The MRR-DWI Mismatch In Patients With Acute Ischemic Stroke Who Received Intravenous Thrombolysis

PurposeThe aim of this analysis was to evaluate the MRA-DWI mismatch (MDM) in patients with acute ischemic stroke who are given intravenous thrombolysis within3-and beyond3-hour time window after symptom onset.MethodsWe retrospectively analyzed the patients visited our hospital with ischemic stroke who received intravenous recombinant tissue plasminogen activator. The MRA-DWI mismatch model was defined as (1) a DWI lesion volume less than25ml in patients with a proximal vessel occlusion; or (2) a DWI lesion volume less than15ml in patients with proximal vessel stenosis or an abnormal finding of a distal vessel. For patient functional assessment, National Institute of Health Stroke Scale (NIHSS) scores on admission and1months later and modified Rankin Scale (mRS) were used.ResultsTwenty-one of43patients (49%) had an MRA-DWI mismatch. Agreement in terms of mismatch classification between the MRA-DWI mismatch model and the PWI-DWI mismatch model was63%. The median NIHSS score at day30after onset improved more for the MDM patients (from11to2) than for the patients without MDM (form8to4.5). The mRS score at day90after onset was significantly more favorable in the MDM patients (0-2in16patients [76%] and3-6in5patients [24%]) than in patients without MDM (0-2in10patients [45%] and3-6in12patients [55%])(P=0.039).ConclusionsThe MRA-DWI mismatch model appears to identify patients with stroke who are likely to benefit from thrombolysis. This method seems to be an alternative of the PWI-DWI mismatch.