Accuracy of the ABC/2 Score for Intracerebral Hemorrhage. Issue 9 (September 2015)

• Record Type: Journal Article
• Authors: Webb, Alastair J.S.; Ullman, Natalie L.; Morgan, Tim C.; Muschelli, John; Kornbluth, Joshua; Awad, Issam A.; Mayo, Stephen; Rosenblum, Michael; Ziai, Wendy; Zuccarrello, Mario; Aldrich, Francois; John, Sayona; Harnof, Sagi; Lopez, George; Broaddus, William C.; Wijman, Christine; Vespa, Paul; Bullock, Ross; Haines, Stephen J.; Cruz-Flores, Salvador; Tuhrim, Stan; Hill, Michael D.; Narayan, Raj; Hanley, Daniel F.
• Is Part Of: Stroke. Volume 46:Issue 9(2015)
• Publication Date: 2015-09
• Subjects: Cerebrovascular disease -- Periodicals; Cerebral circulation -- Periodicals; 616.81
• DOI: 10.1161/STROKEAHA.114.007343
• Languages: English
• ISSNs: 0039-2499

Abstract

<abstract> <title> <x xml:space="preserve">Abstract</x> </title> <sec> <title>Background and Purpose—</title> <p>The ABC/2 score estimates intracerebral hemorrhage (ICH) volume, yet validations have been limited by small samples and inappropriate outcome measures. We determined accuracy of the ABC/2 score calculated at a specialized reading center (RC-ABC) or local site (site-ABC) versus the reference-standard computed tomography–based planimetry (CTP).</p> </sec> <sec> <title>Methods—</title> <p>In Minimally Invasive Surgery Plus Recombinant Tissue-Type Plasminogen Activator for Intracerebral Hemorrhage Evacuation-II (MISTIE-II), Clot Lysis Evaluation of Accelerated Resolution of Intraventricular Hemorrhage (CLEAR-IVH) and CLEAR-III trials. ICH volume was prospectively calculated by CTP, RC-ABC, and site-ABC. Agreement between CTP and ABC/2 was defined as an absolute difference up to 5 mL and relative difference within 20%. Determinants of ABC/2 accuracy were assessed by logistic regression.</p> </sec> <sec> <title>Results—</title> <p>In 4369 scans from 507 patients, CTP was more strongly correlated with RC-ABC (<italic>r</italic><sup>2</sup>=0.93) than with site-ABC (<italic>r</italic><sup>2</sup>=0.87). Although RC-ABC overestimated CTP-based volume on average (RC-ABC, 15.2 cm<sup>3</sup>; CTP, 12.7 cm3), agreement was reasonable when categorized into mild, moderate, and severe ICH (κ=0.75; <italic>P</italic><0.001). This was consistent with overestimation of ICH volume in 6 of 8 previous studies. Agreement with CTP was greater for RC-ABC (84% within 5 mL; 48% of scans within 20%) than for site-ABC (81% within 5 mL; 41% within 20%). RC-ABC had moderate accuracy for detecting ≥5 mL change in CTP volume between consecutive scans (sensitivity, 0.76; specificity, 0.86) and was more accurate with smaller ICH, thalamic hemorrhage, and homogeneous clots.</p> </sec> <sec> <title>Conclusions—</title> <p>ABC/2 scores at local or central sites are sufficiently accurate to categorize ICH volume and assess eligibility for the CLEAR-III and MISTIE III studies and moderately accurate for change in ICH volume. However, accuracy decreases with large, irregular, or lobar clots.</p> </sec> <sec> <title>Clinical Trial Registration—</title> <p>URL: <ext-link ext-link-type="uri" xlink:href="http://www.clinicaltrials.gov" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink">http://www.clinicaltrials.gov</ext-link>. Unique identifier: MISTIE-II NCT00224770; CLEAR-III NCT00784134.</p> </sec> </abstract>