Background: Direct oral anticoagulants have proven to be more efficacious, safe, and easy to use, compared with warfarin, in patients with atrial fibrillation (Afib). An indirect comparison showed apixaban to be more effective and safer than rivaroxaban. But randomized controlled trials and head-to-head comparison data regarding the same have been lacking until now.
Study design: Retrospective cohort study.
Setting: A U.S. nationwide commercial health care claims database was searched for persons older than 18 years, with a new diagnosis of atrial fibrillation or flutter who were started on apixaban or rivaroxaban from Dec. 28, 2012, to Jan. 1, 2019.
Synopsis: Optum Clinformatics was used to identify a total of 99,878 patients who were eligible for the analysis. Of these patients, 39,531 newly prescribed apixaban patients were propensity score matched to 39,351 newly prescribed rivaroxaban patients. After propensity score matching, the study found ischemic stroke or systemic embolism rate for new apixaban users to be 6.6 events per 1,000 person-years versus 8.0 events per 1,000 person-years for new rivaroxaban users (hazard ratio, 0.82; 95% confidence interval, 0.68-0.98). The rate of major bleeding after propensity score matching was 12.9 per 1,000 person-years for new apixaban users versus 21.9 per 1,000 person-years for new rivaroxaban users (HR, 0.58; 95% CI, 0.52-0.66).
This observational study has several limitations including an inability to balance unmeasured confounding factors, both ICD-9 and ICD-10 codes being used for defined outcomes, an inability to account for time-varying confounders for stroke or bleeding, an inability to capture patients from locations other than primary internist and cardiologists, and a shorter follow-up period, compared with that of clinical trials.
Bottom line: In routine practice, apixaban is more effective and safer than rivaroxaban with a lower rate of strokes, systemic embolism, and major bleeding.
Citation: Fralick M et al. Effectiveness and safety of apixaban compared with rivaroxaban for patients with atrial fibrillation in routine practice: a cohort study. Ann Intern Med. 2020 Apr 7..
Dr. Almagdub is a hospitalist and assistant professor of medicine at UK HealthCare, Lexington, Ky.