Physicians' Academy for Cardiovascular Education

Lower bleeding risk with NOACs vs VKA in low-risk AF patients

Effectiveness and Safety of Standard-Dose Non vitamin K Antagonist Oral Anticoagulants and Warfarin Among Patients With Atrial Fibrillation With a Single Stroke Risk Factor - A Nationwide Cohort Study

Lip GYH, Skjøth F, Nielsen PB, et al. - JAMA Cardiol. 2017; published online ahead of print

Background

Randomized clinical trials of NOACs for stroke prevention included mainly AF patients with 2 or more stroke risk factors, with the exception of dabigatran or apixaban studies, in which a few AF patients had only 1 stroke risk factor [1,2].

In this observational cohort study, the comparative effectiveness and safety of standard-dose NOACs (dabigatran at 150mg twice daily, rivaroxaban at 20mg once daily, and apixaban at 5 mg twice daily) compared with warfarin, was evaluated in 14 020 low-risk AF patients included in Danish nationwide databases.

Only patients who had not received OAC treatment within 1 year before entering the study, and with 1 non-gender-related stroke risk factor in the CHA2DS2-VASc score, were recruited. Patients younger than 75 years or with a history of a prior stroke, TIA, systemic embolism, venous thromboembolism, valvular AF, or with contraindications for standard NOAC dose regimens because of renal impairment were excluded from the study. The mean follow-up was 2.6 ± 1.6 years.

The main safety endpoint, defined as ‘any bleeding’ included traumatic and non-traumatic intracranial bleedings, as well as gastrointestinal and clinically relevant non-major bleedings.

Main results

Conclusion

In a Danish observational cohort study, the risk of an ischemic stroke or systemic embolism was similar between NOACs compared with warfarin in AF patients with a single non-sex stroke CHA2DS2-VASc risk factor. Lower mortality rates were seen for all NOACs compared with warfarin, but this appeared to be the consequence of selective prescription patterns. The risk of any bleeding was lower for apixaban and dabigatran compared with warfarin.

These data should be interpreted with caution because of possible residual unmeasured confounding due to selective prescribing and unobserved comorbidities, or other factors known to influence treatment selection that were not present in the data set.

References

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Find this article online at JAMA Cardiology