Adjusted Antiplatelet Therapy and Ischemic Events Post-Stent for Intracranial Aneurysms

Antiplatelet therapy adjustments guided by platelet function monitoring reduced thromboembolic events but enhanced minor or minimal bleeding events in patients with unruptured intracranial aneurysm (UIA) following stent placement, according to study findings published in Stroke.

Following neurointerventional procedures, thromboembolic events are the most common cause of morbidity. For patients who undergo cerebral aneurysm stent placement, standard dual antiplatelet therapy (DAPT) – a combination of 100 mg aspirin and 75 mg clopidogrel – is important to help reduce thromboembolic events. Yet, according to the researchers, some patients with high ontreatment platelet reactivity (HPR) tend to be at a increased risk of thromboembolic events due to inadequate plate inhibition. Platelet function monitoring could help improve clinical outcomes by measuring platelet reactivity so antiplatelet therapy can be adjusted accordingly.

The objective of the current study was to determine whether platelet function monitoring-guided adjustment of antiplatelet therapy could improve clinical outcomes in patients with UIA with stent placement compared with those who received standard DAPT without platelet function monitoring.

The open-label study included 314 patients (mean age, 56.1 years) with UIA who underwent stent placement at a hospital in China. Patients were randomly assigned to either DAPT adjustment guided by platelet function monitoring (n=157) or standard DAPT treatment without platelet function monitoring (n=157).

In the monitoring group, patients underwent platelet function monitoring 1 day prior to intracranial stent placement. Standard light transmittance aggregometry was used to measure platelet aggregation. A second monitoring was conducted 2 weeks after randomization in patients assigned drug adjustment.

Patients who experienced HPR on 75 mg clopidogrel switched to 1 dose of 180 mg ticagrelor prior to the procedure as well as subsequent 2 daily doses of 90 mg ticagrelor following the procedure. Aspirin doses were increased to 200 mg for patients with HPR on aspirin. Treatment adjustments occurred ≥1 day prior to stenting.

A composite frequency of ischemic stroke, transient ischemic attack, stent thrombosis, urgent revascularization, and cerebrovascular death within 7 days of stent placement comprised the primary outcome. The researchers also assessed safety based on a composite frequency of major, minor, or minimal bleeding within a 1-month period following stent implantation.

A significantly greater proportion of patients in the conventional group experienced the primary composite outcome compared with those in the monitoring group (12.1% vs 5.1%, respectively; hazard ratio [HR], 0.39; 95% CI, 0.17–0.92; P =.03). Additionally, the frequency of ischemic stroke was lower in the drug monitoring group (4.5% vs 12.1%; HR, 0.34; 95% CI, 0.14–0.83; P =.01), which the researchers indicated “drove the overall primary combined outcome.”

The combined safety outcome occurred in a greater proportion of patients assigned to DAPT adjustment guided by platelet function monitoring (7.0% vs 1.9%; HR, 3.87; 95% CI, 1.06–14.14; P =.03).

There was also a significant difference between the monitoring and conventional groups in regard to the frequency of minor or minimal bleeding events (6.4% vs 1.3%, respectively; HR, 5.27; 95% CI, 1.14–24.45: P =.02), but there was no difference between the groups in the frequency of major bleeding events (0.6% for both; HR, 1.00; 95% CI, 0.06–16.13; P =1.0).

Study limitations included its open-label design as well as the inclusion of patients from a single center in China, suggesting the findings may not be generalizable across other patient populations.

Despite these limitations, the researchers concluded that their findings “suggest that guided antiplatelet therapy may be a safe and attractive alternative treatment option for UIA patients who have undergone stent placement.”

Reference

Li W, Zhu W, Wang A, et al. Effect of adjusted antiplatelet therapy on preventing ischemic events after stenting for intracranial aneurysms. Stroke. Published online September 20, 2021. doi:10.1161/STROKEAHA.120.032989