Dual Antiplatelet Therapy and Very Early Neurological Deterioration after Non-Cardioembolic Stroke According to...

Early neurological deterioration after ischemic stroke is associated with worse clinical outcome, yet little is known about the frequency and determinants of neurological worsening during the first 24 h after admission. Dual antiplatelet therapy (DAPT) is recommended early after minor non-cardioembolic stroke to reduce recurrent ischemic events, but its relationship with very early deterioration (vEND) and potential differences across stroke etiologies remain unclear.

We conducted a retrospective single-center cohort study including consecutive adults with non-cardioembolic ischemic stroke admitted to a Swiss tertiary stroke center between 2014 and 2023. vEND was defined as neurological worsening within 24 h using 2 thresholds (NIHSS increase ≥4 points [primary] and ≥2 points [secondary]). Patients were categorized according to antiplatelet strategy (newly initiated DAPT vs. single antiplatelet therapy [SAPT]) and stroke etiology (large artery atherosclerosis [LAA] vs. non-LAA). Associations between antiplatelet therapy and vEND were analyzed using propensity score-weighted logistic regression with stabilized inverse probability of treatment weights and doubly robust adjustment. Adjusted predicted probabilities and risk differences were estimated using marginal standardization.

Among 1,207 patients with non-cardioembolic stroke, vEND occurred in 22.2% using the primary definition (NIHSS increase ≥4 points) and in 25.8% using the secondary definition (NIHSS increase ≥2 points). vEND was more frequent in non-LAA than LAA stroke under both definitions (23.5% vs. 17.6% and 26.4% vs. 23.7%, respectively). Patients with LAA were more likely to receive DAPT than those without LAA (33.6% vs. 14.4%, p < 0.001). After weighting and adjustment, the association between antiplatelet therapy and vEND differed by stroke etiology (p_interaction<0.001 [primary] and p_interaction = 0.007 [secondary]). In LAA stroke, DAPT was associated with a numerically lower risk of vEND compared with SAPT (adjusted risk difference [primary definition]: -7.3%, 95% CI: -16.9% to 2.3%). In contrast, among non-LAA stroke patients, DAPT was associated with a higher vEND risk (adjusted risk difference [primary definition]: 16.6%, 95% CI: 7.1%-26.1%). Similar patterns were observed using the secondary vEND definition (NIHSS increase of ≥2 points).

Very early neurological deterioration within the first 24 h after non-cardioembolic stroke is common and occurs more frequently in non-LAA stroke. The association between DAPT and vEND appears to differ by stroke etiology. A lower risk was observed in LAA stroke, whereas the higher risk seen in non-LAA stroke likely reflects confounding by indication. Prospective studies are needed to determine whether intensified platelet inhibition may reduce vEND in LAA-related stroke.