In vivo imaging of brain β-amyloid, a hallmark of Alzheimer disease, may assist in the clinical assessment of suspected Alzheimer disease. OBJECTIVE To determine the sensitivity and specificity of positron emission tomography imaging with flutemetamol injection labeled with radioactive fluorine 18 to detect β-amyloid in the brain using neuropathologically determined neuritic plaque levels as the standard of truth. DESIGN, SETTING, AND PARTICIPANTS Open-label multicenter imaging study that took place at dementia clinics, memory centers, and hospice centers in the United States and England from June 22, 2010, to November 23, 2011. Participants included terminally ill patients who were 55 years or older with a life expectancy of less than 1 year. INTERVENTIONS Flutemetamol injection labeled with radioactive fluorine 18 (Vizamyl; GE Healthcare) administration followed by positron emission tomography imaging and subsequent brain donation. MAIN OUTCOMES AND MEASURES Sensitivity and specificity of flutemetamol injection labeled with radioactive fluorine 18 positron emission tomography imaging for brain β-amyloid. Images were reviewed without and with computed tomography scans and classified as positive or negative for β-amyloid by 5 readers who were blind to patient information. In patients who died, neuropathologically determined neuritic plaque levels were used to confirm scan interpretations and determine sensitivity and specificity. RESULTS Of 176 patients with evaluable images, 68 patients (38%) died during the study, were autopsied, and had neuritic plaque levels determined; 25 brains (37%) were β-amyloid negative; and 43 brains (63%) were β-amyloid positive. Imaging was performed a mean of 3.5 months (range, 0 to 13 months) before death. Sensitivity without computed tomography was 81% to 93% (median, 88%). Median specificity was 88%, with 4 of 5 of the readers having specificity greater than 80%. When scans were interpreted with computed tomography images, sensitivity and specificity improved for most readers but the differences were not significant. The area under the receiver operating curve was 0.90. There were no clinically meaningful findings in safety parameters. CONCLUSIONS AND RELEVANCE This study showed that flutemetamol injection labeled with radioactive fluorine 18 was safe and had high sensitivity and specificity in an end-of-life population. In vivo detection of brain β-amyloid plaque density may increase diagnostic accuracy in cognitively impaired patients.
Background-Inhibition of the acyl coenzyme A:cholesterol acyltransferase (ACAT) enzyme may prevent excess accumulation of cholesteryl esters in macrophages. The ACAT inhibitor avasimibe was shown to reduce experimental atherosclerosis. This study was designed to investigate the effects of avasimibe on human coronary atherosclerosis. Methods and Results-This randomized, double-blind, placebo-controlled trial assessed the effects of avasimibe at dosages of 50, 250, and 750 mg QD on the progression of coronary atherosclerosis as assessed by intravascular ultrasound (IVUS). All patients received background lipid-lowering therapy if necessary to reach a target baseline LDL level Ͻ125 mg/dL (3.2 mmol/L). IVUS and coronary angiography were performed at baseline and repeated after up to 24 months of treatment. Approximately equal percentages of patients across groups received concurrent statin therapy (87% to 89%). The mean total plaque volume at baseline was Ϸ200 mm 3 , and the least squares mean change at end of treatment was 0.7 mm 3 for placebo and 7.7, 4.1, and 4.8 mm 3 for the avasimibe 50, 250, and 750 mg groups, respectively (adjusted Pϭ0.17 [unadjusted Pϭ0.057], 0.37, and 0.37, respectively). Percent atheroma volume increased by 0.4% with placebo and by 0.7%, 0.8%, and 1.0% in the respective avasimibe groups (PϭNS). LDL cholesterol increased during the study by 1.7% with placebo but by 7.8%, 9.1%, and 10.9% in the respective avasimibe groups (PϽ0.05 in all groups). Conclusions-Avasimibe did not favorably alter coronary atherosclerosis as assessed by IVUS. This ACAT inhibitor also caused a mild increase in
A significantly greater number (p < 0.05) of patients with confirmed atherosclerosis treated with atorvastatin reached the target LDL cholesterol concentration at the starting dose than patients treated with fluvastatin or lovastatin, and significantly fewer (p < 0.05) patients treated with atorvastatin required combination therapy with colestipol to achieve target LDL cholesterol concentrations than all other statins tested.
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