Atrial fibrillation in registries

Anticoagulant treatment is a class I recommendation in patients with atrial fibrillation (AF). Mortality post-discharge in AF patients suffering from an ischaemic stroke is substantial,1–3 whereas less is known about outcomes of AF patients suffering from a severe gastrointestinal bleed (GIB). Dr Komen and co-workers from the Netherlands and Sweden have analysed 90-day mortality in AF patients after a stroke or a severe bleed, and assessed associations with the type of antithrombotic treatment at the event. The authors used the Stockholm Healthcare database and report that the 90-day mortality rates were 25.1% after ischaemic stroke, 31.6% after intracranial haemorrhage, and 16.2% after GIB. The authors concluded that mortality rates were high in AF patients suffering from an ischaemic stroke, an intracranial haemorrhage, or a severe GIB, and direct oral anticoagulant (DOAC) treatment was associated with a lower 90-day mortality after intracranial haemorrhage than warfarin. The optimal antithrombotic treatment strategy after transcatheter aortic valve implantation (TAVI) remains uncertain, especially in patients with an indication for oral anticoagulation therapy such as AF.4 In an observational cohort study consisting of 735 patients undergoing TAVI, Dr Butt et al. from Denmark have examined the risk of arterial thrombo-embolism, bleeding, and all-cause mortality in AF patients treated with DOACs vs. vitamin K antagonists (VKAs). The authors concluded that treatment with DOACs was not associated with a significantly different risk of arterial thrombo-embolism, bleeding, or all-cause mortality compared with VKAs. In AF patients, 150 mg b.i.d. dabigatran is the standard dose, yet guidelines recommend 110 mg b.i.d. when bleeding risk is high. In a Danish study using nationwide registries, the aim of the study was to investigate if AF patients are switched from a VKA to the appropriate dose of dabigatran. The authors concluded that among VKA-experienced AF patients one in four were switched to a dabigatran dose, contrary to guideline recommendations. Dr Lip and co-workers have examined the clinical effectiveness and safety of edoxaban 30 mg and 60 mg once daily among Danish patients with AF in a registry study of 3405 patients initiating edoxaban. The authors report that the clinical effectiveness and safety were in line with data from the ENGAGE AF-TIMI 48 trial.5 Warfarin is prescribed commonly to reduce the risk of stroke in patients with AF. The net clinical benefit of warfarin is associated with the proportion of time that international normalized ratio (INR) values are maintained within the therapeutic range, referred to as the time in therapeutic range (TTR).6,7 Dr Harris and co-workers from the UK used health record data for Wales (n = 32 380 patients) to evaluate patients prescribed warfarin who had at least 6 months of INR data. In a multivariable regression analysis, female gender, age (≥75 years), excess alcohol, diabetes, heart failure, ischaemic heart disease, and respiratory disease were independently associated with all markers of poor INR control. The authors concluded that acceptable INR control was poor, and only using TTR to assess effectiveness with warfarin has the potential to miss a large number of patients with non-therapeutic INRs who are likely to be at increased risk. Dr Chan et al. from Taiwan investigated the effectiveness, safety, and outcomes of lower limb events for DOACs vs. warfarin among AF patients with concomitant peripheral artery disease (PAD) in a nationwide retrospective cohort study collected from Taiwan. The authors reported that DOACs were associated with a comparable risk of ischaemic stroke, and a significantly lower risk of major adverse limb events and major bleeding than warfarin among AF patients with concomitant PAD. A study previously published in the journal has reported that rivaroxaban use was associated with a reduced risk of major thrombotic vascular events vs. warfarin, without significantly increasing major bleeding risk in AF patients with concomitant coronary artery disease (CAD) and/or PAD.8 The global prevalence of obesity is steadily increasing, paralleled by a rise in cases of AF. In this issue of the journal, we publish a review paper by Dr Lip and co-workers from the UK entitled ‘Obesity and atrial fibrillation: making inroads through fat’. The management of antithrombotic therapy of patients with AF undergoing percutaneous coronary intervention is a hot topic.9–13 In a review paper by Dr Rubboli and co-workers, the management of antithrombotic therapy of patients with AF undergoing percutaneous coronary intervention is discussed, together with questions and answers.