BALTIMORE – A panel of Medicare advisers has refused to endorse the use of a brain scan that detects the presence of beta-amyloid plaques – a procedure experts say could play a key role in clinical management and Alzheimer’s disease drug research.
Members of MEDCAC (the Medicare Evidence Development and Coverage Advisory Committee) said they need considerably more data before they can recommend that the Centers for Medicare and Medicaid Services cover the procedure.
"We are all eager to decrease the burden of Alzheimer’s, but the real question, which the committee worked hard to answer today, is, ‘How will this test help us to do that?’ " Dr. Rita Redberg, committee chair, said in an interview. "The question we have to keep in mind is whether this test leads to better patient outcomes, or even to better diagnosis. It’s promising but at this time, we don’t have short- or long-term outcomes for the role amyloid scans can play in the diagnosis or management of people with Alzheimer’s."
The refusal was a "big disappointment" to the Alzheimer’s community, said Maria Carrillo, Ph.D., senior director of medical and scientific relations for the Alzheimer’s Association. However, she said in an interview, the association isn’t standing still on this issue.
"We will be recommending to the Centers for Medicare and Medicaid Services that they do consider coverage of beta-amyloid imaging according to the recommendations we made in the appropriate use criteria" on Jan. 28.
The criteria identified three patient groups in which the procedure could be appropriately used: patients with persistent or progressive, unexplained mild cognitive impairment; patients with an established dementia syndrome but an atypical presentation or clinical course; and patients whose dementia began at an unusually young age.
"We certainly understand that this requires development of an evidence base, and we do recommend that as well," Dr. Carrillo said. "But we think there is adequate evidence for the limited use we presented. We will be continuing the studies, but it will take a significant amount of time" to gather the follow-up data the panel requested.
The panel made its decision after hearing several hours of public comment, including statements from physicians who described patients’ experience with the procedure.
Dr. Howard M. Fillit of Mt. Sinai Medical Center, New York, used case reports to describe the impacts of both a negative and positive scan. He discussed an 80-year-old executive with a lifestyle of alcohol and sleeping pill consumption, travel, jet lag, and no exercise, who complained of memory problems. "I diagnosed amnestic MCI [mild cognitive impairment] and started him on acetylcholinesterase inhibitors."
The man had an amyloid PET scan, and "much to my surprise," it came back negative, Dr. Fillit said. Three months after cutting back on alcohol and his sleep medication, modifying travel, and increasing exercise, the patient was cognitively normal. Dr. Fillit discontinued the acetylcholinesterase inhibitors. "He remained in the business he loved, and didn’t have to resign from life."
Conversely, he said, a symptomatic female patient who could not afford the scan has had to leave her job without disability benefits. "She is now being forced to wait in limbo for the test of time."
Most committee members understood this kind of anecdotal benefit. But reimbursement approval demands data that directly links the test to patient outcomes, including improvements in disease management and quality of life.
Those data are scarce, said Dr. Steven Pearson, director of the Institute for Clinical and Economic Review. The agency recently published a report on Alzheimer’s diagnostic tests, aimed at generating the evidence necessary to determine insurance coverage. Only 1 of 15 amyloid PET studies directly examined how the scan might affect patient outcomes.
That industry-sponsored study examined how the scan would have affected clinical decision making for 229 patients evaluated for cognitive complaints, said Dr. Pearson (Alzheimer Dis. Assoc. Disord. 2013 Jan. 14 [doi:10.1097/WAD.0b013e318279d02a]). The patients were selected by memory disorder specialists. Clinicians in the study reviewed the initial symptoms and clinical findings and gave a working diagnosis and management plan both before and after a scan.
The scan resulted in a change of diagnosis for 55% of the cases, and clinicians reported an average increase of 22% in their diagnostic confidence. After seeing the results, 87% of physicians said they would change at least one thing in their clinical management plan.
Of the 86 patients initially diagnosed with probable Alzheimer’s, 12% had a negative scan, effectively ruling out the disorder. Half of these patients who were on Alzheimer’s medications then discontinued them.