A recent study published in JAMA Neurology explores the effect of elevated amyloid levels on subsequent changes in cognition and biomarkers. The findings indicate that in normal people, elevated levels of amyloid can signal cognitive decline. While the authors are not suggesting that these findings should impact current clinical recommendations, the conclusions could impact clinical trials for testing amyloid levels.
According to lead researcher, Ronald C. Petersen, MD, “We found that individuals in the general population who are amyloid positive but cognitively normal do have an increased risk of progressing to cognitive impairment.” He continues, “This occurs at the rate of about 8% to 10% per year, compared to a rate of 1% to 2% in the general population who are not amyloid positive.”
The report concludes, “In persons selected from a population-based study, elevated amyloid levels at baseline were associated with worse cognition and imaging biomarkers at baseline and with greater clinical decline and neurodegeneration. These results have implications for the design of randomized clinical trials for AD.”
Shifting gears, the Alzheimer’s Association and the American College of Radiology have launched a new four-year research study, The Imaging Dementia – Evidence for Amyloid Scanning (IDEAS) Study, to determine the clinical usefulness and value of diagnosing Alzheimer’s and other dementias by using brain positron emission tomography (PET) scans to detect a core feature of Alzheimer’s disease.
Per the Alzheimer’s Association, the IDEAS Study is needed due to the fact that, “Amyloid PET imaging represents a potential major advance in the clinical assessment of people with cognitive impairment. The technology makes amyloid plaques light up on a brain PET scan, enabling for the first time accurate detection of plaques in living people…The purpose of the IDEAS Study is to examine how brain imaging, specifically amyloid PET scan, helps guide doctors in diagnosing and treating Alzheimer’s and other dementias in cases where the cause of cognitive impairment is difficult to diagnose.”
Gil D. Rabinovici, MD, IDEAS Study Chair and Associate Professor at the University of California, San Francisco, states, “We believe the study will show that, in diagnostically uncertain cases, knowledge of amyloid status will lead to significant changes in patient management – such as earlier counseling and prescription of more appropriate drugs – that will translate into improved long-term outcomes.”
As mentioned in an earlier RadSite blog, the PET IDEAS study is in response to the 2013 decision by CMS to decline coverage for amyloid PET imaging scans for dementia and neurodegenerative disease. This study will address two specific aims:
- To assess the impact of amyloid PET on the management of patients meeting appropriate use criteria (AUC).
- To assess the impact of amyloid PET over 12 months on major medical outcomes, such as hospital admissions and emergency room visits in patients enrolled in the study compared to matched patients not in the study.
CMS will provide reimbursement to participating PET facilities for the costs associated with the PET scans under the CMS coverage with evidence development (CED) policy, which requires research study participation as a condition of Medicare payment. In addition, the Alzheimer’s Association and a consortium of PET tracer manufacturers will provide additional funding to support the research infrastructure and analysis.
Final Thoughts | New Research Places Amyloid Levels at Forefront of Alzheimer’s Disease
RadSite is one of the accreditation agencies allowed for free standing or hospital-based facilities who wish to participate in the PET IDEAS Study. To begin a RadSite accreditation for your PET imaging center and learn how you can become a participant in the PET IDEAS Study contact us today!