Amyloid PET Imaging Improves Clinical Management in Dementia Care

Amyloid positron emission tomography (PET) imaging is associated with significant changes in clinical management among older adults with cognitive impairment, according to findings published in Alzheimer’s & Dementia.

Despite increasing reliance on biomarker-based tools to diagnose Alzheimer disease (AD), the effect of amyloid PET imaging on clinical decision-making in diverse patient groups has been understudied. To address this gap, researchers conducted a prospective, observational cohort study (New IDEAS; ClinicalTrials.gov Identifier: NCT04426539), involving 5757 Medicare beneficiaries with mild cognitive impairment or dementia across 151 clinical practices in the United States.

The cohort included 21.7% Black, 20.3% Latinx, and 58.1% individuals from all other races and ethnicities (AORE). The participants were a median age of 75 (IQR, 35-98) years, and 55.9% were women. All participants met 2018 National Institute on Aging–Alzheimer’s Association criteria for mild cognitive impairment or dementia. Management plans and diagnoses were recorded both prior to amyloid PET and approximately 90 days post-imaging. The primary outcome was a composite patient management endpoint, which included changes in AD and non-AD medications as well as counseling related to safety or future planning.

Overall, 59.0% of patients experienced a change in at least 1 component of the composite patient management endpoint following amyloid PET. Changes were most often related to AD-specific medications (42.9%; 95% CI, 41.4%-44.4%), followed by counseling (22.4%; 95% CI, 21.2%-23.6%) and non-AD medications (19.1%; 95% CI, 18.0%-20.3%).

Among patients with mild cognitive impairment, the rate of overall management change was highest in AORE individuals (62.0%; 95% CI, 59.9%-64.2%), compared with Black (55.3%; 95% CI, 51.1%-59.5%) and Latinx (53.7%; 95% CI, 49.2%-58.2%; all P <.001) individuals. In patients with dementia, Latinx individuals had the highest rate of management change (61.9%; 95% CI, 56.7%-67.0%), followed by AORE (58.3%; 95% CI, 55.0%-61.6%) and Black individuals (55.8%; 95% CI, 51.3%-60.3%).

Clinical presentation also influenced outcomes. Among those with typical presentations, management changes occurred in 64.8% (95% CI, 62.8%-66.8%) of patients with mild cognitive impairment and in 60.9% (95% CI, 58.1%-63.8%) of patients with dementia. Atypical presentations were associated with lower but still significant rates of change, with 45.5% (95% CI, 42.1%-48.9%) of patients with atypical presentations of mild cognitive impairment experiencing changes in management and 53.6% (95% CI, 49.5%-57.6%) of patients with dementia experiencing changes (P <.001).

Amyloid PET positivity was a strong predictor of management change. Positive scans were associated with an increase in management changes among patients with mild cognitive impairment (odds ratio [OR], 3.02; 95% CI 2.53-3.59) and among those with dementia (OR, 1.43; 95% CI 1.12-1.83; P <.001). No significant differences in management changes were observed based on ethnoracial identity, education level, or pre-imaging medication use.

In addition to management changes, 32.4% of Black, 29.4% of Latinx, and 29.5% of AORE patients experienced a diagnostic shift from AD to non-AD or vice versa following amyloid PET.

Study limitations include an observational design, reliance on physician-reported outcomes, and lack of long-term follow-up on clinical outcomes.

“PET in a multimodal assessment may reduce the risk of misdiagnosis, personalize treatment more effectively, and ensure that therapies are prescribed when appropriate,” the study authors concluded.

Disclosures: This research was supported by Genentech, the National Institute on Aging, and the Alzheimer’s Association. Multiple study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures.