atrial fibrillation

What Is Atrial Fibrillation?

Author/s: 
Rebecca Voelker

Atrial fibrillation is an abnormal heart rhythm that can cause stroke, heart failure, heart attack, chronic kidney disease, dementia, and death.

Atrial fibrillation is classified as paroxysmal (intermittent episodes lasting 7 days or less), persistent (lasting more than 7 days), long-standing persistent (lasting more than 1 year), or permanent.1

In the US, atrial fibrillation affects about 10.55 million people and is more common among men than women. Other risk factors include older age, smoking, high blood pressure, diabetes, heart disease, high alcohol consumption, sleep apnea, an overactive thyroid gland, and possibly genetic factors.

Atrial Fibrillation: A Review

Author/s: 
Darae Ko, Mina K Chung, Peter T Evans, Emelia J Benjamin, Robert H Helm

Importance: In the US, approximately 10.55 million adults have atrial fibrillation (AF). AF is associated with significantly increased risk of stroke, heart failure, myocardial infarction, dementia, chronic kidney disease, and mortality.

Observations: Symptoms of AF include palpitations, dyspnea, chest pain, presyncope, exertional intolerance, and fatigue, although approximately 10% to 40% of people with AF are asymptomatic. AF can be detected incidentally during clinical encounters, with wearable devices, or through interrogation of cardiac implanted electronic devices. In patients presenting with ischemic stroke without diagnosed AF, an implantable loop recorder (ie, subcutaneous telemetry device) can evaluate patients for intermittent AF. The 2023 American College of Cardiology (ACC)/American Heart Association (AHA)/American College of Clinical Pharmacy (ACCP)/Heart Rhythm Society (HRS) Guideline writing group proposed 4 stages of AF evolution: stage 1, at risk, defined as patients with AF-associated risk factors (eg, obesity, hypertension); stage 2, pre-AF, signs of atrial pathology on electrocardiogram or imaging without AF; stage 3, the presence of paroxysmal (recurrent AF episodes lasting ≤7 days) or persistent (continuous AF episode lasting >7 days) AF subtypes; and stage 4, permanent AF. Lifestyle and risk factor modification, including weight loss and exercise, to prevent AF onset, recurrence, and complications are recommended for all stages. In patients with estimated risk of stroke and thromboembolic events of 2% or greater per year, anticoagulation with a vitamin K antagonist or direct oral anticoagulant reduces stroke risk by 60% to 80% compared with placebo. In most patients, a direct oral anticoagulant, such as apixaban, rivaroxaban, or edoxaban, is recommended over warfarin because of lower bleeding risks. Compared with anticoagulation, aspirin is associated with poorer efficacy and is not recommended for stroke prevention. Early rhythm control with antiarrhythmic drugs or catheter ablation to restore and maintain sinus rhythm is recommended by the 2023 ACC/AHA/ACCP/HRS Guideline for some patients with AF. Catheter ablation is first-line therapy in patients with symptomatic paroxysmal AF to improve symptoms and slow progression to persistent AF. Catheter ablation is also recommended for patients with AF who have heart failure with reduced ejection fraction (HFrEF) to improve quality of life, left ventricular systolic function, and cardiovascular outcomes, such as rates of mortality and heart failure hospitalization.

Conclusions and relevance: AF is associated with increased rates of stroke, heart failure, and mortality. Lifestyle and risk factor modification are recommended to prevent AF onset, recurrence, and complications, and oral anticoagulants are recommended for those with an estimated risk of stroke or thromboembolic events of 2% or greater per year. Early rhythm control using antiarrhythmic drugs or catheter ablation is recommended in select patients with AF experiencing symptomatic paroxysmal AF or HFrEF.

Management of Atrial Fibrillation

Author/s: 
Francis J Alenghat, Jason T Alexander, Gaurav A Upadhyay

Atrial fibrillation has a lifetime prevalence of 15% to 40% and predisposes patients to stroke and cardiac dysfunction. This JAMA Clinical Guidelines Synopsis focuses on recommendations for long-term management of AF, including new paradigms for rhythm control and stroke risk reduction.

Perioperative Management of Patients Taking Direct Oral Anticoagulants

Author/s: 
James D Douketis, Alex C Spyropoulos

Importance: Direct oral anticoagulants (DOACs), comprising apixaban, rivaroxaban, edoxaban, and dabigatran, are commonly used medications to treat patients with atrial fibrillation and venous thromboembolism. Decisions about how to manage DOACs in patients undergoing a surgical or nonsurgical procedure are important to decrease the risks of bleeding and thromboembolism.

Observations: For elective surgical or nonsurgical procedures, a standardized approach to perioperative DOAC management involves classifying the risk of procedure-related bleeding as minimal (eg, minor dental or skin procedures), low to moderate (eg, cholecystectomy, inguinal hernia repair), or high risk (eg, major cancer or joint replacement procedures). For patients undergoing minimal bleeding risk procedures, DOACs may be continued, or if there is concern about excessive bleeding, DOACs may be discontinued on the day of the procedure. Patients undergoing a low to moderate bleeding risk procedure should typically discontinue DOACs 1 day before the operation and restart DOACs 1 day after. Patients undergoing a high bleeding risk procedure should stop DOACs 2 days prior to the operation and restart DOACs 2 days after. With this perioperative DOAC management strategy, rates of thromboembolism (0.2%-0.4%) and major bleeding (1%-2%) are low and delays or cancellations of surgical and nonsurgical procedures are infrequent. Patients taking DOACs who need emergent (<6 hours after presentation) or urgent surgical procedures (6-24 hours after presentation) experience bleeding rates up to 23% and thromboembolism as high as 11%. Laboratory testing to measure preoperative DOAC levels may be useful to determine whether patients should receive a DOAC reversal agent (eg, prothrombin complex concentrates, idarucizumab, or andexanet-α) prior to an emergent or urgent procedure.

Conclusions and relevance: When patients who are taking a DOAC require an elective surgical or nonsurgical procedure, standardized management protocols can be applied that do not require testing DOAC levels or heparin bridging. When patients taking a DOAC require an emergent, urgent, or semiurgent surgical procedure, anticoagulant reversal agents may be appropriate when DOAC levels are elevated or not available.

Progression of Atrial Fibrillation after Cryoablation or Drug Therapy

Author/s: 
Andrade, J.G., Deyell, M. W., Macle, L., Wells, G. A., Bennett, M., Essebag, V., Champagne, J., Roux, J., Yung, D., Skanes, A., Khaykin, Y., Morillo, C., Jolly, U., Novak, P., Lockwood, E., Cadrin-Tourigny, J., Kochhäuser, S., Verma, A.

Background: Atrial fibrillation is a chronic, progressive disorder, and persistent forms of atrial fibrillation are associated with increased risks of thromboembolism and heart failure. Catheter ablation as initial therapy may modify the pathogenic mechanism of atrial fibrillation and alter progression to persistent atrial fibrillation.

Methods: We report the 3-year follow-up of patients with paroxysmal, untreated atrial fibrillation who were enrolled in a trial in which they had been randomly assigned to undergo initial rhythm-control therapy with cryoballoon ablation or to receive antiarrhythmic drug therapy. All the patients had implantable loop recorders placed at the time of trial entry, and evaluation was conducted by means of downloaded daily recordings and in-person visits every 6 months. Data regarding the first episode of persistent atrial fibrillation (lasting ≥7 days or lasting 48 hours to 7 days but requiring cardioversion for termination), recurrent atrial tachyarrhythmia (defined as atrial fibrillation, flutter, or tachycardia lasting ≥30 seconds), the burden of atrial fibrillation (percentage of time in atrial fibrillation), quality-of-life metrics, health care utilization, and safety were collected.

Results: A total of 303 patients were enrolled, with 154 patients assigned to undergo initial rhythm-control therapy with cryoballoon ablation and 149 assigned to receive antiarrhythmic drug therapy. Over 36 months of follow-up, 3 patients (1.9%) in the ablation group had an episode of persistent atrial fibrillation, as compared with 11 patients (7.4%) in the antiarrhythmic drug group (hazard ratio, 0.25; 95% confidence interval [CI], 0.09 to 0.70). Recurrent atrial tachyarrhythmia occurred in 87 patients in the ablation group (56.5%) and in 115 in the antiarrhythmic drug group (77.2%) (hazard ratio, 0.51; 95% CI, 0.38 to 0.67). The median percentage of time in atrial fibrillation was 0.00% (interquartile range, 0.00 to 0.12) in the ablation group and 0.24% (interquartile range, 0.01 to 0.94) in the antiarrhythmic drug group. At 3 years, 8 patients (5.2%) in the ablation group and 25 (16.8%) in the antiarrhythmic drug group had been hospitalized (relative risk, 0.31; 95% CI, 0.14 to 0.66). Serious adverse events occurred in 7 patients (4.5%) in the ablation group and in 15 (10.1%) in the antiarrhythmic drug group.

Conclusions: Initial treatment of paroxysmal atrial fibrillation with catheter cryoballoon ablation was associated with a lower incidence of persistent atrial fibrillation or recurrent atrial tachyarrhythmia over 3 years of follow-up than initial use of antiarrhythmic drugs. (Funded by the Cardiac Arrhythmia Network of Canada and others; EARLY-AF ClinicalTrials.gov number, NCT02825979.).

Adverse Events Associated With the Addition of Aspirin to Direct Oral Anticoagulant Therapy Without a Clear Indication

Author/s: 
Schaefer, J. K., Errickson, J., Li, Y., Kong, X., Alexandris-Souphis, T., Ali, M. A., Decamillo, D., Haymart, B., Kaatz, S., Kline-Rogers, E., Kozlowski, J. H., Krol, G. D., Shankar, S, R., Sood, S. L., Froehlich, J. B., Barnes, G. D.

Importance: It is unclear how many patients treated with a direct oral anticoagulant (DOAC) are using concomitant acetylsalicylic acid (ASA, or aspirin) and how this affects clinical outcomes.

Objective: To evaluate the frequency and outcomes of prescription of concomitant ASA and DOAC therapy for patients with atrial fibrillation (AF) or venous thromboembolic disease (VTE).

Design, setting, and participants: This registry-based cohort study took place at 4 anticoagulation clinics in Michigan from January 2015 to December 2019. Eligible participants were adults undergoing treatment with a DOAC for AF or VTE, without a recent myocardial infarction (MI) or history of heart valve replacement, with at least 3 months of follow-up.

Exposures: Use of ASA concomitant with DOAC therapy.

Main outcomes and measures: Rates of bleeding (any, nonmajor, major), rates of thrombosis (stroke, VTE, MI), emergency department visits, hospitalizations, and death.

Results: Of the study cohort of 3280 patients (1673 [51.0%] men; mean [SD] age 68.2 [13.3] years), 1107 (33.8%) patients without a clear indication for ASA were being treated with DOACs and ASA. Two propensity score-matched cohorts, each with 1047 patients, were analyzed (DOAC plus ASA and DOAC only). Patients were followed up for a mean (SD) of 20.9 (19.0) months. Patients taking DOAC and ASA experienced more bleeding events compared with DOAC monotherapy (26.0 bleeds vs 31.6 bleeds per 100 patient years, P = .01). Specifically, patients undergoing combination therapy had significantly higher rates of nonmajor bleeding (26.1 bleeds vs 21.7 bleeds per 100 patient years, P = .02) compared with DOAC monotherapy. Major bleeding rates were similar between the 2 cohorts. Thrombotic event rates were also similar between the cohorts (2.5 events vs 2.3 events per 100 patient years for patients treated with DOAC and ASA compared with DOAC monotherapy, P = .80). Patients were more often hospitalized while undergoing combination therapy (9.1 vs 6.5 admissions per 100 patient years, P = .02).

Conclusion and relevance: Nearly one-third of patients with AF and/or VTE who were treated with a DOAC received ASA without a clear indication. Compared with DOAC monotherapy, concurrent DOAC and ASA use was associated with increased bleeding and hospitalizations but similar observed thrombosis rate. Future research should identify and deprescribe ASA for patients when the risk exceeds the anticipated benefit.

Outcomes Associated With Oral Anticoagulants Plus Antiplatelets in Patients With Newly Diagnosed Atrial Fibrillation

Author/s: 
Fox, KAA, Velentgas, P, Camm, AJ, Bassand, JP, Fitzmaurice, DA, Gersh, BJ, Goldhaber, SZ, Goto, S, Haas, S, Misselwitz, F, Pieper, KS, Turpie, AGG, Verhegut, FWA, Dabrowski, E, Luo, K, Gibbs, L, Kakkar, AK, GARFIELD-AF Investigators

IMPORTANCE:

Patients with nonvalvular atrial fibrillation at risk of stroke should receive oral anticoagulants (OAC). However, approximately 1 in 8 patients in the Global Anticoagulant Registry in the Field (GARFIELD-AF) registry are treated with antiplatelet (AP) drugs in addition to OAC, with or without documented vascular disease or other indications for AP therapy.

OBJECTIVE:

To investigate baseline characteristics and outcomes of patients who were prescribed OAC plus AP therapy vs OAC alone.

DESIGN, SETTING, AND PARTICIPANTS:

Prospective cohort study of the GARFIELD-AF registry, an international, multicenter, observational study of adults aged 18 years and older with recently diagnosed nonvalvular atrial fibrillation and at least 1 risk factor for stroke enrolled between March 2010 and August 2016. Data were extracted for analysis in October 2017 and analyzed from April 2018 to June 2019.

EXPOSURE:

Participants received either OAC plus AP or OAC alone.

MAIN OUTCOMES AND MEASURES:

Clinical outcomes were measured over 3 and 12 months. Outcomes were adjusted for 40 covariates, including baseline conditions and medications.

RESULTS:

A total of 24 436 patients (13 438 [55.0%] male; median [interquartile range] age, 71 [64-78] years) were analyzed. Among eligible patients, those receiving OAC plus AP therapy had a greater prevalence of cardiovascular indications for AP, including acute coronary syndromes (22.0% vs 4.3%), coronary artery disease (39.1% vs 9.8%), and carotid occlusive disease (4.8% vs 2.0%). Over 1 year, patients treated with OAC plus AP had significantly higher incidence rates of stroke (adjusted hazard ratio [aHR], 1.49; 95% CI, 1.01-2.20) and any bleeding event (aHR, 1.41; 95% CI, 1.17-1.70) than those treated with OAC alone. These patients did not show evidence of reduced all-cause mortality (aHR, 1.22; 95% CI, 0.98-1.51). Risk of acute coronary syndrome was not reduced in patients taking OAC plus AP compared with OAC alone (aHR, 1.16; 95% CI, 0.70-1.94). Patients treated with OAC plus AP also had higher rates of all clinical outcomes than those treated with OAC alone over the short term (3 months).

CONCLUSIONS AND RELEVANCE:

This study challenges the practice of coprescribing OAC plus AP unless there is a clear indication for adding AP to OAC therapy in newly diagnosed atrial fibrillation.

Alcohol Abstinence in Drinkers with Atrial Fibrillation

Author/s: 
Voskoboinik, A., Kalman, J.M., De Silva, A., Nicholls, T., Costello, B., Nanayakkara, S., Prabhu, S., Stub, D., Azzopardi, S., Vizi, D., Wong, G., Nalliah, C., Sugumar, H., Wong, M., Kotschet, E., Kaye D., Taylor, A.J., Kistler, P.M.

BACKGROUND:

Excessive alcohol consumption is associated with incident atrial fibrillation and adverse atrial remodeling; however, the effect of abstinence from alcohol on secondary prevention of atrial fibrillation is unclear.

METHODS:

We conducted a multicenter, prospective, open-label, randomized, controlled trial at six hospitals in Australia. Adults who consumed 10 or more standard drinks (with 1 standard drink containing approximately 12 g of pure alcohol) per week and who had paroxysmal or persistent atrial fibrillation in sinus rhythm at baseline were randomly assigned in a 1:1 ratio to either abstain from alcohol or continue their usual alcohol consumption. The two primary end points were freedom from recurrence of atrial fibrillation (after a 2-week "blanking period") and total atrial fibrillation burden (proportion of time in atrial fibrillation) during 6 months of follow-up.

RESULTS:

Of 140 patients who underwent randomization (85% men; mean [±SD] age, 62±9 years), 70 were assigned to the abstinence group and 70 to the control group. Patients in the abstinence group reduced their alcohol intake from 16.8±7.7 to 2.1±3.7 standard drinks per week (a reduction of 87.5%), and patients in the control group reduced their alcohol intake from 16.4±6.9 to 13.2±6.5 drinks per week (a reduction of 19.5%). After a 2-week blanking period, atrial fibrillation recurred in 37 of 70 patients (53%) in the abstinence group and in 51 of 70 patients (73%) in the control group. The abstinence group had a longer period before recurrence of atrial fibrillation than the control group (hazard ratio, 0.55; 95% confidence interval, 0.36 to 0.84; P = 0.005). The atrial fibrillation burden over 6 months of follow-up was significantly lower in the abstinence group than in the control group (median percentage of time in atrial fibrillation, 0.5% [interquartile range, 0.0 to 3.0] vs. 1.2% [interquartile range, 0.0 to 10.3]; P = 0.01).

CONCLUSIONS:

Abstinence from alcohol reduced arrhythmia recurrences in regular drinkers with atrial fibrillation. (Funded by the Government of Victoria Operational Infrastructure Support Program and others; Australian New Zealand Clinical Trials Registry number, ACTRN12616000256471.).

Keywords 

Meta-Analysis of Oral Anticoagulant Monotherapy as an Antithrombotic Strategy in Patients With Stable Coronary Artery Disease and Nonvalvular Atrial Fibrillation

Author/s: 
Lee, SR, Rhee, TM, Kang, DY, Choi, EK, Oh, S, Lip, GYH

Guidelines recommend oral anticoagulant (OAC) monotherapy without antiplatelet therapy (APT) in patients with nonvalvular atrial fibrillation (AF) with stable coronary artery disease (CAD) of >1 year after myocardial infarction or percutaneous coronary intervention. More evidences are required for the safety and efficacy of OAC monotherapy compared with OAC plus APT. PubMed, EMBASE, and Cochrane Database of Systematic Reviews were systematically searched up to February 2019. Nonrandomized studies and randomized clinical trials comparing OAC monotherapy with OAC plus single APT (SAPT) for patients with stable CAD and nonvalvular AF. The primary end point was major adverse cardiovascular events (composite of ischemic or thrombotic events) and secondary outcomes included major bleeding, stroke, all-cause death, and net adverse events (composite of ischemic, thrombotic, or bleeding events). From 6 trials, 8,855 patients were included. There was no significant difference in major adverse cardiovascular event in patients with AF treated using OAC plus SAPT compared with those treated with OAC monotherapy (hazard ratio [HR] 1.09; 95% confidence interval [CI] 0.92 to 1.29). OAC plus SAPT was associated with a significantly higher risk of major bleeding compared with OAC monotherapy (HR 1.61; 95% CI 1.38 to 1.87), as well as in terms of net adverse event (HR 1.21; 95% CI 1.02 to 1.43). There were no significant differences in rates of stroke and all-cause death. In conclusion, in this meta-analysis, OAC monotherapy and OAC plus SAPT treatment showed similar effectiveness, but OAC monotherapy was significantly associated with a lower risk of bleeding compared with OAC plus SAPT in patients with nonvalvular AF and stable CAD.

Left Atrial Appendages Occlusion: Current Status and Prospective

Author/s: 
Sharma, S.P., Park, P., Lakkireddy, D.

Stroke continues to be a major cause of morbidity and mortality in atrial fibrillation (AF) patients. Oral anticoagulation (OAC) provides protection against stroke and peripheral embolization in AF but significant proportion of patients could not be started on anticoagulation because of bleeding complications. Left atrial appendage harbors clot in about 90% of nonvalvular AF. The advent of left atrial appendage occlusion (LAAO) techniques has provided these patients with alternative to OAC for stroke prophylaxis. Multiple LAAO devices are currently available with Watchman and Amulet being the most commonly used in clinical practice. Randomized studies are available for Watchman device only. Data on Amplatzer Cardiac Plug, Amulet and Lariat devices are limited by the paucity of randomized data. Long-term data on different LAAO techniques are showing promising results. Device related thrombosis continues to be a serious complication associated with LAAO. Future studies should look into comparative effectiveness between different LAAO techniques, optimal patient selection, risk of complications, and anticoagulant treatment after LAAO. This article aims to provide current available evidence on efficacy and safety of different LAAO devices and future prospective.

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