Black hole sign under anticoagulant therapy: A retrospective comparison of warfarin and direct oral anticoagulants

Hirotaka Sato; Manabu Kinoshita; Takuma Takano; Takahiro Sanada; Seiya Fujikawa; Masahiro Toda; Kiyoshi Choji; Teruo Kimura

doi:10.3174/ajnr.A8528

Black hole sign under anticoagulant therapy: A retrospective comparison of warfarin and direct oral anticoagulants

AJNR Am J Neuroradiol. 2024 Oct 9:ajnr.A8528. doi: 10.3174/ajnr.A8528. Online ahead of print.

Authors

Hirotaka Sato¹, Manabu Kinoshita¹, Takuma Takano¹, Takahiro Sanada¹, Seiya Fujikawa¹, Masahiro Toda¹, Kiyoshi Choji¹, Teruo Kimura¹

Affiliation

¹ From the Department of Neurosurgery (Hirotaka Sato, Manabu Kinoshita), Department of Radiology (Masahiro Toda), Asahikawa Medical University, Asahikawa, Hokkaido, Japan; Department of Neurosurgery (Takahiro Sanada, Teruo Kimura), Department of Radiology (Kiyoshi Choji) Japanese Red Kitami Cross Hospital, Kitami, Hokkaido, Japan; the Department of Neurosurgery (Takuma Takano), Sapporo Higashi Tokushukai Hospital, Sapporo, Hokkaido, Japan; the Department of Neurosurgery and Stroke Center (Seiya Fujikawa), Sapporo, Hokkaido, Japan.

PMID: 39384327
DOI: 10.3174/ajnr.A8528

Abstract

Background and purpose: Direct oral anticoagulants (DOAC) have rapidly replaced warfarin. Intracerebral hemorrhage (ICH) is known to be one of the most severe side effects of anticoagulant drugs. The black hole (BH) sign is reportedly a valid radiological sign for predicting hematoma expansion in acute ICH. Here, we hypothesized that the frequency of BH signs might differ between warfarin and DOAC treatment, and critically evaluated the clinical value of the BH sign in acute ICH under warfarin versus DOAC therapy.

Materials and methods: Patients with acute ICH under anticoagulant therapy were enrolled. Hematoma volumes were measured by ABC/2. Radiologists blinded to the clinical information determined the presence or absence of the BH sign on CT images. This study defined a more than 12.5 ml increase in hematoma volume as cases with "expanded hematoma".

Results: We analyzed 111 acute ICH patients under anticoagulant therapy. Among them, 21 patients were treated with antagonists in this cohort. Multivariate logistic regression analysis revealed that the presence of ventricular perforation (p=0.02; adjusted odds ratio (OR): 3.51, 95% confidence interval (CI): 1.32 - 10.2) and the BH sign (p<0.01; adjusted OR: 4.86, 95% CI: 1.73 - 14.3) were significantly different between expanded and non-expanded hematoma cases. Comparison of hematoma volume and the presence of the BH sign between warfarin and DOAC cases indicated significant differences in maximum hematoma volume (p=0.03) and presence of the BH sign (p<0.01). The increase in hematoma volume was significantly greater when the BH sign was present under warfarin therapy (p=0.05). In contrast, the increase in hematoma volume did not differ between cases with and without the BH sign in patients under DOAC therapy (p=0.14) CONCLUSIONS: The BH sign is a useful radiological signature to predict the expansion of acute ICH under anticoagulant therapy. ICH under warfarin tended to present the BH sign more frequently than that under DOAC. The results also showed that the BH sign is more reliable under warfarin than under DOAC therapy in ICH patients.

Abbreviations: AF = atrial fibrillation; BH = black hole; DOAC = direct oral anticoagulants; HU = Hounsfield Unit; ICH= intracerebral hemorrhage.