The susceptibility vessel sign at the proximal M1: A strong predictor for poor outcome after intravenous thrombolysis

• M1 proximal SVS is a predictor of no early recanalization.
• Impact of M1 proximal SVS was investigated in anterior circulation stroke patients.
• M1 proximal SVS was found in 11% patients, of whom none achieved a good outcome.
• M1 proximal SVS is the determining factor of clinical outcome after t-PA therapy.
• Patients with the M1 proximal SVS cannot benefit from t-PA therapy.

BackgroundHalf of acute stroke patients have poor outcomes at 3 months even when treated with intravenous thrombolysis using tissue-plasminogen activator (t-PA) therapy. The aim of the present study was to evaluate the impact of the susceptibility vessel sign (SVS) on magnetic resonance imaging (MRI) T2* at the proximal portion of the middle cerebral artery (M1 proximal SVS) on clinical outcome in anterior circulation stroke patients treated with t-PA.MethodsThe presence of the M1 proximal SVS was assessed before t-PA therapy. Good outcome and poor outcome at 3 months were defined as a modified Rankin Scale score of 0 to 2 and 4 to 6, respectively. The predictive values of the M1 proximal SVS for a good and poor outcome were calculated.Results161 patients (median age [interquartile], 76 [67–83] years; male, 91 [57%]) were enrolled. At 3 months after stroke, 68 (42%) patients achieved a good outcome, and 75 (47%) had a poor outcome. The M1 proximal SVS was found in 17 (11%) patients, of whom none (0%) achieved a good outcome, and 16 (94%) had a poor outcome. The sensitivity and positive predictive value of the M1 proximal SVS for good outcome were very low (0.000 and 0.000, respectively). Furthermore, the specificity and positive predictive value of the M1 proximal SVS for poor outcome were very high (0.988 and 0.941, respectively).ConclusionThe M1 proximal SVS appears to be a strong predictor for poor outcome after t-PA therapy.