UC Study Finds Direct Oral Anticoagulants May Help Some AF Patients

Researchers at the University of Cincinnati (UC) College of Medicine have tested a computerized decision analytic model to determine the benefit an additional class of blood-thinners—direct oral anticoagulants (DOACs) has for patients with atrial fibrillation.

DOCS include four new drugs—rivaroxaban, apixaban, dabigatran and edoxaban—and are now used along with warfarin, a standard medication, for treating atrial fibrillation (AF) patients at UC Health, the affiliate healthcare system of the College of Medicine.

The research team used the decision analytic model to review the medical data of 5,121 adults with nonvalvular atrial fibrillation seen in the UC Health system between January and December 2016 and found that aggregate life expectancy would be improved by 1,508 quality adjusted life years (QALY), explains Mark Eckman, MD, Posey Professor of Clinical Medicine, UC Health physician, and lead study investigator.

The computerized analytic model is known as the Atrial Fibrillation Decision Support Tool (AFDST) and is integrated into UC Health’s electronic health record system. AFDST predicted that patients who have a low risk of bleeding while on blood thinners and a moderate-to-high risk of stroke are the biggest potential beneficiaries while using DOAC therapies. They might see gains of up to 1.8 QALYs by receiving appropriate blood-thinning therapy now that DOACs are available.

The research team’s findings are available online in the American Heart Journal. 

Quality adjusted life years are a calculation of well-being following a treatment or intervention measured in terms of a person’s ability to carry out the activities of daily life free from pain and mental disturbance.

AFDST uses the patient’s age, gender and history of stroke or bleeding, along with whether the individuals had vascular disease, a history of myocardial infarction, alcoholism, intracranial hemorrhage, hypertension, congestive heart failure, diabetes, abnormal liver and other health aliments. The model assigns points based on these characteristics and offers a recommendation along with guidelines on treatment of atrial fibrillation from the American College of Cardiology/American Heart Association/Heart Rhythm Society. AFDST has been in use for about two years and now includes DOAC therapies. 

When DOACs are a therapeutic option, the AFDST recommended oral anticoagulant therapy for 4,134 patients (81 percent) in the study and no antithrombotic therapy or aspirin for 489 patients (9 percent). When warfarin was the only option, oral anticoagulant therapy was recommended for 3,228 patients (63 percent) and no antithrombotic therapy or aspirin for 973 patients (19 percent). Overall, 1,508 QALYs could be gained were treatment changed to that recommended by the AFDST, according to team’s published findings.

Eckman says clinical trials have found that the four DOACs are as good as warfarin, a medication long used for treating AF and stroke.  "In some cases they are even better in terms of stroke prevention,” he says. "They really shine because of their lower risk of bleeding in the brain. The major side effect of all these anticoagulants is bleeding since their role is to thin the blood.”

"Patients with a high risk of stroke and low risk of bleeding benefit the most from anticoagulant therapy,” says Eckman. "While some patients may benefit from a number of different oral anticoagulants there are more nuanced factors that may affect the best decision for any given patient. These may include out-of-pocket costs for the medications, availability of reversal agents, and how often a patient has to come in for blood tests. The AFDST helps physicians and patients consider these factors in making a decision together.”

Atrial fibrillation, an irregular often rapid heart rhythm, affects up to 10 percent of the population age 70 and older, explains Eckman. It also presents a strong risk factor for stroke due to clots forming in the left atrium that then travels to the rest of the body including the brain.

National as well as local data suggest that physicians aren’t providing appropriate blood thinning therapy for a large enough portion of patients with atrial fibrillation, says Eckman. Only 60 percent of patients with atrial fibrillation are getting blood thinning therapies with anticoagulants, so there is under treatment when it comes to stroke prevention.

Blood thinning therapies do come with the risk of causing major bleeding so there is a balance of risk and benefit that patients and physicians must weigh in using them, says Eckman.

Eckman said the computerized tool allows physicians to see what the life expectancy of a patient may be based on whether they receive no therapy, aspirin, warfarin, or any of the other oral anticoagulants as part of their regimen to combat the risk of stroke or bleeding in the brain.

Other faculty and staff in the UC College of Medicine or UC Health contributing to this research are: Alexandru Costea, MD, Mehran Attari, MD, Jitender Munjal, MD, Ruth Wise, Carol Knochelmann, Matthew Flaherty, MD, Pete Baker, Robert Ireton, Brett Harnett, Anthony Leonard, PhD, Dylan Steen, MD, Adam Rose, MD, and John Kues, PhD.

The research was supported in part by a grant from the Heart Rhythm Society funded by Boehringer-Ingelheim Pharmaceuticals; and the National Institutes of Health/National Center for Advancing Translational Sciences.

Disclosures indicate Matthew Flaherty, MD, served as a consultant to Janssen, marker of rivaroxaban, and is on an advisory board for CSL Behring, maker of dabigatran, and Portola. Flaherty also serves on a speaker’s bureau for CSL Behring and Janssen. Eckman has current or recent investigator-initiated grant funding from Pfizer Educational Group, Bristol-Myers Squibb/Pfizer Education Consortium and the Cystic Fibrosis Foundation.