A study of nursing home residents with atrial fibrillation (AF) has found that the use of direct-acting oral anticoagulants (DOACs) has greatly increased since their introduction. As their use increased, use of warfarin decreased.
Nursing home residents with AF have a high risk for ischemic stroke and bleeding events, which is why researchers set out to find out whether DOAC use in nursing home residents was changing.
A national estimate in 2004 indicated that less than one-third of this high‐risk population were using anticoagulants, writes Matthew Alcusky, PharmD, lead author and assistant professor of epidemiology at the University of Massachusetts Medical School in Worcester The study was published in the May 7 issue of the Journal of the American Heart Association.
Alcusky and colleagues estimated the prevalence of oral anticoagulant (OAC) use among Medicare fee-for-service beneficiaries with AF who resided in long-term nursing homes from 2011 through 2016. They examined Medicare Part D claims for apixaban (Eliquis), dabigatran (Pradaxa), edoxaban (Savaysa, Lixiana), rivaroxaban (Xarelto), and warfarin (Coumadin).
The proportion of residents with AF treated with oral anticoagulants was 42.4% as of July 1, 2011, at which time the majority of those treated were using warfarin. Anticoagulant use remained stable through the close of 2013, at which time 42.8% of residents were treated, 35.2% with warfarin and 7.7% with DOACs.
Then, starting in the first half of 2014, the prevalence of anticoagulant use increased during each half‐year through the end of the study (December 31, 2016), at which time 47.8% of residents were treated. “This period (2014–2016) of increasing anticoagulant use coincided with a decline in warfarin use and a rise in DOAC use such that by the end of 2016, the prevalence of warfarin use (24.7%) was nearly equal to DOAC use (23.1%),” Alcusky writes.
Dabigatran use increased during the early study period and peaked in the first half of 2012 before stabilizing in the range of 2.2% to 3.1% through 2016. In contrast, the prevalence of rivaroxaban and apixaban use continued to rise through the end of the study.
Over the five years (2012-2016) after its market entry, rivaroxaban use increased from 0.4% to 8.3%. During the four full years after market entry (2013–2016), apixaban use also rose from 0.1% to 12.6%. In contrast, edoxaban use remained rare after its approval in 2015.
“Increases in anticoagulant use among U.S. nursing home residents with atrial fibrillation coincided with declining warfarin use and increasing DOAC use,” Alcusky writes.
Before the availability of DOACs, use of oral anticoagulants was reported to be low among high‐risk older adults with AF in the United States and internationally, according to the researchers. Estimates of anticoagulant use among U.S. nursing home residents with AF in the 1990s and early 2000s suggested that around two-thirds of residents were not treated with warfarin.
“At that time, reports of high rates of adverse events and labile international normalized ratios for nursing home residents were accompanied by physician uncertainty about the relative benefits and risks of warfarin in the long‐term care setting. This uncertainty about the net benefit of treatment continues to affect anticoagulant prescribing decisions for high‐risk older adults,” Alcusky writes.
Even after a marked increase in anticoagulant use between 2004 and 2016, more than half of nursing home residents with AF remain untreated, the researchers discovered. “The large majority of residents with AF are at high risk for stroke, evidenced by 85% of residents with a CHA2DS2‐Vasc score of ≥4,” Alcusky writes.
However, with recent availability of DOAC reversal agents and emerging observational evidence reinforcing trial findings in real‐world populations, including the frail, it is likely the gradual increase in anticoagulation of nursing home residents and ongoing shift from warfarin to DOACs will continue, according to Alcusky.