Year: 2016
Type: article
Abstract: Oral anticoagulation is highly effective at preventing stroke in patients with atrial fibrillation (AF).Warfarin and other vitamin K antagonist oral anticoagulants reduce stroke by roughly two-thirds compared with placebo. 1 Four recently developed non-vitamin K antagonist oral anticoagulants (NOACs) offer important advantages over warfarin, including an approximate 50% reduction in intracranial hemorrhage and no requirement for routine monitoring.[2][3][4][5] In trials comparing these 4 NOACs with warfarin in patients with AF, the relative effects on stroke, bleeding, and intracranial hemorrhage have been consistent across many subgroups defined by baseline patient factors.Nevertheless, given the cost of NOACs to patients and health care systems, it is valid to question whether there are cohorts of patients with AF for whom warfarin results in good enough outcomes that the absolute incremental benefit of NOACs would be small and the standard of care (ie, warfarin) remains the preferred option.Warfarin is a complex drug with many food and drug interactions and requires regular therapeutic monitoring of the standardized international normalized ratio (INR).A target INR of between 2 and 3 is considered ideal to optimize safety and efficacy, and the time in therapeutic range has been developed as an indicator of the quality of warfarin management.6 In both clinical trials and practice, there is substantial heterogeneity in time in therapeutic range across countries, centers, and patients.The availability of INR data for warfarin invites the question, "Do patients with consistently excellent INR control have good outcomes on warfarin-perhaps good enough that the absolute benefit of NOACs would be small?"In this issue of JAMA Cardiology, Björck and colleagues 7 report an observational analysis of several large clinical and administrative data sets from Sweden investigating, among other things, the safety and effectiveness of well-managed warfarin in patients with AF and the association between individual patient time in therapeutic range and outcomes.They found relatively low overall rates of death and intracranial hemorrhage, particularly in the absence of renal failure or concomitant aspirin and among patients with good INR control (time in therapeutic range ≥70%).Based on these findings, the authors conclude that "well-managed warfarin therapy is-…still a valid alternative for AF-associated stroke prevention."7 This statement is almost certainly true for some patients; however, whether the current analysis helps to identify those
Source: JAMA Cardiology
Authors: John H. Alexander, Laine E. Thomas
Institution: Duke Clinical Research Institute
Language: English
Subfield: Cardiology and Cardiovascular Medicine
Field: Medicine
Domain: Health Sciences
Open Access status: bronze
OpenAlex ID: W2336971866