Cardioversion of atrial fibrillation

2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Atrial Fibrillation: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The "2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Atrial Fibrillation" provides recommendations to guide clinicians in the treatment of patients with atrial fibrillation.

METHODS

A comprehensive literature search was conducted from May 12, 2022, to November 3, 2022, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Library, the Agency for Healthcare Research and Quality, and other selected databases relevant to this guideline. Additional relevant studies, published through November 2022, during the guideline writing process, were also considered by the writing committee and added to the evidence tables, where appropriate.

STRUCTURE

Atrial fibrillation is the most sustained common arrhythmia, and its incidence and prevalence are increasing in the United States and globally. Recommendations from the "2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation" and the "2019 AHA/ACC/HRS Focused Update of the 2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation" have been updated with new evidence to guide clinicians. In addition, new recommendations addressing atrial fibrillation and thromboembolic risk assessment, anticoagulation, left atrial appendage occlusion, atrial fibrillation catheter or surgical ablation, and risk factor modification and atrial fibrillation prevention have been developed.

2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Atrial Fibrillation: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The "2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Patients With Atrial Fibrillation" provides recommendations to guide clinicians in the treatment of patients with atrial fibrillation.

METHODS

A comprehensive literature search was conducted from May 12, 2022, to November 3, 2022, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Library, the Agency for Healthcare Research and Quality, and other selected databases relevant to this guideline. Additional relevant studies, published through November 2022, during the guideline writing process, were also considered by the writing committee and added to the evidence tables, where appropriate.

STRUCTURE

Atrial fibrillation is the most sustained common arrhythmia, and its incidence and prevalence are increasing in the United States and globally. Recommendations from the "2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation" and the "2019 AHA/ACC/HRS Focused Update of the 2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation" have been updated with new evidence to guide clinicians. In addition, new recommendations addressing atrial fibrillation and thromboembolic risk assessment, anticoagulation, left atrial appendage occlusion, atrial fibrillation catheter or surgical ablation, and risk factor modification and atrial fibrillation prevention have been developed.

Electric cardioversion in patients treated with oral anticoagulants: embolic material in the left atrial appendage

Atrial fibrillation (AF) remains the most common arrhythmia. The sinus rhythm restoration procedure without adequate anticoagulant preparation may lead to a thromboembolic event in approximately 5-7% of patients. The initiation of oral anticoagulation significantly reduces this risk by inhibiting formation of embolic material in the heart cavities, especially in the left atrial appendage (LAA). However, there is a group of patients who develop embolic material in the LAA despite oral anticoagulation treatment. The best treatment method to dissolve thrombus in the LAA is not clear, due to the lack of studies with adequate power and endpoints that can determine the best management strategy. We present clinical trials comparing the efficacy and safety of oral anticoagulants in patients undergoing AF cardioversion. We evaluate the frequency of LAA thrombus formation in patients with AF on treatment with oral anticoagulants. Furthermore, we discuss the effectiveness of various treatment strategies on LAA thrombus resolution.

Atrial Fibrillation Occurring During Acute Hospitalization: A Scientific Statement From the American Heart Association

Acute atrial fibrillation is defined as atrial fibrillation detected in the setting of acute care or acute illness; atrial fibrillation may be detected or managed for the first time during acute hospitalization for another condition. Atrial fibrillation after cardiothoracic surgery is a distinct type of acute atrial fibrillation. Acute atrial fibrillation is associated with high risk of long-term atrial fibrillation recurrence, warranting clinical attention during acute hospitalization and over long-term follow-up. A framework of substrates and triggers can be useful for evaluating and managing acute atrial fibrillation. Acute management requires a multipronged approach with interdisciplinary care collaboration, tailoring treatments to the patient's underlying substrate and acute condition. Key components of acute management include identification and treatment of triggers, selection and implementation of rate/rhythm control, and management of anticoagulation. Acute rate or rhythm control strategy should be individualized with consideration of the patient's capacity to tolerate rapid rates or atrioventricular dyssynchrony, and the patient's ability to tolerate the risk of the therapeutic strategy. Given the high risks of atrial fibrillation recurrence in patients with acute atrial fibrillation, clinical follow-up and heart rhythm monitoring are warranted. Long-term management is guided by patient substrate, with implications for intensity of heart rhythm monitoring, anticoagulation, and considerations for rhythm management strategies. Overall management of acute atrial fibrillation addresses substrates and triggers. The 3As of acute management are acute triggers, atrial fibrillation rate/rhythm management, and anticoagulation. The 2As and 2Ms of long-term management include monitoring of heart rhythm and modification of lifestyle and risk factors, in addition to considerations for atrial fibrillation rate/rhythm management and anticoagulation. Several gaps in knowledge related to acute atrial fibrillation exist and warrant future research.

Left atrial appendage thrombus in patients with atrial fibrillation who underwent oral anticoagulation

BACKGROUND

Electric cardioversion of atrial fibrillation (AF) is associated with an increased risk of embolism, with embolic material existing in the heart cavities. The initiation of oral anticoagulation therapy reduces the risk of thromboembolic events. The aims of this study were to evaluate the prevalence of left atrial appendage (LAA) thrombi in non-valvular AF, to compare vitamin K antagonists (VKAs) and non-vitamin K oral anticoagulants (NOACs) with respect to thrombus prevalence, and to evaluate the rate of LAA thrombus persistence on repeat transesophageal echocardiography (TEE) after treatment change.

METHODS

We enrolled 160 consecutive AF patients who presented with an AF duration > 48 h and had undergone TEE before cardioversion.

RESULTS

Left atrial appendage thrombus was observed in 12 (7.5%) patients, and spontaneous echo contrast 4 was observed in 19 (11.8%) patients; the incidence was similar between the NOAC and VKA groups (8.9% vs. 3.6% and 12.4% vs. 18.5 %, respectively). Among patients on NOAC, thrombus prevalence was detected in 8.4% of users of rivaroxaban, 8% of users of dabigatran, and 12.5% of users of apixaban.

CONCLUSIONS

The LAA thrombus developed in 7.5% of patients despite anticoagulation therapy, demonstrating similar prevalence rates among patients either on NOAC or VKA. Lower mean LAA flow velocity and a history of vascular disease were independent predictors of embolic material in the LAA. It seems that in the case of embolic materials in LAA under NOAC treatment, switching to VKA provides additional clinical benefit to the patients.

Cardioversion of atrial fibrillation and atrial flutter revisited: current evidence and practical guidance for a common procedure

Cardioversion is widely used in patients with atrial fibrillation (AF) and atrial flutter when a rhythm control strategy is pursued. We sought to summarize the current evidence on this important area of clinical management of patients with AF including electrical and pharmacological cardioversion, peri-procedural anticoagulation and thromboembolic complications, success rate, and risk factors for recurrence to give practical guidance.

Antithrombotic treatment management in low stroke risk patients undergoing cardioversion of atrial fibrillation <48 h duration: results of an EHRA survey

Data supporting the safety of cardioversion (CV) of atrial fibrillation (AF) without anticoagulation in patients with AF duration <48 h are scarce. Observational studies suggest that the risk of stroke in these patients is very low when the definite duration of the AF episode is of <48 h and the clinical risk profile as estimated through the CHA2DS2VASc score is low (a score of 0 for men and 1 for women). As the recent 2020 European Society of Cardiology (ESC) guidelines indication for this clinical scenario is based mainly on consensus, we sent out a survey to assess the current clinical practice on anticoagulation prior to and post-CV in patients with AF <24-48 h duration and low stroke risk across centres in Europe. Of the 136 respondents, half were affiliated to university hospitals (68/136; 50%). Non-university hospitals (50/136; 36%) and private hospitals (2/136; 1.4%) accounted over a third of respondents. The main findings of our survey were (i) heterogeneity in the anticoagulation management both before and post-CV in low stroke-risk patients with AF <48 h, (ii) higher utilization of periprocedural low-molecular-weight heparin than of non-vitamin K antagonist oral anticoagulant, (iii) higher utilization of pre-CV transoesophageal echocardiography for electrical CV than for pharmacological CV regardless of the duration of AF, (iv) high adherence to a 4-week post-CV oral anticoagulant (OAC) therapy, mainly for electrical CV, and finally, (v) perceived higher acceptance of lack of post-CV OAC therapy in patients with <24 h than 24-48 h episode duration. The results obtained in this survey highlight the need for more research providing definitive clarification on the safety of CV without anticoagulation in patients with short duration AF.

Determinants of left atrium thrombi in scheduled cardioversion: an ENSURE-AF study analysis

Aims

ENSURE-AF (NCT 02072434) was the largest prospective randomized clinical trial of anticoagulation for cardioversion in atrial fibrillation (AF), which also provides the largest prospective dataset for transoesophageal echocardiography (TOE) prior to cardioversion. This ancillary analysis investigated determinants of TOE-detected left atrium thrombi (LAT) in patients scheduled for electrical cardioversion (ECV).

Methods and results

The ENSURE-AF multicentre PROBE evaluation trial compared edoxaban 60 mg once daily (QD) with enoxaparin/warfarin in 2199 subjects undergoing ECV of non-valvular AF. Patients were stratified by the use of TOE, anticoagulant experience, and selected edoxaban dose. Electrical cardioversion was cancelled or deferred when TOEdetected LAT. In total, 1183 subjects were stratified to the TOE arm and LAT was reported in 91 (8.2%). In univariate analysis, age ≥75 years (26.4% vs. 16.9%, P = 0.0308), lower weight (86.5 ± 15.0 vs. 90.7 ± 18.0 kg, P = 0.0309), lower creatinine clearance (80.1 ± 30.6 vs. 93.2 ± 33.9 mL/min, P = 0.0007), heart failure (59.3% vs. 43.0%, P = 0.0029), and diuretic treatment (53.9% vs. 40.1%, P = 0.0141) were more prevalent in the LAT group. Non-significant trends were seen for higher mean CHA₂DS₂-VASc score (3.0 ± 1.41 vs. 2.7 ± 1.48, P = 0.0571) and more prevalent anticoagulation use prior to enrolment (60.4% vs. 50.3%, P = 0.0795) in the LAT group. In logistic regression analysis, age (P = 0.0202) and heart failure (P = 0.0064) were independently associated with LAT.

Conclusion

Elective ECV is commonly cancelled or deferred due to TOE-detected LAT in patients with non-valvular AF. Age ≥75 years and heart failure were associated with the presence of LAT.

Cerebrovascular Dysfunction in Atrial Fibrillation

It is now well established that besides being the most common sustained arrhythmia, atrial fibrillation (AF) is a major healthcare burden. Risk of debilitating stroke is increased in AF patients, but even in the absence of stroke, this population is at heightened risk of cognitive decline, depression, and dementia. The reasons for this are complex, multifactorial, and incompletely understood. One potential contributing mechanism is cerebrovascular dysfunction. Cerebral blood flow is regulated by chemical, metabolic, autoregulatory, neurogenic, and systemic factors. The dysfunction in one or more of these mechanisms may contribute to the elevated risk of cognitive decline and cerebrovascular events in AF. This short review presents the evidence for diminished cerebral blood flow, cerebrovascular carbon dioxide reactivity (i.e., cerebrovascular vasodilatory reserve), cerebral autoregulation, and neurovascular coupling in AF patients when compared to control participants in sinus rhythm. Further work is needed to understand the physiological mechanisms underpinning these observations and their clinical significance in atrial fibrillation patients.

How to overcome cardiovascular challenges in COVID-19 patients: a guide for common practice

The COVID-19 epidemic initially started in Wuhan, China in December 2019 due to SARS-CoV-2. SARS-CoV-2 is genetically similar to the bat beta-coronavirus genus, but the novel specie of this genus can infect humans. The most common clinical features of COVID-19 are fever, cough, myalgia, fatigue, expectoration, and dyspnea. The primary reported mortality rate was about 2-3% in China; however, it reached up to 10% among patients with underlying cardiovascular diseases. The primary epidemiological investigations showed a high prevalence of underlying cardiovascular diseases in more than 40% of infected patients. A high prevalence of hypertension, ischemic heart disease, and diabetes were reported among deceased patients in Italy. Previous experiments in different pandemic situations showed that the cardiovascular system has been affected in many ways. Previous studies on SARS-CoV and MERS-CoV reported that cardiovascular co-morbidities had a direct correlation with the risk of infection, the severity of disease, and the mortality rate. Therefore, brief and available protocols for controlling the negative effects of this novel respiratory infection on the cardiovascular system, especially in a high-risk populations with underlying cardiovascular conditions, is one of the most serious concerns among healthcare providers. Herein, we aimed to review the available data on the cardiac manifestation of COVID-19. Besides, we described useful maps for the better treatment of COVID-19 infection in patients with underlying cardiovascular conditions, as a high-risk group of patients.

Clinical factors related to successful or unsuccessful cardioversion in the EdoxabaN versus warfarin in subjectS UndeRgoing cardiovErsion of Atrial Fibrillation (ENSURE-AF) randomized trial

BACKGROUND

EdoxabaN versus warfarin in subjectS UndeRgoing cardiovErsion of Atrial Fibrillation evaluated use of nonvitamin K antagonist oral anticoagulant edoxaban vs enoxaparin-warfarin in patients with nonvalvular atrial fibrillation undergoing electrical cardioversion.

HYPOTHESIS

To assess clinical factors related to successful or unsuccessful cardioversion. To evaluate whether differences in adverse events based on anticoagulation strategy may exist.

METHODS

In this multicenter prospective randomized open-label blinded end-point evaluation trial, 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. Successful cardioversion was confirmed by 12-lead electrocardiography-documented sinus rhythm.

RESULTS

Cardioversion was successful in 1578 patients; in 355 patients, cardioversion was unsuccessful. Male, high body weight, high body mass index (BMI), coronary artery disease, concomitant aspirin, or prior statins use were more common in patients with unsuccessful cardioversion; international normalized ratio control did not differ by cardioversion success. On multivariate analysis, gender (P < .05), body weight (P = .0196) and BMI (P = .0377) emerged as independent predictors of successful cardioversion. There were no significant differences in primary efficacy (a composite of stroke, systemic embolic event, myocardial infarction, and cardiovascular death during overall study period) regardless of cardioversion success. There were no significant differences in bleeding rates, regardless of cardioversion outcome; notwithstanding low numbers, edoxaban and enoxaparin-warfarin did not differ.

CONCLUSIONS

Male gender, higher mean weight and higher mean BMI were associated with unsuccessful cardioversion. Efficacy and safety outcomes were low and did not differ by cardioversion success.

WITHDRAWN: Pharmacological cardioversion for atrial fibrillation and flutter

BACKGROUND

Atrial fibrillation is the commonest cardiac dysrhythmia. It is associated with significant morbidity and mortality. There are two approaches to the management of atrial fibrillation: controlling the ventricular rate or converting to sinus rhythm in the expectation that this would abolish its adverse effects.

OBJECTIVES

To assess the effects of pharmacological cardioversion of atrial fibrillation in adults on the annual risk of stroke, peripheral embolism, and mortality.

SEARCH METHODS

We searched the Cochrane Controlled Trials Register (Issue 3, 2002), MEDLINE (2000 to 2002), EMBASE (1998 to 2002), CINAHL (1982 to 2002), Web of Science (1981 to 2002). We hand searched the following journals: Circulation (1997 to 2002), Heart (1997 to 2002), European Heart Journal (1997-2002), Journal of the American College of Cardiology (1997-2002) and selected abstracts published on the web site of the North American Society of Pacing and Electrophysiology (2001, 2002).

SELECTION CRITERIA

Randomised controlled trials or controlled clinical trials of pharmacological cardioversion versus rate control in adults (>18 years) with acute, paroxysmal or sustained atrial fibrillation or atrial flutter, of any duration and of any aetiology.

DATA COLLECTION AND ANALYSIS

One reviewer applied the inclusion criteria and extracted the data. Trial quality was assessed and the data were entered into RevMan.

MAIN RESULTS

We identified two completed studies AFFIRM (n=4060) and PIAF (n=252). We found no difference in mortality between rhythm control and rate control relative risk 1.14 (95% confidence interval 1.00 to 1.31).Both studies show significantly higher rates of hospitalisation and adverse events in the rhythm control group and no difference in quality of life between the two treatment groups.In AFFIRM there was a similar incidence of ischaemic stroke, bleeding and systemic embolism in the two groups. Certain malignant dysrhythmias were significantly more likely to occur in the rhythm control group. There were similar scores of cognitive assessment.In PIAF, cardioverted patients enjoyed an improved exercise tolerance but there was no overall benefit in terms of symptom control or quality of life.

AUTHORS' CONCLUSIONS

There is no evidence that pharmacological cardioversion of atrial fibrillation to sinus rhythm is superior to rate control. Rhythm control is associated with more adverse effects and increased hospitalisation. It does not reduce the risk of stroke. The conclusions cannot be generalised to all people with atrial fibrillation. Most of the patients included in these studies were relatively older (>60 years) with significant cardiovascular risk factors.

WITHDRAWN: Electrical cardioversion for atrial fibrillation and flutter

BACKGROUND

Atrial fibrillation increases stroke risk and adversely affects cardiovascular haemodynamics. Electrical cardioversion may, by restoring sinus rhythm, improve cardiovascular haemodynamics, reduce the risk of stroke, and obviate the need for long-term anticoagulation.

OBJECTIVES

To assess the effects of electrical cardioversion of atrial fibrillation or flutter on the risk of thromboembolic events, strokes and mortality (primary outcomes), the rate of cognitive decline, quality of life, the use of anticoagulants and the risk of re-hospitalisation (secondary outcomes) in adults (>18 years).

SEARCH METHODS

We searched the Cochrane CENTRAL Register of Controlled Trials (1967 to May 2004), MEDLINE (1966 to May 2004), Embase (1980 to May 2004), CINAHL (1982 to May 2004), proceedings of the American College of Cardiology (published in Journal of the American College of Cardiology 1983 to 2003), www.trialscentral.org, www.controlled-trials.com and reference lists of articles. We hand-searched the indexes of the Proceedings of the British Cardiac Society published in British Heart Journal (1980 to 1995) and in Heart (1995 to 2002); proceedings of the European Congress of Cardiology and meetings of the Joint Working Groups of the European Society of Cardiology (published in European Heart Journal 1983-2003); scientific sessions of the American Heart Association (published in Circulation 1990-2003). Personal contact was made with experts.

SELECTION CRITERIA

Randomised controlled trial or controlled clinical trials of electrical cardioversion plus 'usual care' versus 'usual care' only, where 'usual care' included any combination of anticoagulants, antiplatelet drugs and drugs for 'rate control'. We excluded trials which used pharmacological cardioversion as the first intervention, and trials of new onset atrial fibrillation after cardiac surgery. There were no language restrictions.

DATA COLLECTION AND ANALYSIS

For dichotomous data, odds ratios were calculated; and for continuous data, the weighted mean difference was calculated.

MAIN RESULTS

We found three completed trials of electrical cardioversion (rhythm control) versus rate control, recruiting a total of 927 participants (Hot Cafe; RACE; STAF) and one ongoing trial (J-RHYTHM). There was no difference in mortality between the two strategies (OR 0.83; CI 0.48 to 1.43). There was a trend towards more strokes in the rhythm control group (OR 1.9; 95% CI 0.99 to 3.64). At follow up, three domains of quality of life (physical functioning, physical role function and vitality) were significantly better in the rhythm control group (RACE 2002; STAF 2003).

AUTHORS' CONCLUSIONS

Electrical cardioversion (rhythm control) led to a non-significant increase in stroke risk but improved three domains of quality of life.

Practical Implementation of Anticoagulation Strategy for Patients Undergoing Cardioversion of Atrial Fibrillation

Anticoagulation is routinely prescribed to patients with persistent AF before cardioversion to reduce the risk of thromboembolic events. As direct oral anticoagulants (DOACs) have a rapid onset of action, a consistent anticoagulant effect, if taken correctly, and do not need monitoring or dose adjustments, there is considerable interest in their use for patients with AF undergoing cardioversion. Post-hoc analyses show that DOACs are safe to use prior to and following cardioversion. In addition, two randomised controlled trials, X-VeRT and ENSURE-AF, have demonstrated the efficacy and safety of the DOACs rivaroxaban and edoxaban, respectively, in this setting. The use of DOACs allows cardioversions to be performed promptly and reduces the number of cancelled procedures compared with the use of warfarin.

The incidence and prognosis of renal dysfunction following cardioversion of atrial fibrillation

OBJECTIVE

Limited data are available regarding the incidence and clinical impact of renal dysfunction following cardioversion of atrial fibrillation. The objective of this study was to assess the incidence and implications of renal dysfunction following cardioversion of atrial fibrillation.

METHODS

We conducted a nested case-control study to determine the incidence, timing, risk factors and outcome of atrial fibrillation cardioversion associated with renal dysfunction (AFCARD) in a tertiary medical center. Consecutive patients undergoing direct current cardioversion (DCCV) for atrial fibrillation in our institution during 2008-2009 with measurements of creatinine before and following cardioversion were included. AFCARD was defined as a rise in serum creatinine greater than 25% from baseline within a week following DCCV.

RESULTS

One hundred and twelve patients were included in the study, of whom 19 (17%) developed AFCARD. One patient required hemodialysis. Patients with AFCARD had a higher incidence of advanced heart failure, diabetes mellitus and were more frequently treated with digoxin and enoxaparin. Patients with AFCARD had a significantly decreased survival rate at 1 year (63 vs. 92%; p < 0.001).

CONCLUSIONS

AFCARD is relatively common and is associated with increased mortality. These findings suggest a role for close surveillance of renal function following DCCV.

Altered transforming growth factor-beta signaling in a murine model of thoracic aortic aneurysm

OBJECTIVE

Thoracic aortic aneurysms (TAAs) develop by a multifactorial process involving maladaptive signaling pathways that alter the aortic vascular environment. Transforming growth factor-beta (TGF-beta) has been implicated in regulating the structure and composition of the extracellular matrix by differential activation of various intracellular signaling pathways. However, whether and to what degree TGF-beta signaling contributes to TAA development remains unclear. Accordingly, the hypothesis that alterations in TGF-beta signaling occur during aneurysm formation was tested in a murine model of TAA.

METHODS

TAAs were surgically induced in mice (C57BL/6J) and aortas were analyzed at predetermined time points (1, 2, and 4 weeks post-TAA induction). Quantitative real-time PCR (QPCR) was performed to evaluate the expression of 84 relevant TGF-beta superfamily genes, and the protein levels of key signaling intermediates were measured by immunoblotting. Results were compared to unoperated reference control mice.

RESULTS

QPCR revealed increased expression of TGF-beta superfamily ligands (Gdf-2, -6, -7, Inhba), ligand inhibitors (Bmper, Chrd, Gsc), and transcriptional regulators (Dlx2, Evi1), among other genes (Cdkn2b, Igf1, IL-6). Protein levels of TGF-beta receptor(II), Smad2, Smad1/5/8, phospho-Smad1/5/8, and Smurf1 were increased from control values post-TAA induction. Both TGF-beta receptor(I) and Smad4 were decreased from control values, while ALK-1 levels remained unchanged.

CONCLUSIONS

These alterations in the TGF-beta pathway suggest a mechanism by which primary signaling is switched from a TGF-betaR(I)/Smad2-dependent response, to an ALK-1/Smad1/5/8 response, representing a significant change in signaling outcome, which may enhance matrix degradation.

Electrical cardioversion for atrial fibrillation and flutter

BACKGROUND

Atrial fibrillation increases stroke risk and adversely affects cardiovascular haemodynamics. Electrical cardioversion may, by restoring sinus rhythm, improve cardiovascular haemodynamics, reduce the risk of stroke, and obviate the need for long-term anticoagulation.

OBJECTIVES

To assess the effects of electrical cardioversion of atrial fibrillation or flutter on the risk of thromboembolic events, strokes and mortality (primary outcomes), the rate of cognitive decline, quality of life, the use of anticoagulants and the risk of re-hospitalisation (secondary outcomes) in adults (>18 years).

SEARCH STRATEGY

We searched the Cochrane CENTRAL Register of Controlled Trials (1967 to May 2004), MEDLINE (1966 to May 2004), Embase (1980 to May 2004), CINAHL (1982 to May 2004), proceedings of the American College of Cardiology (published in Journal of the American College of Cardiology 1983 to 2003), www.trialscentral.org, www.controlled-trials.com and reference lists of articles. We hand-searched the indexes of the Proceedings of the British Cardiac Society published in British Heart Journal (1980 to 1995) and in Heart (1995 to 2002); proceedings of the European Congress of Cardiology and meetings of the Joint Working Groups of the European Society of Cardiology (published in European Heart Journal 1983-2003); scientific sessions of the American Heart Association (published in Circulation 1990-2003). Personal contact was made with experts.

SELECTION CRITERIA

Randomised controlled trial or controlled clinical trials of electrical cardioversion plus 'usual care' versus 'usual care' only, where 'usual care' included any combination of anticoagulants, antiplatelet drugs and drugs for 'rate control'. We excluded trials which used pharmacological cardioversion as the first intervention, and trials of new onset atrial fibrillation after cardiac surgery. There were no language restrictions.

DATA COLLECTION AND ANALYSIS

For dichotomous data, odds ratios were calculated; and for continuous data, the weighted mean difference was calculated.

MAIN RESULTS

We found three completed trials of electrical cardioversion (rhythm control) versus rate control, recruiting a total of 927 participants (Hot Cafe; RACE; STAF) and one ongoing trial (J-RHYTHM). There was no difference in mortality between the two strategies (OR 0.83; CI 0.48 to 1.43). There was a trend towards more strokes in the rhythm control group (OR 1.9; 95% CI 0.99 to 3.64). At follow up, three domains of quality of life (physical functioning, physical role function and vitality) were significantly better in the rhythm control group (RACE 2002; STAF 2003).

AUTHORS' CONCLUSIONS

Electrical cardioversion (rhythm control) led to a non-significant increase in stroke risk but improved three domains of quality of life.

Pharmacological cardioversion for atrial fibrillation and flutter

BACKGROUND

Atrial fibrillation is the commonest cardiac dysrhythmia. It is associated with significant morbidity and mortality. There are two approaches to the management of atrial fibrillation: controlling the ventricular rate or converting to sinus rhythm in the expectation that this would abolish its adverse effects.

OBJECTIVES

To assess the effects of pharmacological cardioversion of atrial fibrillation in adults on the annual risk of stroke, peripheral embolism, and mortality.

SEARCH STRATEGY

We searched the Cochrane Controlled Trials Register (Issue 3, 2002), MEDLINE (2000 to 2002), EMBASE (1998 to 2002), CINAHL (1982 to 2002), Web of Science (1981 to 2002). We hand searched the following journals: Circulation (1997 to 2002), Heart (1997 to 2002), European Heart Journal (1997-2002), Journal of the American College of Cardiology (1997-2002) and selected abstracts published on the web site of the North American Society of Pacing and Electrophysiology (2001, 2002).

SELECTION CRITERIA

Randomised controlled trials or controlled clinical trials of pharmacological cardioversion versus rate control in adults (>18 years) with acute, paroxysmal or sustained atrial fibrillation or atrial flutter, of any duration and of any aetiology.

DATA COLLECTION AND ANALYSIS

One reviewer applied the inclusion criteria and extracted the data. Trial quality was assessed and the data were entered into RevMan.

MAIN RESULTS

We identified two completed studies AFFIRM (n=4060) and PIAF (n=252). We found no difference in mortality between rhythm control and rate control relative risk 1.14 (95% confidence interval 1.00 to 1.31). Both studies show significantly higher rates of hospitalisation and adverse events in the rhythm control group and no difference in quality of life between the two treatment groups. In AFFIRM there was a similar incidence of ischaemic stroke, bleeding and systemic embolism in the two groups. Certain malignant dysrhythmias were significantly more likely to occur in the rhythm control group. There were similar scores of cognitive assessment. In PIAF, cardioverted patients enjoyed an improved exercise tolerance but there was no overall benefit in terms of symptom control or quality of life.

AUTHORS' CONCLUSIONS

There is no evidence that pharmacological cardioversion of atrial fibrillation to sinus rhythm is superior to rate control. Rhythm control is associated with more adverse effects and increased hospitalisation. It does not reduce the risk of stroke. The conclusions cannot be generalised to all people with atrial fibrillation. Most of the patients included in these studies were relatively older (>60 years) with significant cardiovascular risk factors.

[The efficacy of scheduled cardioversion in atrial fibrillation. Comparison of two schemes of treatment: electrical versus pharmacological cardioversion]

INTRODUCTION AND OBJECTIVES

Atrial fibrillation is an arrhythmia with high morbidity and mortality. Restoring sinus rhythm is one of the principle objectives in its management. The present study aimed to assess the efficacy of scheduled cardioversion on atrial fibrillation by comparing two different therapeutic approaches: electrical vs. pharmacological cardioversion.

PATIENTS AND METHOD

Two hundred thirty patients with atrial fibrillation of more than 48 hours duration and requiring sinus rhythm restoration were included. One hundred forty-four patients underwent external electrical cardioversion and 86 patients received quinidine. We analyzed the rate of success, duration of hospital stay, complications and clinical and echocardiographic variable that might predict success.

RESULTS

Sinus rhythm was restored in 181 of 230 patients (79%). The rate of success was 77% (111/144 patients) in the electrical group and 81% (70 of 86 patients) in the pharmacological group (ns). In 13 pharmacological group patients for whom the first attempt failed attempt, a second attempt with electrical cardioversion was made and was successful in 8 patients (61%). No embolic complication was recorded and only two electrical disturbances were seen. Only atrial fibrillation lasting less than 8 weeks was associated with a higher success rate (p < 0.01).

CONCLUSIONS

Scheduled cardioversion in atrial fibrillation is an effective technique with a high success rate and a very low rate of complication. Electrical cardioversion and pharmacological cardioversion with quinidine are similarly effective, although the latter involves a longer hospital stay.

Electrical cardioversion for atrial fibrillation and flutter

BACKGROUND

Atrial fibrillation increases the risk of stroke, increases the risk of cognitive impairment, and adversely affects cardiovascular haemodynamics. Electrical cardioversion for atrial fibrillation has been in use since the 1960s; the rationale is that restoration of sinus rhythm improves cardiovascular haemodynamics, reduces the risk of stroke, and obviates the need for long-term anticoagulation.

OBJECTIVES

To assess the effects of electrical cardioversion of atrial fibrillation or atrial flutter on the annual risk of thromboembolic events, strokes and mortality (primary outcomes measures), the rate of cognitive decline, quality of life, the use of anticoagulants and the risk of re-hospitalisation (secondary outcome measures) in adults (>18 years) with acute, paroxysmal or sustained atrial fibrillation or atrial flutter, of any duration and any aetiology.

SEARCH STRATEGY

One reviewer searched the Cochrane Controlled Clinical Trials Register (2000 Issue 4), MEDLINE (1966 to December 2000), EMBASE (1980 to December 2000), CINAHL (1982 to November 2000) and proceedings of the American College of Cardiology (published in the Journal of the American College of Cardiology 1983 to 2000). Reference lists of articles were searched. Personal contact was made with experts in the field. A second reviewer handsearched proceedings of the British Cardiac Society (published in British Heart Journal (1980 to 1995) and in Heart (1995 to May 2001); proceedings of the European Congress of Cardiology and meetings of the Joint Working Groups of the European Society of Cardiology (published in European Heart Journal 1983-2000); scientific sessions of the American Heart Association (published in Circulation 1990-2000).

SELECTION CRITERIA

Randomised controlled trial or controlled clinical trials of electrical cardioversion plus 'usual care' versus 'usual care' only, where 'usual care' included any combination of the following: anticoagulants, antiplatelet drugs and drugs for 'rate control', in adults (>18 years) with acute, paroxysmal or sustained atrial fibrillation or atrial flutter, of any duration and any aetiology.

DATA COLLECTION AND ANALYSIS

It was planned to extract study data onto data extraction forms. The planned analysis was by the statistical package in RevMan.

MAIN RESULTS

No completed randomised trials or controlled clinical trials of electrical cardioversion were found. Two ongoing trials were identified.

REVIEWER'S CONCLUSIONS

There were no data from completed randomised controlled trials or controlled clinical trials to either support or refute the use of electrical cardioversion for atrial fibrillation. Randomised trials of electrical cardioversion are required.

Management of patients with syncope and cardiac arrhythmias in an emergency department observation unit

Syncope is an ideal condition for the emergency observation setting because of its difficulty in diagnosis, many causes, high liability, and variable diagnostic approaches. Hospital admissions can be averted with appropriate patient selection for a short-term observation period. Atrial fibrillation is a common presenting condition in the emergency department. With aggressive management, the appropriately selected patient can have restoration of sinus rhythm and be safely discharged home.

Coagulation indicators in patients with paroxysmal atrial fibrillation: effects of electric and pharmacologic cardioversion

The aim of this study was to determine whether paroxysmal atrial fibrillation (PAF) and/or restoration to sinus rhythm with electric or pharmacologic cardioversion induce modifications to the coagulation system. Thirty-five patients with PAF undergoing either electric (n = 11) or pharmacologic (n = 24) cardioversion were studied. Fibrinopeptide A and D-dimer blood samples were taken immediately before and after cardioversion at different intervals. When compared with the control group (n = 70), the precardioversion fibrinopeptide A plasma values were significantly elevated (11.8 vs 2.5 ng/mL). Fibrinopeptide A plasma values were significantly reduced 5 minutes after cardioversion (11.8 vs 5.3 ng/mL) and remained stable throughout the follow-up sequential measurements. D-dimer plasma values were significantly increased (measured at 12 hours and at day 7) in patients who underwent electrical cardioversions only. A positive correlation (R(2) = 0.76) was found between the energy delivered for cardioversion to sinus rhythm and D-dimer plasma values on day 7. In patients with PAF, levels of fibrinopeptide A, an indicator of coagulation activation, are elevated and soon reduced by the restoration of sinus rhythm. Electric, but not pharmacologic, cardioversion induces an early activation of the fibrinolytic system.

Severe nodal arrhythmia following direct current cardioversion for atrial flutter

A case of long-lasting nodal arrhythmia and severe hypotension following DC cardioversion for atrial flutter is presented. The patient, treated with the selective serotonin reuptake inhibitor sertraline and with sotalol, thiopental and digoxin, showed no sign of organic disease or drug intoxication. We suggest that drug interaction in combination with the DC shock and an altered sympaticus/parasympaticus balance during anaesthesia provoked the incident.

Atrial fibrillation and its relationship to dental care

BACKGROUND

The number of Americans diagnosed with and treated for atrial fibrillation, or AF, continues to rise.

TYPES OF STUDIES REVIEWED

To determine how AF may affect the provision of dental care, the author conducted a literature search, using terms such as "atrial fibrillation" and "dental care." He found a lack of information on these combined topics. Therefore, the author extrapolated information from scientific peer-reviewed articles on AF, medical and surgical management of AF, and dental care to determine appropriate guidelines for dental treatment of patients with AF.

RESULTS

The author found that complications can arise from AF and that medical management of AF can affect the delivery of dental care. Dentists should determine the underlying cause of AF to decide if antibiotic prophylaxis is indicated. Patients who are receiving anticoagulation therapy may not need to alter their therapy schedules for minor oral surgery procedures. Anxiety as a result of AF may require use of anxiety-reducing protocols before dental treatment.

CLINICAL IMPLICATIONS

To reduce potential complications associated with dental care, dental practitioners should be familiar with AF and its treatment. Dental management of patients with AF may require treatment modifications, but generally will not deviate significantly from routine standards.

Direct current cardioversion does not cause cardiac damage: evidence from cardiac troponin T estimation

AIM

To determine whether elective direct current (dc) cardioversion of atrial fibrillation/flutter causes myocardial damage.

METHODS AND RESULTS

Cardiac troponin T and creatine kinase were estimated 20-28 hours after dc cardioversion in 51 patients who received dc shocks for elective cardioversion of chronic atrial fibrillation/flutter. Although creatine kinase was raised in 44 patients, cardiac troponin T was undetectable in all patients.

CONCLUSION

Cardiac damage does not occur as a result of cardioversion.

Ibutilide. A review of its pharmacological properties and clinical potential in the acute management of atrial flutter and fibrillation

Ibutilide is the first 'pure' class III antiarrhythmic drug to become available. Its predominant action is prolongation of the myocardial action potential duration. This appears to be achieved by a unique ionic mechanism of action that involves activation of a late inward sodium current and possibly blockade of the rapidly activating component of the cardiac delayed rectifier potassium current. Intravenous ibutilide 0.01 to 0.025 mg/kg or 1 to 2 mg successfully converted atrial flutter or fibrillation to sinus rhythm in 33 to 49% of patients in 2 placebo-controlled trials involving 439 patients with sustained arrhythmia. In a third trial in 300 patients who developed atrial flutter or fibrillation after cardiac surgery, ibutilide 2 mg successfully converted the arrhythmia in 57% of patients. The mean times to conversion were < or = 30 minutes in these trials. In 3 comparative trials, ibutilide was significantly more effective than racemic sotalol or procainamide in terminating atrial flutter or fibrillation. The pretreatment duration of the arrhythmia is an important predictor of the success of ibutilide treatment; the greatest conversion rates are achieved when the arrhythmia is of recent onset (i.e. < or = 30 days' duration). Ibutilide is more effective in terminating atrial flutter than atrial fibrillation. Adverse events associated with ibutilide are predominantly cardiovascular. Sustained polymorphic ventricular tachycardia developed in 1.7%, and non-sustained polymorphic ventricular tachycardia in 2.7%, of 586 patients treated with ibutilide in clinical trials. However, no proarrhythmia-related deaths have been reported with the use of ibutilide. The drug has minimal haemodynamic effects and is associated with few noncardiovascular adverse events. Thus, ibutilide is a useful agent for the pharmacological cardioversion of recent-onset atrial fibrillation or flutter, provided that adequate steps are taken to monitor for proarrhythmic events. The drug causes few noncardiovascular adverse events and has minimal haemodynamic effects. Furthermore, it appears to be more effective than procainamide (especially in patients with atrial flutter) and racemic sotalol.

A survey of atrial fibrillation in general practice: the West Birmingham Atrial Fibrillation Project

BACKGROUND

The management of atrial fibrillation (AF) has changed substantially in recent years, especially with a greater appreciation of the prophylactic role of antithrombotic therapy against stroke. There is therefore a need for further information on the prevalence of AF in Britain, the prevalence of (and contraindications to) anticoagulant treatment, and the factors that influence doctors' decisions in treating AF, including the investigation of patients with this arrhythmia.

AIM

To investigate the prevalence, clinical features and management of patients with AF in a general practice setting.

METHOD

Cross-sectional survey of patients using treatment prescriptions and clinical records in two general practices from the west of Birmingham (serving a patient population of 16,519) where 4522 subjects (27.4%) were aged > or = 50 years.

RESULTS

One hundred and eleven (2.4%) patients who were aged > or = 50 years were found to be in AF (42 males; mean age 76.6, SD 9.1); 77.5% were Caucasian, 2.7% Afro-Caribbean, 0.9% Asian, and 0.9% mixed race; in 20 cases there was no information on ethnicity. Of the AF patients, 5.4% were aged 50-60 years, 16.2% aged 61-70 years, 20.7% aged 71-75 years, 20.7% aged 76-80 years, 24.3% aged 81-85 years, and 12.6% aged > 85 years old, with female patients being significantly older than males. Eighty-one patients (73%) had chronic AF, while 30 patients (27%) had paroxysmal AF. The most common associated factors were hypertension (36.9%) and ischaemic heart disease (28.8%), with no obvious cause for AF in six patients. Cardiac failure was associated with AF in 34 patients (30.6%), and stroke had occurred in 29 patients (18%). Only 20 patients (18%) had had an echocardiogram, 26 (23.4%) a chest X-ray, and 58 (52.3%) thyroid function test. Only 30.6% had ever presented to hospital practice. Warfarin was prescribed to 40 patients (36%), with anticoagulation intensity monitoring by the general practitioner (GP) in three cases (7.5%), by a hospital clinic in 30 (75%), and by both GP and hospital in seven cases (17.5%). Of those not anticoagulated (n = 71), only 12 patients (16.9%) had contraindications to warfarin therapy. Patients treated with warfarin were younger than those who were not prescribed warfarin (71.3 versus 79.6 years, P < 0.001). Aspirin was being prescribed for 21 patients (18.9%), primarily for previous myocardial infarction. Only five patients (4.5%) had ever had attempted cardioversion.

CONCLUSION

Atrial fibrillation is a common arrhythmia in general practice, and is commonly associated with hypertension, ischaemic heart disease and heart failure. There is a suboptimal application of standard investigations and use of antithrombotic therapy or attempted cardioversion; and few patients have presented to hospital practice. Guidelines on the management of this common arrhythmia in general practice are required.

Plasma fibrinogen and fibrin D-dimer in patients with atrial fibrillation: effects of cardioversion to sinus rhythm

Cardioversion of atrial fibrillation carries a serious risk of major thromboembolism and stroke. To determine whether or not the procedure alters plasma levels of fibrin D-dimer (a marker of intravascular fibrin turnover and thrombus formation) and plasma fibrinogen (associated with stroke and thromboembolism), we performed a prospective study in 19 patients with atrial fibrillation in whom cardioversion was attempted: seven patients without prior oral anticoagulant therapy (but with intravenous heparin for 24 h) (Group I), and 12 patients with full oral anticoagulation pre- and post-cardioversion (Group II). Plasma fibrinogen and fibrin D-dimer were measured pre-cardioversion, and at Days 3, 7 and 14 post-cardioversion. In Group I, there was a significant reduction in median plasma fibrin D-dimer levels by 14 days following cardioversion (200 vs. 52 ng/ml; paired Wilcoxon test, P = 0.02). In Group II, there was no change in median plasma fibrin D-dimer levels over the 14 days following cardioversion. There were no significant changes in plasma fibrinogen with cardioversion in either group of patients. The reduction of plasma fibrin D-dimer in Group I suggests a beneficial reduction of intravascular fibrin turnover and thrombogenesis by the cardioversion of patients with atrial fibrillation to sinus rhythm. Furthermore, it strongly suggests that it is atrial fibrillation itself which is the major risk of thromboembolism and that the risk continues for up to 14 days post-cardioversion. In Group II, the low pre-cardioversion fibrin D-dimer levels and lack of change with cardioversion is consistent with the prophylactic effect of warfarin therapy against thromboembolism during the cardioversion of atrial fibrillation.