Simplified Edinburgh CT Criteria for Identification of Lobar Intracerebral Hemorrhage Associated With Cerebral Amyloid Angiopathy

Abstract

Background and Objectives:In patients with lobar intracerebral hemorrhage(ICH) etiological characterization represents a trade-off between feasibility, resource allocation, and diagnostic certainty. This study investigated the accuracy and clinical utility of the simplified Edinburgh CT criteria to identify underlying cerebral amyloid angiopathy(CAA).Methods:This external validation analyzed 210 consecutive patients with lobar ICH and available CT&MRI studies from a prospective single-center observational cohort study(2006-2015,UKER-ICH,NCT03183167). We investigated the simplified Edinburgh CT-based criteria’s inter-rater variability and diagnostic accuracy for identification of ICH associated with probable CAA according to MRI-based modified Boston criteria as a reference standard. We evaluated the simplified Edinburgh criteria’s utility by decision curve analysis, comparing the theoretical clinical net-benefit(weighted benefit–harm at varying threshold probabilities) of the high-risk category(finger-like-projections and subarachnoid hemorrhage) for ruling-in and the low-risk category(neither finger-like-projections nor subarachnoid hemorrhage) for ruling-out with the assumptions of no or all patients having CAA(default-strategies).Results:Of 210 patients, 70(33.3%) had high-risk, 67(31.9%) had medium-risk, and 73(34.8%) had low-risk for CAA associated ICH according to simplified Edinburgh CT criteria, showing moderate inter-rater variability. Discrimination was good(AUROC:0.74,95%CI 0.67–0.81) without evidence of poor calibration(Hosmer–Lemeshow,p=0.54) for validation of MRI-based diagnosis of probable CAA(n=94/210,44.8%). The rule-in criteria, i.e. high-risk, had 87.1%(79.3-92.3) specificity, and the rule-out criteria, i.e. low-risk, had 80.9%(71.1-88.0) sensitivity. Decision curve analysis suggested a theoretical clinical net-benefit for ruling-in but not for ruling-out probable CAA compared to default-strategies.Discussion:Applying the simplified Edinburgh CT criteria during diagnostic work-up seems clinically useful and may accurately identify CAA in patients with lobar ICH.Classification of Evidence:This study provides Class II evidence that in patients with lobar hemorrhages, simplified Edinburgh Criteria accurately identifies those at high risk of CAA.