2011 ACCF/AHA/HRS Focused Update on the Management of Patients With Atrial Fibrillation (Updating the 2006 Guideline)

In-hospital complications associated with catheter ablation of atrial fibrillation in the United States between 2000 and 2010: analysis of 93 801 procedures

BACKGROUND

Atrial fibrillation ablation has made tremendous progress with respect to innovation, efficacy, and safety. However, limited data exist regarding the burden and trends in adverse outcomes arising from this procedure. The aim of our study was to examine the frequency of adverse events attributable to atrial fibrillation (AF) ablation and the influence of operator and hospital volume on outcomes.

METHODS AND RESULTS

With the use of the Nationwide Inpatient Sample, we identified AF patients treated with catheter ablation. We investigated common complications including cardiac perforation and tamponade, pneumothorax, stroke, transient ischemic attack, vascular access complications (hemorrhage/hematoma, vascular complications requiring surgical repair, and accidental arterial puncture), and in-hospital death described with AF ablation, and we defined these complications by using validated International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis codes. An estimated 93,801 AF ablations were performed from 2000 to 2010. The overall frequency of complications was 6.29% with combined cardiac complications (2.54%) being the most frequent. Cardiac complications were followed by vascular complications (1.53%), respiratory complications (1.3%), and neurological complications (1.02%). The in-hospital mortality was 0.46%. Annual operator (<25 procedures) and hospital volume (<50 procedures) were significantly associated with adverse outcomes. There was a small (nonsignificant) rise in overall complication rates.

CONCLUSIONS

The overall complication rate was 6.29% in patients undergoing AF ablation. There was a significant association between operator and hospital volume and adverse outcomes. This suggests a need for future research into identifying the safety measures in AF ablations and instituting appropriate interventions to improve overall AF ablation outcomes.

Current and new oral antithrombotics in non-valvular atrial fibrillation: a network meta-analysis of 79 808 patients

BACKGROUND

Antithrombotic therapy reduces stroke, embolism and mortality in patients with atrial fibrillation (AF); however, meta-analyses have focused on pairwise comparisons of treatments.

OBJECTIVE

To synthesise the evidence from trials using a multiple treatment comparison methods thereby permitting a broader comparison across multiple therapies.

DESIGN, SETTING, PATIENTS

Randomised controlled trials in patients with AF of antithrombotics were identified from MEDLINE, Embase, and Cochrane Central Register of Controlled Trials through May 2012. We performed a random-effects model within a Bayesian framework using Markov Chain Monte Carlo simulation to calculate pooled OR and 95% credibility intervals (CrI). We also ranked therapies by their likelihood of leading to the best results for the outcomes.

MAIN OUTCOME MEASURE

Multiple endpoints including stroke, embolism, death and bleeding.

RESULTS

We identified 20 studies with 79 808 patients allocated to 8 treatments: ASA, ASA plus clopidogrel, vitamin K antagonists (VKAs), dabigatran 110 mg, dabigatran 150 mg, rivaroxaban, apixaban or placebo/control. Compared with placebo/control, dabigatran 150 mg was associated with the lowest risk of stroke (OR=0.25, 0.15-0.43), the composite of ischaemic stroke or systemic embolism (OR=0.26, 0.12-0.54) and mortality (OR=0.53, 0.28-0.88). ASA plus clopidogrel was associated with the highest risk of major bleeding (OR=3.65, 1.22-13.56). In simulated comparisons, the novel oral anticoagulants ranked better than VKA or antiplatelet therapies for prevention of stroke, ischaemic stroke or systemic embolism and mortality.

CONCLUSIONS

In this network meta-analysis, novel oral anticoagulants were the most promising treatments to reduce stroke, stroke or systemic embolism, and all-cause mortality in patients with AF.

Supraventricular and ventricular arrhythmias

Cardiac arrhythmias comprise of a heterogeneous group of disorders which manifest in a wide range of clinical presentations. They can be associated with underlying cardiac disease and portend a grave prognosis, with some arrhythmias being rapidly fatal. Other arrhythmias, however are relatively benign and can be asymptomatic or may be a mere inconvenience for the patient. All primary care physicians can expect to encounter some forms of arrhythmias during the course of their practice. This review article provides a brief overview of the commonly seen tachyarrhythmias for the general practitioner and provides relevant updates on the recent developments in our understanding of their mechanisms and management.

Clinical strategies for selecting oral anticoagulants in patients with atrial fibrillation

Atrial fibrillation is a common arrhythmia. One of the important aspects of the management of atrial fibrillation is stroke prevention. Warfarin has been the longstanding anticoagulant used for stroke prevention in patients with atrial fibrillation. There are now three novel oral anticoagulants, which have been studied in randomized controlled trials and subsequently approved by the Federal Drug Administration for stroke prevention in patients with atrial fibrillation. Special patient populations, including renal insufficiency, elderly, prior stroke, and extreme body weights, were represented to varying degrees in the clinical trials of the novel oral anticoagulants. Furthermore, there is variation in the pharmacokinetics and pharmacodynamics of each anticoagulant, which affect the patient populations differently. Patients and clinicians are faced with the task of selecting among the available anticoagulants, and this review is designed to be a tool for clinical decision-making.

Weighted gene coexpression network analysis of human left atrial tissue identifies gene modules associated with atrial fibrillation

BACKGROUND

Genetic mechanisms of atrial fibrillation (AF) remain incompletely understood. Previous differential expression studies in AF were limited by small sample size and provided limited understanding of global gene networks, prompting the need for larger-scale, network-based analyses.

METHODS AND RESULTS

Left atrial tissues from Cleveland Clinic patients who underwent cardiac surgery were assayed using Illumina Human HT-12 mRNA microarrays. The data set included 3 groups based on cardiovascular comorbidities: mitral valve (MV) disease without coronary artery disease (n=64), coronary artery disease without MV disease (n=57), and lone AF (n=35). Weighted gene coexpression network analysis was performed in the MV group to detect modules of correlated genes. Module preservation was assessed in the other 2 groups. Module eigengenes were regressed on AF severity or atrial rhythm at surgery. Modules whose eigengenes correlated with either AF phenotype were analyzed for gene content. A total of 14 modules were detected in the MV group; all were preserved in the other 2 groups. One module (124 genes) was associated with AF severity and atrial rhythm across all groups. Its top hub gene, RCAN1, is implicated in calcineurin-dependent signaling and cardiac hypertrophy. Another module (679 genes) was associated with atrial rhythm in the MV and coronary artery disease groups. It was enriched with cell signaling genes and contained cardiovascular developmental genes including TBX5.

CONCLUSIONS

Our network-based approach found 2 modules strongly associated with AF. Further analysis of these modules may yield insight into AF pathogenesis by providing novel targets for functional studies.

Limited English proficient patients and time spent in therapeutic range in a warfarin anticoagulation clinic

Background

While anticoagulation clinics have been shown to deliver tailored, high‐quality care to patients receiving warfarin therapy, communication barriers with limited English proficient (LEP) patients may lead to disparities in anticoagulation outcomes.

Methods and Results

We analyzed data on 3770 patients receiving care from the Massachusetts General Hospital Anticoagulation Management Service (AMS) from 2009 to 2010. This included data on international normalized ratio (INR) tests and patient characteristics, including language and whether AMS used a surrogate for primary communication. We calculated percent time in therapeutic range (TTR for INR between 2.0 and 3.0) and time in danger range (TDR for INR <1.8 or >3.5) using the standard Rosendaal interpolation method. There were 241 LEP patients; LEP patients, compared with non‐LEP patients, had a higher number of comorbidities (3.2 versus 2.9 comorbidities, P=0.004), were more frequently uninsured (17.0% versus 4.3%, P<0.001), and less educated (47.7% versus 6.0% ≤high school education, P<0.001). LEP patients compared with non‐LEP patients spent less TTR (71.6% versus 74.0%, P=0.007) and more TDR (12.9% versus 11.3%, P=0.018). In adjusted analyses, LEP patients had lower TTR as compared with non‐LEP patients (OR 1.5, 95% CI [1.1, 2.2]). LEP patients who used a communication surrogate spent less TTR and more TDR.

Conclusion

Even within a large anticoagulation clinic with a high average TTR, a small but significant decrease in TTR was observed for LEP patients compared with English speakers. Future studies are warranted to explore how the use of professional interpreters impact TTR for LEP patients.

Electrophysiology Procedures

Invasive electrophysiologic procedures have evolved and increased in frequency significantly over the past 2 decades. The complexity and nature of the various procedures offered have also changed, and complex ablations for atrial fibrillation and ventricular tachycardia have become commonplace. These procedures often require the services of an anesthesiologist. An understanding of the specific nature and challenges of these procedures may be helpful in planning the optimal anesthetic and patient management. A paired review of these issues has been written from the standpoint of a practicing anesthesiologist. This review is written from the viewpoint of a cardiac electrophysiologist and will focus on the intra-procedural management of patients undergoing both cardiac implantable device implantation as well as catheter-based ablations, with a specific focus on the catheter ablation of atrial fibrillation. Ultimately, the proper management of these patients will facilitate successful procedural outcomes while maintaining a high degree of patient safety.

Benefit-risk assessment of dronedarone in the treatment of atrial fibrillation

Rhythm control in atrial fibrillation (AF) can be achieved using pharmacological therapy. Amiodarone is the most efficacious anti-arrhythmic agent; however, its use is limited due to an unfavourable safety profile, including pro-arrhythmia, thyroid, liver, skin and pulmonary complications. Dronedarone, which is structurally similar to amiodarone, was developed to try and achieve a favourable balance of efficacy and risk. Dronedarone has been evaluated in several large clinical trials, which have shown reduced mortality and hospitalization rates in patients with non-permanent AF. In patients with permanent AF and/or heart failure, dronedarone has been shown to cause increased mortality and morbidity and should not be used in these groups. Compared with amiodarone, dronedarone has fewer toxic effects (thyroid, skin, pulmonary) and, although less efficacious, may be used as first-line therapy for maintenance of sinus rhythm in patients with non-permanent AF. Clinicians must be vigilant in monitoring their patients to ensure they do not develop permanent AF or heart failure.

Anti-Arrhythmic Agents in the Treatment of Atrial Fibrillation

Although atrial fibrillation (AF) is the most common sustained arrhythmia seen during daily cardiovascular physician practice, its management remained a challenge for cardiology physician as there was no single anti-arrhythmic agents proved to be effective in converting atrial fibrillation and kept its effectiveness in maintaining sinus rhythm over long term. Moreover all the anti-arrhythmic agents that are used in treatment of AF were potentially pro-arrhythmic especially in patients with coronary artery disease and structurally abnormal heart. Some of these drugs also have serious non cardiac side effects that limit its long term use in the management of atrial fibrillation. Several new and investigational anti-arrhythmic agents are emerging but data supporting their effectiveness and safety are still limited. In this systematic review we examine the efficacy and safety of these medications supported by the major published randomized trials, meta-analyses and review articles and conclude with a summary of guidelines recommendations.

Chronic atrial fibrillation causes left ventricular dysfunction in dogs but not goats: experience with dogs, goats, and pigs

Structural remodeling in chronic atrial fibrillation (AF) occurs over weeks to months. To study the electrophysiological, structural, and functional changes that occur in chronic AF, the selection of the best animal model is critical. AF was induced by rapid atrial pacing (50-Hz stimulation every other second) in pigs (n = 4), dogs (n = 8), and goats (n = 9). Animals underwent MRIs at baseline and 6 mo to evaluate left ventricular (LV) ejection fraction (EF). Dogs were given metoprolol (50-100 mg po bid) and digoxin (0.0625-0.125 mg po bid) to limit the ventricular response rate to <180 beats/min and to mitigate the effects of heart failure. The pacing leads in pigs became entirely encapsulated and lost the ability to excite the heart, often before the onset of sustained AF. LV EF in dogs dropped from 54 ± 11% at baseline to 33 ± 7% at 6 mo (P < 0.05), whereas LV EF in goats did not drop significantly (69 ± 8% at baseline vs. 60 ± 9% at 6 mo, P = not significant). After 6 mo of AF, fibrosis levels in dog atria and ventricles increased, whereas only atrial fibrosis levels increased in goats compared with control animals. In our experience, the pig model is not appropriate for chronic rapid atrial pacing-induced AF studies. Rate-controlled chronic AF in the dog model developed HF and LV fibrosis, whereas the goat model developed only atrial fibrosis without ventricular dysfunction and fibrosis. Both the dog and goat models are representative of segments of the patient population with chronic AF.

A new risk scheme to predict ischemic stroke and other thromboembolism in atrial fibrillation: the ATRIA study stroke risk score

BACKGROUND

More accurate and reliable stroke risk prediction tools are needed to optimize anticoagulation decision making in patients with atrial fibrillation (AF). We developed a new AF stroke prediction model using the original Anticoagulation and Risk Factors in Atrial Fibrillation (ATRIA) AF cohort and externally validated the score in a separate, contemporary, community-based inception AF cohort, ATRIA-Cardiovascular Research Network (CVRN) cohort.

METHODS AND RESULTS

The derivation ATRIA cohort consisted of 10 927 patients with nonvalvular AF contributing 32 609 person-years off warfarin and 685 thromboembolic events (TEs). The external validation ATRIA-CVRN cohort included 25 306 AF patients contributing 26 263 person-years off warfarin and 496 TEs. Cox models identified 8 variables, age, prior stroke, female sex, diabetes mellitus, heart failure, hypertension, proteinuria, and eGFR<45 mL/min per 1.73 m(2) or end-stage renal disease, plus an age×prior stroke interaction term for the final model. Point scores were assigned proportional to model coefficients. The c-index in the ATRIA cohort was 0.73 (95% CI, 0.71 to 0.75), increasing to 0.76 (95% CI, 0.74 to 0.79) when only severe events were considered. In the ATRIA-CVRN, c-indexes were 0.70 (95% CI, 0.67 to 0.72) and 0.75 (95% CI, 0.72 to 0.78) for all events and severe events, respectively. The C-index was greater and net reclassification improvement positive comparing the ATRIA score with the CHADS2 or CHA2DS2-VASc scores.

CONCLUSIONS

The ATRIA stroke risk score performed better than existing risk scores, was validated successfully, and showed improvement in predicting severe events, which is of greatest concern. The ATRIA score should improve the antithrombotic decision for patients with AF and should provide a secure foundation for the addition of biomarkers in future prognostic models.

Platelet antiaggregants in stroke prevention

Antiplatelet agents are one of the main interventions for recurrent ischemic stroke prevention. Their time of use, dosage, and combination of therapy have different effects in terms of stroke risk reduction and adverse effects. This review provides an evidence-based update of the latest on antiplatelet therapy for stroke prevention.

Practice implications of the Atrial Fibrillation Guidelines

Atrial fibrillation is one of the most common and complex cardiac arrhythmias. Using currently available evidence, leading medical societies have established recommendations for the optimal management of atrial fibrillation. These guidelines have recently been updated by 4 consensus groups: the European Society of Cardiology, the American College of Chest Physicians, the Canadian Cardiovascular Society, and a task force of 3 societies from the United States: the American College of Cardiology Foundation, the American Heart Association, and the Heart Rhythm Society. The present review focused on the similarities and differences among these recently updated guidelines. Key revisions included updated information on newer treatments for rhythm control, treatment options to reduce atrial fibrillation complications, and updated anticoagulant management for thromboprophylaxis.

Individualized therapy in patients with atrial fibrillation: new look at atrial fibrillation

Atrial fibrillation (AF) is the most common sustained arrhythmia and is associated with significant morbidity and mortality, the so-called AF burden. Despite significant progress in the understanding, the mechanisms and pathophysiology of AF treatments are often unsatisfactory. This in part may be related to the complexity of this arrhythmia, as well as its evolution overtime. Atrial fibrillation has many aetiologies and underlying causes. The anti-arrhythmic drugs (AADs) and interventions aimed at controlling AF should therefore be based on aetiology and associated conditions, rather than electrophysiological mechanisms. The current guideline in the management of AF in most part is based on safety and outcome. This review will discuss the approach to management, based on primary prevention of AF with the aim to target at risk factors, triggers, specific substrates related to aetiology rather than mechanisms. The development of new pharmacological agents and therapeutic strategies should consider not only evidence based, but also include patient-specific personalized context system biology and pharmacology; otherwise, we will continue to see moderate drug efficacy at best and negative results and outcomes.

Left atrial appendage closure with the Watchman device in patients with a contraindication for oral anticoagulation: the ASAP study (ASA Plavix Feasibility Study With Watchman Left Atrial Appendage Closure Technology)

OBJECTIVES

The purpose of this study was to assess the safety and efficacy of left atrial appendage (LAA) closure in nonvalvular atrial fibrillation (AF) patients ineligible for warfarin therapy.

BACKGROUND

The PROTECT AF (Watchman Left Atrial Appendage System for Embolic Protection in Patients With Atrial Fibrillation) trial demonstrated that LAA closure with the Watchman device (Boston Scientific, Natick, Massachusetts) was noninferior to warfarin therapy. However, the PROTECT AF trial only included patients who were candidates for warfarin, and even patients randomly assigned to the LAA closure arm received concomitant warfarin for 6 weeks after Watchman implantation.

METHODS

A multicenter, prospective, nonrandomized study was conducted of LAA closure with the Watchman device in 150 patients with nonvalvular AF and CHADS₂ (congestive heart failure, hypertension, age ≥75 years, diabetes mellitus, and prior stroke or transient ischemic attack) score ≥1, who were considered ineligible for warfarin. The primary efficacy endpoint was the combined events of ischemic stroke, hemorrhagic stroke, systemic embolism, and cardiovascular/unexplained death.

RESULTS

The mean CHADS₂ score and CHA₂DS₂-VASc (CHADS₂ score plus 2 points for age ≥75 years and 1 point for vascular disease, age 65 to 74 years, or female sex) score were 2.8 ± 1.2 and 4.4 ± 1.7, respectively. History of hemorrhagic/bleeding tendencies (93%) was the most common reason for warfarin ineligibility. Mean duration of follow-up was 14.4 ± 8.6 months. Serious procedure- or device-related safety events occurred in 8.7% of patients (13 of 150 patients). All-cause stroke or systemic embolism occurred in 4 patients (2.3% per year): ischemic stroke in 3 patients (1.7% per year) and hemorrhagic stroke in 1 patient (0.6% per year). This ischemic stroke rate was less than that expected (7.3% per year) based on the CHADS₂ scores of the patient cohort.

CONCLUSIONS

LAA closure with the Watchman device can be safely performed without a warfarin transition, and is a reasonable alternative to consider for patients at high risk for stroke but with contraindications to systemic oral anticoagulation. (ASA Plavix Feasibility Study With Watchman Left Atrial Appendage Closure Technology [ASAP]; NCT00851578).

Contemporary approach to electrical and pharmacological cardioversion of atrial fibrillation

In patients with atrial fibrillation (AF), a rhythm-control strategy may be adopted when there are unacceptable symptoms from AF, failure of rate control, and/or the presence of comorbidities, such as heart failure, that may improve with restoration of sinus rhythm. When a rhythm-control strategy is chosen and the patient is in persistent AF, cardioversion will be necessary to convert the rhythm to sinus. Patients with AF present for > 48 hours must be effectively anticoagulated both prior to and after cardioversion. With newer oral anticoagulants, achieving effective anticoagulation is faster and more reliable, with no requirement for blood test monitoring. Cardioversion can be accomplished either electrically or pharmacologically, and in some cases, electrical cardioversion may be facilitated pharmacologically. Electrical cardioversion has a higher success rate compared with pharmacological cardioversion in the short-term. Pharmacological cardioversion is usually accomplished with intravenous ibutilide, oral flecainide or propafenone, or intravenous amiodarone. Oral amiodarone and dofetilide also result in chemical cardioversion in some patients over a longer period of time. Long-term success in the maintenance of sinus rhythm post-cardioversion can be increased with the use of antiarrhythmic drugs. Alternatively, when AF is recurrent and symptomatic despite the use of antiarrhythmic drugs, catheter ablation is a reasonable option for many patients. Cardioversion may be incorporated into the management approach of persistent AF when the primary therapeutic option chosen is catheter ablation.

Mythmaking in medical education and medical practice

BACKGROUND

Despite the emergence of evidence-based medicine, gaps in medical knowledge are filled by tradition, common sense, and experience, giving rise to medical myths.

METHODS

We explored the origins of and evidence related to four medical myths: patients with shellfish allergies should not receive intravenous contrast, patients with atrial fibrillation of less than 48 hours' duration do not require anticoagulation before cardioversion, patients with suspected meningitis should have a computed tomography (CT) scan before a lumbar puncture, and patients with respiratory disease should not receive β-blockers. We conducted a literature review to describe each myth's origins and the quality of supporting evidence.

RESULTS

All patients with allergies, including but not limited to seafood allergies, are at an increased risk for anaphylactoid reactions to radiocontrast. No conclusive studies indicate that patients with atrial fibrillation of less than 48 hours' duration do not require anticoagulation before cardioversion. A CT scan before lumbar puncture in suspected acute bacterial meningitis is a clinically inefficient precaution. β-blockers can be safely used in patients with respiratory disease and may even prevent cardiac events in these patients.

CONCLUSIONS

These familiar myths have maintained prominent roles in medical thinking because they represent wisdom passed down from eminent sources, they teach physiology and medical skills, and they offer physicians a sense of control in the face of uncertainty. In addition to providing scientific evidence, changing physicians' practice requires acknowledging that even meticulous care cannot always avert bad outcomes.

Review of epidemiology and management of atrial fibrillation in developing countries

BACKGROUND

Atrial fibrillation (AF) is the commonest sustained cardiac arrhythmia. In developing countries, AF is a growing public health problem with the epidemiologic transition from communicable to non-communicable diseases. However, relatively little is known about AF in the developing world. The aim of this review is to examine in developing countries the prevalence, associated medical conditions and management of AF.

METHODS

A literature search was conducted via MEDLINE and EMBASE (1990-2012).

RESULTS

Seventy studies were included in the review. The prevalence of AF in the general population ranged from 0.03% to 1.25%, while the prevalence of AF in hospital-based studies varied from 0.7% to 55.7%. Prevalence of AF in Africa was lower than in other regions. The most common conditions associated with AF were hypertension (10.3%-71.9%) and valvular heart disease (5.6%-66.3%). The prevalence of stroke in patients with AF ranged from 6.7% to 27%. The utilization of anticoagulants was highly variable (2.7%-72.7%). Approximately half of the patients with AF using warfarin had therapeutic International Normalized Ratios (INR). There was a high prevalence of use of rate control therapies (55.3%-87.3%).

CONCLUSIONS

The limited studies available suggest that in the developing world there is a significant prevalence of AF, which is predominantly associated with hypertension and valvular heart disease, and carries a risk of stroke. Highly variable use of anticoagulants may be related to different health care and socioeconomic settings. More studies are needed to improve understanding of the epidemiology and management of AF in developing countries.

AGE AND EFFECTIVENESS AND SAFETY OF VARIOUS ANTITHROMBOTIC THERAPY VARIANTS IN PATIENTS WITH NONVALVULAR ATRIAL FIBRILLATION

Aim. To compare effectiveness and safety of warfarin, dabigatran, and clopidogrel therapy as thromboembolism (TE) prevention strategy across the age groups in patients with nonvalvular atrial fibrillation (AF).

Material and methods. The study included 189 patients (110 men and 79 women), aged 65–80 years, with nonvalvular AF. All participants were divided into two groups: Group I (n=126) included patients aged 65–74 years. They were administered warfarin (n=43), in the dose providing the INR levels of 2,0–3,0; dabigatran (n=41) in the dose of 110 mg twice a day; and clopidogrel (n=42) in the dose of 75 mg/d. Group II (n=63) included patients aged 75–80 years. They were administered warfarin (n=22), dabigatran (n=20), and clopidogrel (n=21) in identical doses.

Results. In the younger age group, the 6-month treatment with dabigatran (110 mg twice a day), compared to the warfarin treatment, was associated with a similar incidence of ischemic stroke, but a lower risk of major bleeding (4,8% vs. 27,9%; p<0,05). The treatment with clopidogrel prevented stroke as effectively as the therapy with warfarin or dabigatran, and was reasonably safe. In the older age group, there was no significant difference in the incidence of TE and hemorrhagic complications between dabigatran and warfarin groups.

Conclusion. While selecting the antithrombotic therapy strategy in 65–74-year-old patients with nonvalvular AF, dabigatran and clopidogrel could be regarded as an acceptable alternative to warfarin.

Oral anticoagulation to reduce risk of stroke in patients with atrial fibrillation: current and future therapies

Atrial fibrillation (AF) is associated with an increased incidence and severity of strokes. The burden of AF-related stroke is expected to increase in parallel with the aging of the population. Oral anticoagulation with warfarin has been the pharmacologic standard for stroke risk reduction in patients with AF. When used with close attention to dosing and monitoring, warfarin is effective prophylactic therapy against thromboembolic stroke. However, it is underused by physicians, in part because of the known risks of adverse events with warfarin. Consequently, many patients with AF live with an avoidably elevated risk of stroke. New options, ie, oral anticoagulants with novel mechanisms of action, have recently been approved to reduce the risk of stroke in AF, and others are in development. These newer agents may address some of the complexities of warfarin use while providing similar or better efficacy and safety.

Oral anticoagulation therapy in heart failure patients in sinus rhythm: a systematic review and meta-analysis

BACKGROUND

Heart failure (HF) patients show high morbidity and mortality rate with increased risk of malignant arrhythmia and thromboembolism. Anticoagulation reduces embolic event and death rates in HF patients with atrial fibrillation, but if antithrombotic therapy is beneficial in patients with HF in sinus rhythm is still debated.

METHODOLOGY AND PRINCIPAL FINDINGS

We conducted a systematic review of prospective, randomized controlled trials (RCTs) to assess the efficacy and safety of oral anticoagulant therapies (OATs) compared to antiplatelet treatment in HF patients in sinus rhythm. MEDLINE, Web of Science, CENTRAL and Scopus databases were searched up to May 2012. Four RCTs were identified and a total of 3663 patients were included in the meta-analysis. Patients with both ischemic and non-ischemic HF were included. There was no significant difference in mortality (odds ratio (OR) 1.01, 95% confidence interval (CI) 0.86 to 1.19) between OATs group and antiplatelet drug group. OATs have reduced ischemic stroke risk (OR 0.49, 95% CI 0.32 to 0.74), but have increased major bleeding risk (OR 2.01, 95% CI 1.40 to 2.88) compared to antiplatelet treatment.

CONCLUSION

In HF patients in sinus rhythm OATs do not show a better risk-benefit profile compared to antiplatelet treatment in cardioembolism prevention. Warfarin and aspirin seem to be similar in reducing mortality. Warfarin reduces the incidence of ischemic stroke, but increases major bleedings. Thus, it is possible to speculate that aspirin prescription be indicated in patients with high risk of bleeding, whereas warfarin could be preferred in patients with high thromboembolic risk.

Sex and gender differences in clinical medicine

Sex and gender differences in frequent diseases are more widespread than one may assume. In addition, they have significant yet frequently underestimated consequences on the daily practice of medicine, on outcomes and effects of therapies. Gender medicine is a novel medical discipline that takes into account the effects of sex and gender on the health of women and men. The major goal is to improve health and health care for both, for women as well as for men. We give in this chapter an overview on sex and gender differences in a number of clinical areas, in cardiovascular diseases, pulmonary diseases, gastroenterology and hepatology, in nephrology, autoimmune diseases, endocrinology, hematology, neurology. We discuss the preferential use of male animals in drug development, the underrepresentation of women in early and cardiovascular clinical trials, sex and gender differences in pharmacology, in pharmacokinetics and pharmacodynamics, in management and drug use. Most guidelines do not include even well-known sex and gender differences. European guidelines for the management of cardiovascular diseases in pregnancy have only recently been published. Personalized medicine cannot replace gender-based medicine. Large databases reveal that gender remains an independent risk factor after ethnicity, age, comorbidities, and scored risk factors have been taken into account. Some genetic variants carry a different risk in women and men. The sociocultural dimension of gender integrating lifestyle, environment, stress, and other variables cannot be replaced by a sum of biological parameters. Because of this prominent role of gender, clinical care algorithms must include gender-based assessment.

Anaesthetic Management of Parturient with Acute Atrial Fibrillation for Emergency Caesarean Section

A 31-year-antenatal lady with critical mitral stenosis presented for emergency caesarean section with fetal distress. She had acute onset atrial fibrillation. She was given a combined spinal epidural (CSE) anaesthesia and her arrhythmia was successfully managed after delivery of the baby with intravenous calcium channel blocker. Mitral stenosis is the most common valvular heart disease complicating pregnancy in developing countries. The physiological changes during pregnancy may exacerbate their cardiac symptoms. They may present with complications like congestive cardiac failure, atrial fibrillation, or pulmonary thromboembolism during the antenatal, intrapartum, or postpartum period. Here we discuss the management of parturient woman with high maternal and fetal risk presenting for emergency caesarean. The merits of regional anaesthesia and the importance of invasive monitoring are also discussed.

[Scope of the latest RE-LY substudies: clinical implications]

The approval of the use of dabiatran in stroke prevention in patients with nonvalvular atrial fibrilation (NVAF) is based on the results of the RE-LY (Randomized Evaluation of Long-Term Anticoagulation Therapy) trial, one of the largest studies to date in this entity. In this trial, dabigatran showed similar safety and efficacy to warfarin in primary and secondary prevention of stroke in patients with AF. At a dose of 150 mg twice daily, dabigatran was superior to warfarin in the prevention of stroke or systemic embolism and the 110 mg dose twice daily showed similar efficacy and greater safety, given the lower incidence of hemorrhage. These results were consistently found in the various subanalyses, with some slight differences of interest for clinical practice. The ideal candidates for dabiatran are patients with NVAF suitable for cardioversion, who require short periods of anticoagulation, patients in remote geographical areas with difficulty in achieving good anticoagulation control or good control with anti-vitamin K treatment due to IRN fluctuations, and patients with a low risk of hemorrhage and a CHADS score ≥ 3 and/or with prior stroke, whenever there are no contraindications. The choice of dabigatran dose should be evaluated according to the patient's individual characteristics (caution must be exercised when prescribing this drug in the elderly and in renal insufficiency) and embolic and/or hemorrhagic risk. Studies of the long-term safety of this drug, pharmacoeconomic analyses in Spain and post-commercialization pharmacovigilance data are required before the definitive uses of this drug can be established.

Rate or rhythm control for atrial fibrillation: update and controversies

Atrial fibrillation is associated with increased mortality and considerable morbidity, including stroke, heart failure, and diminished quality of life. Despite these adverse outcomes, rhythm control has not demonstrated benefit in clinical trials. Antiarrhythmic medications, including recently developed agents, have limited efficacy in achieving durable sinus rhythm and substantial toxicity. A rate-control strategy is therefore more attractive for minimally symptomatic patients, but younger and more symptomatic patients may benefit from restoration of sinus rhythm. Catheter ablation is more effective than medications in preventing arrhythmia recurrence, avoids adverse effects associated with antiarrhythmic drugs, and should be considered early in symptomatic patients when success is likely. However, more definitive data are needed from randomized trials assessing long-term outcomes after ablation, including stroke risk and mortality. Clinical decision tools help select the appropriate management for individual patients. Lenient rate management is easy to achieve and seems reasonably safe for certain patients, although the optimum rate varies with individual comorbidities. Because safer and more effective pharmacologic and interventional therapies are now available, an individualized approach to atrial fibrillation management is essential.

Atrial fibrillation in heart failure

Heart failure (HF) and atrial fibrillation (AF) are highly prevalent debilitating conditions that often coexist and are frequently encountered in clinical practice. The presence of chronic AF is a marker of worse prognosis in patients with HF, and the onset of new AF in those with chronic HF is associated with increased morbidity and mortality. Advances in the development of novel drugs, nonpharmacologic modalities, and therapeutic strategies, as well the increased understanding of the pathobiology of HF and AF, are key to mitigating the tremendous public health burden that is associated with these conditions.

Systematic review and adjusted indirect comparison meta-analysis of oral anticoagulants in atrial fibrillation

BACKGROUND

Oral anticoagulants such as apixaban, dabigatran, and rivaroxaban are alternatives to warfarin for preventing events in patients with atrial fibrillation. Direct comparative studies between agents are unavailable. Our objective was to conduct an adjusted indirect comparison meta-analysis between new oral agents in atrial fibrillation.

METHODS AND RESULTS

We searched MEDLINE and Cochrane Central through February 2012 for randomized, controlled trials in patients with atrial fibrillation evaluating apixaban, dabigatran, or rivaroxaban versus warfarin. For dabigatran, only data from the Food and Drug Administration-approved dose were included. Outcomes included the composite of stroke or systemic embolism, any stroke, and major bleeding among, others. Outcomes were initially pooled using standard random-effects methods, producing risk ratio and 95% confidence intervals. Adjusted indirect comparisons using these pooled estimates were then performed. A total of 44 733 patients from 4 studies were analyzed. Most analyses yielded no differences between agents. Dabigatran lowered risk of composite outcome (risk ratio, 0.75; 95% confidence interval, 0.57-1.00), ischemic stroke (0.67; 0.48-0.93), and hemorrhagic stroke (0.45; 0.45-0.99) versus rivaroxaban. No differences in all strokes or mortality were seen. Apixaban lowered the risk of major bleeding (0.74; 0.60-0.91) and gastrointestinal bleeding (0.58; 0.41-0.82) versus dabigatran and major bleeding versus rivaroxaban (0.68; 0.55-0.83), but increased systemic emboli versus rivaroxaban (3.86; 1.17-12.75).

CONCLUSIONS

Significant differences in efficacy and safety parameters may exist between oral anticoagulant agents in patients with atrial fibrillation. Apixaban lowers the risk of major and gastrointestinal bleeding versus dabigatran and rivaroxaban. Dabigatran lowers the composite of stroke or systemic emboli, and ischemic stroke versus rivaroxaban. Head-to-head clinical trials are required to confirm these findings.