Reasons for Exclusion From Intravenous Thrombolysis in Acute Ischemic Stroke: Experience From a Moroccan Stroke Unit

Abstract

Background and objective The rate of intravenous thrombolysis (IVT) in acute ischemic stroke (AIS) is still low due to several absolute and relative contraindications, including admission time delay, which remains the main reason for exclusion from thrombolysis. In this study, we aimed to identify reasons for non-thrombolysis at our stroke center. Methods This retrospective study included all patients with a final diagnosis of AIS as per our stroke prospective register from 2014 to 2019. Reasons for non-thrombolysis were analyzed for all AIS and for patients admitted within 4.5 hours from symptom onset. From 2014 to 2016, a non-contrast CT scan was the unique imaging modality used to decide on performing IVT. In 2017, CT angiography was added to the imaging protocol. Results Among 3,562 patients with AIS, 3,365 (94.4%) were excluded from thrombolysis; 2,871 (80.6%) were admitted out of the IVT time window, which represents the main reason for exclusion from thrombolysis. Thrombolysis alert (TA) was triggered for 691 (19.4%) patients, and 197 patients had IVT (which represents 28.5% of TA and 5.5% of all AIS). Minor stroke and rapidly improving symptoms of stroke were also reasons for non-thrombolysis, which explain the high-average initial National Institutes of Health Stoke Scale (NIHSS) score of more than 12 in the thrombolysis group. CT angiography allows for the analysis of the supra-aortic trunks, the circle of Willis, and the collateral status. Therefore, during the period when a CT angiography scan was used, there were more IVTs for minor strokes, rapidly improving strokes, and AIS patients admitted beyond the IVT time window. Conclusions This study highlights the common reasons for exclusion from thrombolysis. Efforts should be undertaken to avoid admission time delays. Also, based on our findings, minor stroke and improving stroke no longer represent absolute contraindications for IVT in AIS.

Keywords: acute ischemic stroke; contraindications; ct angiography scan; intravenous thrombolysis; minor stroke; rapidly improvement stroke.

Figure 1. Rates of thrombolysis alerts and thrombolyzed patients over the years