Speed of tPA-Induced Clot Lysis Predicts DWI Lesion Evolution in Acute Stroke

Abstract

Background and Purpose-We sought to evaluate the impact of the speed of recanalization on the evolution of diffusionweighted imaging (DWI) lesions and outcome in stroke patients treated with tissue-type plasminogen activator (tPA). Methods-We evaluated 113 consecutive stroke patients with a middle cerebral artery occlusion who were treated with intravenous tPA. All patients underwent multiparametric magnetic resonance imaging studies, including DWI and perfusion-weighted imaging before and 36 to 48 hours after administration of a tPA bolus. Patients were continuously monitored with transcranial Doppler during the first 2 hours after tPA administration.

Interactions between Nitrous Oxide and Tissue Plasminogen Activator in a Rat Model of Thromboembolic Stroke

“…23 At 45 min after the onset of brain ischemia, rats were administered tPA in the form of Actilyse. In line with the findings of clinical studies of tPA-treated patients, 37,38 we found that rats injected with tPA exhibited full cerebral reperfusion 40 min after tPA injection. All physiologic parameters, including arterial pressure, decreased to within normal range values (table 1).…”

Impact of Tissue Plasminogen Activator on the Neurovascular Unit: From Clinical Data to Experimental Evidence

“…Depending on timing when recanalization status was assessed and on technique used, the recanalization rates after intravenous rtPA varied widely, with an overall estimate of B46% (Rha and Saver, 2007). The speed of clot dissolution by thrombolysis appears to affect the evolution of the ischemic lesion and clinical outcome (Delgado-Mederos et al, 2007). Vessel recanalization rates also vary depending on thrombus location with lower rates in proximal vs. distal arteries, suggesting that the burden of thrombus is important (Rha and Saver, 2007;Del Zoppo et al, 1992;Saqqur et al, 2007).…”

Expediting MRI-Based Proof-of-Concept Stroke Trials Using an Earlier Imaging End Point

“…Treatment with tPA aims at recanalization ideally assessed within hours. 21 Effects on final infarct volume of thrombolytic-induced reperfusion are expected to occur early and later lesion evolution appears to be unrelated to thrombolytic effects. This may not be the case with neuroprotective drugs, which may potentially require later scanning times.…”