The quest to reduce stroke treatment delays at a Melbourne metropolitan primary stroke centre over the past two decades.

BACKGROUND: Reducing door-to-needle time (DNT) for intravenous thrombolysis in acute ischaemic stroke can lead to improved patient outcomes. Long-term reports on DNT trends in Australia are lacking in the setting of extension of the thrombolysis time window, addition of mechanical thrombectomy and increasing presentations. AIMS: To examine 17-year trends of DNT and identify factors associated with improved DNT at a high-volume, metropolitan primary stroke centre. METHOD: Retrospective study between 2003 and 2019 of all thrombolysis cases using departmental stroke database. Since most strategies were implemented from 2012 onwards, intervention period has been defined as period 2012-2019. Factors associated with DNT reduction were examined by regression modelling. RESULTS: Fifteen strategies were identified including alterations to 'Code Stroke' processes. One thousand, two hundred and fifty patients were thrombolysed, with 737 (58.8%) treated during the intervention period. The proportion of DNT ≤60-min rose from average of 22.5% during 2003-2012 to 63% during 2015-2018 and 71% in 2019. However, median DNT has only marginally improved from 58 to 51 min between 2015 and 2019. Faster DNT was independently associated with two modifiable workflow factors, 'Direct-to-CT' protocol (P < 0.001) and acute stroke nurse presence (P < 0.005). Over time, treated patients were older and less independent (P < 0.001), and the number of annual stroke admissions and 'Code Stroke' activations have risen by fourfold and 10-fold to 748 and 1298 by 2019 respectively. CONCLUSIONS: Targeted quality improvement initiatives are key to reducing thrombolysis treatment delays in the Australian metropolitan setting. Relative stagnation in DNT improvement is concerning and needs further investigation.

Caught in Action - Evolving Emergent Large Vessel Occlusion and Collateral Failure During Alteplase Infusion for Acute Ischemic Stroke.

BACKGROUND: Published reports of acute deterioration during alteplase infusion for acute ischemic stroke due to development of partial to complete large vessel occlusion and collateral failure are sparce. MATERIALS AND METHODS: We describe an 84-year-old patient with a fluctuating clinical course due to evolving emergent large vessel occlusion of right M1 segment of the middle cerebral artery and collateral failure during alteplase infusion. Potential mechanisms of acute deterioration within 24 h after thrombolysis are discussed. RESULTS: Urgent mechanical thrombectomy was performed with resultant partial recanalization and small volume residual infarcts at 72 h magnetic resonance imaging of brain. CONCLUSIONS: Progression from partial to complete occlusion may occur within minutes, even during administration of intravenous thrombolytics in hyper-acute stroke. In patients who deteriorate within 24 h of stroke onset, non-contrast CT of brain, followed by CT perfusion and angiography, is the imaging protocol of choice in the mechanical thrombectomy era.

Large Vessel Occlusion Sites Affect Agreement Between Outputs of Three Computed Tomography Perfusion Software Packages.

OBJECTIVES: Computed tomography perfusion (CTP) data are important for hyperacute stroke decision making. Available comparisons between outputs of different CTP software packages show variable outcomes. Evaluation for factors associated with agreement between the volume estimates is limited. We assessed for differences in core and penumbra volume estimates of three CTP software packages - AutoMIStar, RAPID, and Vitrea - and analyzed factors associated with agreement between the volume estimates. MATERIALS AND METHODS: Differences between software estimates of penumbra and core volumes were calculated for each patient with suspected acute ischemic stroke who underwent CTP. Exploratory hierarchical clustering and principal component analysis were performed to identify factors of decreased volume estimate agreement. Two-sample t-tests were performed, stratified by large vessel occlusion (LVO) location. RESULTS: 579 CTP studies were performed; 267 were normal, 139 artifacts, with 172 included in the final analysis. 79/172 had LVO of internal carotid artery (ICA, n = 20), M1 (n = 38) and proximal M2 (n = 21). LVO was the only factor associated with decreased software package agreement, and proximal LVO location was associated with general trend of increasing mean differences and standard deviations between software packages (range of mean differences [SD]: non-LVO, -17-6 [4-33] ml; M2, -40-13 [5-39] ml; M1, -43-26 [16-58] ml; ICA, -76-39 [22-97] ml). CONCLUSIONS: Core and penumbra volume estimates can be affected by LVO location significantly between CTP software packages.