Impact of chronic antiplatelet therapy on clinical outcomes of posterior circulation acute ischemic stroke.

OBJECTIVE

Posterior circulation acute ischemic stroke (PCS) is a leading cause of neurologic disability, yet the hospital course of patients receiving chronic antiplatelet therapy (cAPT) remains unclear. This study evaluates the effect of cAPT on PCS outcomes, including patients undergoing endovascular thrombectomy (EVT).

METHODS

This retrospective cross-sectional study used the National Inpatient Sample (2015-2022), including adult (≥18 years) hospitalizations in the United States for PCS with reported NIH Stroke Scale. Outcomes included inpatient mortality, routine discharge, complications, and receipt of reperfusion therapy. Propensity score-based inverse probability of treatment weighting (IPTW) adjusted for confounding factors, including stroke severity. Multivariable logistic regression was used to estimate adjusted odds ratios (aORs) and 95% confidence intervals (CIs).

RESULTS

Among 148,740 PCS hospitalizations, 46,125 (31.0%) were receiving cAPT. These patients demonstrated reduced likelihood of undergoing intravascular thrombolysis (aOR: 0.902, 95% CI [0.835-0.975], p = 0.009) and EVT (0.868 [0.764-0.987], p = 0.031) compared to patients not on cAPT. Following IPTW, cAPT was associated with reduced inpatient mortality (0.581 [0.496-0.680], p < 0.001) and increased routine discharge (1.14 [1.08-1.21], p < 0.001). These patients also demonstrated reduced hemorrhagic transformation (0.767 [0.695-0.846], p < 0.001) and cerebral edema/herniation (0.761 [0.698-0.831], p < 0.001). Among hospitalizations undergoing EVT, cAPT was associated with reduced inpatient mortality (0.556 [0.408-0.757], p < 0.001), increased routine discharge (1.60 [1.18-2.16], p = 0.003), and reduced hemorrhagic transformation (0.778 [0.705-0.858], p < 0.001).

DISCUSSION: cAPT was associated with favorable inpatient outcomes in PCS, including lower mortality without an increased risk of serious neurological complications. Positive associations persisted among patients undergoing EVT. Prospective research is needed to confirm these results and guide therapeutic strategies.