麻豆传媒

Choice of direct oral anticoagulant (DOAC) mattered for clinical outcomes among adults with atrial fibrillation (Afib), a study based on U.S. insurance claims found.

Apixaban (Eliquis) users had significantly lower rates of ischemic stroke or systemic embolism than those on rivaroxaban (Xarelto, 6.6 vs 8.0 per 1,000 person-years, HR 0.82, 95% CI 0.68-0.98), according to researchers led by Michael Fralick, MD, PhD, of Brigham and Women's Hospital in Boston, reporting online in the .

Apixaban was also associated with better safety in terms of decreased incidence of intracranial hemorrhage or GI bleeding compared with rivaroxaban (12.9 vs 21.9 per 1,000 person-years, HR 0.58, 95% CI 0.52-0.66).

"Findings were robust across several subgroup and sensitivity analyses, including a population restricted to patients older than 70 years," the researchers wrote. The study wasn't initiated or funded by either drug's manufacturer.

In 2011, rivaroxaban became the first DOAC to be approved by the FDA for the indication of stroke prevention in non-valvular Afib. More than a year later, apixaban received from the agency.

In Fralick's retrospective cohort study, 39,351 people with non-valvular Afib seeking routine care who were newly prescribed apixaban were propensity-score matched to the same number newly prescribed rivaroxaban and followed over an average around 290 days.

All had been identified from a U.S. nationwide commercial healthcare claims database from Optum (most patients within Optum are covered by employer-sponsored insurance).

The investigators found 59,172 adults newly prescribed apixaban 5 mg and 40,706 prescribed rivaroxaban 20 mg. The apixaban group was slightly older, more likely to have a diagnosis of kidney or cardiovascular disease, and taking slightly more medications at baseline.

After propensity-score matching, baseline characteristics were well-balanced between groups. Mean age was 69 years. Women accounted for 40% of the cohort.

In terms of rare adverse events, hepatitis was relatively common in this population, occurring at 13.1 cases per 1,000 person-years with apixaban and 12.3 cases per 1,000 person-years with rivaroxaban. Vasculitis rates were numerically lower with apixaban compared with rivaroxaban (1.06 vs 1.21 per 1,000 person-years).

Because this was an observational study, unmeasured confounding may have played a role in the results. The authors noted they had incomplete lab data and lacked information on over-the-counter medication use. Moreover, patients' outcomes were defined by diagnostic codes rather than outcome adjudication, Fralick and colleagues cautioned.

"The results of our study are concordant with those of the among randomized controlled trials suggesting that apixaban was safer than rivaroxaban and with those of subsequent ," study authors maintained.

"Until head-to-head clinical trial data are available, the results of our study, which included a large sample of patients seen in routine care, provides updated evidence in support of ," they concluded.

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