Apixaban for stroke prevention in subclinical atrial fibrillation detected by an implantable cardiac monitor: A subgroup analysis of ARTESiA.

BACKGROUND

The ARTESiA trial randomized patients with a pacemaker (PM), implantable cardioverter-defibrillator (ICD), or implantable cardiac monitor (ICM) and with subclinical atrial fibrillation to either apixaban or aspirin.

OBJECTIVE

We aimed to explore the effects of apixaban in the subset of patients with an ICM.

METHODS

We assessed the efficacy outcome of stroke or systemic embolism and the safety outcome of major bleeding, stratifying by device type.

RESULTS

Of 4012 participants, 209 (5.2%) had ICM and 3803 (94.8%) had PM/ICD. Patients with ICM were younger (74.9 ± 7.4 vs 76.9 ± 7.6 years) and more likely to be female (50.2% vs 35.3%) and to have a previous stroke (24.9% vs 7.7%) than those with PM/ICD. In the ICM cohort, stroke/systemic embolism occurred in 1 of 103 in the apixaban group (0.3%/year) vs 9 of 106 in the aspirin group (2.6%/year) (hazard ratio [HR], 0.11; [95% confidence interval {CI}, 0.01-0.88]; absolute risk reduction [ARR] 2.31%/year [95% CI, 0.55-4.07]). The corresponding rates in the PM/ICD cohort were 0.8%/year with apixaban vs 1.2%/year with aspirin (HR, 0.69 [95% CI, 0.49-0.98]; ARR 0.36%/year [95% CI, 0.02-0.70]; Pinteraction = .078 and .002, respectively). Among patients with ICM, major bleeding occurred at 1.3%/year vs 1.1%/year for apixaban vs aspirin (HR, 1.13 [95% CI, 0.30-4.31]). No significant difference in HR or ARR was observed across the device types (Pinteraction = .808 and .406, respectively).

CONCLUSION

In ARTESiA, patients with ICM experienced a stroke rate of 2.6%/year on aspirin, higher than that in the remaining trial population. The risk was significantly reduced by apixaban, consistent with the overall ARTESiA results.