A roundup of the latest news in the area of anticoagulation.
Anticoagulant treatment after intracerebral haemorrhage in patients with AF
Anticoagulant treatment may be initiated seven to eight weeks after intracerebral haemorrhage (ICH) in patients with atrial fibrillation (AF), to optimise the benefit from treatment and minimise risk, according to a nationwide observational study published recently in Stroke.1
The study aimed to provide observational data on the relationship between the timing of antithrombotic treatment and the competing risks of severe thrombotic and haemorrhagic events in a cohort of Swedish patients with AF and ICH.
Patients with AF and a first-ever ICH were identified in the Swedish Stroke Register, Riksstroke, 2005 to 2012. Riksstroke was linked with other national registers to find information on treatment, comorbidity, and outcome. The optimal timing of treatment in patients with low and high thromboembolic risk was described through cumulative incidence functions separately for thrombotic and haemorrhagic events and for the combined end point vascular death or nonfatal stroke.
The study included 2,619 ICH survivors with AF. Anticoagulant treatment was associated with a reduced risk of vascular death and nonfatal stroke in high-risk patients with no significantly increased risk of severe haemorrhage. The benefit seemed to be greatest when treatment was started seven to eight weeks after ICH.
For high-risk women, the total risk of vascular death or stroke recurrence within three years was 17.0% when anticoagulant treatment was initiated eight weeks after ICH and 28.6% without any antithrombotic treatment (95% confidence interval for difference, 1.4%–21.8%). For high-risk men, the corresponding risks were 14.3% versus 23.6% (95% confidence interval for difference, 0.4%–18.2%).
Atrial fibrillation more prevalent in dialysis patients than expected…
The prevalence of AF in haemodialysis patients in Vienna, Austria, is significantly higher than previously thought, and only half of the patients affected are treated with an anticoagulant, according to a multi-centre study led by MedUni Vienna published recently in PLOS ONE.2
In the VIVALDI (Vienna InVestigation of AtriaL fibrillation and thromboembolism in hemoDIalysis patients) study, researchers investigated the clinical-scientific conflict regarding the risk of stroke and thromboembolic complications in patients on haemodialysis, especially those with AF.
Scientists analysed a cohort of 626 patients to provide a representative sample of the entire Viennese dialysis population of around 850 people and conducted direct patient surveys and extensive research of medical records to obtain a much more accurate picture of the prevalence of AF than was possible in previous studies.
“We found that the prevalence of AF increases with age and it is particularly common in male patients but, despite the risk of stroke associated with AF, only half of those affected are being treated with an anticoagulant,” said lead author Dr Oliver Königsbrügge.
The study addresses a cross-disciplinary internistic problem and identifies the underestimated role of AF when it comes to the care of patients with end-stage kidney disease. Subsequent investigations conducted as part of the VIVALDI study will prospectively examine risk factors for thromboembolism, stroke, and bleeding, the authors add.
…but how safe is warfarin in AF haemodialysis patients?
The optimal management of stroke prophylaxis in hemodialysis patients with atrial fibrillation (AF) is controversial.
Cardiologist Dr Brandon Kai (West Hollywood, California, USA and affiliated with Cedars-Sinai Medical Center) and colleagues have conducted a retrospective, population-based study3 over 10 years, to determine the risk of mortality, stroke, and bleeding associated with the use of warfarin in haemodialysis patients with AF. Association of warfarin use with mortality, stroke, and bleeding was determined via propensity-score matched Cox-proportional hazard models.
Among the 4,286 AF patients on haemodialysis, 989 patients (23%) were prescribed warfarin. Propensity score matching was used to identify 888 matched pairs with similar baseline characteristics.
Warfarin use was associated with lower risk of all-cause death (hazard ratio [HR]: 0.78, 95% confidence interval [CI]: 0.67-0.89) and lower risk of ischaemic stroke (HR 0.67, 95% CI 0.45-0.99). Warfarin use was not associated with a higher risk of haemorrhagic stroke or gastrointestinal bleeding. The treatment effect was largest in the group with the best INR control as measured by TTR (time in therapeutic range).
Subgroup analyses showed warfarin use was associated with survival benefit in most subgroups. The two subgroups that did not benefit were patients with a history of haemorrhagic stroke and patients with concurrent aspirin use.
Automated software promotes anticoagulation, reduces stroke risk
Oral anticoagulants (OACs) substantially reduce risk of stroke in AF, but uptake is suboptimal. Electronic health records enable automated identification of people at risk but not receiving treatment. Researchers investigated the effectiveness of a software tool (AURAS-AF [Automated Risk Assessment for Stroke in Atrial Fibrillation]) designed to identify such individuals during routine care, with the results published recently in Stroke.4
Screen reminders appeared each time the electronic health records of an eligible patient was accessed until a decision had been taken over OAC treatment. Where OACs were not started, clinicians were prompted to indicate a reason. Control practices continued usual care. The primary outcome was the proportion of eligible individuals receiving OAC at six months. Secondary outcomes included rates of cardiovascular events and reports of adverse effects of the software on clinical decision-making.
In the study, from authors led by Dr Tim Holt (Nuffield Department of Primary Care Health Sciences, Oxford University), 47 practices were randomised. The mean proportion–prescribed OAC at six months was 66.3% (SD=9.3) in the intervention arm and 63.9% (9.5) in the control arm (adjusted difference 1.21% [95% confidence interval −0.72 to 3.13]). Incidence of recorded transient ischaemic attack was higher in the intervention practices (median 10.0 versus 2.3 per 1,000 patients with AF; P=0.027), but at 12 months, the authors found a lower incidence of both all cause stroke (P=0.06) and haemorrhage (P=0.054). No adverse effects of the software were reported.
No significant change in OAC prescribing occurred, the authors found. A greater rate of diagnosis of transient ischaemic attack (possibly because of improved detection or overdiagnosis) was associated with a reduction (of borderline significance) in stroke and haemorrhage over 12 months.
Anticoagulation Achievement Awards 2017
The prestigious Anticoagulation Achievement Awards are seeking applications from outstanding clinical teams and individuals who provide exemplary care for any patient who has been diagnosed with AF or a blood clot such as a deep vein thrombosis (DVT) or pulmonary embolism (PE).
It is important that those who are passionate about providing excellent anticoagulation services should be recognised and rewarded. To this end, the Anticoagulation Achievement Awards have been developed by AntiCoagulation Europe (ACE) in partnership with Thrombosis UK, Anticoagulation in Practice, Thrombus, the AF Association and Arrhythmia Alliance.
If you are a clinician or you know a clinician who makes all the difference to patients care for a relevant conditions, please share this information with them. Not only could they receive national recognition for their services and care, but they could also win a £1,000 bursary.
Applications must be received by the 10th May 2017. The Awards ceremony will be on the 11th October 2017 in The Houses of Parliament.
Further information and application forms are available here: www.anticoagulationawards.org
Do women with AF experience more severe strokes?
Women with AF do not only have an increased risk of stroke when compared with men but also experience more severe strokes, according to a study published recently in Stroke.5
In this cross-sectional study, 74,425 adults with acute ischaemic stroke from the Austrian Stroke Unit Registry were included between March 2003 and January 2016. In 63,563 patients, data on the National Institutes of Health Stroke Scale on admission to the stroke unit, presence of AF, vascular risk factors, and comorbidities were complete. Analysis was done according to a multivariate regression model.
Stroke severity in general increased with age. AF-related strokes were more severe than strokes of other causes. Sex-related differences in stroke severity were only seen in stroke patients with AF. Median (Q25,75) National Institutes of Health Stroke Scale score points were 9 (4,17) in women and 6 (3,13) in men (P<0.001). The interaction between AF and sex on stroke severity was independent of age, previous functional status, vascular risk factors, and vascular comorbidities and remained significant in various subgroups.
References
1. Pennlert J, Overholser R, Asplund K, Carlberg B, Rompaye BV, Wiklund PG, Eriksson M. Optimal timing of anticoagulant treatment after intracerebral hemorrhage in patients with atrial fibrillation. Stroke 2017;48:314–20. https://doi.org/10.1161/STROKEAHA.116.014643
2. Königsbrügge O, Posch F, Antlanger M, et al. Prevalence of atrial fibrillation and antithrombotic therapy in hemodialysis patients: cross-sectional results of the Vienna InVestigation of AtriaL Fibrillation and Thromboembolism in Patients on HemoDIalysis (VIVALDI). PLoS ONE;12:e0169400. http://doi.org/10.1371/journal.pone.0169400
3. Kai B, Bogorad Y, Nguyen LA, et al. Warfarin use and the risk of mortality, stroke, and bleeding in hemodialysis patients with atrial fibrillation. Heart Rhythm 2017. http://dx.doi.org/10.1016/j.hrthm.2017.01.047
4. Holt TA, Dalton A, Marshall T, et al. Automated software system to promote anticoagulation and reduce stroke risk: cluster-randomized controlled trial. Stroke 2017. https://doi.org/10.1161/STROKEAHA.116.015468
5. Clemens Lang, Leonhard Seyfang, Julia Ferrari, et al. Do women with atrial fibrillation experience more severe strokes? Results from the Austrian Stroke Unit Registry. Stroke 2017. https://doi.org/10.1161/STROKEAHA.116.015900
