A Systems Biology Strategy on Differential Gene Expression Data Discloses Some Biological Features of Atrial Fibrillation

Atrial fibrillation (AF), the most common cardiac arrhythmia, is associated with extensive structural, contractile, and electrophysiological remodeling. In this manuscript we re-analyzed gene expression data from a microarray experiment on AF patients and control tissues, using a new paradigm based on a posteriori unsupervised strategy in which the discrimination of patients comes out from purely syntactical premises. This paradigm, more adherent to biological reality where genes work in highly connected networks, allowed us to get both a very precise patients/control discrimination and the discovery of cell adhesion/tissue modeling and inflammation processes as the main dimensions of AF

Protocol for Birmingham Atrial Fibrillation Treatment of the Aged study (BAFTA): a randomised controlled trial of warfarin versus aspirin for stroke prevention in the management of atrial fibrillation in an elderly primary care population.

Background Atrial fibrillation (AF) is an important independent risk factor for stroke. Randomised controlled trials have shown that this risk can be reduced substantially by treatment with warfarin or more modestly by treatment with aspirin. Existing trial data for the effectiveness of warfarin are drawn largely from studies in selected secondary care populations that under-represent the elderly. The Birmingham Atrial Fibrillation Treatment of the Aged (BAFTA) study will provide evidence of the risks and benefits of warfarin versus aspirin for the prevention of stroke for older people with AF in a primary care setting. Study design A randomised controlled trial where older patients with AF are randomised to receive adjusted dose warfarin or aspirin. Patients will be followed up at three months post-randomisation, then at six monthly intervals there after for an average of three years by their general practitioner. Patients will also receive an annual health questionnaire. 1240 patients will be recruited from over 200 practices in England. Patients must be aged 75 years or over and have AF. Patients will be excluded if they have a history of any of the following conditions: rheumatic heart disease; major non-traumatic haemorrhage; intra-cranial haemorrhage; oesophageal varices; active endoscopically proven peptic ulcer disease; allergic hypersensitivity to warfarin or aspirin; or terminal illness. Patients will also be excluded if the GP considers that there are clinical reasons to treat a patient with warfarin in preference to aspirin (or vice versa). The primary end-point is fatal or non-fatal disabling stroke (ischaemic or haemorrhagic) or significant arterial embolism. Secondary outcomes include major extra-cranial haemorrhage, death (all cause, vascular), hospital admissions (all cause, vascular), cognition, quality of life, disability and compliance with study medication

Troponin utilization in patients presenting with atrial fibrillation/flutter to the emergency department: retrospective chart review

Abstract Background There are few recommendations about the use of cardiac markers in the investigation and management of atrial fibrillation/flutter. Currently, it is unknown how many patients with atrial fibrillation/flutter undergo troponin testing, and how positive troponin results are managed in the emergency department. We sought to look at the emergency department troponin utilization patterns. Methods We performed a retrospective chart review of patients with atrial fibrillation/flutter presenting to the emergency department at three centers. Outcome measures included the rates of troponins ordered by emergency doctors, number of positive troponins, and those with positive troponins treated as acute coronary syndrome (ACS) by consulting services. Results Four hundred fifty-one charts were reviewed. A total of 388 (86%) of the patients had troponins ordered, 13.7% had positive results, and 4.9% were treated for ACS. Conclusions Troponin tests are ordered in a high percentage of patients with atrial fibrillation/flutter presenting to emergency departments. Five percent of our total patient cohort was diagnosed as having acute coronary syndrome by consulting services

Update on anti-coagulation in atrial fibrillation

Atrial fibrillation (AF), the most common clinically relevant arrhythmia, affects 2.2 million individuals in the USA and 4.5 million in Europe, resulting in significant morbidity and mortality. Pharmacotherapy aimed at controlling both heart rate and rhythm is employed to relieve AF symptoms, though debate continues about which approach is preferable. AF prevalence rises with age from 0.4% to 1% in the general population to 11% in those aged >70 years. AF is associated with a pro-thrombotic state and other comorbidities; age, hypertension, heart failure and diabetes mellitus all play a key role in AF pathogenesis. Anti-coagulation is essential for stroke prevention in patients with AF and is recommended for patients with one or more risk factors for stroke. Used within the recommended therapeutic range, warfarin and other vitamin K antagonists decrease the incidence of stroke and mortality in AF patients. Warfarin remains under-used, however, because of the perceived high risk of haemorrhage, narrow therapeutic window and need for regular monitoring. Several novel anti-coagulants show promise in AF-related stroke prevention. In particular, the novel, oral, direct thrombin inhibitor, dabigatran etexilate, recently licensed by the US Food and Drug Administration (FDA) and Health Canada has shown improved efficacy and safety compared with warfarin for stroke prevention in AF, and has the potential to replace warfarin in this indication. The increasing number of new therapeutic options, including improved anti-arrhythmic agents, novel anti-coagulants and more accessible ablation techniques, are likely to deliver better care for AF patients in the near future

Normalization of a conversation tool to promote shared decision making about anticoagulation in patients with atrial fibrillation within a practical randomized trial of its effectiveness: a cross-sectional study.

BACKGROUND: Shared decision making (SDM) implementation remains challenging. The factors that promote or hinder implementation of SDM tools for use during the consultation, including contextual factors such as clinician burnout and organizational support, remain unclear. We explored these factors in the context of a practical multicenter randomized trial evaluating the effectiveness of an SDM conversation tool for patients with atrial fibrillation considering anticoagulation therapy. METHODS: In this cross-sectional study, we recruited clinicians who were regularly involved in conversations with patients regarding anticoagulation for atrial fibrillation. Clinicians reported their characteristics and burnout symptoms using the two-item Maslach Burnout Inventory. Clinicians were trained in using the SDM tool, and they recorded their perceptions of the tool's normalization potential using the Normalization MeAsure Development (NoMAD) survey instrument and verbally reflected on their answers to these survey questions. When possible, the training sessions and clinicians' verbal responses to the conversation tool were recorded. RESULTS: Our study comprised 183 clinicians recruited into the trial (168 with survey responses and 112 with recordings). Overall, clinicians gave high scores to the normalization potential of the intervention; they endorsed all domains of normalization to the same extent, regardless of site, clinician characteristics, or burnout ratings. In interviews, clinicians paid significant attention to making sense of the tool. Tool buy-in seemed to depend heavily on their ability to see the tool as accurate and "evidence-based" and their perceptions of having time in the consultation to use it. CONCLUSIONS: While time in the consultation remains a barrier, we did not find a significant association between burnout symptoms and normalization of an SDM conversation tool. Possible areas for improving the normalization of SDM conversation tools in clinical practice include enabling collaboration among clinicians to implement the tool and reporting how clinicians elsewhere use the tool. Direct measures of normalization (i.e., observing how often clinicians access the tool in practice outside of the clinical trial) may further elucidate the role that contextual factors, such as clinician burnout, play in the implementation of SDM. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02905032. Registered on 9 September 2016

Effect of the Implantable Atrial Defibrillator on the Natural History of Atrial Fibrillation

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75480/1/j.1540-8167.1999.tb00296.x.pd

Accuracy of methods for diagnosing atrial fibrillation using 12-lead ECG: a systematic review and meta-analysis

Background: Screening for atrial fibrillation (AF) using 12-lead-electrocardiograms (ECGs) has been recommended; however, the best method for interpreting ECGs to diagnose AF is not known. We compared accuracy of methods for diagnosing AF from ECGs. Methods: We searched MEDLINE, EMBASE, CINAHL and LILACS until March 24, 2014. Two reviewers identified eligible studies, extracted data and appraised quality using the QUADAS-2 instrument. Meta-analysis, using the bivariate hierarchical random effects method, determined average operating points for sensitivities, specificities, positive and negative likelihood ratios (PLR, NLR) and enabled construction of Summary Receiver Operating Characteristic (SROC) plots. Results: 10 studies investigated 16 methods for interpreting ECGs (n = 55,376 participant ECGs). The sensitivity and specificity of automated software (8 studies; 9 methods) were 0.89 (95% C.I. 0.82–0.93) and 0.99 (95% C.I. 0.99–0.99), respectively; PLR 96.6 (95% C.I. 64.2–145.6); NLR 0.11 (95% C.I. 0.07–0.18). Indirect comparisons with software found healthcare professionals (5 studies; 7 methods) had similar sensitivity for diagnosing AF but lower specificity [sensitivity 0.92 (95% C.I. 0.81–0.97), specificity 0.93 (95% C.I. 0.76–0.98), PLR 13.9 (95% C.I. 3.5–55.3), NLR 0.09 (95% C.I. 0.03–0.22)]. Sub-group analyses of primary care professionals found greater specificity for GPs than nurses [GPs: sensitivity 0.91 (95% C.I. 0.68–1.00); specificity 0.96 (95% C.I. 0.89–1.00). Nurses: sensitivity 0.88 (95% C.I. 0.63–1.00); specificity 0.85 (95% C.I. 0.83–0.87)]. Conclusions: Automated ECG-interpreting software most accurately excluded AF, although its ability to diagnose this was similar to all healthcare professionals. Within primary care, the specificity of AF diagnosis from ECG was greater for GPs than nurses