Amyloid PET and clinical management in a diverse, cognitively impaired population: The New IDEAS Study

INTRODUCTION: The New Imaging Dementia–Evidence for Amyloid Scanning (IDEAS) study (NCT04426539) evaluated the association between amyloid positron emission tomography (PET) and changes in clinical management among ethnoracially diverse, clinically heterogeneous patients. METHODS: We assessed diagnosis and management plan before and 90 ± 30 days after amyloid PET among Medicare beneficiaries who met 2018 National Institute on Aging–Alzheimer's Association criteria for mild cognitive impairment (MCI) or dementia. We aimed to identify ≥ 30% change in a composite patient management endpoint (CPME; i.e., changes in Alzheimer's disease [AD]/non-AD medications, changes in counseling). RESULTS: Among 5757 participants (median age 75 years; 21.7% Black, 20.3% Latinx, 58.1% all other races/ethnicities [AORE]), a change in CPME occurred in 59.0% (95% confidence interval 57.6%–60.5%) of individuals post PET. Change varied by ethnoracial identity and type of clinical presentation: Black (MCI: 55.3%, dementia: 55.8%), Latinx (MCI: 53.7%, dementia: 61.9%), AORE (MCI: 62.0%, dementia: 58.3%), typical (MCI: 64.8%, dementia: 60.9%), atypical (MCI 45.5%, dementia: 53.6%). DISCUSSION: Amyloid PET is associated with clinical management among diverse, clinically heterogeneous populations. Highlights: Changes in management plan occurred in 59% of patients 90 days after amyloid positron emission tomography. Rates of change in management exceeded the pre-specified goal of > 30% across ethnoracial groups. Rates of change in management also exceeded > 30% among amnestic and non-amnestic Alzheimer's disease presentations.