乌鸦传媒

Direct oral anticoagulants (DOACs) appeared safer and more effective than warfarin for people with valvular atrial fibrillation (Afib) in a retrospective propensity score-matched analysis.

Patients newly prescribed DOACs from 2010 to 2019 had rates of combined ischemic stroke or systemic embolism reach 3.9 per 100 person-years, a significant reduction from the 6.0 events per 100 person-years observed with peers newly prescribed warfarin (HR 0.64, 95% CI 0.59-0.70).

As for safety, major bleeding rates, counting intracranial or GI bleeds, totaled 7.1 vs 10.6 events per 100 person-years (HR 0.67, 95% CI 0.63-0.72), according to a group led by Ghadeer Dawwas, MSc, PhD, of the Perelman School of Medicine at the University of Pennsylvania, Philadelphia, writing in .

"These data may be used to guide risk-benefit discussions regarding anticoagulant choices for patients with valvular Afib," Dawwas' team said.

"Our results suggest that patients with a broad definition of VHD [valvular heart disease] may be able to safely use DOACs in accordance with . However, because the sample of patients with mitral valve regurgitation or stenosis was limited, further study is required," study authors noted.

In the study, apixaban (Eliquis) and rivaroxaban (Xarelto) were consistently associated with fewer effectiveness and safety events compared with warfarin; dabigatran (Pradaxa) was also tied to reduced bleeding, but was no better than warfarin for effectiveness (HR 1.03, 95% CI 0.81-1.31).

"We found a gradual shift in prescribing from warfarin to DOACs throughout the study period, consistent with prior research suggesting that DOACs are commonly prescribed for valvular Afib. This is unsurprising given warfarin's shortcomings," Dawwas and colleagues wrote.

"Unlike warfarin, DOACs have relatively short half-lives, no drug-food interactions, fewer drug-drug interactions, and convenient dosing and do not require routine laboratory monitoring. These advantages have led to rapid uptake of DOACs in patients with nonvalvular Afib and have positioned DOACs as first-line treatment options according to international guidelines," the group said.

Evidence for the effectiveness and safety of DOACs in valvular Afib remains limited, however, and few DOAC trials have included these patients, the authors noted.

The present study included valvular Afib patients who were new users of DOACs (off-label) or warfarin. Participants were identified from OptumInsight Clinformatics, an administrative database capturing a privately insured U.S. population.

Just over 56,000 patients were matched into DOAC-warfarin pairs for the analysis. Mean age was 81, and the cohort was roughly split between sexes. A CHA₂DS₂-VASc score ≥3 was recorded for 17% of people; HAS-BLED scores ≥2 were noted for 15%.

Median follow-up was 134 days for DOAC users and 124 days for warfarin users.

Such short follow-up was a major limitation of the study, Dawwas' group acknowledged.

Furthermore, the investigators lacked data on lifestyle variables, over-the-counter prescriptions, severity of valvular disease; and information on prescribing clinicians.

"Finally, the study results may not be generalizable to patients with valvular Afib without commercial health insurance or those with surgical or transcatheter valve replacement who do not have Afib," the group warned.

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