Abstract TP092: Utility of Plasma Phosphorylated Tau 217 in Patients with Cerebrovascular Disease and Cognitive Impairment

Introduction: Cerebral amyloid angiopathy (CAA) involves beta-amyloid deposition within cerebral vasculature posing an increased risk of lobar hemorrhagic events and cognitive impairment. Plasma phosphorylated tau-217 (p-tau 217), a biomarker of Alzheimer’s pathology, may provide insight into both cognitive impairment and the presence of hemorrhagic lesions in suspected CAA patients. Methods: This is a retrospective analysis of prospectively collected patients seen in an outpatient stroke clinic who were referred for cerebrovascular disease with a primary complaint of subjective cognitive impairment. Patients underwent brain magnetic resonance imaging (MRI) and were classified as those with lobar hemorrhages (LH), at least 10 lobar cerebral microbleeds (CMB), or neither features. Serum p-tau 217 levels were also collected and classified as negative if ≤0.185 pg/ml, intermediate if 0.186-0.324 pg/ml, or positive if ≥0.325 pg/ml. Results: Of 49 patients included in the analysis, mean age was 75±9 years and 51% were female. P-tau 217 was positive in 20 (41%), intermediate in 13 (27%) and negative in 16 (33%) patients. Of 19 (39%) patients who had hemorrhagic features on imaging, 13 had LH, 6 had CMB, and 3 had both LH and CMB. Patients without LH or CMB were more likely to be p-tau217 negative than patients with LH or CMB (43% vs 16%, p = 0.06). In a subset of patients who underwent formal neuropsychology testing (n=30), patients with major neurocognitive disorders had higher mean p-tau 217 levels compared to those with mild neurocognitive disorder and normal cognitive profile (0.502 vs 0.298 vs 0.275 pg/ml; p = 0.13). Conclusions: Among patients seen in an outpatient stroke clinic for cerebrovascular disease and a primary complaint of cognitive impairment, the majority of patients had elevated p-tau 217 levels. Patients without LH, CMBs or major neurocognitive disorders were more likely to test negative for p-Tau 217. These results suggest the potential utility in testing for p-tau 217 levels among patients with cerebrovascular disease, who have primary complaints of cognitive impairment.