Impact of amyloid-PET in daily clinical management of patients with cognitive impairment fulfilling appropriate use criteria

Abstract

To evaluate the use of amyloid-positron emission tomography (PET) in routine clinical practice, in a selected population with cognitive impairment that meets appropriate use criteria (AUC). A multicenter, observational, prospective case-series study of 211patients from 2 level-3 hospitals who fulfilled clinical AUC for amyloid-PET scan in a naturalistic setting. Certainty degree was evaluated using a 5-point Likert scale: 0 (very low probability); 1 (low probability); 2 (intermediate probability); 3 (high probability); and 4 (practically sure), before and after amyloid PET. The treatment plan was considered as cognition-specific or noncognition-specific. Amyloid-PET was positive in 118 patients (55.9%) and negative in 93 patients (44.1%). Diagnostic prescan confidence according amyloid-PET results showed that in both, negative and positive-PET subgroup, the most frequent category was intermediate probability (45.7% and 55.1%, respectively). After the amyloid-PET, the diagnostic confidence showed a very different distribution, that was, in the negative-PET group the most frequent categories are very unlikely (70.7%) and unlikely (29.3%), while in the positive-PET group were very probable (57.6%) and practically sure (39%). Only in 14/211 patients (6.6%) the result of the amyloid-PET did not influence the diagnostic confidence, while in 194 patients (93.4%), the diagnostic confidence improved significantly after amyloid-PET results. The therapeutic intention was modified in 93 patients (44.1%). Specific treatment for Alzheimer disease was started, before amyloid-PET, in 80 patients (37.9%). This naturalistic study provides evidence that the implementation of amyloid-PET is associated with a significant improvement in diagnostic confidence and has a high impact on the therapeutic management of patients with mild cognitive impairment fulfilled clinical AUC.

Amyloid Positron Emission Tomography and Subsequent Health Care Use Among Medicare Beneficiaries With Mild Cognitive Impairment or Dementia

“…In a previous report, amyloid PET was associated with changes in core elements of management in more than 60% and changes in diagnosis in more than 35% of patients in the IDEAS study . These changes may translate into improved health outcomes by refining the diagnosis and treatment plan and may, in and of themselves, justify the clinical utility of amyloid PET, despite the null association with hospitalizations and ED visits found in the present study. Use of symptomatic drugs for AD, such as cholinesterase inhibitors and memantine, which in the IDEAS study were altered in 43% of patients after amyloid PET, had a modest association with rates of hospitalizations and time to institutionalization in a skilled nursing facility, and other studies suggested an association with reduced risk of mortality .…”

Outcomes of clinical utility in amyloid-PET studies: state of art and future perspectives

“…Based on the issue examined in the papers, we have identified three main outcome domains: (a) clinician-centered outcomes , quantifying the impact on the diagnostic procedure in terms of physician’s diagnostic confidence and patient management; (b) patient- and caregiver-centered outcomes , operationalizing the ultimate target of patients benefit; and (c) health economics-centered outcomes , consisting either of costs alone or of combined evidence of costs and other impacts on health resource utilization (Table 2 ). (a) Most of the selected studies (25/32, 78%) [ 9 , 11 , 13 – 35 ] included outcomes belonging to the clinician-centered domain and assessed the incremental diagnostic value for physicians, e.g., in terms of diagnostic change and increased diagnostic confidence (25/32, 78%), and changes in the planning of patient management (17/32, 53%) (Table 2 ). Amyloid-PET led to diagnostic revision in 19–79% of cases, to increased diagnostic confidence (9–49%), and to revise management plans (24–89% of cases) [ 13 – 35 ].…”

“…(a) Most of the selected studies (25/32, 78%) [ 9 , 11 , 13 – 35 ] included outcomes belonging to the clinician-centered domain and assessed the incremental diagnostic value for physicians, e.g., in terms of diagnostic change and increased diagnostic confidence (25/32, 78%), and changes in the planning of patient management (17/32, 53%) (Table 2 ). Amyloid-PET led to diagnostic revision in 19–79% of cases, to increased diagnostic confidence (9–49%), and to revise management plans (24–89% of cases) [ 13 – 35 ]. (b) Patient- and caregiver-centered outcomes are reported in 28% (9/32) [ 9 , 11 , 24 , 30 , 33 , 36 – 39 ] of the studies and mainly assessed the patients’ and caregivers’ distress after amyloid-pet-based diagnosis disclosure (8/32, 25%) (Table 2 ).…”

“…Amyloid-PET validation is now in phase 4, entailing studies based on real-world patients, where the biomarker is not only assessed, but also used to support diagnosis and treatment [ 4 , 5 ]. Reflective of this, preliminary outcomes of impact are becoming to be available (Table 2 ), though mostly confined to outcomes assessing the utility of the exam during the diagnostic workup (clinician-centered outcomes, 78%) [ 9 , 11 , 13 – 35 ]. This outcome domain is indeed the first that can be collected as clinical innovations enter phase 4 validation studies.…”

Scottish Intercollegiate Guidelines Network Guidance on Dementia: The Investigation of Suspected Dementia (SIGN 168) with Focus on Biomarkers—Executive Summary

“…Several additional longitudinal studies published since the systematic review have each identified changes in diagnosis, diagnostic confidence, and/or patient manage-ment. [16][17][18][19][20] One study was from the United Kingdom. This retrospective single-arm study examined the utility of aPET with 18F-florbetapir for patients attending a tertiary referral clinic.…”