Amyloid PET scans improve outcomes in AD patients

Alzheimer’s disease (AD) patients with cognitive impairment or dementia who were referred for amyloid PET scans had fewer hospitalizations compared with a matched control group, according to a study published October 9 in JAMA Neurology.

The percentage of patients impacted was small – just 4.5% over one year, the authors noted – but the finding has important implications, wrote lead author Gil Rabinovic, MD, of the University of California, San Francisco.

“In the context of the increased morbidity and mortality associated with hospitalization in patients with dementia, even a small reduction in hospitalization rates may have important implications for public health,” the group wrote.

In clinical care, amyloid PET scans are used to diagnose and manage Alzheimer’s disease patients based on the amounts of beta-amyloid plaque the scans reveal in the brain. These plaques drive symptoms and are the target of several recently approved treatments.

In previous evidence from the Imaging Dementia–Evidence for Amyloid Scanning (IDEAS) study, amyloid PET was associated with changes in patient management in 60.2% of patients with mild cognitive impairment (MCI) and 63.5% of patients with dementia, the authors noted.

In this study, the researchers aimed to further elucidate these associations in IDEAS patients by analyzing the impact of amyloid PET scans on inpatient hospitalizations and emergency department (ED) visits over 12 months.

The group included 6,848 participants who had been recruited at 595 clinical sites that provide specialty memory care across the U.S. Eligible participants were Medicare beneficiaries 65 years or older with a diagnosis of MCI or dementia. Each participant was matched to a control Medicare beneficiary who had not undergone amyloid PET.

Overall, 1,467 of participants (21.4%) with positive amyloid PET scans were hospitalized within 12 months compared with 1,081 participants (25.7%) with negative amyloid PET scans, according to the findings.

“Participants with a positive amyloid PET result were at a lower risk of hospitalization than participants with a negative result,” the group wrote.

However, 12-month emergency department visit rates were nearly identical between the two cohorts (44.8% in both the IDEAS study and control cohorts) and both outcomes fell short of a prespecified effect size of 10% to be considered statistically significant, the researchers added.

Ultimately, further evaluation will be necessary to understand the mechanisms through which amyloid PET is associated with mortality, the researchers wrote.

“Continued follow-up of IDEAS study participants, planned for up to three years after study enrollment, will be important for evaluating the association between amyloid PET and longer-term health outcomes in this cohort,” Rabinovic and colleagues concluded.

The full article can be found here.