Apixaban and Aspirin Equal in Preventing Stroke Recurrence in Cardiopathy: Daily Dose

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Last week, we reported on findings from a study published in JAMA that compared anticoagulation vs antiplatelet therapy for secondary stroke prevention in patients with cryptogenic stroke and evidence of atrial cardiopathy.

The study

Researchers recruited participants from 185 sites in the National Institutes of Health StrokeNet network and the Canadian Stroke Consortium. Inclusion criteria required age greater than 45 years, a clinical diagnosis of cryptogenic stroke, brain imaging to rule out hemorrhagic stroke and brain MRI and CT to rule out other etiologies. Key exclusion criteria, among other factors, included any history of atrial fibrillation (AF) or left ejection fraction <30%.

Eligible individuals were then screened for atrial cardiopathy, defined as at least one of 3 biomarkers known to be associated with a 2-fold greater risk of stroke: P-wave terminal force in ECG lead V1 greater than 5000 μV × ms, serum N-terminal pro-B-type natriuretic peptide (NT-proBNP) level greater than 250 pg/mL, or left atrial diameter index of 3 cm/m2 or greater on echocardiogram.

Of an initial pool of 3745 persons with cryptogenic stroke recruited between February 1, 2018, and December 14, 2022, 1015 were assessed as meeting at least 1 of the required criteria for cardiopathy. The final participants were randomly assigned in a 1:1 ratio to receive apixaban 5 mg twice daily (n = 507) or aspirin 81 mg once daily (n = 508).

The findings

The investigators reported that after a planned interim analysis in December 2022, the trial was stopped based on the finding that the hazard ratio (HR) for apixaban versus aspirin lay within the pre-specified interim boundaries for futility. There were no safety concerns identified at the time.

Participants had a mean age of 68.0 years, 54.3% were women, and 87.5% completed the full follow-up period.

After the mean follow-up period of 1.8 years, researchers identified the primary outcome of recurrent stroke in 40 participants in the apixaban group (annualized rate, 4.4%) and 40 patients in the aspirin group (annualized rate, 4.4%) (HR,1.00; 95% CI, 0.64 - 1.55). They also reported findings of a post-hoc analysis performed in 149 patients who had AF documented after randomization that revealed no significant difference in the rate of recurrent stroke between the group treated with apixaban (annualized rate, 1.8%) and with aspirin (annualized rate, 2.2%) (HR, 0.84; 95% CI, 0.19 - 3.74).

Analysis of secondary outcomes found recurrent stroke or death occurred in 67 patients in the apixaban group (annualized rate, 7.3%) and 62 patients in the aspirin group (annualized rate, 6.8%) (HR, 1.08; 95% CI, 0.76 - 1.52).

Authors' comment

"In patients with cryptogenic stroke and evidence of atrial cardiopathy without atrial fibrillation, apixaban did not significantly reduce recurrent stroke risk compared with aspirin."

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