Knowing the amyloid status of patients who have symptoms of mild cognitive impairment or dementia affects diagnosis and alters care management, according to the authors of a study running online in Dementia and Geriatric Cognitive Disorders.
Michael J. Pontecorvo, PhD, of Eli Lilly’s Avid Radiopharmaceuticals and colleagues at numerous medical institutions sent 618 patients for florbetapir (18F) PET neuroimaging, then randomized them 1:1 for amyloid assessment either immediately (information group) or after one year (control group).
At the three-month mark following imaging, physicians checked all patients (n = 602 due to absenteeism) and recorded summaries of actual patient management since the post-scan visit.
Analyzing the results, the researchers found that a much higher proportion of patients in the immediate feedback arm had a change in diagnosis compared to the controls (32.6 percent vs. 6.4 percent).
Similarly, a higher proportion of patients receiving immediate feedback had a change in management plan (68 percent vs. 55.5 percent), mainly driven by changes in medication.
Specifically, acetyl-cholinesterase inhibitor (AChE-I) drugs were prescribed to 67 percent of the amyloid-positive and 27 percent of the amyloid-negative subjects in the information group compared with 56 percent and 43 percent, respectively, in the control group.
These between-group differences persisted until the 12-month visit, the authors report.
They believe theirs was the first randomized, controlled, prospective study to look at the impact of amyloid imaging on diagnosis as well as actual patient management and outcomes.
“Physicians’ access to PET scan results changed the diagnosis in a direction consistent with the scan,” the authors write. “The changes in patient management were greater in the information group, which immediately received the amyloid PET scan results, than in the control group. The group difference in management composite outcome was driven by changes in AD medication, particularly in AChE-I use, in a direction consistent with the scan.”
They note that there were no group differences in cognitive performance or health outcomes at one year and no evidence that being randomized to the information group was associated with increased safety risk.
Journal publisher Karger has posted the study in full for free.