Abstract 153: Long-Term Risk Of Stroke After Posterior Reversible Encephalopathy Syndrome

Abstract

Introduction: Posterior reversible encephalopathy syndrome (PRES) can cause brain infarction and hemorrhage in the acute phase. We hypothesized that PRES is also associated with an increased long-term risk of stroke. Methods: We performed a retrospective cohort study using statewide all-payer claims data from 2016-2018 for all admissions to nonfederal hospitals in 11 states. Adult patients with PRES were compared to patients with TIA (positive control) and renal colic (negative control), as done in prior studies. The primary outcome was any stroke, and secondary outcomes were ischemic and hemorrhagic stroke. Diagnoses were ascertained using ICD-10-CM codes. We excluded patients with stroke before and during index admissions for PRES and controls. We used Cox proportional hazards analyses to evaluate associations between PRES and stroke, adjusting for demographics, stroke risk factors, and factors associated with PRES (cancer, kidney disease, rheumatological disease). In a sensitivity analysis, stroke events within 4 weeks of index admissions were excluded. Results: We identified 3,086 patients with PRES, 85,189 with TIA, and 3,094 with renal colic. Patients with PRES (55±17 years) and renal colic (54±18 years) were younger than those with TIA (72±14 years). Median follow-up was 1.1 years and similar between groups. Stroke incidence was 3.2 per 100 person-years after PRES, 3.8 per 100 person-years after TIA, and 0.4 per 100 person-years after renal colic (Figure). After adjustment, patients with PRES had a similar stroke risk as patients with TIA (HR, 0.9; 95% CI, 0.8-1.2), and a higher stroke risk than patients with renal colic (HR, 2.6; 95% CI, 2.0-3.5). Compared to TIA, PRES had a higher risk of hemorrhagic stroke (HR, 2.9; 95% CI, 2.2-3.9) and a lower risk of ischemic stroke (HR, 0.7; 95% CI, 0.6-0.9). Results were similar with a 4-week washout period. Conclusions: PRES is associated with an increased risk of future stroke, specifically hemorrhagic stroke.