Prevalence of Left Atrial Thrombus and Dense Spontaneous Echo Contrast in Patients With Short-Term Atrial Fibrillation < 48 Hours Undergoing Cardioversion: Value of Transesophageal Echocardiography to Guide Cardioversion

Novel scoring system derived from meta-analysis and validated in cohort population for predicting 1-year atrial fibrillation recurrence after cryoballoon catheter ablation: The HeLPS-Cryo score

BACKGROUND

Atrial fibrillation (AF) recurrence rates in 1 year after cryoballoon ablation catheter (CBCA) are still high. We purposed to identify strong predictors for AF recurrence after the successful CBCA procedure and develop a new scoring system based only on pre-procedural parameters.

METHODS

In the derivation phase, a systematic review and meta-analysis identified the strong predictors of AF recurrence after the CBCA. The pooled hazard ratio (HR) was used to create the new scoring system. The second phase validated the new scoring system in the cohort population.

RESULTS

A meta-analysis including 29 cohort studies with 16196 participants confirmed that persistent AF, stroke, heart failure, and left atrial diameter (LAD) >40 mm were powerful predictors for AF recurrence after the CBCA procedure. The HeLPS-Cryo (heart failure [1], left atrial dilatation [1], persistent AF [2], and stroke [2]) was developed based on those pre-procedural predictors. It was validated in 140 patients receiving CBCA procedures and revealed excellent predictive performance for 1-year AF recurrence (AUC = 0.8877; 95% CI = 0.8208 to 0.9546). The HeLPS-Cryo score of ≥3 could predict 1-year AF recurrence with sensitivity and specificity of 78.9% and 87.9%, respectively. The positive predictive value was 66.7%, and the negative predictive value was 93.1%.

CONCLUSION

The HeLPS-Cryo score can help the physician estimate the probability of 1-year AF recurrence after the successful CBCA procedure. Patients with HeLPS-Cryo score <3 are good candidates for the CBCA procedure.

Is there a temporal relationship between atrial fibrillation and stroke? A review

Importance

Atrial fibrillation (AF) is an established risk factor for ischaemic stroke. The introduction of continuous cardiac rhythm monitoring devices has enabled detection of brief and asymptomatic episodes of AF.

Observations

The search yielded 727 studies, 11 of which met the inclusion criteria. Four studies suggested a strong temporal association between episodes of AF and stroke, while seven indicated a weak relationship. The conflicting nature of the studies may be attributed to inconsistencies in ischaemic stroke verification (n=5/11), event rate and power (n=6/11) and lack of controlling for anticoagulation (n=10/11), mitigating the relationship between AF episodes and stroke.

Conclusions and relevance

The temporal relationship between AF and stroke still remains unclear due to varying study methodology, lack of control for anticoagulation and inconsistent stroke subtyping. Our review identifies limitations to the current literature and makes recommendations for future studies assessing the temporal relationship between AF episodes and cardioembolic stroke.

Antithrombotic Therapy for Patients Undergoing Cardiac Electrophysiological and Interventional Procedures: JACC State-of-the-Art Review

Electrophysiological and interventional procedures have been increasingly used to reduce morbidity and mortality in patients experiencing cardiovascular diseases. Although antithrombotic therapies are critical to reduce the risk of stroke or other thromboembolic events, they can nonetheless increase the bleeding hazard. This is even more true in an aging population undergoing cardiac procedures in which the combination of oral anticoagulants and antiplatelet therapies would further increase the hemorrhagic risk. Hence, the timing, dose, and combination of antithrombotic therapies should be carefully chosen in each case. However, the maze of society guidelines and consensus documents published so far have progressively led to a hazier scenario in this setting. Aim of this review is to provide-in a single document-a quick, evidenced-based practical summary of the antithrombotic approaches used in different cardiac electrophysiology and interventional procedures to guide the busy clinician and the cardiac proceduralist in their everyday practice.

Does Duration of Symptoms Reliably Predict Detection of Left Atrial Thrombus in Newly Diagnosed Atrial Fibrillation

Background

Large prospective trials attribute minimal thromboembolic risk for cardioversion of atrial fibrillation (AF) when duration of symptoms is shorter than 48 hours. Our goal is to compare the prevalence of left atrial appendage (LAA) thrombus as demonstrated by a Trans esophageal echocardiography (TEE) exam between patients presenting with less or more than 48 hours of AF symptoms.

Methods

Observational cohort study including consecutive patients hospitalized with primary diagnosis of new onset AF, not previously treated with oral anticoagulation. All patients underwent TEE to exclude LAA thrombus, regardless of symptoms duration. Patients were divided into two groups based on AF duration: 1) early presenters: up to 48 hours, 2) later presenters: longer than 48 hours.

Results

The study included 122 patients mean age 65.8 years). The "early presenters" were younger, with less co-morbidities. LAA thrombus was detected in 13(21%) of 62 early presenters, compared to 20 (33%) of 60 patients of the second group (P=0.12). Significant predictors of LAA thrombus in the whole cohort by univariate analysis were ≥65 years of age (1.051, P=0.017), acute heart failure (2.394, P=0.038), and history of coronary artery/ peripheral vascular disease (2.7, P= 0.019). Notably neither duration of symptoms nor CHA2DS2-VASc score significantly predicted LAA thrombus. Inmultivariate analysis, only age ≥65 was found to be a significant predictor of LAA thrombus.

Conclusions

LAA thrombus in patients presenting within 48 hours of AF symptoms onset is not uncommon. Duration of symptoms is not reliable for excluding LAA thrombus.

Transesophageal echocardiography for cardiovascular risk estimation in patients with sepsis and new-onset atrial fibrillation: a multicenter prospective pilot study

Background

Echocardiographic parameters have been poorly investigated for estimating cardiovascular risk in patients with sepsis and new-onset atrial fibrillation. We aim to assess the prevalence of transesophageal echocardiographic abnormalities and their relationship with cardiovascular events in mechanically ventilated patients with sepsis and new-onset atrial fibrillation.

Methods

In this prospective multicenter pilot study, left atrial/left atrial appendage (LA/LAA) dysfunction, severe aortic atheroma, and left ventricular systolic dysfunction were assessed using an initial transesophageal echocardiographic study, which was repeated after 48–72 h to detect LA/LAA thrombus formation. The study outcome was a composite of cardiovascular events at day 28, including arterial thromboembolic events (ischemic stroke, non-cerebrovascular arterial thromboembolism, LA/LAA thrombus), major bleeding, and all-cause death.

Results

The study population comprised 94 patients (septic shock 63%; 35% women; median age 69 years). LA/LAA dysfunction, severe aortic atheroma, and left ventricular systolic dysfunction were detected in 17 (19%), 22 (24%), and 27 (29%) patients, respectively. At day 28, the incidence of cardiovascular events was 46% (95% confidence interval [CI]: 35 to 56). Arterial thromboembolic events and major bleeding occurred in 7 (7%) patients (5 ischemic strokes, 1 non-cerebrovascular arterial thromboembolism, 2 left atrial appendage thrombi) and 18 (19%) patients, respectively. At day 28, 27 patients (29%) died. Septic shock (hazard ratio [HR]: 2.36; 95% CI 1.06 to 5.29) and left ventricular systolic dysfunction (HR: 2.06; 95% CI 1.05 to 4.05) were independently associated with cardiovascular events.

Conclusions

Transesophageal echocardiographic abnormalities are common in mechanically ventilated patients with sepsis and new-onset atrial fibrillation, but only left ventricular systolic dysfunction was associated with cardiovascular events at day 28.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13613-021-00934-1.

Outcomes of transesophageal echocardiogram-guided electrical cardioversion in patients with atrial fibrillation greater than 48 hours treated in the emergency department versus the cardiology ward: A retrospective comparison study

BACKGROUND

The current emergency medicine literature on cardioversion for atrial fibrillation (AF) describes its performance on those who are hemodynamically unstable, present within 48 hours of the onset of the arrhythmia, or are on long-term anticoagulants. For patients who are not anticoagulated and present with atrial fibrillation for more than 48 hours, one option is to perform a transesophageal echocardiogram and then synchronized cardioversion in the absence of atrial clot. The objective of this study is to compare outcomes of patients presenting to the emergency department (ED) with atrial fibrillation (AF) of more than 48 hours who underwent a transesophageal echocardiogram (TEE) and subsequent cardioversion in the ED versus the cardiology ward.

METHODS

This was a retrospective comparison study of patients who presented to the ED with AF for more than 48 hours, underwent a transesophageal echocardiogram, and then were electrically cardioverted either in the emergency department or in the cardiology ward. Outcomes include: time to cardioversion, length of hospital stay, rate of successful cardioversion, and rate of complications.

RESULTS

Electrical cardioversion was performed in the ED on 94 patients (62%) and the cardiology ward on 57 (38%). Over 90% of cardioversions were successful in both groups. Time to cardioversion was significantly less in the ED group versus the cardiology group (1.04 ± 0.9 days versus 3.81 ± 1.9; P < .001). Similarly, the mean length of hospital stay was less for the ED group (1.6 ± 1.6 days versus 7.3 ± 3.5; P < .001).

CONCLUSION

Patients who present in atrial fibrillation for more than 48 hours and then have a TEE undergo electrical cardioversion faster in the ED compared with the cardiology ward. This clinical pathway also results in a shorter length of hospital stay without having more side effects.

Vorhofflimmern und NOAK-Therapie: Benötigen wir eine transösophageale Echokardiografie vor Kardioversion?

Vorhofflimmern ist ein häufiger Grund für einen Schlaganfall. Insbesondere Patienten ohne adäquate Antikoagulation haben ein erhöhtes Risiko für thromboembolische Ereignisse (ca. 5–7%). Es liegt eine Assoziation zwischen Kardioversionen und embolischen Ereignissen vor. Durch eine orale Antikoagulation (OAK) mit Nicht-Vitamin-K-Antagonisten (NOAK) kann dieses Risiko auf unter 1% reduziert werden. Es gibt 2 unterschiedliche Kardioversionsstrategien. Zum einen kann eine Kardioversion nach 3-wöchiger effektiver Antikoagulation ohne weitere Bildgebung durchgeführt werden. Zum anderen kann nach Ausschluss einer intrakardialen Thrombenbildung durch eine TEE umgehend sicher kardiovertiert werden. Bei Vorhofflimmern sollte nach der Kardioversion eine effektive Antikoagulation für mindestens 4 Wochen erfolgen, unabhängig vom CHA2DS2-VASc-Score. Eine Bildgebung mittels TEE ist notwendig, wenn die Dauer einer effektiven Antikoagulation <3 Wochen ist, Unsicherheiten bezüglich der regelmäßigen und lückenlosen Medikamenteneinnahme bestehen oder ein hohes Risiko für linksatriale Thromben besteht.

Antithrombotic Therapy for Stroke Patients with Cardiovascular Disease

Prevention of ischemic stroke relies on the use of antithrombotic medications comprising antiplatelet agents and anticoagulation. Stroke risk is particularly high in patients with cardiovascular disease. This review will focus on the role of antithrombotic therapies in the context of different types of cardiovascular disease. We will discuss oral antiplatelet medications and both IV and parental anticoagulants. Different kinds of cardiovascular disease contribute to stroke via distinct pathophysiological mechanisms, and the optimal treatment for each varies accordingly. We will explore the mechanism of stroke and evidence for antithrombotic therapy in the following conditions: atrial fibrillation, prosthetic heart values (mechanical and bioprosthetic), aortic arch atherosclerosis, congestive heart failure (CHF), endocarditis (infective and nonbacterial thrombotic endocarditis), patent foramen ovale (PFO), left ventricular assist devices (LVAD), and extracorporeal membrane oxygenation (ECMO). While robust data exist for antithrombotic use in conditions such as atrial fibrillation, optimal treatment in many situations remains under active investigation.

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 Iowa less aggressive protocol: A mixed-methods study on the novel treatment protocol of atrial fibrillation

OBJECTIVES

Atrial fibrillation is the most common cardiac dysrhythmia in the United States. Our aim was to determine if a novel protocol for management of atrial fibrillation was feasible to implement in an emergency department (ED). Interviews were conducted with ED physicians and physician assistants to identify themes in relation to the clinical use and impleon of the protocol.

METHODS

A novel protocol was developed by a multi-disciplinary team and implemented in an academic ED. The protocol used cardiac computed tomography (CT) to rule out left atrial thrombus in patients with greater than 12 h of symptoms and high risk of thromboembolism, or any patient with greater than 48 h of symptoms. Patients who underwent cardiac CT or electrical cardioversion were followed up at 30 days via telephone to monitor for recurrence or adverse thromboembolic events. Providers were interviewed to identify themes regarding protocol usage, barriers to its use, and future changes to increase utilization.

RESULTS

Patients with atrial fibrillation in the ED were eligible for inclusion. Twenty-nine patients were treated using the protocol. Seven patients (24%) underwent cardiac CT prior to electrical cardioversion. Cardioversion success rate was 83%, with 69% of patients discharged home. Thirty-day follow-up was completed on 25 patients (86%). Six patients (24%) had reoccurrence of atrial fibrillation requiring subsequent cardioversion. No patients experienced stroke or thromboembolic event. Interviews were conducted with 14 providers. Usage barriers included time, availability, and additional work-up. Six subthemes were identified for future changes including EMR order set, frequent reminders, increased education, increased awareness, activation energy, and EMR pop-ups.

CONCLUSION

The Iowa Less Aggressive Protocol is a novel treatment protocol for the ED management of atrial fibrillation that was feasible to implement and use. Providers viewed the protocol favorably and identified areas of improvement for future use.

Cardioversion Safety - Are We Doing Enough?

There is a considerable periprocedural risk of thromboembolic events in atrial fibrillation patients undergoing cardioversion, and treatment with anticoagulants is therefore a hallmark of cardioversion safety. Based on retrospective subgroup analyses and prospective studies, non-vitamin K anticoagulants are at least as efficient as vitamin K-antagonists in preventing thromboembolic complications after cardioversion. The risk of thromboembolic complications after cardioversion very much depends on the comorbidities in a given patient, and especially heart failure, diabetes, and age >75 years carry a markedly increased risk. Cardioversion has been considered safe within a 48-h time window after onset of atrial fibrillation without prior treatment with anticoagulants, but recent studies have set this practice into question based on e.g. erratic debut assessment of atrial fibrillation. Therefore, a simple and more practical approach is here suggested, where early cardioversion is performed only in hemodynamically unstable patients.

Comparing TEE- vs Non-TEE-guided cardioversion of atrial fibrillation: The ENSURE-AF trial

BACKGROUND

ENSURE-AF (NCT02072434) assessed therapy with edoxaban vs enoxaparin-warfarin in patients with nonvalvular atrial fibrillation (AF) undergoing elective electrical cardioversion (ECV).

OBJECTIVES

To evaluate clinical features and primary efficacy (composite of stroke, systemic embolic events, myocardial infarction and cardiovascular mortality during study period) and safety endpoints (composite of major and clinically relevant nonmajor bleeding during on-treatment period) in patients awaiting ECV of AF with a transesophageal echocardiography (TEE)-guided vs a non-TEE-guided strategy.

METHODS

In this prospective, randomized, open-label, blinded endpoint study, 2199 patients were randomized to edoxaban 60 mg once-daily (30 mg for creatinine clearance 15-50 mL/min, weight ≤60 kg and/or concomitant use of P-glycoprotein inhibitor) or enoxaparin-warfarin. Primary efficacy endpoint and safety endpoint were reported. Associates of TEE use, efficacy endpoint and safety endpoint were explored using multivariable logistic regression.

RESULTS

In total, 589 patients from the edoxaban stratum and 594 from the enoxaparin-warfarin stratum were allocated to the TEE-guided strategy. Primary efficacy was similar regardless of TEE approach (P = .575). There were no significant differences in bleeding rates, regardless of TEE approach (P = .677). Independent predictors of TEE use were as follows: history of ischaemic stroke/ transient ischaemic attack, hypertension and valvular heart disease. Mean CHA₂ DS₂ VASc and HAS-BLED score were independent predictors of the efficacy endpoint whilst mean age was an independent predictor of the safety endpoint.

CONCLUSIONS

Thromboembolic and bleeding events were not different between patients undergoing TEE-guided strategy and in those undergoing an optimized conventional anticoagulation approach for ECV of AF.

Stroke and thromboembolism prevention in atrial fibrillation

Prevention of stroke and systemic thromboembolism remains the cornerstone for management of atrial fibrillation (AF) and flutter. Multiple risk assessment models for stroke and systemic thromboembolism are currently available. The score, with its known limitations, remains as the recommended risk stratification tool in most major guidelines. Once at-risk patients are identified, vitamin K antagonists (VKAs) and, more recently, direct oral anticoagulants (DOACs) are the primary medical therapy for stroke prevention. In those with contraindication for long-term anticoagulation, left atrial appendage occluding devices are developing as a possible alternative therapy. Some controversy exists regarding anticoagulation management for cardioversion of acute AF (<48 hours); however, systemic anticoagulation precardioversion and postcardioversion is recommended for those with longer duration of AF. Anticoagulation management peri-AF ablation is also evolving. Uninterrupted VKA and DOAC therapy has been shown to reduce perioperative thromboembolic risk with no significant escalation in major bleeding. Currently, under investigation is a minimally interrupted approach to anticoagulation with DOACs periablation. Questions remain, especially regarding the delivery of anticoagulation care and integration of wearable rhythm monitors in AF management.

Cardioversion for atrial fibrillation - how to prevent thromboembolic complications?

Cardioversion is an essential component of rhythm control strategy for atrial fibrillation. The thromboembolic risk of cardioversion is well established and the mechanisms behind the phenomenon have been comprehensively described. There are several clinical aspects that are important to take into consideration when assessing the safety of cardioversion. Before proceeding to cardioversion, the probability of early treatment failure and antiarrhythmic treatment options to prevent recurrences should be carefully evaluated to avoid the risks of repeated futile cardioversions. Effective periprocedural anticoagulation is the mainstay in thromboembolic complication prevention and the first week after rhythm conversion is the most vulnerable period in this respect. Early timing of cardioversion appears to be another important measure to decrease the risk of thromboembolic complications. Transoesophageal echocardiography is useful in clinical scenarios where early cardioversion is desirable due to debilitating clinical symptoms and a short duration of arrhythmia or the adequacy of preceding anticoagulation is uncertain. However, it does not lessen the need for effective anticoagulation after cardioversion. This review summarizes the recent scientific discoveries to improve the safety of cardioversion for atrial fibrillation. Key messages Cardioversion for atrial fibrillation entails a significant risk of thromboembolic complications, especially during the first week after the procedure. The intensity of periprocedural anticoagulation and the timing of cardioversion appear to be significant determinants of the risk of thromboembolism. Awareness of the clinical aspects influencing cardioversion safety should be raised.

Safety of cardioversion in atrial fibrillation lasting less than 48 h without post-procedural anticoagulation in patients at low cardioembolic risk

Currently, there is no unified consensus on short-term anticoagulation after cardioversion of atrial fibrillation lasting less than 48 h in low-cardioembolic-risk patients. The aim of this study is to evaluate the rate of transient ischemic attacks, stroke and death in this subset of patients after cardioversion without post-procedural anticoagulation. In a prospective observational study, patients with recent-onset AF undergoing cardioversion attempts in the Emergency Department were evaluated over the past 3 years. Inclusion criteria were conversion to sinus rhythm, low thromboembolic risk defined by a CHA2DS2VASc score of 0-1 points for males (0-2 points for females aged over 65 years), and hospital discharge without anticoagulant treatment. Patients with severe valvular heart disease, underlying systemic causes of AF, and those discharged with anticoagulant therapy were excluded. The main outcomes measured were TIA, stroke and death at thirty days' follow-up after discharge. During the study period, 218 successful cardioversions, obtained both electrically and pharmacologically, were performed on 157 patients. One hundred and eleven patients were males (71%), the mean age was 55.2 years (±standard deviation 10.7), 99 patients (63%) reported a CHA2DS2VASc score of 0, and the remaining 58 (37%) had a risk profile of 1 point. Of these, latter 8 were females (5%) older than 65 years (risk score 2 points). At the thirty days outcome, none of the 150 enrolled patients who completed a follow-up visit has reported TIA or stroke, nor died, in the overall 211 successful cardioversions evaluated. In our study, the rate of thromboembolic events after cardioversion of recent-onset AF of less than 48 h duration, in patients with a 0-1 CHA2DS2VASc risk profile (females 0-2), appeared to be extremely low even in absence of post-procedural anticoagulation. These findings seem to confirm data from previous studies, and suggest that routine post-procedural short-term anticoagulation may be considered as an overtreatment in this very low-risk subset of patients.

Recent advances in the management of transient ischemic attacks

Significant advances in our understanding of transient ischemic attack (TIA) have taken place since it was first recognized as a major risk factor for stroke during the late 1950's. Recently, numerous studies have consistently shown that patients who have experienced a TIA constitute a heterogeneous population, with multiple causative factors as well as an average 5-10% risk of suffering a stroke during the 30 days that follow the index event. These two attributes have driven the most important changes in the management of TIA patients over the last decade, with particular attention paid to effective stroke risk stratification, efficient and comprehensive diagnostic assessment, and a sound therapeutic approach, destined to reduce the risk of subsequent ischemic stroke. This review is an outline of these changes, including a discussion of their advantages and disadvantages, and references to how new trends are likely to influence the future care of these patients.

Sex, age, and time to cardioversion. Risk factors for cardioversion of acute atrial fibrillation from the FinCV study

BACKGROUND

Female sex, old age, and time to cardioversion increase the risk of thromboembolic complications (TEC) after cardioversion of atrial fibrillation (AF) < 48 h. The interaction of these variables is not known. We investigated the interaction of sex, age, and time to electrical cardioversion (ECV) on TEC in anticoagulant-naive patients with acute AF.

METHODS AND RESULTS

The primary outcome was a TEC within 30 days following ECV. Patients were divided into three age groups and time to cardioversion into <12 h and ≥12 h in 4715 ECVs. TEC occurred in 40 (0.8%) patients. In multivariate analysis, female sex, time to ECV, and vascular disease were independent predictors of TEC. For patients ≤75 cardioverted within 12 h, the incidence of TEC was low. In patients >75 TEC increased in both sexes and particularly in women (1.4% vs. 0.9%, p = 0.03). When ECVs exceeded 12 h, the risk of TEC was two- to four-fold higher in women in all age groups.

CONCLUSIONS

The risk of TEC increases substantially in patients >75 and ECVs ≥12 h, particularly in women. Time to cardioversion should be added to risk-stratification of ECVs of acute AF. Key messages The ideal timing of cardioversion is still unknown and not based on solid evidence. Delay to cardioversion ≥12 h should be added to the risk stratification of atrial fibrillation cardioversion. Female sex increases the risk of complications and failure of cardioversion after electrical cardioversion of atrial fibrillation <48 h, especially with age >75 years and time to cardioversion exceeding 12 h.

Prevalence of left atrial thrombus in patients with non-valvular atrial fibrillation. A systematic review and meta-analysis of the literature

We performed a meta-analysis about the prevalence of left atrial thrombus (LAT) in patients with atrial fibrillation (AF) undergoing trans-esophageal echocardiography (TEE). Studies reporting on LAT presence in AF patients were systematically searched in the PubMed, Web of Science, Scopus and EMBASE databases and the pooled LAT prevalence was evaluated as weighted mean prevalence (WMP). Seventy-two studies (20,516 AF patients) showed a LAT WMP of 9.8 % (95 %CI: 7.6 %-12.5 %). LAT presence was associated with a higher age (mean difference: 2.56, 95 %CI: 1.49-3.62), and higher prevalence of female gender (OR: 1.35, 95 %CI: 1.04-1.75), hypertension (OR: 1.78, 95 %CI: 1.38-2.30), diabetes mellitus (OR: 1.86, 95 %CI: 1.33-2.59) and chronic heart failure (OR: 3.67, 95 %CI: 2.40-5.60). Overall, LAT patients exhibited a higher CHADS2-score (mean difference 0.88, 95 %CI: 0.68-1.07) and a higher risk of stroke/systemic embolism (OR: 3.53, 95 %CI: 2.24-5.56) compared with those without LAT. A meta-regression showed an inverse association between LAT prevalence and the presence of anticoagulation (Z-value: -7.3, p< 0.001). Indeed, studies in which 100 % of patients received oral anticoagulation reported a 3.4 % WMP of LAT (95 %CI: 1.3 %-8.7 %), whereas studies in which 0 % of patients received anticoagulation showed a LAT WMP of 7.4 % (95 %CI: 2.3 %-21.5 %). Our data suggest that LAT is present in ≍10 % of AF patients, and is associated with a 3.5-fold increased risk of stroke/systemic embolism. Interestingly, LAT is also reported in some of patients receiving anticoagulation. The implementation of the screening of LAT in AF patients before cardioversion/ablation could be useful for the prevention of vascular events.

Cardioversion Of Atrial Fibrillation And Oral Anticoagulation

The risk of thromboembolic events is a major concern in cardioversion of atrial fibrillation. The vast majority of these events occur in the first week following cardioversion. Processes promoting thrombus formation occur early and thrombus may appear in the left atrium within 48 hours of atrial fibrillation. The risk of thromboembolic events also increases with the presence of stroke risk factors. Thus, the current guidelines recommend that also patients with acute atrial fibrillation should undergo cardioversion under cover of unfractionated or low-molecular weight heparin followed by oral anticoagulation for at least 4 weeks in patients at moderate-to-high risk for stroke. Delay of cardioversion < 12 hours from the symptom onset seems to cause a marked increase in the risk of stroke. Thus, short term anticoagulation should be considered also for patients with a low CHA₂DS₂VASc score if the delay to cardioversion is 12-48 hours.

Absence of left atrial stunning after cardioversion of recent-onset atrial fibrillation in patients at low-stroke risk

OBJECTIVE

The aim of the present study was to evaluate the presence and degree of spontaneous echo contrast (SEC) in the left atrium and of left atrial appendage (LAA) contractility before and after cardioversion (CV) in patients with recent-onset atrial fibrillation (AF).

METHODS

Our study included 56 patients divided into two groups: group 1, comprising 32 clinically stable patients who were admitted to the Emergency Department with less than or equal to 48 h duration AF, and who underwent transoesophageal echocardiography (TEE)-guided CV; and the control group (group 2), comprising 24 patients admitted to the Cardiological Department for elective TEE-guided CV of greater than 48 h AF. All patients underwent repeat TEE within 1 h after successful CV.

RESULTS

Patients with recent-onset AF (group 1) showed no thrombogenic milieu at baseline without any evidence of atrial stunning after successful CV. SEC mean grade (0-3 grading) was 0.09±0.3 versus 0.12±0.4 after CV (P=0.98), and LAA flow velocity was 60.7±19.4 versus 56.7±20.5 cm/s after CV (P=0.07). Group 2 patients showed a significantly higher degree of SEC compared with those in group 1 (0.09±0.3 vs. 0.66±0.7, P=0.0093) and significantly lower LAA flow velocities (60.7±19.4 vs. 32.5±12.4, P<0.0001), with significant worsening after successful CV (SEC degree: 0.66±0.9 vs. 1.37±0.9, P=0.0093; LAA flow velocity: 32.5±12.4 vs. 20.4±12.7 cm/s, P<0.0001).

CONCLUSION

The absence of thrombogenic milieu and of left atrial stunning after CV in patients with recent-onset AF favours early CV without anticoagulation, at least in patients with a low thromboembolic risk profile. These patients could be discharged earlier from urgent care.

Left atrial thrombus formation and resolution during dabigatran therapy: A Japanese Heart Rhythm Society report

BACKGROUND

Protocols on the use of novel oral anticoagulants for stroke prevention in patients with atrial fibrillation (AF) undergoing electrical cardioversion (ECV) are lacking.

AIM

The study was aimed at evaluating the efficacy of dabigatran (Dabi) treatment in preventing peri-ECV stroke.

METHODS

A retrospective survey of the incidence and fate of left atrial (LA) thrombus during Dabi therapy in patients with AF was conducted between December 2012 and January 2013 by the Japanese Heart Rhythm Society.

RESULTS

A total of 198 patients from 299 institutions underwent transesophageal echocardiography (TEE) to rule out LA thrombus before ECV. Of these, LA thrombus was found in eight patients (4%), who tended to be older (67.3 vs. 61.3 years, p=0.175), had higher CHADS2 scores (1.88 vs. 0.95, p=0.058), and a higher prevalence of prior stroke or transient ischemic attack (22.2% vs. 2.6%, p=0.034) than those without LA thrombus. Of the eight patients with LA thrombus, one had LA thrombus during a Dabi 150 mg b.i.d treatment, whereas the remaining seven were receiving 110 mg b.i.d for 3 weeks or longer. In 6 of the 8 patients with LA thrombus, a second TEE was performed, revealing complete resolution of LA thrombus in five; among these five patients, one received Dabi dosage of 150 mg b.i.d unchanged, two received an increased dosage from 110 mg to 150 mg b.i.d, and two were switched to warfarin. Two patients had a stroke 3 and 15 days after ECV, and one had a major large intestine bleeding episode during Dabi therapy.

CONCLUSIONS

LA thrombus developed in 4% of patients with AF receiving Dabi. Older patients with a higher CHADS2 score receiving a lower Dabi dosage were more likely to develop LA thrombus, which was resolved with a prolonged or increased dosage. A higher Dabi dosage may be more beneficial before ECV but prospective randomized studies would be needed to confirm these results.

Transesophageal echocardiography-guided cardioversion after cardiac operations

BACKGROUND

Transesophageal echocardiography (TEE) is often performed during cardiac operations. The need to repeat TEE to exclude left atrial or left atrial appendage thrombus before direct current cardioversion (DCCV) in patients with a recent intraoperative TEE showing no thrombus is unclear. We sought to determine the incidence of and risk factors for new thrombus in patients undergoing TEE-guided DCCV after cardiac operations.

METHODS

We reviewed 817 patients referred for TEE-guided DCCV within 30 days of a cardiac operation and an intraoperative TEE. Patients were excluded if the intraoperative TEE showed thrombus or a surgical left atrial appendage intervention was performed. Univariate logistic regression identified risk factors for thrombus.

RESULTS

The study included 362 patients (71% male) with a mean age of 69 years. Median time from the operation to DCCV was 6 days. Thrombus was present in 13 patients (3.6%) on TEE before cardioversion; DCCV was cancelled in these patients. Heart failure was associated with a significantly higher risk of new thrombus formation (7% vs 2%; odds ratio, 3.26; 95% confidence interval, 1.07 to 9.95). Preoperative atrial arrhythmias, duration of perioperative arrhythmias, level of anticoagulation, and time from operation to DCCV were not significantly associated with thrombus. Thrombus was not associated with 30-day mortality.

CONCLUSIONS

Development of new thrombus in patients with atrial arrhythmias early after cardiac operations is not uncommon, especially in patients with heart failure. Patients at high risk for thromboembolic events should undergo TEE before DCCV, even if a recent intraoperative TEE showed no thrombus.

Left ventricular mass predicts left atrial appendage thrombus in persistent atrial fibrillation

AIMS

Atrial fibrillation (AF) can result in the development of left atrial appendage (LAA) thrombi. We sought to examine demographic and echocardiographic predictors of LAA thrombus in patients with persistent AF.

METHODS AND RESULTS

One hundred and sixty-five patients in persistent AF (36 with LAA thrombus and 129 without thrombus) were studied. Demographic and cardiovascular risk factors were retrospectively examined. Transthoracic (TTE) and transoesophageal echocardiography (TOE) were performed to assess the size and function of the left ventricle (LV), left atrium (LA), LAA, and spontaneous echo contrast (SEC) in the LA and right atrium (RA). Univariate demographic predictors of LA thrombus included systolic blood pressure, ischaemic heart disease and congestive heart failure. Indexed LV mass and septal E' velocity on TTE and mean LAA emptying velocity and the presence of SEC in both the LA and RA on TOE were predictors of thrombus. In a multiple logistic regression analysis the only independent predictor of thrombus was indexed LV mass (P < 0.001). Receiver operator characteristic curve analysis also demonstrated that indexed LV mass had the highest area under the curve (AUC: 0.98).

CONCLUSION

In the present study, increased LV mass was the strongest predictor of LAA thrombus in persistent AF. LA SEC and RA SEC were univariate predictors of LAA thrombus but did not add predictive value to a multivariate model including LV mass. This study highlights the importance of diagnosing and treating LV hypertrophy associated with persistent AF, which may reduce the risk of LAA thrombus and thrombo-embolic stroke.

Role of CHADS2 score in evaluation of thromboembolic risk and mortality in patients with atrial fibrillation undergoing direct current cardioversion (from the ACUTE Trial Substudy)

The CHADS(2) (congestive heart failure, hypertension, age >75 years, diabetes mellitus, stroke or transient ischemic attack [2 points]) scoring scheme has been found to be a good predictor of stroke risk in patients with nonvalvular atrial fibrillation (AF). However, the value of the CHADS(2) scoring system in the risk stratification of patients with AF who undergo direct-current cardioversion has not yet been specifically investigated. In this study, a subgroup of 541 patients from the Assessment of Cardioversion Using Transesophageal Echocardiography (ACUTE) study who had AF for >48 hours and planned to undergo transesophageal echocardiography before direct-current cardioversion were enrolled. Each patient had a CHADS(2) score calculated. Of the patients with CHADS(2) scores of 0, 14 (10%) were found to have left atrial appendage thrombi on transesophageal echocardiography. After 6 months of follow up, patients with CHADS(2) scores of 3 to 6 showed a significantly higher mortality rate in comparison with patients with lower CHADS(2) scores (4.3% vs 0.5%, p = 0.004), despite their similar prevalence of left atrial appendage thrombus and stroke (thrombus: 13.4% vs 11.6%, p = 0.60; stroke: 0% vs 0.3%, p = 0.70). In conclusion, the CHADS(2) scoring system may be useful for predicting short-term mortality risk in patients with AF receiving elective direct-current cardioversion. However, in the preprocedural risk assessment of these patients, the CHADS(2) scoring system is not reliable in predicting risk for left atrial appendage thrombus formation, especially in patients with low CHADS(2) scores.

Antithrombotic therapy for atrial fibrillation: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines

BACKGROUND

The risk of stroke varies considerably across different groups of patients with atrial fibrillation (AF). Antithrombotic prophylaxis for stroke is associated with an increased risk of bleeding. We provide recommendations for antithrombotic treatment based on net clinical benefit for patients with AF at varying levels of stroke risk and in a number of common clinical scenarios.

METHODS

We used the methods described in the Methodology for the Development of Antithrombotic Therapy and Prevention of Thrombosis Guidelines: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines article of this supplement.

RESULTS

For patients with nonrheumatic AF, including those with paroxysmal AF, who are (1) at low risk of stroke (eg, CHADS(2) [congestive heart failure, hypertension, age ≥ 75 years, diabetes mellitus, prior stroke or transient ischemic attack] score of 0), we suggest no therapy rather than antithrombotic therapy, and for patients choosing antithrombotic therapy, we suggest aspirin rather than oral anticoagulation or combination therapy with aspirin and clopidogrel; (2) at intermediate risk of stroke (eg, CHADS(2) score of 1), we recommend oral anticoagulation rather than no therapy, and we suggest oral anticoagulation rather than aspirin or combination therapy with aspirin and clopidogrel; and (3) at high risk of stroke (eg, CHADS(2) score of ≥ 2), we recommend oral anticoagulation rather than no therapy, aspirin, or combination therapy with aspirin and clopidogrel. Where we recommend or suggest in favor of oral anticoagulation, we suggest dabigatran 150 mg bid rather than adjusted-dose vitamin K antagonist therapy.

CONCLUSIONS

Oral anticoagulation is the optimal choice of antithrombotic therapy for patients with AF at high risk of stroke (CHADS(2) score of ≥ 2). At lower levels of stroke risk, antithrombotic treatment decisions will require a more individualized approach.