Safety of NOAC instead of aspirin in ACS patients

ACC 2017 A safety study of rivaroxaban versus aspirin on top of P2Y12 therapy in ACS patients, showed that this dual antithrombotic regimen had a similar risk of clinically significant bleeding.

Background

Dual antiplatelet therapy (DAPT) has been the cornerstone of the treatment of ACS and is recommended by guidelines for the post-ACS therapy. However, despite optimal DAPT, approximately 10% of ACS patients present with recurrent ischaemic events. The addition of certain anticoagulants to DAPT led to further reduction of ischaemic events in this setting, with a 3- to 4-fold increase in major bleedings. Studies including patients with an indication for full-dose oral anticoagulation undergoing PCI, suggested, however, that withholding aspirin was not associated with an increase in ischaemic events but with a lower risk of major bleedings.

In this study, the safety of a low dose of the oral anticoagulant rivaroxaban, a direct factor Xa inhibitor, was compared with aspirin, on top of a P2Y12 inhibitor, in 3037 post-ACS patients.

Main results

• The median duration of treatment with blinded study drug was 291 days (IQR: 239–354) and the median duration of follow-up was 326 days (IQR: 284–383).
• Premature treatment discontinuation occurred in 11% of patients treated with rivaroxaban vs. 13% of patients treated with aspirin. Early discontinuation of P2Y12 inhibitor therapy was 4.4% in the overall population.
• 49% of patients presented with STEMI, 40% with NSTEMI, and 11% with unstable angina. 87% of patients were treated with PCI for their index ACS before randomisation.
• The primary endpoint of TIMI non-CABG clinically significant bleeding occurred in 5% of patients on rivaroxaban and 5% of patients on aspirin (HR: 1.09; 95% CI: 0.80–1.50; P=0.5840). The most common type of bleeding was TIMI bleeding requiring medical attention (4% in the rivaroxaban group and 4% in the aspirin group), with a low frequency of severe or major bleeding events using TIMI bleeding definitions.
• Using the ISTH definition for major bleeding, a higher rate of bleeding was noted with rivaroxaban compared with aspirin (2% vs. 1%; P=0.0420), but there were no differences using GUSTO or BARC bleeding definitions, regardless of severity.
• The frequency of the composite ischaemic endpoint of CV death, MI, stroke, or definite stent thrombosis was 5% in both groups (HR: 1.06; 95% CI: 0.77–1.46; P=0.7316).

Conclusion

Disclosures

Our coverage of ACC.17 is based on the information provided during the congress.

The accompanying article was published today in The Lancet