Hyperintense Acute Reperfusion Marker Sign in Patients with Diffusion Weighted Image-negative Transient Ischemic Attack

BackgroundThe hyperintense acute reperfusion marker (HARM) sign is a hyperintense signal observed on postcontrast fluid-attenuated recovery inversion images and is strongly associated with cerebral ischemic insults. The clinical significance of the HARM sign in transient ischemic attack (TIA) has rarely been studied, unlike that in stroke. This study investigated the association between the HARM sign and clinical factors of diffusion-weighted imaging (DWI)-negative TIA, and the relationship between the HARM sign and recurrence of TIA and ischemic stroke. MethodsWe included 329 consecutive patients with DWI-negative TIA and divided them into two groups according to the HARM sign: 299 patients in the HARM(-) group and 30 patients in the HARM(+) group. Clinical information, brain imaging and follow-up data were collected from medical records and phone calls, and compared using HARM sign. ResultsThe HARM(+) patients were older and had higher systolic blood pressure, shorter symptom duration, and more frequent history of recent TIA or stroke and symptomatic artery stenosis or occlusion. Multivariate logistic regression revealed that recent TIA or stroke within 12 months (OR 6.623), symptom duration under 1 hour (OR 2.735), and relevant artery stenosis or occlusion (OR 2.761) were independently associated with the HARM sign. Cortical symptoms including aphasia were more prevalent in the HARM(+) group. During follow-up, HARM(+) patients showed higher recurrence rates of ischemic stroke (13.3% vs. 3.0%, p = 0.023). However, multivariate Cox analysis indicated that symptomatic stenosis or occlusion, rather than the HARM sign, was independently associated with stroke recurrence. ConclusionThe HARM sign in DWI-negative TIA patients is linked to older age, recent cerebrovascular events, shorter symptom duration, and large artery stenosis or occlusion. While the HARM sign correlates with higher recurrence of ischemic stroke, large artery stenosis or occlusion is the primary independent predictor.