In the JournalsPerspective

Aspirin, rivaroxaban similar for recurrent stroke prevention in certain patients

In patients with embolic stroke of undetermined source and carotid atherosclerosis, aspirin and rivaroxaban were equally effective at preventing recurrent stroke, but aspirin was safer, according to new data from the NAVIGATE ESUS trial.

According to the analysis published in Stroke, there was no statistically significant difference in the primary outcome of ischemic stroke recurrence at a median follow-up of 11 months between the therapies in patients with carotid stenosis (rivaroxaban, 5 per 100 patient-years; aspirin, 5.9 per 100 patient-years; HR = 0.85; 95% CI, 0.39-1.87) or patients with carotid plaques (rivaroxaban, 5.9 per 100 patient-years; aspirin, 4.9 per 100 patient-years; HR = 1.2; 95% CI, 0.86-1.68).

Researchers also found that patients with carotid plaque and treated with rivaroxaban (Xarelto, Janssen/Bayer) had higher incidence of major bleeding than those treated with aspirin (2 per 100 patient-years vs. 0.5 per 100 patient-years; HR = 3.75; 95% CI, 1.63-8.65).

“It has been hypothesized that the absence of benefit for stroke reduction in the NAVIGATE-ESUS trial could be attributed to the inclusion of patients with non-stenotic carotid atherosclerosis, who may respond better to antiplatelet inhibition rather than oral anticoagulation,” George Ntaion, MD, of the department of internal medicine at the University of Thessaly, Larissa, Greece, and colleagues wrote. “In our analysis, there was no statistically significant treatment interaction between patients with and without carotid stenosis or plaque; however, there were trends of differing treatment effects among participants with vs. without carotid atherosclerosis.”

According to the study, compared with patients with carotid stenosis, those without had similar incidence of ischemic stroke recurrence (with, 5.4 per 100 patient-years; without, 4.9 per 100 patient-years; HR, 1.11; 95% CI, 0.73-1.69).

Additionally, patients with carotid plaque had a significantly higher rate of ischemic stroke than those without (5.4 per 100 patient-years vs. 4.3 per 100 patient-years, HR; 1.23; 95% CI, 0.99-1.54).

Researchers analyzed patient data (mean age, 67 years; 38% women) from the NAVIGATE-ESUS trial, comparing once-daily 15-mg rivaroxaban with 100-mg aspirin, to determine the efficacy of antithrombotic regimens in patients with carotid atherosclerosis, identified as either carotid stenosis or carotid plaque.

The researchers stated that the subanalysis of carotid stenosis was performed in 4,644 patients (38.1% women) and the subanalysis of carotid plaque was performed in 7,212 patients (38.5% women).

“Aspirin was safer than rivaroxaban, consistent with the findings in the overall NAVIGATE-ESUS population,” the authors wrote. “Despite trends in differing treatment effects, there was no significant treatment interaction between patients with and without carotid stenosis or plaque. Carotid plaque was much more often present ipsilateral to the qualifying ischemic stroke than contralateral, supporting an important etiological role of nonstenotic carotid atherosclerosis in ESUS patients.” – by Scott Buzby

Disclosures: Ntaios reports he received speaker fees, advisory board fees and research support from Amgen, Bayer, Bristol-Myers Squibb/Pfizer, Boehringer Ingelheim, Elpen, Galenica, Sanofi and Winmedica. All fees were paid to his institution, the University of Thessaly. Please see the study for all other authors’ relevant financial disclosures.

In patients with embolic stroke of undetermined source and carotid atherosclerosis, aspirin and rivaroxaban were equally effective at preventing recurrent stroke, but aspirin was safer, according to new data from the NAVIGATE ESUS trial.

According to the analysis published in Stroke, there was no statistically significant difference in the primary outcome of ischemic stroke recurrence at a median follow-up of 11 months between the therapies in patients with carotid stenosis (rivaroxaban, 5 per 100 patient-years; aspirin, 5.9 per 100 patient-years; HR = 0.85; 95% CI, 0.39-1.87) or patients with carotid plaques (rivaroxaban, 5.9 per 100 patient-years; aspirin, 4.9 per 100 patient-years; HR = 1.2; 95% CI, 0.86-1.68).

Researchers also found that patients with carotid plaque and treated with rivaroxaban (Xarelto, Janssen/Bayer) had higher incidence of major bleeding than those treated with aspirin (2 per 100 patient-years vs. 0.5 per 100 patient-years; HR = 3.75; 95% CI, 1.63-8.65).

“It has been hypothesized that the absence of benefit for stroke reduction in the NAVIGATE-ESUS trial could be attributed to the inclusion of patients with non-stenotic carotid atherosclerosis, who may respond better to antiplatelet inhibition rather than oral anticoagulation,” George Ntaion, MD, of the department of internal medicine at the University of Thessaly, Larissa, Greece, and colleagues wrote. “In our analysis, there was no statistically significant treatment interaction between patients with and without carotid stenosis or plaque; however, there were trends of differing treatment effects among participants with vs. without carotid atherosclerosis.”

According to the study, compared with patients with carotid stenosis, those without had similar incidence of ischemic stroke recurrence (with, 5.4 per 100 patient-years; without, 4.9 per 100 patient-years; HR, 1.11; 95% CI, 0.73-1.69).

Additionally, patients with carotid plaque had a significantly higher rate of ischemic stroke than those without (5.4 per 100 patient-years vs. 4.3 per 100 patient-years, HR; 1.23; 95% CI, 0.99-1.54).

Researchers analyzed patient data (mean age, 67 years; 38% women) from the NAVIGATE-ESUS trial, comparing once-daily 15-mg rivaroxaban with 100-mg aspirin, to determine the efficacy of antithrombotic regimens in patients with carotid atherosclerosis, identified as either carotid stenosis or carotid plaque.

The researchers stated that the subanalysis of carotid stenosis was performed in 4,644 patients (38.1% women) and the subanalysis of carotid plaque was performed in 7,212 patients (38.5% women).

“Aspirin was safer than rivaroxaban, consistent with the findings in the overall NAVIGATE-ESUS population,” the authors wrote. “Despite trends in differing treatment effects, there was no significant treatment interaction between patients with and without carotid stenosis or plaque. Carotid plaque was much more often present ipsilateral to the qualifying ischemic stroke than contralateral, supporting an important etiological role of nonstenotic carotid atherosclerosis in ESUS patients.” – by Scott Buzby

Disclosures: Ntaios reports he received speaker fees, advisory board fees and research support from Amgen, Bayer, Bristol-Myers Squibb/Pfizer, Boehringer Ingelheim, Elpen, Galenica, Sanofi and Winmedica. All fees were paid to his institution, the University of Thessaly. Please see the study for all other authors’ relevant financial disclosures.

    Perspective
    Larry B. Goldstein

    Larry B. Goldstein

    The primary study found that 15 mg of rivaroxaban per day did not reduce stroke compared with aspirin in patients with embolic stroke of undetermined source. This is an exploratory subgroup analysis that is appropriate for hypothesis generation.  Because of this, and because the parent trial was neutral, this secondary analysis should not in itself affect clinical practice. There is no current evidence that anticoagulation is of benefit in reducing the risk of recurrent stroke in patients with an ESUS.

    This was an exploratory analysis, as the parent trial found no benefit of rivaroxaban compared with  aspirin among ESUS patients with evidence of carotid atherosclerosis. It should be recognized that as part of the definition of ESUS, patients cannot have significant (> 50%) stenosis of a carotid artery proximal to the qualifying stroke.

    The study did find that carotid plaque was present more frequently in the carotid artery proximal to the stroke. A causal relationship, however, remains unproven. There is no evidence that endarterectomy is of benefit in this population.

    • Larry B. Goldstein, MD, FAAN, FANA, FAHA
    • Cardiology Today Editorial Board Member
      University of Kentucky

    Disclosures: Goldstein reports no relevant financial disclosures.