Study: High Numbers of At-Risk Patients Stop Taking Anticoagulants

Most patients with a type of irregular heartbeat that calls for treatment with anticoagulants eventually stop taking them, with nearly a quarter quitting their medication in the first 3 months, a new study has found.

The findings, presented Monday at the 2016 American Heart Association (AHA) Scientific Sessions, offer the first glimpse of a long-term collaboration between the insurer Anthem and Boehringer Ingelheim, which makes the novel oral anticoagulant, dabigatran, sold as Pradaxa. The data presented at AHA in New Orleans represent the first part of a 3-phase project to gather information about patient treatment and adherence or oral anticoagulants (OACs), according to a statement from the pharmaceutical company.

An abstract presented in Monday’s poster session said researchers examined medical and pharmacy claims for newly diagnosed patients with non-valvular atrial fibrillation (NVAF) a heart rhythm disorder that causes a rapid, irregular heartbeat. Guidelines call for patients with NVAF to take OACs to reduce their stroke risk.¹

“For patients with NVAF, the primary goal of anticoagulation treatment is to reduce the risk of stroke,” said Sabine Rusk, MD, senior vice president, Medicine and Regulatory Affairs at Boehringer Ingelheim, who noted in a statement that atrial fibrillation accounts for more than 15% of all strokes in the United States. “It is critical that we continue to educate physicians on the benefits, risks, and importance of treatment to reduce this risk.”

Researchers from HealthCore examined records from 45,092 newly diagnosed with NVAF from from November 1, 2010, to November 30, 2013. Only 41.4% were prescribed OACs, which are warfarin, dabigatran, rivaroxaban, and apixaban. Compared with those left untreated, those treated were slightly younger (average age of 70 years ± 12.2 for treated patients, compared with an average age of 71 ±14.3 for untreated), and more likely to be male (59.7% vs 52.5%). Patients who were not prescribed OACs also had higher stroke risk and higher bleed risk.

After an average follow-up period of 2.25 years, researchers found that nearly three-quarters of the patients (72.7%) completely discontinued OAC treatment, including 23% who stopped within 3 months. More than half (55%) had stopped taking medication at the 1-year mark.

The researchers noted in their abstract that the patients with the highest stroke risk also had the highest bleed risk. While this phase of the collaboration did not explore the reasons why patients stopped taking their medication, future phases will look at this question, according to the statement from Boehringer Ingelheim.

The study was funded by Boehringer Ingelheim.

Comparative effectiveness study. A study of a national claims database from Taiwan has found that the novel oral anticoagulants dabigatran, sold as Pradaxa, and rivaroxaban, sold as Xarelto, are associated with lower risks of ischemic stroke and lower risks of all-cause death, according to a study released today at the 2016 American Heart Association Scientific Sessions.

The findings were scheduled to be presented during the “Best of AHA Specialty Conferences” poster session. Researchers extracted claims for 16,930 adults diagnosed with atrial fibrillation and prescribed warfarin (11,151) dabigatran (4280) and rivaroxaban (1499). The mean age was 72.7 years, and the median follow-up was 8.7 months. The study period was June 1, 2012 to December 31, 2013.

Compared with patients taking warfarin, those taking dabigatran had lower risks of ischemic stroke (aHR 0.48, 95% CI 0.39-0.59), as did those taking rivaroxaban (aHR 0.50, 95% CI, 0.36-0.69). Both NOACs were also associated with a lower risk of all-cause death than warfarin: aHR 0.37, 95% CI 0.38-0.46 for dabigatran and 0.50, 95% CI 0.37-0.66 for rivaroxaban. The NOACs were also associated with lower risk of intracranial hemorrhage, and arterial embolism/thrombosis.²

References

1. Jain R, Fu AC, Weng C, et al. Treatment and persistence with oral anticoagulants among newly diagnosed patients with non-valvular atrial fibrillation in a commercially insured and Medicare Advantage population. Presented at the 2016 American Heart Association Scientific Sessions, November 14, 2016. Abstract M2075.

2. Lai CL, Chen HM, Lin TT, et al. Comparative effectiveness and clinical safety between dabigatran, rivaroxaban, and warfarin. Presented at the 2016 American Heart Association Scientific Sessions, November 14, 2016. Abstract QCORI10.