Anna GarrettRisks of warfarin use may outweigh benefits in AF, CKD
Chronic kidney disease (CKD) is associated with increased atrial fibrillation (AF) and greater risk of thromboembolic events, bleeding, and mortality. The use of warfarin in patients with AF and CKD can be a problem because of that added bleeding risk. A literature review suggests that the risks of warfarin therapy in patients with AF and CKD may outweigh the benefits.
The study included >11,600 patients with CKD and AF who were treated with warfarin. In patients with AF and non-end-stage CKD, warfarin use resulted in a lower risk of ischemic stroke/thromboembolism and mortality, but had no effect on major bleeding. In patients with AF and end-stage renal disease, warfarin had no effect on the risks of stroke and mortality, but increased the risks of major bleeding.
At present, anticoagulation is recommended for patients with AF and mild-moderate CKD. In those with severe CKD, warfarin still may be beneficial, provided that it is well-managed and a TTR>70% is maintained.
Source: Dahal K, Kunwar S, Rijal J, et al. Stroke, major bleeding, and mortality outcomes in warfarin users with atrial fibrillation and chronic kidney disease: A meta-analysis of observational studies. Chest. 2016;149(4):951-959.
Benefits of early aspirin therapy underestimated in stroke, TIA
Aspirin is recommended for secondary prevention after transient ischemic attack (TIA) or ischemic stroke, based on trials showing a 13% reduction in long-term risk of recurrent stroke.
To assess the benefits of early aspirin therapy, investigators used pooled data from all trials of aspirin vs. control for secondary prevention. Patients were stratified according to the length of time from their initial event (<6 weeks, 6-12 weeks, >12 weeks). The study included 15,778 participants from 12 studies.
Aspirin reduced the 6-week risk of recurrent ischemic stroke by about 60% and of disabling or fatal ischemic stroke by about 70%, with greatest benefit noted in patients presenting with TIA or minor stroke. Some further reduction in risk of ischemic stroke accrued for aspirin vs. control from 6 to 12 weeks; after 12 weeks there was no benefit.
The authors also pooled data for 40,531 participants from three trials of aspirin vs. control in major acute stroke. The reduction in risk of recurrent ischemic stroke at 14 days was most evident in patients with less severe baseline deficits, and was substantial (60% reduction) by the second day after starting treatment.
The authors concluded that the considerable early benefit from aspirin warrants public education about self-administration after possible TIA.
Source: Rothwell PM, Algra A, Chen Z, et al. Effects of aspirin on risk and severity of early recurrent stroke after transient ischaemic attack and ischaemic stroke: Time-course analysis of randomised trials. Lancet. 2016. Published online May 18, 2016. http://bit.ly/timecourseaspirin.
Is oral anticoagulation use safe in patients with history of ICH?
A Taiwanese study examined risks and benefits of antithrombotic therapy in AF patients with previous intracerebral hemorrhage (ICH ) treated with warfarin or antiplatelet drugs vs. no antithrombotic therapies.
This study used the National Health Insurance Research Database in Taiwan. Among 307,640 patients who have AF with a CHA2DS2-VASc score ≥2, 12,917 patients with a history of ICH were identified and assigned to one of three groups: no treatment, antiplatelet therapy, and warfarin.
Among patients with previous ICH, rates of ICH and ischemic stroke in untreated patients were 4.2 and 5.8 per 100 person-years, respectively. Among warfarin users, annual ICH and ischemic stroke rates were 5.9% and 3.4%, respectively. Among users of antiplatelet agents, the rates were 5.3% per year and 5.2% per year, respectively. The greatest benefit was seen in patients with a CHA2DS2-VASc score ≥6.
Source: Chao T, Liu C, Liao J, et al. Use of oral anticoagulants for stroke prevention in patients with atrial fibrillation who have a history of intracranial hemorrhage. Circulation. 2016;133:1540-1547.