Office of Research & Development |
  |
Photo: ©iStock/clubfoto
January 7, 2025
By Tristan Horrom
VA Research Communications
"VA is uniquely positioned to provide end-to-end care for Veteran patients."
In one of the first research collaborations between VA and the Food and Drug Administration (FDA) on a drug intervention trial, a VA research team with support from FDA will study which of two medications works more effectively and is safer for treating Veterans with nonvalvular atrial fibrillation, a heart condition that causes irregular heart rhythm and puts patients at risk for stroke.
The study, which is scheduled to begin recruiting in the spring of 2025 and ultimately will include 100 VA sites nationwide, will compare real-world clinical outcomes for patients taking either apixaban or rivaroxaban, two FDA-approved blood thinners that have been in widespread clinical use for over a decade.
Veterans volunteering for the trial will be prescribed one of the two blood thinners, and then the researchers will follow them via the VA’s electronic health record. By accessing such health record data electronically, the researchers will be able to conduct the study as a point-of-care trial, meaning Veterans can participate as part of their normal health care at their regular VA facility rather than in a specialized academic setting. This will allow for a broader and more diverse study population from both urban and rural health care settings, which will help make the results more robust.
In addition to informing healthcare provided to Veterans, the study is relevant to FDA efforts to promote the use of reliable and relevant data from routine clinical practice (real-world data) in drug development.
Veterans participating in the trial will go about their normal lives and care once they are assigned to either the apixaban or rivaroxaban group, so they will not face any extra burdens from additional visits. Since both drugs are already being used widely in clinical practice, the researchers do not see any additional risk to patients.
“VA is uniquely positioned to provide end-to-end care for Veteran patients, from initial atrial fibrillation screening through treatment and monitoring of risk factors such as hypertension and obesity,” said study co-lead Dr. William Boden, of the VA Boston Healthcare System. “As the largest integrated health care system in the U.S., VA has significantly scaled its atrial fibrillation and arrhythmia care programs.
“The clinical care ecosystem is administered largely by non-study personnel,” he continued. “The VA pharmacists who run the nation-wide anticoagulation clinics will be instrumental to making sure patients are being properly enrolled, that they’re being put on the right agent, that there’s no confusion with dosing or medication changes, and that they are being monitoring closely for any bleeding complications or side effects. Veterans will have their whole care teams involved.”
Over the past decade, direct oral anticoagulants such as apixaban (sold commercially as Eliquis) or rivaroxaban (sold commercially as Xarelto) have increasingly replaced the older drug warfarin as the preferred blood thinner treatment for atrial fibrillation patients at risk of stroke and embolism since they have been shown to be safer than warfarin. While the newer medications are prescribed widely both in the United States and internationally, they have never been compared directly before. In addition to comparing the beneficial effects of the two drugs, the trial may also reveal potential risks and benefits of the drugs for different patient types, such as women, the elderly, and those with abnormal kidney function.
“Because they have never been compared directly, we don’t really know for sure if one drug might be more effective in preventing stroke, or if one drug might be safer in terms of bleeding risk,” explained study co-lead Dr. Cara Pellegrini of the San Francisco VA Health Care System. “So, the two main things that we’re going to be looking at are efficacy – how effective is the medication at preventing stroke? – and safety – how likely is it for someone to have a bleeding event on these medications?”
The researchers are seeking to enroll 10,000 Veterans 65 or older who have nonvalvular atrial fibrillation, but the study will also include a subset of younger Veterans with atrial fibrillation. The VA research team is also making a special effort to recruit women and people from different ethnic and racial backgrounds for the trial, as well as a mix of rural- and urban-living Veterans, to make the study group as representative of the overall VA population as possible.
Veterans will be recruited through their primary care providers and VA’s anticoagulation clinics and followed for at least three years. Patients diagnosed with atrial fibrillation are often referred to anticoagulation clinics for specialty care and monitoring.
At least 10.5 million people in the United States are estimated to have atrial fibrillation, the majority of whom are over 65 years of age. Atrial fibrillation, the most common type of irregular heartbeat, increases the risk of stroke five-fold. About 15,000 Veterans suffer a stroke each year, and atrial fibrillation is a major cause of such events.
The VA’s Office of Research and Development is also planning a second arm of the study, in which they will test a screening tool to test asymptomatic patients at high risk for atrial fibrillation. While this screening arm of the study will be conducted alongside the treatment trial, it will start about a year after the treatment trial begins and will recruit a separate set of up to 25,000 Veteran participants as the screening trial does not involve FDA funding.
VA Research Currents archives || Sign up for VA Research updates
