Favorable prognosis in posterior circulation ischemic stroke: Insights from a nationwide stroke databank

Introduction: Clinical trials have historically underrepresented patients with posterior circulation ischemic stroke (PCIS). This study aimed to comprehensively assess the clinical characteristics and outcomes of PCIS patients compared to those with anterior circulation ischemic stroke (ACIS).

Methods: A retrospective analysis was conducted using data from the Japan Stroke Data Bank, encompassing 20 years across 130 stroke centers. The study focused on patients diagnosed with PCIS or ACIS.

Results: Among 37,069 patients reviewed, 7425 had PCIS, whereas 29,644 had ACIS. PCIS patients were younger and had a lower female representation than ACIS patients. Notably, PCIS patients had more favorable outcomes: 71% achieved a modified Rankin Scale of 0-2 or showed no deterioration at discharge (17 days at the median after admission), compared to 60% for ACIS patients (p < 0.001). Factors associated with an unfavorable outcome in the PCIS subgroup were older age, female sex (assigned at birth), history of hypertension, and higher National Institute of Health Stroke Scale (NIHSS) scores at admission. In both sexes, older age and higher NIHSS scores were negatively associated with favorable outcomes.

Conclusions: PCIS patients demonstrated a more favorable prognosis than ACIS patients. Factors like older age, female sex, and higher NIHSS scores at admission were identified as independent predictors of unfavorable outcomes in PCIS patients. Older age and higher NIHSS scores at admission were common independent negative factors for a favorable outcome regardless of sex.