NOACs proven safe, effective in Asians with atrial fibrillation

Use of nonvitamin K antagonist oral anticoagulants (NOACs) helps prevent thromboembolic events in Asian patients with atrial fibrillation (AF), with fewer bleeding events relative to warfarin therapy, according to the results of a study presented at the recent EHRA 2023.

“In Asian patients with AF, NOAC was effective and safe to prevent thromboembolic events with less bleeding compared to warfarin,” said the investigators led by associate professor Seung-Young Roh of Korea University in Seoul, Republic of South Korea.

“NOACs are effective to prevent stroke in patients with AF,” they noted. However, real world long-term data on the efficacy and safety of these drugs compared to warfarin in Asians are scarce.

To address this, Roh and colleagues performed this study and examined the safety and efficacy of NOAC in an Asian population diagnosed with AF. They reviewed the medical records of patients using the registry of four tertiary referral hospitals between 1 January 2012 and 31 December 2020. The primary outcome measured was the composite of thromboembolism, major bleeding, and all-cause mortality.

A total of 19,994 patients with AF (median age 72 years, 41.5 percent female, 35.5 percent on warfarin, median CHA2DS2-VASc score 3) who received oral anticoagulation were included in the analysis. [Roh, et al, EHRA 2023).

The rate of the composite of thromboembolism, major bleeding, and all-cause mortality was lower in the NOAC group as compared with the warfarin group (5.5 percent vs 6.0 percent per year; hazard ratio [HR] with NOAC, 0.70, 95 percent confidence interval [CI], 0.63‒0.77; p<0.001 for superiority).

Specifically, the rate of ischaemic event was 2.2 percent per year in the NOAC group compared with 2.8 percent per year in the warfarin group (HR, 0.56, 95 percent CI, 0.48‒0.65; p<0.001).

For major bleeding, the corresponding rates were 1.9 percent and 2.2 percent per year (HR, 0.69, 95 percent CI, 0.58‒0.82; p<0.001), while those for all-cause death were 1.9 percent vs 3.2 percent, respectively (HR, 0.85, 95 percent CI, 0.71‒1.02; p=0.08).

Octogenarian Asians

The above findings were consistent with those of a previous study, led by Hyue Mee Kim from the Department of Internal Medicine, Seoul National University Hospital in Seoul, Republic of Korea, which involved octogenarian Asian patients with AF.

Kim and colleagues reported the potential association of NOACs with reduced risks of thromboembolic events, major bleeding, and all-cause death compared with warfarin despite the use of reduced doses in most patients (85.6 percent). [PLoS One 2019;14:e0211766]

Patients who received NOAC had a lower risk of thromboembolic events (1.84 vs 2.71 per 100 person-years; HR, 0.134, 95 percent CI, 0.038‒0.479; p=0.002), major bleeding (1.48 vs 2.72 per 100 person-years; HR, 0.110, 95 percent CI, 0.024‒0.493; p=0.001), and all-cause death (2.57 vs 3.50 per 100 person-years; HR, 0.298, 95 percent CI, 0.108‒0.824; p=0.020).

Overall, 19 thromboembolic events and 18 major bleeding events occurred during 14 months of follow-up, according to the researchers.