WASHINGTON – The off-label use of novel oral anticoagulants for stroke prevention in patients with valvular atrial fibrillation has climbed steeply since the drugs reached the marketplace, mirroring the medications’ rapid adoption for the approved indication of preventing strokes in nonvalvular AF, according to Dr. Sandeep Mahrendra Jani*.
An analysis of 190,227 nonvalvular atrial fibrillation (NVAF) patients in 95 practices participating in the American College of Cardiology’s National Cardiovascular Data Registry – PINNACLE Registry – showed that during the first quarter of 2011, just 4.8% were on dabigatran, the sole novel oral anticoagulant then available. By the fourth quarter of 2012, however, 14.9% of NVAF patients were on a novel oral anticoagulant, either dabigatran or the subsequently approved rivaroxiban, he reported at the annual meeting of the ACC.
Similarly, among 2,142 registry participants with valvular atrial fibrillation (AF), the use of any novel oral anticoagulant shot up from 2.7% in the first quarter of 2011 to 13.8% in the fourth quarter of 2012, noted Dr. Jani of Medstar Washington (D.C.) Hospital Center.
During this time – prior to the arrival of apixiban on the market – the use of warfarin for stroke prevention in patients with NVAF declined from 47.9% to 44.3%. Among patients with valvular atrial fibrillation, the prevalence of warfarin therapy fell from 65.8% in the first quarter of 2011 to 60.1% in fourth quarter 2012.
During the first quarter of 2011, 51.2% of all patients with NVAF and 66.4% with valvular AF were on any oral anticoagulant. By fourth quarter 2012, these rates had increased to 56.9% and 66.8%, respectively.
The use of dabigatran in patients with valvular AF took a hit in late 2012 in response to the premature halt of the RE-ALIGN (Dabigatran Etexilate in Patients With Mechanical Heart Valves) trial, followed by the Food and Drug Administration’s warning against using dabigatran in patients with mechanical heart valves. Dabigatran was used by 2.7% of valvular AF patients in the first quarter of 2011, rising steadily to 12.1% by the third quarter of 2012, then plunging to just 1.4% in the year’s final quarter.
In light of the rapidly accelerating use of novel oral anticoagulants in patients with valvular AF, despite a lack of evidence of efficacy for stroke prevention in this setting, further studies are a priority, Dr. Jani said.
The PINNACLE registry is funded by the ACC, with founding sponsorship provided by Bristol-Myers Squibb and Pfizer. Dr. Jani reported having no relevant financial conflicts.
*Correction, 4/29/2014: An earlier version of this article misstated the name of study author Dr. Sandeep Mahrendra Jani.