Safety of Mechanical Thrombectomy with Combined Intravenous Thrombolysis in Stroke Treatment 4.5 to 9 Hours from Symptom Onset

An extended time window for intravenous thrombolysis (IVT) for acute stroke patients up to 9 hours from symptom onset has been established in recent trials, excluding patients who received mechanical thrombectomy (MT). We therefore investigated whether combined therapy with IVT and MT (IVT+MT) is safe in patients with ischemic stroke and large vessel occlusion (LVO) in an extended time window. We retrospectively analyzed patients with anterior circulation ischemic stroke and LVO who were treated within 4.5 to 9 hours after symptom onset using MT with or without IVT. Primary endpoint was the occurrence of any intracranial hemorrhage (ICH). Multivariable logistic regression was used to adjust for potential confounders. In total, 168 patients were included in the study, 44 (26%) were treated with IVT+ MT. 133 (79%) patients had a M1-/distal carotid artery occlusion. Median ASPECT-Score was 8 (IQR 7-10) and complete reperfusion (mTICI 2b-3) was achieved in 132 (79%) patients. 18 (41%) of the patients in the IVT+MT group developed any ICH vs. 45 (36%) patients in the direct MT group (p=0.587). Symptomatic ICH occurred in 5 (11%) patients with IVT+MT vs. 8 (6%) patients receiving direct MT (p=0.295). In multivariable analysis, IVT+MT was not an independent predictor of ICH (adjusted for NIHSS, degree of reperfusion, symptom-onset-to-treatment time and therapy with tirofiban; OR 0.95 [95% CI 0.43-2.08], p=0.896). Mechanical thrombectomy in stroke patients seems to be safe with combined intravenous thrombolysis within 4.5 to 9 hours after onset as it did not significantly increase the risk for intracranial hemorrhage.