Hemorrhagic transformation (HT) is a complication of stroke [1 Tissue plasminogen activator for acute ischemic stroke. The National Institute of Neurological Disorders and Stroke rt-PA Stroke Study Group N Engl J Med 1995 ;  333 (24) : 1581-1587

Cliccare qui per andare alla sezione Riferimenti] that can occur spontaneously or after treatment. We aimed to assess the interrater and intrarater reliability of HT diagnosis.

Studies assessing the reliability of the European Cooperative Acute Stroke Study (ECASS) classification [2Hacke W., Kaste M., Fieschi C., Toni D., Lesaffre E., von Kummer R., e al. Intravenous thrombolysis with recombinant tissue plasminogen activator for acute hemispheric stroke. The European Cooperative Acute Stroke Study (ECASS) JAMA 1995 ;  274 (13) : 1017-1025 [cross-ref]

Cliccare qui per andare alla sezione Riferimenti] of HT or of the presence (yes/no) of HT were systematically reviewed. Eighteen raters independently examined 30 post-thrombectomy [3Berkhemer O.A., Fransen P.S., Beumer D., van den Berg L.A., Lingsma H.F., Yoo A.J., e al. A randomized trial of intraarterial treatment for acute ischemic stroke N Engl J Med 2015 ;  372 (1) : 11-20 [cross-ref]

Cliccare qui per andare alla sezione Riferimenti] computed tomography scans selected from the Aspiration versus Stentriever (ASTER) trial [4Lapergue B., Blanc R., Gory B., Labreuche J., Duhamel A., Marnat G., e al. Effect of Endovascular Contact Aspiration vs Stent Retriever on Revascularization in Patients With Acute Ischemic Stroke and Large Vessel Occlusion: The ASTER Randomized Clinical Trial JAMA 2017 ;  318 (5) : 443-452 [cross-ref]

Cliccare qui per andare alla sezione Riferimenti]. They were asked whether there was HT (yes/no), what the ECASS classification of the particular scan (0/HI1/HI2/PH1/PH2) was, and whether they would prescribe an antiplatelet agent if it was otherwise indicated. Agreement [5Farzin B., Gentric J.C., Pham M., Tremblay-Paquet S., Brosseau L., Roy C., e al. Agreement studies in radiology research Diagn Interv Imaging 2017 ;  98 (3) : 227-233 [cross-ref]

Cliccare qui per andare alla sezione Riferimenti] was measured with Fleiss’ and Cohen's kappa statistics.

The systematic review yielded 4 studies involving few (≤3) raters with heterogeneous results. In our 18-rater study, agreement for the presence of HT was moderate (κ=0.55, 95%CI [0.41–0.68]). Agreement for ECASS classification was only fair for all 5 categories, but agreement improved to substantial (k=0.72, 95%CI [0.69-0.75]) after dichotomizing ECASS into 0/HI1/HI2/PH1 versus PH2. The interrater agreement for the decision to reintroduce antiplatelet therapy was moderate for all raters, but substantial among vascular neurologists (κ=0.70 [0.57–0.84]).

The ECASS classification may involve too many categories and the diagnosis of HT may not be easily replicable, except in the presence of a large parenchymal hematoma.

URL: www.clinicaltrials.gov/ Unique identifier: NCT02523261.