- Patients with amnestic mild cognitive impairment (MCI) had high risk for progression to probable Alzheimer’s disease if they had a combination of β-amyloid on positive emission tomography (PET), low hippocampal volume, and poorer cognitive status.
Why this matters
- Biomarkers have been incorporated into criteria for assessing nature of mild cognitive impairment.
- Overall, 42.2% of cohort had positive PET result.
- 36-month rate of progression to probable Alzheimer’s disease: 36.2% overall, 53.6% in patients with positive PET, 22.8% in patients with negative PET.
- Risk for progression increased going from positive PET result alone (HR, 2.51; P<.001) then addition of low hippocampal volume (HR, 5.60; P<.001) and further addition of poorer cognitive status (late mild cognitive impairment defined by Logical Memory Scale II score) (HR, 8.45; P<.001).
- Prospective multicenter European and US cohort study of 232 patients with amnestic mild cognitive impairment who underwent flutemetamol F 18, labeled PET, then had local clinical assessments every 6 months for up to 3 years.
- Physicians strictly blinded to PET results.
- Main outcome: probable Alzheimer’s disease (independently adjudicated without knowledge of imaging, PET results).
- Funding: GE Healthcare.
- Fairly high progression rate among patients with negative PET.
- Possible misclassification regarding probable Alzheimer’s disease.