human LA compared with systemic circulation. AF additionally induces endothelial dysfunction and inflammation. These findings suggest that although rapid atrial rates increase the thrombogenic risk, AF may further potentiate this risk.

Usefulness of transesophageal echocardiography to confirm clinical utility of CHA2DS2-VASc and CHADS2 scores in atrial flutter

The CHA(2)DS(2)-VASc and CHADS(2) risk stratification schemes are used to predict thromboembolism and ischemic stroke in patients with atrial fibrillation. However, limited data are available regarding the utility of these risk stratification schemes for stroke in patients with atrial flutter. A retrospective analysis of 455 transesophageal echocardiographic studies in patients with atrial flutter was performed to identify left atrial (LA) thrombi and/or spontaneous echocardiographic contrast (SEC). The CHA(2)DS(2)-VASc (Congestive heart failure, Hypertension, Age ≥75 years [doubled risk weight], Diabetes mellitus, previous Stroke/transient ischemic attack [doubled risk weight], Vascular disease, Age 65 to 74 years, Sex) and CHADS(2) (Congestive heart failure, Hypertension, Age ≥75 years, Diabetes mellitus, previous Stroke/transient ischemic attack [double risk weight]) scores were calculated to stratify the risk of stroke or transient cerebrovascular ischemic events. Transesophageal echocardiography revealed LA thrombi in 5.3% and SEC in 25.9% of patients. Using CHADS(2), LA thrombus was found in 2.2% of the low-intermediate-risk group and 8.3% of the high-risk group (p = 0.005). SEC was found in 19.8% of the low-intermediate-risk group and 32% of the high-risk group (p = 0.004). Using CHA(2)DS(2)-VASc, LA thrombus was found in 1.7% of the low-intermediate-risk group and 6.5% of the high-risk group (p = 0.053). SEC was found in 11.8% of the low-intermediate-risk group versus 30.9% of the high-risk group (p = 0.004). The sensitivity for LA thrombus/SEC with a high CHADS(2) and CHA(2)DS(2)-VASc score was 64.8% and 88.7%, respectively (p = 0.0001). The specificity for LA thrombus/SEC with high CHADS(2) and CHA(2)DS(2)-VASc scores was 52.6% and 28.9%, respectively (p = 0.0001). In conclusion, both CHA(2)DS(2)-VASc and CHADS(2) scores are useful for stroke risk stratification in patients with atrial flutter. CHA(2)DS(2)-VASc had greater sensitivity for LA thrombus and SEC detection at the cost of reduced specificity.

TEE screening in Atrial flutter: A single-centre experience with retrospective validation of a new risk score for the presence of atrial thrombi

Transesophageal echocardiography (TEE) has been proposed as a screening tool to exclude the presence of atrial thrombi and left atrial spontaneous echocontrast before cardioverting persistent atrial flutter (AFl) and atrial fibrillation (AF). However in pure AFl a very low prevalence of atrial thrombi has been observed by many investigators: a confirmation of this finding would make TEE screening redundant. We review our database of patients with AFl who underwent TEE screening before cardioversion in the last 5 years. A new risk score for the presence of left atrial thrombus (AFLAT score) is here proposed, as a potential tool to avoid unnecessary TEE exams. Out of the 106 patients examined, in fourteen left atrial thrombi were diagnosed (13%). Only two cases belonged to the pure AFl subgroup (prevalence=3%), while twelve cases were detected in the subgroup of AFl patients with previous AF episodes (prevalence=32%, p<0.001). All of the fourteen patients with a positive TEE for thrombus were identified by a AFLAT score >2. The validation of this index in a larger and prospective setting would lead to a 85% reduction in unnecessary TEE exams in patients with pure AFl undergoing cardioversion.

[Invasive electrophysiology: complications, nightmares and their management]

Most minor side effects of ablation in the right atrium and right ventricle relate to femoral venous catheterization but there is a small risk of severe complications including atrioventricular (AV) block, damage of surrounding structures and thromboembolic events. Impairment of AV conduction can occur during ablation of atrioventricular re-entrant tachycardia, ablation of anteroseptal, mid-septal and parahisian accessory pathways, ablation of ectopic atrial tachycardia originating from the vicinity of the atrioventricular node and when ablating the septal isthmus for typical atrial flutter. Damage of the right coronary artery is a very rare complication after inferior isthmus ablation with high energy. The thromboembolic risk during and after cardioversion and ablation of atrial flutter is higher than previously recognized and anticoagulation therapy decreases this risk. The risk of perforation and tamponade during ablation in the right atrium and right ventricle is very low but particular caution is necessary in thin-walled structures such as the coronary sinus and the upper right ventricular outflow tract. Phrenic nerve injury can be avoided by pacing from the mapping electrode before application of radiofrequency energy at the right atrial free wall. Limitation of power output depending on the site of ablation and titration of energy application with continuous control of temperature and impedance should be considered to minimize the risk of complications.

Atrial fibrillation in the elderly

Atrial fibrillation is increasingly prevalent among older adults. It causes approximately 24% of strokes in patients aged 80 to 89 years. The management of atrial fibrillation is directed at preventing thromboembolism and controlling the heart rate and rhythm. Stroke prevention is most effectively accomplished through administering anticoagulants such as warfarin, although older patients have higher hemorrhagic risk. Cognitive dysfunction, functional impairments, and increased fall risk further complicate warfarin management in elderly patients. The use of risk stratification schemes can help guide the anticoagulation decision, although the benefits of warfarin generally outweigh the risks in most older patients with atrial fibrillation. Pharmacologic rate control has been shown to result in similar outcomes compared with pharmacologic restoration of sinus rhythm and should be the initial therapy for elderly patients. Anti-arrhythmic medications should be selected based on an individual patient's coexisting medical conditions. In symptomatic patients who fail pharmacologic therapy, invasive strategies such as AV nodal ablation may help improve quality of life and symptoms, although such strategies do not obviate the need for antithrombotic therapy.

Trends in Risk of Stroke in Patients with a Hospital Diagnosis of Nonvalvular Atrial Fibrillation: National Cohort Study in Denmark, 1980–2002

AIM

We examined trends in incidence of stroke of any nature (ischemic and/or hemorrhagic) in subjects with a hospital diagnosis of nonvalvular atrial fibrillation or flutter in Denmark from 1980 to 2002 by sex, age and conditions of comorbidity.

METHODS

We identified all individuals, aged 40-89 years, with an incident hospital diagnosis of atrial fibrillation or flutter and no history of stroke or heart valve disease in the Danish National Registry of Patients, and subjects were followed in the Danish National Registry of Patients for occurrence of an incident diagnosis of stroke of any nature (ischemic and/or hemorrhagic) and in the Danish Civil Registration System (emigration and vital status). We used multivariate Cox proportional hazard regression analysis to estimate trends in incidence of stroke.

RESULTS

Nonvalvular atrial fibrillation or flutter was diagnosed in 141,493 subjects (75,126 men and 66,367 women), and during follow-up 15,964 subjects had an incident diagnosis of stroke. The hazard ratios for stroke in the last 3-year period compared to the first 5-year period, adjusted for 10-year age group, conditions of comorbidity, and general stroke trend in the Danish population were 0.78 (95% CI 0.70-0.86) in men, and 0.80 (95% CI 0.72-0.88) in women. The reduction in risk of stroke by calendar year was most prominent in patients aged 40-74 years.

CONCLUSION

We observed a modest decrease in risk of stroke in subject with atrial fibrillation in Denmark during calendar years 1980-2002. However, we could not control for any changes in diagnostic performance, admission practice, and medical management of patients with atrial fibrillation.