Alzheimer's Imaging Consortium

Area of Science:

• Neurology
• Biomarkers
• Neuroimaging

Background:

• Cerebral amyloid angiopathy (CAA) diagnosis is crucial for Alzheimer's disease (AD) patients undergoing anti-amyloid immunotherapy due to its association with amyloid-related imaging abnormalities.
• The Boston criteria are standard for identifying probable CAA in memory clinics, but its prevalence and characteristics in cognitively impaired AD patients are not well-defined.

Purpose of the Study:

• To determine the prevalence of CAA in cognitively impaired older adults with biomarker-confirmed AD (CI-AD) using the updated Boston criteria (v2.0).
• To compare the cognitive, clinical, and biomarker profiles of CI-AD patients with and without CAA.

Main Methods:

• Retrospective analysis of 415 probable AD patients (mean age 73.8 years) with confirmed AD biomarkers.
• MRI scans were reviewed for CAA probability using the Boston criteria (v2.0), classifying patients into AD-CAA (high probability) and AD-nCAA (low probability) groups.
• Patient characteristics and biomarker data were compared between groups using statistical tests.

Main Results:

• 29% of AD patients were classified as AD-CAA, while 71% were AD-nCAA.
• Cognitive severity, global cognition, verbal episodic memory, and executive functions were comparable between AD-CAA and AD-nCAA groups.
• AD-CAA patients were older, more likely to use antiplatelet therapy, and had higher cardiovascular disease prevalence, but similar cardiovascular risk factors and AD biomarker profiles.

Conclusions:

• The prevalence of CAA in AD patients identified via the Boston criteria was lower than pathology-based estimates.
• Cognitive profiles and AD biomarker patterns appear similar in memory clinic AD patients irrespective of their CAA probability.
• Further research is warranted on the utility of the Boston criteria in memory clinic populations with AD.