The Investigator-initiated, double-blind, Non vitamin K antagonist Oral anticoagulants in Patients with Atrial High-Rate Episodes Trial (NOAH-AFNET 6)

Presented at the ESC congress 2023 by: Paulus Kirchhof, MD - Hamburg, Germany

Introduction and methods

In 20% of patients with an implanted pacemaker, defibrillator, or loop recorder atrial high-rate episodes (AHRE) are detected. These AHRE are rare and short and resemble atrial fibrillation. Also, they are detected in up to 30% of elderly patients with CVD. Clinicians may prescribe oral anticoagulation (OAC) in patients with AHRE, but evidence of effectiveness is lacking.

Therefore, the NOAH-AFNET 6 trial was performed. This was an investigator-initiated, randomized, double-blind, double-dummy trial in which the effect of anticoagulation with edoxaban was compared to no anticoagulation (placebo or aspirin based on accepted indications). In total, 2,536 patients with AHRE were enrolled who had CV conditions (CHA₂DS₂VASc score of 4). Median follow-up was 21 months.

The primary outcome was a composite of stroke, systemic embolism, or CV death. The composite safety outcome was major bleeding or all-cause death.

Main results

- The primary outcome of stroke, systemic embolism or CV death occurred in 83 patients in the edoxaban group vs. in 101 patients in the placebo group (P=0.15).

- Major bleeding of death was increased in the edoxaban group compared to the placebo group (149 patients vs. 114 patients; HR 1.31, 95%CI:1.07-1.67, P=0.03).

Conclusion

In the NOAH-AFNET 6 trial, treatment of patients with AHRE with edoxaban did not result in prevention of stroke, systemic embolism or CV death and did increase the rate of bleeding compared to patients without anticoagulation.

Paulus Kirchhof said: “NOAH – AFNET 6 demonstrates that anticoagulation should not be used in patients with AHRE until atrial fibrillation is documented by ECG. Better methods to estimate stroke risk in patients with rare atrial arrhythmias are needed.”

During the discussion it was noted that data of the ARTESIA trial are anticipated and will further inform clinicians on the use of anticoagulation in patients with subclinical AF.

- Our reporting is based on the information provided at the ESC Congress -

Watch the video by Paulus Kirchhof The results of the NOAH-AFNET 6 trial were simultaneously published in the NEJM