Beating the Clock: Time Delays to Thrombolytic Therapy with Advanced Imaging and Impact of Optimized Workflow

Organizational Factors Determining Access to Reperfusion Therapies in Ischemic Stroke-Systematic Literature Review

BACKGROUND

After onset of acute ischemic stroke (AIS), there is a limited time window for delivering acute reperfusion therapies (ART) aiming to restore normal brain circulation. Despite its unequivocal benefits, the proportion of AIS patients receiving both types of ART, thrombolysis and thrombectomy, remains very low. The organization of a stroke care pathway is one of the main factors that determine timely access to ART. The knowledge on organizational factors influencing access to ART is sparce. Hence, we sought to systematize the existing data on the type and frequency of pre-hospital and in-hospital organizational factors that determine timely access to ART in patients with AIS.

METHODOLOGY

Literature review on the frequency and type of organizational factors that determine access to ART after AIS. Pubmed and Scopus databases were the primary source of data. OpenGrey and Google Scholar were used for searching grey literature. Study quality analysis was based on the Newcastle-Ottawa Scale.

RESULTS

A total of 128 studies were included. The main pre-hospital factors associated with delay or access to ART were medical emergency activation practices, pre-notification routines, ambulance use and existence of local/regional-specific strategies to mitigate the impact of geographic distance between patient locations and Stroke Unit (SU). The most common intra-hospital factors studied were specific location of SU and brain imaging room within the hospital, and the existence and promotion of specific stroke treatment protocols. Most frequent factors associated with increased access ART were periodic public education, promotion of hospital pre-notification and specific pre- and intra-hospital stroke pathways. In specific urban areas, mobile stroke units were found to be valid options to increase timely access to ART.

CONCLUSIONS

Implementation of different organizational factors and strategies can reduce time delays and increase the number of AIS patients receiving ART, with most of them being replicable in any context, and some in only very specific contexts.

Generalization of the right acute stroke promotive strategies in reducing delays of intravenous thrombolysis for acute ischemic stroke: A meta-analysis

The generalization of successful efforts for reducing time delays in intravenous thrombolysis (IVT) could help facilitate its utility and benefits in acute ischemic stroke (AIS) patients.We searched the PubMed and Embase databases for articles reporting interventions to reduce time delays in IVT, published between January 1995 and September 2017. The IVT rate was chosen as the primary outcome, while the compliance rates of onset-to-door time (prehospital delay) and door-to-needle time (in-hospital delay) within the targeted time frame were the secondary outcomes. Interventions designed to reduce prehospital, in-hospital, or total time delays were quantitatively described in meta-analyses. The efficacy of postintervention improvement was illustrated as odds ratios (ORs) and 95% confidence intervals (95% CIs).In total, 86 papers (17 on prehospital, 56 on in-hospital, and 13 on total delay) encompassing 17,665 IVT cases were enrolled, including 28 American, 23 Asian, 30 European, and 5 Australian studies. The meta-analysis revealed statistically significant improvement in promoting IVT delivery after prehospital improvement interventions with an OR of 1.45 (95% CI, 1.23-1.71) for the new transportation protocol, 1.38 (95% CI, 1.11-1.73) for educational and training programs, and 1.83 (95% CI, 1.44-2.32) for comprehensive prehospital stroke code. The benefits of reducing in-hospital delay were much greater in developed western countries than in Asian countries, with ORs of 2.90 (95% CI, 2.51-3.34), 2.17 (95% CI, 1.95-2.41), and 1.89 (95% CI, 1.74-2.04) in American, European, and Asian countries, respectively. And telemedicine (OR, 2.26; 95% CI, 2.08-2.46) seemed to work better than pre-notification alone (OR, 1.94; 95% CI, 1.74-2.17) and in-hospital organizational improvement programs (OR, 2.10; 95% CI, 1.97-2.23). Mobile stroke treatment unit and use of a comprehensive stroke pathway in the pre- and in-hospital settings significantly increased IVT rates by reducing total time delay, with ORs of 2.01 (95% CI, 1.60-2.51) and 1.77 (95% CI, 1.55-2.03), respectively.Optimization of the work flow with organizational improvement or novel technology could dramatically reduce pre- and in-hospital time delays of IVT in AIS. This study provided detailed information on the net and quantitative benefits of various programs for reducing time delays to facilitate the generalization of appropriate AIS management.

Diagnostic accuracy of whole-brain computed tomography perfusion for detection of ischemic stroke in patients with mild neurological symptoms

Mild and minor acute neurological symptoms may lead to diagnostic uncertainty, resulting in a heterogeneous group of patients with true ischemic events and stroke mimics with a potential for poor outcomes. More than half of ischemic stroke patients present as minor strokes (National Institutes of Health Stroke Scale score <6). Whole-brain computed tomography perfusion can be used as a diagnostic test for minor stroke, offering a potential method of reducing diagnostic uncertainty in these patients. We hypothesize that whole-brain computed tomography perfusion imaging features could accurately predict infarction in patients with minor neurological deficits. This retrospective chart review enrolled consecutive patients suspected of acute ischemic stroke with a National Institutes of Health Stroke Scale score <6, who underwent whole-brain computed tomography perfusion and follow-up diffusion-weighted magnetic resonance imaging at our institution. Sensitivity, specificity, positive and negative predictive values, and positive and negative likelihood ratios were calculated for whole-brain computed tomography perfusion, using follow-up diffusion-weighted magnetic resonance imaging as a reference standard. A total of 524 patients (mean age: 67 years; range: 17-96 years; 56% men) met the inclusion criteria. Patients were excluded for non-diagnostic ( n = 25) or missing maps ( n = 8) scans, non-ischemic findings ( n = 7), and lack of follow-up magnetic resonance imaging ( n = 336). The final analysis included 148 patients who underwent diffusion-weighted magnetic resonance imaging. Whole-brain computed tomography perfusion has a sensitivity of 0.57 (95% CI: 0.45-0.69) and a specificity of 0.82 (95% CI: 0.71-0.90). The positive and negative predictive values and positive and negative likelihood ratios were 75%, 67%, 3.09, and 0.53, respectively. Our analysis suggests that although whole-brain computed tomography perfusion may offer some value as an adjunctive test for improving confidence in offering stroke treatment, it is not sufficiently sensitive or specific to accurately predict cerebral infarcts in patients with minor neurological symptoms.