Mayblyum DV, Becker JA, Jacobs HIL, et al. - This study sought to correlate how structural MRI, fluorodeoxyglucose (FDG), and flortaucipir (FTP) PET signals predict cognitive decline in high-amyloid vs low-amyloid participants with the goal of determining which biomarker combination would result in the highest increase of statistical power for prevention trials. Researchers designed a prospective cohort study examining data from clinically normal adults from the Harvard Aging Brain Study with MRI, FDG, FTP, and Pittsburgh compound B-PET acquired within a year and prospective cognitive evaluations over a mean 3-year follow-up. They examined the relationship between biomarkers and cognitive decline using linear mixed-effect models with random intercepts and slopes, adjusting for demographics. The study examined data from 131 participants (52 women, age 73.98 ± 8.29 years). The findings revealed that entorhinal hypometabolism is a strong and independent predictor of subsequent cognitive decline, making FDG a potentially useful biomarker to increase power in clinical trials in preclinical Alzheimer disease.