Secondary Stroke Prevention in Atrial Fibrillation: New Insights Into an Old Problem.

Abstract

See related article, p 1464 The detection and treatment of nonvalvular atrial fibrillation (NVAF) constitute areas of active research yielding novel technologies that result in lively debates among general medicine, cardiology, and neurology specialists. Non–vitamin K antagonist oral anticoagulants (NOAC), approved by Food and Drug Administration (FDA) within the first half of this decade, have been increasingly adopted as first-line agents for stroke prevention in NVAF.1 These medications have shown noninferiority for stroke prevention against warfarin arms with suboptimal international normalized ratio control in patient populations with low mean embolic risk scores for ≈2 years of follow-up. Except ROCKET-AF (Rivaroxaban; The Rivaroxaban Once Daily Oral Direct Factor Xa Inhibition Compared with Vitamin K Antagonism for Prevention of Stroke and Embolism Trial in Atrial Fibrillation) that enrolled a large patient population (55%) presenting after an ischemic stroke or transient ischemic attack, the phase III studies of NOACs mostly included primary prevention cohorts (≈80%).2 The mean time in therapeutic range of patients enrolled in warfarin arms of the 3 most commonly used NOACs was in the 55% to 62% range (rivaroxaban, dabigatran, and apixaban). Comparing NOACs to warfarin in that setting suggested equivalent benefit for embolic prevention and a lower risk of intracerebral hemorrhage (ICH) favoring NOACs in patients who were at low ICH risk during study enrollment. Real-world experience with NOACs has been positive to date when used in patient populations similar to their phase III studies, that is, patients with good kidney function, no prior history of ICH, and no perceived high risk for major hemorrhage. A specific reversal agent for dabigatran was FDA approved for use in emergency procedures or in uncontrolled bleeding, and another drug is awaiting approval for the more commonly used Factor Xa inhibitors. These are good news as reversal of anticoagulation can make …