Abstract T P56: M1 Proximal SVS Should Be a Strong Predictor for Poor Outcome after tPA Therapy

Abstract

BACKGROUND AND PURPOSE: Although intravenous thrombolysis using tPA can improve the clinical outcome in patients with acute ischemic stroke, a half of the patients complains of poor outcomes at 3 months. We previously reported that the susceptibility vessel sign (SVS) shown on MRI T2* at the proximal portion of the middle cerebral artery is a strong predictor for no early recanalization. The aim of the present study is to evaluate the impact of the M1 proximal SVS on poor outcome in acute patients with anterior-circulation stroke. METHODS:Consecutive patients treated with tPA were enrolled. Patients treated with intra-arterial intervention were excluded. Initial neurological deficit was assessed using the NIHSS score. The extent of the early ischemic change was evaluated using the DWI-ASPECTS. The presence of M1 proximal SVS was assessed before tPA therapy. Poor outcome at 3 months was defined as a mRS of 4 to 6. Results: One-hundred and sixty patients (median age, 76 years [67-83], male; 91 [57%]) were enrolled. Seventy-four (46%) patients had poor outcome (P group), and 86 (54%) had a non-poor outcome (NP group). Patients in the P group were older than those in the NP group (77 [69-84] versus 74 [64-81], p=0.010). NIHSS score was higher in the P group than the NP group (17 [13-20] vs. 8 [5-13], p<0.001). Regarding the imaging parameter, 16 (22%) patients in the P group and only 1 (1%) in the NP group had M1 proximal SVS (p<0.002). Patients in the P group had lower initial DWI-ASPECTS compared to those in the NP group (7 [5-9] versus 9 [7-10], p<0.001). Internal carotid artery occlusion was seen in 19 (26%) patients in the P group and 6 (7%) in the NP group (p=0.002). The glucose level was slightly higher in the P group compared to the NP group (140 mg/dl [120-182] vs. 130 mg/dl [116-164], p=0.076). Multivariate regression analysis revealed that proximal M1-SVS (OR:14.17, 95%CI:1.47-136.42, p=0.022) was the strong predictor for poor outcome, followed by NIHSS score ≥14 (OR:7.95, 95%CI:3.26-19.37, p<0.001), and glucose ≥125 mg/dl (OR:2.83, 95%CI:1.22-6.57, p=0.016) after adjusting age, onset treatment time, DWI-ASPECTS, cardioembolic stroke, and internal carotid artery occlusion. Conclusions: M1 proximal SVS should be a strong predictor for poor outcome after tPA therapy.