Reducing door-to-puncture times for intra-arterial stroke therapy: a pilot quality improvement project

Reducing Door-to-Puncture Times for Mechanical Thrombectomy in a Large Tertiary Hospital

Background and Objectives

Endovascular therapy (EVT) for stroke has emerged as an important therapy for selected stroke patients, and shorter times to clot removal improve functional outcomes. EVT requires the close coordination of multiple departments and poses unique challenges to care coordination in large hospitals. We present the results of our quality improvement project that aimed to improve our door-to-groin puncture (DTP) times for patients who undergo EVT after direct presentation to our emergency department.

Methods

We conducted time-motion studies to understand the full process of an EVT activation and conducted Gemba walks in multiple hospitals. We also reviewed the literature and interviewed stakeholders to create interventions that were implemented over 4 Plan-Do-Study-Act (PDSA) cycles. We retrospectively collected data starting from baseline and during every PDSA cycle. During each cycle, we studied the impact of the interventions, adjusted the interventions, and generated further interventions. A variety of interventions were introduced targeting all aspects of the EVT process. This included parallel processing to reduce waiting time, standardization of protocols and training of staff, behavioral prompts in the form of a stroke clock, and push systems to empower staff to facilitate the forward movement of the patient. A novel role-based communication app to facilitate group communications was also used.

Results

Eighty-eight patients spanning across 22 months were analyzed. After the final PDSA cycle, the median DTP time was reduced by 36.5% compared with baseline (130 minutes (interquartile range [IQR] 111-140) to 82.5 minutes (IQR 74.8-100)). There were improvements in all phases of the EVT process with the largest time savings occurring in EVT decision to patient arrival at the angiosuite. Interventions that were most impactful are described.

Discussion

EVT is a complex process involving multiple processes and local factors. Analysis of the process from all angles and intervening on multiple small aspects can add up to significant improvements in DTP times.

Optimizing workflow of urgent stroke endovascular intervention: A focused lean six sigma project

INTRODUCTION

Urgent endovascular intervention is currently accepted as the primary and critical therapeutic approach to patients whose acute ischemic stroke results from a large arterial occlusion (LAO). In this context, one of the quality metrics most widely applied to the assessment of emergency systems performance is the "door-to-puncture" (D-P) time. We undertook a project to identify the subinterval of the D-P metric causing the most impact on workflow delays and created a narrowly focused project on improving such subinterval.

METHODS

Using the DMAIC (i.e., define, measure, analyze, improve and control) approach, we retrospectively reviewed our quality stroke data for calendar year (CY) 2021 (i.e., baseline population), completed a statistical process control assessment, defined the various subintervals of the D-P interval, and completed a Pareto analysis of their duration and their proportional contribution to the D-P interval. We retooled our workflow based on these analyses and analyzed the data resulting from its implementation between May and December 2022 (i.e., outcome population).

RESULTS

The baseline population included 87 patients (44 men; mean age = 67.2 years). Their D-P process was uncontrolled, and times varied between 35-235 minutes (Mean = 97; SD = 38.40). Their door to angiography arrival (D-AA) subinterval was significantly slower than their arrival to puncture (AA-P) (73.4 v. 23.5 minutes; p < 0.01), accounted for 73% of the average length of the D-P interval. The group page activation to angiography arrival (GP-AA) subinterval accounted for 41.5% of the entire D-AA duration, making it the target of our project. The outcome population originally consisted of 38 patients (15 men; mean age = 70.3 years). Their D-P process was controlled, its times varying between 43-177 minutes (Mean = 85.8; SD = 34.46), but not significantly difference than the baseline population (p = 0.127). Their target subinterval GP-AA varied between 0-37 minutes and was significantly improved from the baseline population (Mean = 13.21 v. 29.68; p < 0.001).

CONCLUSIONS

It seems feasible and reasonable to analyze the subinterval components of complex quality metrics such as the D-P time and carry out more focused quality improvement projects. Care must be exercised when interpreting the impact on overall system performance, due to unexpected variations within interdependent subprocesses. The application of a robust and comprehensive LSS continuous quality improvement process in any CSC will have to include individualized focused projects that simultaneously control the different components of overall system performance.

Epidemiology, organization, diagnosis and treatment of acute ischemic stroke

The management of acute ischemic stroke is changing. Over the period of 2010-2050, the number of incident strokes is expected to be more than double. Rapid access to mechanical thrombectomy for patients with large vessel occlusion is critically associated with their functional outcome. Moreover, patients with first pass effect had a better clinical outcome, lower mortality, and fewer procedural adverse events. We discuss some advances in acute ischemic stroke regarding the organization, the diagnosis and the treatment.

Current and future trends in acute ischemic stroke treatment: direct-to-angiography suite, middle vessel occlusion, large core, and minor strokes

Since the publication of the landmark thrombectomy trials in 2015, the field of endovascular therapy for ischemic stroke has been rapidly growing. The very low number needed to treat to provide functional benefits shown by the initial randomized trials has led clinicians and investigators to seek to translate the benefits of endovascular therapy to other patient subgroups. Even if the treatment effect is diminished, currently available data has provided sufficient information to extend endovascular therapy to large infarct core patients. Recently, published data have also shown that sophisticated imaging is not necessary for late time- window patients. As a result, further research into patient selection and the stroke pathway now focuses on dramatically reducing door-to-groin times and improving outcomes by circumventing classical imaging paradigms altogether and employing a direct-to-angio suite approach for selected large vessel occlusion patients in the early time window. While the results of this approach mainly concern patients with severe deficits, there are further struggles to provide evidence of the efficacy and safety of endovascular treatment in minor stroke and large vessel occlusion, as well as in patients with middle vessel occlusions. The current lack of good quality data regarding these patients provides significant challenges for accurately selecting potential candidates for endovascular treatment. However, current and future randomized trials will probably elucidate the efficacy of endovascular treatment in these patient populations.

Automated Large Vessel Occlusion Detection Software and Thrombectomy Treatment Times: A Cluster Randomized Clinical Trial

Importance

The benefit of endovascular stroke therapy (EVT) in large vessel occlusion (LVO) ischemic stroke is highly time dependent. Process improvements to accelerate in-hospital workflows are critical.

Objective

To determine whether automated computed tomography (CT) angiogram interpretation coupled with secure group messaging can improve in-hospital EVT workflows.

Design, Setting, and Participants

This cluster randomized stepped-wedge clinical trial took place from January 1, 2021, through February 27, 2022, at 4 comprehensive stroke centers (CSCs) in the greater Houston, Texas, area. All 443 participants with LVO stroke who presented through the emergency department were treated with EVT at the 4 CSCs. Exclusion criteria included patients presenting as transfers from an outside hospital (n = 158), in-hospital stroke (n = 39), and patients treated with EVT through randomization in a large core clinical trial (n = 3).

Intervention

Artificial intelligence (AI)-enabled automated LVO detection from CT angiogram coupled with secure messaging was activated at the 4 CSCs in a random-stepped fashion. Once activated, clinicians and radiologists received real-time alerts to their mobile phones notifying them of possible LVO within minutes of CT imaging completion.

Main Outcomes and Measures

Primary outcome was the effect of AI-enabled LVO detection on door-to-groin (DTG) time and was measured using a mixed-effects linear regression model, which included a random effect for cluster (CSC) and a fixed effect for exposure status (pre-AI vs post-AI). Secondary outcomes included time from hospital arrival to intravenous tissue plasminogen activator (IV tPA) bolus in eligible patients, time from initiation of CT scan to start of EVT, and hospital length of stay. In exploratory analysis, the study team evaluated the impact of AI implementation on 90-day modified Rankin Scale disability outcomes.

Results

Among 243 patients who met inclusion criteria, 140 were treated during the unexposed period and 103 during the exposed period. Median age for the complete cohort was 70 (IQR, 58-79) years and 122 were female (50%). Median National Institutes of Health Stroke Scale score at presentation was 17 (IQR, 11-22) and the median DTG preexposure was 100 (IQR, 81-116) minutes. In mixed-effects linear regression, implementation of the AI algorithm was associated with a reduction in DTG time by 11.2 minutes (95% CI, -18.22 to -4.2). Time from CT scan initiation to EVT start fell by 9.8 minutes (95% CI, -16.9 to -2.6). There were no differences in IV tPA treatment times nor hospital length of stay. In multivariable logistic regression adjusted for age, National Institutes of Health Stroke scale score, and the Alberta Stroke Program Early CT Score, there was no difference in likelihood of functional independence (modified Rankin Scale score, 0-2; odds ratio, 1.3; 95% CI, 0.42-4.0).

Conclusions and Relevance

Automated LVO detection coupled with secure mobile phone application-based communication improved in-hospital acute ischemic stroke workflows. Software implementation was associated with clinically meaningful reductions in EVT treatment times.

Trial Registration

ClinicalTrials.gov Identifier: NCT05838456.

Extended Multimodal Flat Detector CT Imaging in Acute Ischemic Stroke: A Pilot Study

By using Flat detector computed tomography (FD-CT), a one-stop-shop approach in the diagnostic workup of acute ischemic stroke (AIS) might be achieved. Although information on upstream vessels is warranted, dedicated FD-CT protocols which include the imaging of the cervical vasculature are still lacking. We aimed to prospectively evaluate the implementation of a new multimodal FD-CT protocol including cervical vessel imaging in AIS patients. In total, 16 patients were included in this study. Eight patients with AIS due to large vessel occlusion (LVO) prospectively received a fully multimodal FD-CT imaging, including non-enhanced flat detector computed tomography (NE-FDCT), dynamic perfusion flat detector computed tomography (FD-CTP) and flat detector computed tomography angiography (FD-CTA) including cervical imaging. For comparison of time metrics and image quality, eight AIS patients, which received multimodal CT imaging, were included retrospectively. Although image quality of NE-FDCT and FD-CTA was rated slightly lower than NE-CT and CTA, all FD-CT datasets were of diagnostic quality. Intracerebral hemorrhage exclusion and LVO detection was reliably possible. Median door-to-image time was comparable for the FD-CT group and the control group (CT:30 min, IQR27-58; FD-CT:44.5 min, IQR31-55, p = 0.491). Door-to-groin-puncture time (CT:79.5 min, IQR65-90; FD-CT:59.5 min, IQR51-67; p = 0.016) and image-to-groin-puncture time (CT:44 min, IQR30-50; FD-CT:14 min, IQR12-18; p < 0.001) were significantly shorter, when patients were directly transferred to the angiosuite, where FD-CT took place. Our study indicates that using a new fully multimodal FD-CT approach including imaging of cervical vessels for first-line imaging in AIS patients is feasible and comparable to multimodal CT imaging with substantial potential to streamline the stroke workflow.

One-stop stroke management platform reduces workflow times in patients receiving mechanical thrombectomy

Background and purpose

Clinical outcome in patients who received thrombectomy treatment is time-dependent. The purpose of this study was to evaluate the efficacy of the one-stop stroke management (OSSM) platform in reducing in-hospital workflow times in patients receiving thrombectomy compared with the traditional model.

Methods

The data of patients who received thrombectomy treatment through the OSSM platform and traditional protocol transshipment pathway were retrospectively analyzed and compared. The treatment-related time interval and the clinical outcome of the two groups were also assessed and compared. The primary efficacy endpoint was the time from door to groin puncture (DPT).

Results

There were 196 patients in the OSSM group and 210 patients in the control group, in which they were treated by the traditional approach. The mean DPT was significantly shorter in the OSSM group than in the control group (76 vs. 122 min; P < 0.001). The percentages of good clinical outcomes at the 90-day time point of the two groups were comparable (P = 0.110). A total of 121 patients in the OSSM group and 124 patients in the control group arrived at the hospital within 360 min from symptom onset. The mean DPT and time from symptom onset to recanalization (ORT) were significantly shorter in the OSSM group than in the control group. Finally, a higher rate of good functional outcomes was achieved in the OSSM group than in the control group (53.71 vs. 40.32%; P = 0.036).

Conclusion

Compared to the traditional transfer model, the OSSM transfer model significantly reduced the in-hospital delay in patients with acute stroke receiving thrombectomy treatment. This novel model significantly improved the clinical outcomes of patients presenting within the first 6 h after symptom onset.

Viz.ai Implementation of Stroke Augmented Intelligence and Communications Platform to Improve Indicators and Outcomes for a Comprehensive Stroke Center and Network

BACKGROUND AND PURPOSE

Comprehensive stroke centers continually strive to narrow neurointerventional time metrics. Although process improvements have been put in place to streamline workflows, complex pathways, disparate imaging locations, and fragmented communications all highlight the need for continued improvement.

MATERIALS AND METHODS

This Quality Improvement Initiative (VISIION) was implemented to assess our transition to the Viz.ai platform for immediate image review and centralized communication and their effect on key performance indicators in our comprehensive stroke center. We compared periods before and following deployment. Sequential patients having undergone stroke thrombectomy were included. Both direct arriving large-vessel occlusion and Brain Emergency Management Initiative telemedicine transfer large-vessel occlusion cases were assessed as were subgroups of OnHours and OffHours. Text messaging thread counts were compared between time periods to assess communications. Mann-Whitney U and Student t tests were used.

RESULTS

Eighty-two neurointerventional cases were analyzed pre vs. post time periods: (DALVO-OnHours 7 versus 7, DALVO-OffHours 10 versus 5, BEMI-OnHours 13 versus 6, BEMI-OffHours 17 versus 17). DALVO-OffHours had a 39% door-to-groin reduction (157 versus 95 minutes, P = .009). DALVO-All showed a 32% reduction (127 versus 86 minutes, P = .006). BEMI-All improved 33% (42 versus 28 minutes, P = .036). Text messaging thread counts improved 30% (39 versus 27, P = .04).

CONCLUSIONS

There was an immediate improvement following Viz.ai implementation for both direct arriving and telemedicine transfer thrombectomy cases. In the greatest opportunity subset (direct arriving large-vessel occlusion-OffHours: direct arriving cases requiring team mobilization off-hours), we noted a 39% improvement. With Viz.ai, we noted that immediate access to images and streamlined communications improved door-to-groin time metrics for thrombectomy. These results have implications for future care processes and can be a model for centers striving to optimize workflow and improve thrombectomy timeliness.

Understanding Delays in MRI-based Selection of Large Vessel Occlusion Stroke Patients for Endovascular Thrombectomy

PURPOSE

Given the efficacy of endovascular thrombectomy (EVT), optimizing systems of delivery is crucial. Magnetic resonance imaging (MRI) is the gold standard for evaluating tissue viability but may require more time to obtain and interpret. We sought to identify determinants of arrival-to-puncture time for patients who underwent MRI-based EVT selection in a real-world setting.

METHODS

Patients were identified from a prospectively maintained database from 2011-2019 that included demographics, presentations, treatments, and outcomes. Process times were obtained from the medical charts. MRI times were obtained from time stamps on the first sequence. Linear and logistic regressions were used to infer explanatory variables of arrival-to-puncture times and effects of arrival-to-puncture time on functional outcomes.

RESULTS

In this study 192 patients (median age 70 years, 57% women, 12% non-white) underwent MRI-based EVT selection. 66% also underwent computed tomography (CT) at the hub before EVT. General anesthesia was used for 33%. Among the entire cohort, the median arrival-to-puncture was 102 min; however, among those without CT it was 77 min. Longer arrival-to-puncture times independently reduced the odds of 90-day good outcome (∆mRS ≤ 2 from pre-stroke, aOR = 0.990, 95%CI = 0.981-0.999, p = 0.040) when controlling for age, NIHSS, and good reperfusion (TICI 2b-3). Independent determinants of longer arrival-to-puncture were CT plus MRI (β = 0.205, p = 0.003), non-white race/ethnicity (β = 0.162, p = 0.012), coronary disease (β = 0.205, p = 0.001), and general anesthesia (β = 0.364, p < 0.0001).

CONCLUSION

Minimizing arrival-to-puncture time is important for outcomes. Real-world challenges exist in an MRI-based EVT selection protocol; avoiding double imaging is key to saving time. Racial/ethnic disparities require further study. Understanding variables associated with delay will inform protocol changes.

Optimizing Door-to-Groin Puncture Time: The Mayo Clinic Experience

OBJECTIVES

To provide a better understanding of methods that can be used to improve patient outcomes by reducing the door-to-groin puncture (DTP) time and present the results of a stroke quality improvement project (QIP) conducted by Mayo Clinic Arizona's stroke center.

METHODS

We conducted a systematic literature search of Ovid MEDLINE(R), Ovid EMBASE, Scopus, and Web of Science for studies that evaluated DTP time reduction strategies. Those determined eligible for the purpose of this analysis were assessed for quality. The strategies for DTP time reduction were categorized on the basis of modified Target: Stroke Phase III recommendations and analyzed using a meta-analysis. The Mayo Clinic QIP implemented a single-call activation system to reduce DTP times by decreasing the time from neurosurgery notification to case start.

RESULTS

Fourteen studies were selected for the analysis, consisting of 2277 patients with acute ischemic stroke secondary to large-vessel occlusions. After intervention, all the studies showed a reduction in the DTP time, with the pooled DTP improvement being the standardized mean difference (1.37; 95% confidence interval, 1.20-1.93; τ²=1.09; P<.001). The Mayo Clinic QIP similarly displayed a DTP time reduction, with the DTP time dropping from 125.1 to 82.5 minutes after strategy implementation.

CONCLUSION

Computed tomography flow modifications produced the largest and most consistent reduction in the DTP time. However, the reduction in the DTP time across all the studies suggests that any systematic protocol aimed at reducing the DTP time can produce a beneficial effect. The relative novelty of mechanical thrombectomy and the consequential lack of research call for future investigation into the efficacy of varying DTP time reduction strategies.

Impact of COVID-19 on emergency department management of stroke and STEMI. A narrative review

The novel coronavirus of 2019 (COVID-19) has resulted in a global pandemic; COVID-19 has resulted in significant challenges in the delivery of healthcare, including emergency management of multiple diagnoses, such as stroke and ST-segment myocardial infarction (STEMI). The aim of this study was to identify the impacts of the COVID-19 pandemic on emergency department care of stroke and STEMI patients. In this study a review of the available literature was performed using pre-defined search terms, inclusion criteria, and exclusion criteria. Our analysis, using a narrative review format, indicates that there was not a significant change in time required for key interventions for stroke and STEMI emergent management, including imaging (door-to-CT), tPA administration (door-to-needle), angiographic reperfusion (door-to-puncture), and percutaneous coronary intervention (door-to-balloon). Potential future areas of investigation include how emergency department (ED) stroke and STEMI care has adapted in response to different COVID-19 variants and stages of the pandemic, as well as identifying strategies used by EDs that were successful in providing effective emergency care in the face of the pandemic.

Direct to Angiosuite Versus Conventional Imaging in Suspected Large Vessel Occlusion: A Systemic Review and Meta-Analysis

BACKGROUND

There is growing evidence to suggest that the direct transfer to angiography suite (DTAS) approach for patients with suspected large vessel occlusion stroke potentially requiring mechanical thrombectomy shortens treatment times and improves outcomes compared with the direct transfer to conventional imaging (DTCI) model. Therefore, we conducted this meta-analysis to compare both approaches to build more concrete evidence to support this innovative treatment concept.

METHODS

All potentially relevant studies published in 4 electronic databases/search engines (PubMed, Web of Science, Cochrane Library, and Scopus) from inception to November 2021 were reviewed. Eligible studies were included if they enrolled ≥10 patients in both groups, were published in English, and reported baseline and procedural characteristics and outcomes. Relevant data were then extracted and analyzed.

RESULTS

Among 4514 searched studies, 7 qualified for the analysis with 1971 patients (DTAS=675, DTCI=1296). Times from door to puncture (mean difference, -30.76 minutes [95% CI, -43.70 to -17.82]; P<0.001) as well as door-to-reperfusion (mean difference=-33.24 minutes [95% CI, -51.82 to -14.66]; P<0.001) were significantly shorter and the rates of functional independence (modified Rankin Scale score, 0-2: risk ratio [RR], 1.25 [95% CI, 1.02-1.53]; P=0.03) at 90 days were higher in the DTAS versus the DTCI approach. There was no difference across the DTAS and DTCI groups in terms of the rates of successful reperfusion (modified Thrombolysis in Cerebral Infarction score 2B-3: RR, 1.03 [95% CI, 0.95-1.12]; P=0.42), near-complete/full reperfusion (modified Thrombolysis in Cerebral Infarction 2C-3: RR, 0.89 [95% CI, 0.74-1.08]; P=0.23), symptomatic intracranial hemorrhage (RR, 0.81 [95% CI, 0.56-1.17]; P=0.26), or fair outcomes (modified Rankin Scale score, 0-3: RR, 1.14 [95% CI, 0.88-1.47]; P=0.32) or mortality (RR, 0.98 [95% CI, 0.67-1.44]; P=0.93) at 90 days. Subgroup analysis showed no significant difference in 90-day functional independence across approaches in transfer patients (RR, 1.20 [95% CI, 0.96-1.51]; P=0.11).

CONCLUSIONS

Our meta-analysis showed that the DTAS approach seems to be associated with improved time metrics and functional outcomes with comparable safety to the DTCI approach. Ongoing multicenter randomized clinical trials will hopefully provide more definite data about this promising approach.

Effect of "drip-and-ship" and "drip-and-drive" on endovascular treatment of acute ischemic stroke with large vessel occlusion: a single-center retrospective study

BACKGROUND

Patients with acute ischemic stroke (AIS) caused by large vessel occlusion (LVO) were usually transferred from a primary stroke center (PSC) to a comprehensive stroke center (CSC) for endovascular treatment (drip-and-ship [DS]), while driving the doctor from a CSC to a PSC to perform a procedure is an alternative strategy (drip-and-drive [DD]).

PURPOSE

To compare the efficacy and prognosis of the two strategies.

MATERIAL AND METHODS

From February 2017 to June 2019, 62 patients with LVO received endovascular treatment via the DS and DD models and were retrospectively analyzed from the stroke alliance based on our CSC. Primary endpoint was door-to-reperfusion (DTR) time. Secondary endpoints included puncture-to-recanalization (PTR) time, modified Thrombolysis in Cerebral Infarction (mTICI) rates at the end of the procedure, and modified Rankin Scale (mRS) at 90 days.

RESULTS

Forty-one patients received the DS strategy and 21 patients received the DD strategy. The DTR time was significantly longer in the DS group compared to the DD group (315.5 ± 83.8 min vs. 248.6 ± 80.0 min; P < 0.05), and PTR time was shorter (77.2 ± 35.9 min vs. 113.7 ± 69.7 min; P = 0.033) compared with the DD group. Successful recanalization (mTICI 2b/3) was achieved in 89% (36/41) of patients in the DS group and 86% (18/21) in the DD group (P = 1.000). Favorable functional outcomes (mRS 0-2) were observed in 49% (20/41) of patients in the DS group and 71% (15/21) in the DD group at 90 days (P = 0.089).

CONCLUSION

Compared with the DS strategy, the DD strategy showed more effective and a trend of better clinical outcomes for AIS patients with LVO.

The weekend effect on mechanical thrombectomy: A nationwide analysis before and after the pivotal 2015 trials

OBJECTIVES:

MATERIALS AND METHODS:

RESULTS:

CONCLUSIONS:

The effectiveness of systemic and endovascular intra-arterial thrombectomy protocol for decreasing door-to-recanalization time duration

Objective

Variable treatment strategies and protocols have been applied to reduce time durations in the process of acute stroke management. The aim of this study is to investigate the effectiveness of our intra-arterial thrombectomy (IAT) protocol for decreasing door-to-recanalization time duration and improve successful recanalization.

Methods

A systemic and endovascular protocol included door-to-image, image-to-puncture and puncture-to-recanalization. We retrospectively analyzed the patients of pre- (Sep 2012–Apr 2014) and post-IAT protocol (May 2014–Jul 2018). Univariate analysis was used for the statistical significance according to variable factors (age, gender, the location of occluded vessel, successful recanalization TICI 2b-3). Independent t-test was used to compare the time duration.

Results

Among all 267 patients with acute stroke of anterior circulation, there were 50 and 217 patients with pre- and post-IAT protocol. Age, gender, and the location of occluded vessel have no statistical significance (p＞0.05). In pre- and post-IAT group, successful recanalization was 39 of 50 (78.0%) and 185/217 (85.3%), respectively (p＜0.05). Post-IAT (48.8%, 106/217) group had a higher tendency of good outcome than pre-IAT group (36.0%, 18/50) (p＞0.05). Pre- and post-IAT group showed 61.7±21.4 vs. 25±16.0 (p＜0.05), 102.0±29.8 vs. 82.7±30.4 (min) (p＜0.05), and 79.1±47.5 vs. 58.4±75.3 (p＜0.05) in three steps, respectively.

Conclusions

We suggest that the application of systemic and endovascular IAT protocols showed a significant time reduction for faster recanalization in patients with LVO. To build-up the well-designed IAT protocol through puncture-to-recanalization can be needed to decrease time duration and improve clinical outcome in recanalization therapy in acute stroke patients.

Pre- and Interhospital Workflow Times for Patients With Large Vessel Occlusion Stroke Transferred for Endovasvular Thrombectomy

Background: Patients with large vessel occlusion (LVO) stroke are often initially admitted to a primary stroke center (PSC) and subsequently transferred to a comprehensive stroke center (CSC) for endovascular thrombectomy (EVT). This interhospital transfer delays initiation of EVT. To identify potential workflow improvements, we analyzed pre- and interhospital time metrics for patients with LVO stroke who were transferred from a PSC for EVT.

Methods: We used data from the regional emergency medical services and our EVT registry. We included patients with LVO stroke who were transferred from three nearby PSCs for EVT (2014–2021). The time interval between first alarm and arrival at the CSC (call-to-CSC time) and other time metrics were calculated. We analyzed associations between various clinical and workflow-related factors and call-to-CSC time, using multivariable linear regression.

Results: We included 198 patients with LVO stroke. Mean age was 70 years (±14.9), median baseline NIHSS was 14 (IQR: 9–18), 136/198 (69%) were treated with intravenous thrombolysis, and 135/198 (68%) underwent EVT. Median call-to-CSC time was 162 min (IQR: 137–190). In 133/155 (86%) cases, the ambulance for transfer to the CSC was dispatched with the highest level of urgency. This was associated with shorter call-to-CSC time (adjusted β [95% CI]: −27.6 min [−51.2 to −3.9]). No clinical characteristics were associated with call-to-CSC time.

Conclusion: In patients transferred from a PSC for EVT, median call-to-CSC time was over 2.5 h. The highest level of urgency for dispatch of ambulances for EVT transfers should be used, as this clearly decreases time to treatment.

In-hospital acute stroke workflow in acute stroke - Systems-based approaches

Clinical outcomes of acute ischaemic stroke patients have significantly improved with the advent of reperfusion therapy. However, time continues to be a critical factor. Reducing treatment delays by improving workflows can improve the efficacy of acute reperfusion therapy. Systems-based approaches have improved in-hospital temporal parameters, maximizing the utility of reperfusion therapies and improving clinical benefit to patients. However, studies aimed at optimizing and hence reducing treatment delays in emergency department (ED) settings are limited. The aim of this article is to discuss existing systems-based approaches to optimize ED acute stroke workflows and its value in reducing treatment delays and identify gaps in existing workflows that need optimization. Identifying gaps in acute stroke workflow, variations in processes and challenges in implementation, in the in-hospital settings, is essential for systems-based interventions to be effective in delivering improved outcomes for patients with acute ischaemic stroke.

How do treatment times impact on functional outcome in stroke patients undergoing thrombectomy in Germany? Results from the German Stroke Registry

BACKGROUND

Functional outcome post-stroke depends on time to recanalization. Effect of in-hospital delay may differ in patients directly admitted to a comprehensive stroke center and patients transferred via a primary stroke center. We analyzed the current door-to-groin time in Germany and explored its effect on functional outcome in a real-world setting.

METHODS

Data were collected in 25 stroke centers in the German Stroke Registry-Endovascular Treatment a prospective, multicenter, observational registry study including stroke patients with large vessel occlusion. Functional outcome was assessed at three months by modified Rankin Scale. Association of door-to-groin time with outcome was calculated using binary logistic regression models.

RESULTS

Out of 4340 patients, 56% were treated primarily in a comprehensive stroke center and 44% in a primary stroke center and then transferred to a comprehensive stroke center ("drip-and-ship" concept). Median onset-to-arrival at comprehensive stroke center time and door-to-groin time were 103 and 79 min in comprehensive stroke center patients and 225 and 44 min in primary stroke center patients. The odds ratio for poor functional outcome per hour of onset-to-arrival-at comprehensive stroke center time was 1.03 (95%CI 1.01-1.05) in comprehensive stroke center patients and 1.06 (95%CI 1.03-1.09) in primary stroke center patients. The odds ratio for poor functional outcome per hour of door-to-groin time was 1.30 (95%CI 1.16-1.46) in comprehensive stroke center patients and 1.04 (95%CI 0.89-1.21) in primary stroke center patients. Longer door-to-groin time in comprehensive stroke center patients was associated with admission on weekends (odds ratio 1.61; 95%CI 1.37-1.97) and during night time (odds ratio 1.52; 95%CI 1.27-1.82) and use of intravenous thrombolysis (odds ratio 1.28; 95%CI 1.08-1.50).

CONCLUSION

Door-to-groin time was especially relevant for outcome of comprehensive stroke center patients, whereas door-to-groin time was much shorter in primary stroke center patients.Clinical Trial Registration: https://clinicaltrials.gov/ct2/show/NCT03356392. Unique identifier NCT03356392.

Effects of a Feedback-Demanding Stroke Clock on Acute Stroke Management: A Randomized Study

BACKGROUND AND PURPOSE

This randomized study aimed to evaluate whether the use of a stroke clock demanding active feedback from the stroke physician accelerates acute stroke management.

METHODS

For this randomized controlled study, a large-display alarm clock was installed in the computed tomography room, where admission, diagnostic work-up, and intravenous thrombolysis occurred. Alarms were set at the following target times after admission: (1) 15 minutes (neurological examination completed); (2) 25 minutes (computed tomography scanning and international normalized ratio determination by point-of-care laboratory completed); and (3) 30 minutes (intravenous thrombolysis started). The responsible stroke physician had to actively provide feedback by pressing a buzzer button. The alarm could be avoided by pressing the button before time out. Times to therapy decision (primary end point, defined as the end of all diagnostic work-up required for decision for or against recanalizing treatment), neurological examination, imaging, point-of-care laboratory, needle, and groin puncture were assessed by a neutral observer. Functional outcome (modified Rankin Scale) was assessed at day 90.

RESULTS

Of 107 participants, 51 stroke clock patients exhibited better stroke-management metrics than 56 control patients. Times from door to (1) end of all indicated diagnostic work-up (treatment decision time; 16.73 versus 26.00 minutes, P<0.001), (2) end of neurological examination (7.28 versus 10.00 minutes, P<0.001), (3) end of computed tomography (11.17 versus 14.00 minutes, P=0.002), (4) end of computed tomography angiography (14.00 versus 17.17 minutes, P=0.001), (5) end of point-of-care laboratory testing (12.14 versus 20.00 minutes, P<0.001), and (6) needle times (18.83 versus 47.00 minutes, P=0.016) were improved. In contrast, door-to-groin puncture times and functional outcomes at day 90 were not significantly different.

CONCLUSIONS

This study showed that the use of a stroke clock demanding active feedback significantly improves acute stroke-management metrics and, thus, represents a potential low-cost strategy for streamlining time-sensitive stroke treatment.

Public health and cost consequences of time delays to thrombectomy for acute ischemic stroke

OBJECTIVE

To determine public health and cost consequences of time delays to endovascular thrombectomy (EVT) for patients, health care systems, and society, we estimated quality-adjusted life-years (QALYs) of EVT-treated patients and associated costs based on times to treatment.

METHODS

The Markov model analysis was performed from US health care and societal perspectives over a lifetime horizon. Contemporary data from 7 trials within the Highly Effective Reperfusion Evaluated in Multiple Endovascular Stroke Trials (HERMES) collaboration served as data source. Aside from cumulative lifetime costs, we calculated the net monetary benefit (NMB) to determine the economic value of care. We used a contemporary willingness-to-pay threshold of $100,000 per QALY for NMB calculations.

RESULTS

Every 10 minutes of earlier treatment resulted in an average gain of 39 days (95% prediction interval 23-53 days) of disability-free life. Overall, the cumulative lifetime costs for patients with earlier or later treatment were similar. Patients with later treatment had higher morbidity-related costs but over a shorter time span due to their shorter life expectancy, resulting in similar lifetime costs as in patients with early treatment. Regarding the economic value of care, every 10 minutes of earlier treatment increased the NMB by $10,593 (95% prediction interval $5,549-$14,847) and by $10,915 (95% prediction interval $5,928-$15,356) taking health care and societal perspectives, respectively.

CONCLUSIONS

Any time delay to EVT reduces QALYs and decreases the economic value of care provided by this intervention. Health care policies to implement efficient prehospital triage and to accelerate in-hospital workflow are urgently needed.

The KEEP SIMPLEST Study: Improving In-House Delays and Periinterventional Management in Stroke Thrombectomy-A Matched Pair Analysis

BACKGROUND AND PURPOSE

Although the treatment window for mechanical thrombectomy (MT) in patients with acute ischemic stroke (AIS) has been extended in recent years, it has been proven that recanalizing treatment must be administered as soon as possible. We present a new standard operating procedure (SOP) to reduce in-house delay, standardize periinterventional management and improve patient safety during MT.

METHODS

KEep Evaluating Protocol Simplification In Managing Periinterventional Light Sedation for Endovascular Stroke Treatment (KEEP SIMPLEST) was a prospective, single-center observational study aimed to compare aspects of periinterventional management in AIS patients treated according to our new SOP using a combination of esketamine and propofol with patients having been randomized into conscious sedation (CS) in the Sedation versus Intubation for Endovascular Stroke TreAtment (SIESTA) trial. Primary outcome was early neurological improvement at 24h using the National Institutes of Health Stroke Scale, and secondary outcomes were door-to-recanalization, recanalization grade, conversion rate and modified Rankin Scale (mRS) at 3 months.

RESULTS

Door-to-recanalization time (128.6 ± 69.47 min vs. 156.8 ± 75.91 min; p = 0.02), mean duration of MT (92.01 ± 52 min vs. 131.9 ± 64.03 min; p < 0.001), door-to-first angiographic image (51.61 ± 31.7 min vs. 64.23 ± 21.53 min; p = 0.003) and computed tomography-to-first angiographic image time (31.61 ± 20.6 min vs. 44.61 ± 19.3 min; p < 0.001) were significantly shorter in the group treated under the new SOP. There were no differences in early neurological improvement, mRS at 3 months or other secondary outcomes between the groups. Conversion rates of CS to general anesthesia were similar in both groups.

CONCLUSION

An SOP using a novel sedation regimen and optimization of equipment and procedures directed at a leaner, more integrative and compact periinterventional management can reduce in-house treatment delays significantly in stroke patients receiving thrombectomy in light sedation and demonstrated the safety and feasibility of our improved approach.

Emerging Technologies in Optimizing Pre-Intervention Workflow for Acute Stroke

Over the last several years, thrombectomy for large vessel occlusions (LVOs) has emerged as a standard of care for acute stroke patients. Furthermore, the time to reperfusion has been identified as a predictor of overall patient outcomes, and much effort has been made to identify potential areas to target in enhancing preintervention workflow. As medical technology and stroke devices improve, nearly all time points can be affected, from field stroke triage to automated imaging interpretation to mass mobile stroke code communications. In this article, we review the preintervention stroke workflow with specific regard to emerging technologies in improving time to reperfusion and overall patient outcomes.

Reducing door-to-reperfusion time in acute stroke endovascular therapy using magnetic resonance imaging as a screening modality

Background

The feasibility of performing MRI first for patients with suspected hyperacute stroke in real-world practice has not been fully examined. Moreover, most past studies of reducing door-to-reperfusion time (DRT) in endovascular treatment (EVT) were conducted using CT. The aim of this study was to evaluate the feasibility of an MRI-first policy and to examine the effects of a quality improvement (QI) process for reducing DRT using MRI.

Methods

From January 2013 to December 2018, consecutive patients with acute stroke who came to hospital directly and were treated with emergent EVT were prospectively enrolled into the present study. In principle, MRI was performed first for patients with suspected acute stroke. A step-by-step QI process for decreasing DRT was adopted during this period. Time metrics for EVT were compared between specific time periods.

Results

A total of 180 patients (71 women; median age 76 years (range 69–64); National Institutes of Health Stroke Scale score 17 (range 10–23)) were included in the present study. More patients in the late phase were managed with the MRI-first policy (p<0.001). DRT (199 min in Phase 1, 135 min in Phase 2, 129 min in Phase 3, and 121 min in Phase 4, p<0.001) was significantly reduced across the phases. The percentage of patients with DRT <120 min increased significantly across time periods (p<0.001). Symptomatic intracerebral hemorrhage did not increase across phases (p=0.575).

Conclusion

An MRI-first policy was feasible, and DRT decreased considerably with a step-by-step QI process. This process may be applicable to other hospitals.

Acute ischaemic stroke interventions: large vessel occlusion and beyond

Care for acute ischaemic stroke is one of the most rapidly evolving fields due to the robust outcomes achieved by mechanical thrombectomy. Large vessel occlusion (LVO) accounts for up to 38% of acute ischaemic stroke and comes with devastating outcomes for patients, families and society in the pre-intervention era. A paradigm shift and a breakthrough brought mechanical thrombectomy back into the spotlight for acute ischaemic stroke; this was because five randomised controlled trials from several countries concluded that mechanical thrombectomy for acute stroke offered overwhelming benefits. This review article will present a comprehensive overview of LVO management, techniques and devices used, and the future of stroke therapy. In addition, we review our institution experience of mechanical thrombectomy for posterior and distal circulation occlusion.

A Visual Task Management Application for Acute Ischemic Stroke Care

Background: To maximize the effect of intravenous (IV) thrombolysis and/or endovascular therapy (EVT) for acute ischemic stroke (AIS), stroke centers need to establish a parallel workflow on the basis of a code stroke (CS) protocol. At Kokura Memorial Hospital (KMH), we implemented a CS system in January 2014; however, the process of information sharing within the team has occasionally been burdensome.

Objective: To solve this problem using information communication technology (ICT), we developed a novel application for smart devices, named “Task Calc. Stroke” (TCS), and aimed to investigate the impact of TCS on AIS care.

Methods: TCS can visualize the real-time progress of crucial tasks for AIS on a dashboard by changing color indicators. From August 2015 to March 2017, we installed TCS at KMH and recommended its use during normal business hours (NBH). We compared the door-to-computed tomography time, the door-to-complete blood count (door-to-CBC) time, the door-to-needle for IV thrombolysis time, and the door-to-puncture for EVT time among three treatment groups, one using TCS (“TCS-based CS”), one not using TCS (“phone-based CS”), and one not based on CS (“non-CS”). A questionnaire survey regarding communication problems was conducted among the CS teams at 3 months after the implementation of TCS.

Results: During the study period, 74 patients with AIS were transported to KMH within 4.5 h from onset during NBH, and 53 were treated using a CS approach (phone-based CS: 26, TSC-based CS: 27). The door-to-CBC time was significantly reduced in the TCS-based CS group compared to the phone-based CS group, from 31 to 19 min (p = 0.043). Other processing times were also reduced, albeit not significantly. The rate of IV thrombosis was higher in the TCS-based CS group (78% vs. 46%, p = 0.037). The questionnaire was correctly filled in by 34/38 (89%) respondents, and 82% of the respondents felt a reduction in communication burden by using the TCS application.

Conclusions: TCS is a novel approach that uses ICT to support information sharing in a parallel CS workflow in AIS care. It shortens the processing times of critical tasks and lessens the communication burden among team members.

Single Centre Experience on Decision Making for Mechanical Thrombectomy Based on Single-Phase CT Angiography by Including NCCT and Maximum Intensity Projection Images - A Comparison with Magnetic Resonance Imaging after Non-Contrast CT

Objective

The purpose of this study was to suggest that computed tomography angiography (CTA) is valuable as the only preliminary examination for mechanical thrombectomy (MT). MT after single examination of CTA including non-contrast computed tomography (NCCT) and maximum intensity projection (MIP) improves door-to-puncture time as well as results in favorable outcomes.

Methods

A total of 157 patients who underwent MT at Dong Kang Medical Center from April 2015 to March 2019 were divided into two groups based on the examination performed prior to MT : CTA group who underwent CTA with NCCT and MIP, and NCCT+magnetic resonance image (MRi) group who underwent MRI including perfusion images after NCCT. In the two groups, time to CTA imaging or NCCT+MRi imaging after symptom onset, and time to arterial puncture and reperfusion were characterized as time-related outcomes. The evaluation of vascular recanalization after MT was defined as a modified thrombolysis in cerebral infarction (mTICI) scale. National Institutes of Health Stroke Scale (NIHSS) was assessed at the time of the visit to the emergency room and modified Rankin Scale (mRS) was assessed after 90 days.

Results

Typically, there were 34 patients in the CTA group and 33 patients in the NCCT+MRi group. A significantly shorter delay for door-to-puncture time was observed (mean, 86±22.1 vs. 176±47.5 minutes; p<0.01). Also, a significantly shorter door-to-imege time in the CTA group was observed (mean, 13±6.8 vs. 93±30.8 minutes; p<0.01). Moreover, a significantly shorter onset-to-puncture time was observed (mean, 195±128.0 vs. 314±157.6 minutes; p<0.01). Reperfusion result of mTICI ≥2b was 100% (34/34) in the CTA group and 94% (31/33) in the NCCT+MRi group, and mTICI 3 in 74% (25/34) in the CTA group and 73% (24/33) in the NCCT+MRi group. Favorable functional outcomes (mRS score ≤2 at 90 days) were 68% (23/34) in the CTA group and 60% (20/33) in the NCCT+MRi group.

Conclusion

A single-phase CTA including NCCT and MIP images was performed as a single preliminary examination, which led to a reduction in the time of the procedure and resulted in good results of prognosis. Consequently, it is concluded that this method is of sufficient value as the only preliminary examination for decision making.

Clinical prediction of thrombectomy eligibility: A systematic review and 4-item decision tree

BACKGROUND

A clinical large anterior vessel occlusion (LAVO)-prediction scale could reduce treatment delays by allocating intra-arterial thrombectomy (IAT)-eligible patients directly to a comprehensive stroke center.

AIM

To subtract, validate and compare existing LAVO-prediction scales, and develop a straightforward decision support tool to assess IAT-eligibility.

METHODS

We performed a systematic literature search to identify LAVO-prediction scales. Performance was compared in a prospective, multicenter validation cohort of the Dutch acute Stroke study (DUST) by calculating area under the receiver operating curves (AUROC). With group lasso regression analysis, we constructed a prediction model, incorporating patient characteristics next to National Institutes of Health Stroke Scale (NIHSS) items. Finally, we developed a decision tree algorithm based on dichotomized NIHSS items.

RESULTS

We identified seven LAVO-prediction scales. From DUST, 1316 patients (35.8% LAVO-rate) from 14 centers were available for validation. FAST-ED and RACE had the highest AUROC (both >0.81, p < 0.01 for comparison with other scales). Group lasso analysis revealed a LAVO-prediction model containing seven NIHSS items (AUROC 0.84). With the GACE (Gaze, facial Asymmetry, level of Consciousness, Extinction/inattention) decision tree, LAVO is predicted (AUROC 0.76) for 61% of patients with assessment of only two dichotomized NIHSS items, and for all patients with four items.

CONCLUSION

External validation of seven LAVO-prediction scales showed AUROCs between 0.75 and 0.83. Most scales, however, appear too complex for Emergency Medical Services use with prehospital validation generally lacking. GACE is the first LAVO-prediction scale using a simple decision tree as such increasing feasibility, while maintaining high accuracy. Prehospital prospective validation is planned.

Streamlined triage and transfer protocols improve door-to-puncture time for endovascular thrombectomy in acute ischemic stroke

OBJECTIVE

Shorter time from symptom onset to treatment is associated with improved outcomes in patients who undergo mechanical thrombectomy for treatment of acute ischemic stroke due to emergent large vessel occlusion. In this work, we detail pre-thrombectomy process improvements in a multi-hospital network and report the effect on door-to-puncture time in patients undergoing mechanical thrombectomy.

PATIENTS AND METHODS

A streamlined workflow was adopted to minimize door-to-puncture time. Key features of this workflow included rapid and concurrent clinical and radiological evaluation with point-of-care image interpretation, pre-transfer IV thrombolysis and CTA for transferred patients, immediate transport to the angiography suite potentially before neurointerventional radiology team arrival, and minimalist room setup. Door-to-puncture time was measured prospectively and analyzed retrospectively for 78 consecutive patients treated between January 2015 and December 2015. Statistical analysis was performed using the F-test on individual coefficients of a linear regression model.

RESULTS

From quarter 1 to quarter 4, the number of thrombectomies performed increased by 173% (11 patients to 30 patients, p = 0.002), and there was a significant increase in the proportion of transferred patients that underwent pre-transfer CTA (p = 0.04). During this interval, overall median door-to-puncture time decreased by 74% (147 min to 39 min, p < 0.001); this decrease was greatest in transferred patients with pre-transfer CTA (81% decrease, 129 min to 25 min, p < 0.001) and smallest in patients presenting directly to the emergency department (52% decrease, 167 min to 87 min, p < 0.001).

CONCLUSION

Simple workflow improvements to streamline in-hospital triage and perform critical workup at transferring hospitals can produce reductions in door-to-puncture time.

Protocols for Endovascular Stroke Treatment Diminish the Weekend Effect Through Improvements in Off-Hours Care

Introduction: The weekend effect is a well-recognized phenomenon in which patient outcomes worsen for acute strokes presenting outside routine business hours. This is attributed to non-uniform availability of services throughout the week and evenings and, though described for intravenous thrombolysis candidates, is poorly understood for endovascular stroke care. We evaluated the impact of institutional protocols on the weekend effect, and the speed and outcome of endovascular therapy as a function of time of presentation.

Method: This study assesses a prospective observational cohort of 129 consecutive patients. Patients were grouped based on the time of presentation during regular work hours (Monday through Friday, 07:00–19:00 h) vs. off-hours (overnight 19:00–07:00 h and weekends) and assessed for treatment latency and outcome.

Results: Treatment latencies did not depend on the time of presentation. The door to imaging interval was comparable during regular and off-hours (median time 21 vs. 19 min, respectively, p < 0.50). Imaging to groin puncture was comparable (71 vs. 71 min, p < 1.0), as were angiographic and functional outcomes. Additionally, treatment intervals decreased with increased protocol experience; door-to-puncture interval significantly decreased from the first to the fourth quarters of the study period (115 vs. 94 min, respectively, p < 0.006), with the effect primarily seen during off-hours with a 28% reduction in median door-to-puncture times.

Conclusions: Institutional protocols help diminish the weekend effect in endovascular stroke treatment. This is driven largely by improvement in off-hours performance, with protocol adherence leading to further decreases in treatment intervals over time.

Neuro-Interventional Management of Acute Ischemic Stroke

Restoration of cerebral blood flow is the most important step in preventing irreversible damage to hypoperfused brain cells after ischemic stroke from large-vessel occlusion. For those patients who do not respond to (or are not eligible for) intravenous thrombolysis, endovascular therapy has become standard of care. A shift is currently taking place from rigid time windows for intervention (time is brain) to physiology-driven paradigms that rely heavily on neuroimaging. At this time, one can reasonably anticipate that more patients will be treated, and that outcomes will keep improving. This article discusses in detail recent advances in endovascular stroke therapy.

Consensus Statements by Korean Society of Interventional Neuroradiology and Korean Stroke Society: Hyperacute Endovascular Treatment Workflow to Reduce Door-to-Reperfusion Time

Recent clinical trials demonstrated the clinical benefit of endovascular treatment (EVT) in patients with acute ischemic stroke due to large vessel occlusion. These trials confirmed that good outcome after EVT depends on the time interval from symptom onset to reperfusion and that in-hospital delay leads to poor clinical outcome. However, there has been no universally accepted in-hospital workflow and performance benchmark for rapid reperfusion. Additionally, wide variety in workflow for EVT is present between each stroke centers. In this consensus statement, Korean Society of Interventional Neuroradiology and Korean Stroke Society Joint Task Force Team propose a standard workflow to reduce door-to-reperfusion time for stroke patients eligible for EVT. This includes early stroke identification and pre-hospital notification to stroke team of receiving hospital in pre-hospital phase, the transfer of stroke patients from door of the emergency department to computed tomography (CT) room, warming call to neurointervention (NI) team for EVT candidate prior to imaging, NI team preparation in parallel with thrombolysis, direct transportation from CT room to angiography suite following immediate decision of EVT and standardized procedure for rapid reperfusion. Implementation of optimized workflow will improve stroke time process metrics and clinical outcome of the patient treated with EVT.

Diagnosing cerebral ischemia with door-to-thrombolysis times below 20 minutes

Objectives

To clarify diagnostic accuracy and consequences of misdiagnosis in the admission evaluation of stroke-code patients in a neurologic emergency department with less than 20-minute door-to-thrombolysis times.

Methods

Accuracy of admission diagnostics was studied in an observational cohort of 1,015 stroke-code patients arriving by ambulance as candidates for recanalization therapy between May 2013 and November 2015. Immediate admission evaluation was performed by a stroke neurologist or a neurology resident with dedicated stroke training, primarily utilizing CT-based imaging.

Results

The rate of correct admission diagnosis was 91.1% (604/663) for acute cerebral ischemia (ischemic stroke/TIA), 99.2% (117/118) for hemorrhagic stroke, and 61.5% (144/234) for stroke mimics. Of the 150 (14.8%) misdiagnosed patients, 135 (90.0%) had no acute findings on initial imaging and 100 (67.6%) presented with NIH Stroke Scale score 0 to 2. Misdiagnosis altered medical management in 70 cases, including administration of unnecessary treatments (thrombolysis n = 13, other n = 24), omission of thrombolysis (n = 5), delays to specific treatments of stroke mimics (n = 13, median 56 [31–93] hours), and delays to antiplatelet medication (n = 14, median 1 [1–2] day). Misdiagnosis extended emergency department stay (median 6.6 [4.7–10.4] vs 5.8 [3.7–9.2] hours; p = 0.001) and led to unnecessary stroke unit stay (n = 10). Detailed review revealed 8 cases (0.8%) in which misdiagnosis was possible or likely to have worsened outcomes, but no death occurred as a result of misdiagnosis.

Conclusions

Our findings support the safety of highly optimized door-to-needle times, built on thorough training in a large-volume, centralized stroke service with long-standing experience. Augmented imaging and front-loaded specialist engagement are warranted to further improve rapid stroke diagnostics.

Consensus Statements by Korean Society of Interventional Neuroradiology and Korean Stroke Society: Hyperacute Endovascular Treatment Workflow to Reduce Door-to-Reperfusion Time

Recent clinical trials demonstrated the clinical benefit of endovascular treatment (EVT) in patients with acute ischemic stroke due to large vessel occlusion. These trials confirmed that good outcome after EVT depends on the time interval from symptom onset to reperfusion and that in-hospital delay leads to poor clinical outcome. However, there has been no universally accepted in-hospital workflow and performance benchmark for rapid reperfusion. Additionally, wide variety in workflow for EVT is present between each stroke centers. In this consensus statement, Korean Society of Interventional Neuroradiology and Korean Stroke Society Joint Task Force Team propose a standard workflow to reduce door-to-reperfusion time for stroke patients eligible for EVT. This includes early stroke identification and pre-hospital notification to stroke team of receiving hospital in pre-hospital phase, the transfer of stroke patients from door of the emergency department to computed tomography (CT) room, warming call to neurointervention team for EVT candidate prior to imaging, neurointervention team preparation in parallel with thrombolysis, direct transportation from CT room to angiography suite following immediate decision of EVT and standardized procedure for rapid reperfusion. Implementation of optimized workflow will improve stroke time process metrics and clinical outcome of the patient treated with EVT.

Improving Door to Groin Puncture Time for Mechanical Thrombectomy via Iterative Quality Protocol Interventions

Introduction: Delays in door to groin puncture time (DGPT) for patients with ischemic stroke caused by acute large vessel occlusions (LVO) are associated with worse clinical outcomes. We present the results of a quality improvement protocol for endovascular stroke treatment at the University of California, San Diego (UCSD) that aimed to minimize DGPT.

Materials and Methods: Our stroke team implemented a series of quality improvement measures to decrease DGPT, with a target of 90 minutes or less. Sixty-three patients treated at our center were retrospectively divided into three groups based on the date of their intervention as a proxy for the implementation of process improvement protocols: 23 patients treated from July to December 2015, 24 patients treated from January to July 2016, and 16 patients treated from July 2016 to December 2016. Multivariate log-linear and logistic regression analyses were used to assess the predictors of prolonged DGPT and compliance with target DGPT (<90 min), respectively.

Results: Date of intervention—a proxy for the implementation of process improvement protocols—was predictive of compliance with target DGPT. Patients treated from July 2016 to December 2016—after the full implementation of process improvements—were 3.2 times more likely to meet or exceed the target DGPT compared to patients treated from July 2015 to December 2015 (p=0.011). When adjusting for potential confounders in a multivariate analysis, patients in the final cohort were associated with shorter DGPT (Exp(B)=0.61, p=0.013) and remained significantly more likely to achieve the DGPT goal (OR=14.2, p=0.007).

Conclusion: An iterative quality improvement process can significantly improve DGPT. This analysis demonstrates the utility of a formal quality improvement system at an academic comprehensive stroke center.

Impact of onset-to-groin puncture time within three hours on functional outcomes in mechanical thrombectomy for acute large-vessel occlusion

Introduction Endovascular treatment for acute ischemic stroke with acute large-vessel occlusion (ALVO) has established benefits, and rapid treatment is vital for mechanical thrombectomy in ALVO. Time from onset of stroke to groin puncture (OTP) is a practical and useful clinical marker, and OTP should be shortened to obtain the maximum benefit of thrombectomy. Objective The aim of the present study was to assess the impact of early treatment of anterior circulation stroke within three hours after symptom onset and to evaluate the role of OTP in determining outcomes after endovascular therapy. Methods Consecutive patients with acute stroke due to major artery (internal carotid or middle cerebral arteries) occlusion who underwent endovascular recanalization between March 2014 and January 2017 were retrospectively evaluated. Patients were stratified by OTP into three categories: 0-≤3 h, >3-≤6 h, and >6 h. The primary outcome measure was a 90-day modified Rankin scale score of 0-2 (good outcome). Results Data were analyzed from 100 patients (mean age, 76.6 years; mean National Institutes of Health Stroke Scale score, 17). Groin puncture occurred within 0-≤3 h in 51 patients, >3-≤6 h in 28, and >6 h in 21. Median OTP in each group was 126 min (range, 57-168 min), 238 min (range, 186-360 min) and 728 min (range, 365-1492 min), respectively. On multivariable logistic regression analysis, category of OTP represented an independent predictor of patient outcome (adjusted odds ratio, 0.48; 95% confidence interval, 0.25-0.93; p = 0.029). Conclusions OTP is a prehospital and in-hospital workflow-based indicator. In this single-center study, OTP was found to independently affect functional outcomes after endovascular stroke treatment.

Predictors of Good Outcome After Endovascular Therapy for Vertebrobasilar Occlusion Stroke

BACKGROUND AND PURPOSE

Endovascular therapy is increasingly used in acute ischemic stroke treatment and is now considered the gold standard approach for selected patient populations. Prior studies have demonstrated that eventual patient outcomes depend on both patient-specific factors and procedural considerations. However, these factors remain unclear for acute basilar artery occlusion stroke. We sought to determine prognostic factors of good outcome in acute posterior circulation large vessel occlusion strokes treated with endovascular therapy.

METHODS

We reviewed our prospectively collected endovascular databases at 2 US tertiary care academic institutions for patients with acute posterior circulation strokes from September 2005 to September 2015 who had 3-month modified Rankin Scale documented. Baseline characteristics, procedural data, and outcomes were evaluated. A good outcome was defined as a 90-day modified Rankin Scale score of 0 to 2. The association between clinical and procedural parameters and functional outcome was assessed.

RESULTS

A total of 214 patients qualified for the study. Smoking status, creatinine levels, baseline National Institutes of Health Stroke Scale score, anesthesia modality (conscious sedation versus general anesthesia), procedural length, and reperfusion status were significantly associated with good outcomes in the univariate analysis. Multivariate logistic regression indicated that only smoking (odds ratio=2.61; 95% confidence interval, 1.23-5.56; P=0.013), low baseline National Institutes of Health Stroke Scale score (odds ratio=1.09; 95% confidence interval, 1.04-1.13; P<0.0001), and successful reperfusion status (odds ratio=10.80; 95% confidence interval, 1.36-85.96; P=0.025) were associated with good outcome.

CONCLUSIONS

In our retrospective case series, only smoking, low baseline National Institutes of Health Stroke Scale score, and successful reperfusion status were associated with good outcome in patients with posterior circulation stroke treated with endovascular therapy.

Wide Variability in Prethrombectomy Workflow Practices in the United States: A Multicenter Survey

BACKGROUND AND PURPOSE

Clinical outcomes in patients with acute ischemic stroke caused by large vessel occlusion depend on the speed and quality of workflows leading to mechanical thrombectomy. In the absence of universally accepted best practices for workflow, developing stroke hospitals can benefit from improved awareness of real-world workflows in effect at experienced centers. To this end, we surveyed prethrombectomy workflow practices at stroke centers throughout the United States.

MATERIALS AND METHODS

E-mail and phone interviews were conducted with neurointerventional team members at 30 experienced, endovascular-capable stroke centers. Questions were chosen to reflect workflow components of triage, team activation, transport, case setup, and anesthesia.

RESULTS

There is wide variation in prethrombectomy workflows. At 53% of institutions, nonphysician staff respond to stroke alerts alongside physicians. Imaging triage involves noninvasive angiography or perfusion imaging at 97% and 63% of institutions, respectively. Neurointerventional consultation is initiated before the completion of neuroimaging at 86% of institutions, and the team is activated before a final treatment decision at 59%. The neurointerventional team most commonly arrives within 30 minutes. Patients may be transported to the neuroangiography suite before team arrival at 43% of institutions. Procedural trays are set up in advance of team arrival at 13% of centers; additional thrombectomy devices are centrally stored at 54%. A power injector for angiographic runs is consistently used at 43% of institutions. Anesthesiology routinely supports thrombectomies at 67% of institutions.

CONCLUSIONS

Prethrombectomy workflows vary widely between experienced centers. Improved awareness of real-world workflows and their variations may help to guide institutions in designing their own protocols of care.

Effect of Retrievable Stent Size on Endovascular Treatment of Acute Ischemic Stroke: A Multicenter Study

BACKGROUND AND PURPOSE

In clinical practice, stent diameter is one of the variable properties important for endovascular treatment. A consensus guideline for stent retriever size selection has yet to be established. The aim of this study was to investigate the effects of different diameters of Solitaire retrievers on outcomes.

MATERIALS AND METHODS

Of 628 patients enrolled from the Endovascular Treatment for Acute Anterior Circulation Ischemic Stroke Registry, 256 were treated with the Solitaire 4-mm device and 372, with the 6-mm device. We matched patients treated with the 2 stent sizes using propensity score analysis. The successful outcome was reperfusion as measured by the modified Thrombolysis in Cerebral Infarction score immediately postprocedure and the dichotomized modified Rankin Scale score at 90 days. Symptomatic intracerebral hemorrhage and in-hospital mortality were also recorded.

RESULTS

After propensity score analysis, group outcomes did not differ. In addition, in patients with atherosclerosis-related occlusion, a higher reperfusion rate (P = .021) was observed in the Solitaire 4 group, as well as a shorter time interval (P = .002) and fewer passes (P = .025). Independent predictors of successful reperfusion in patients with atherosclerotic disease on logistic analysis were the small stent (OR, 3.217; 95% CI, 1.129-9.162; P = .029) and the propensity score acting as a covariate (OR, 52.84; 95% CI, 3.468-805.018; P = .004).

CONCLUSIONS

We found no evidence of a differential effect of intra-arterial therapy based on the size of Solitaire retrievers. In patients with atherosclerotic disease, favorable reperfusion was associated with deployment of a small stent.

Diffusion and Perfusion MR Imaging in Acute Stroke: Clinical Utility and Potential Limitations for Treatment Selection

Magnetic resonance (MR) diffusion-weighted imaging (DWI) and perfusion-weighted imaging (PWI) offer unique insight into acute ischemic stroke pathophysiology. These techniques may offer the ability to apply pathophysiology to accurately individualize acute stroke reperfusion treatment, including extending the opportunity of reperfusion treatment to well beyond the current time-based treatment windows.This review examines the use of DWI and PWI in the major stroke trials, their current clinical utility, and potential limitations for reperfusion treatment selection. DWI and PWI continue to be investigated in ongoing randomized controlled trials, and continued research into these techniques will help achieve the goal of tissue-based decision making and individualized acute stroke treatment.

Pre and intrahospital workflow for acute stroke treatment

PURPOSE OF REVIEW

With the recent demonstration of the effectiveness of rapid recanalization of large vessel occlusions in acute ischemic stroke, it is important to assess the current status of pre and intrahospital workflow for acute stroke.

RECENT FINDINGS

We will review trends in the evaluation and treatment of acute stroke and offer suggestions for how best to advance the workflow for acute stroke care in the coming years.

SUMMARY

Future research is needed for: field use of clinical scores for predicting large vessel occlusions, telemedicine to facilitate prehospital triage, and pre and intrahospital processes for optimizing stroke care delivery.

Neurocritical Care of Emergent Large-Vessel Occlusion: The Era of a New Standard of Care

Acute ischemic stroke continues to be one of the leading causes of morbidity and mortality worldwide. Recent advances in mechanical thrombectomy techniques combined with prereperfusion computed tomographic angiography for patient selection have revolutionized stroke care in the past year. Peri- and postinterventional neurocritical care of the patient who has had an emergent large-vessel occlusion is likely an equally important contributor to the outcome but has been relatively neglected. Critical periprocedural management issues include streamlining care to speed intervention, blood pressure optimization, reversal of anticoagulation, management of agitation, and selection of anesthetic technique (ie, general vs monitored anesthesia care). Postprocedural critical care issues that might modulate neurological outcome include blood pressure and glucose optimization, avoidance of fever or hyperoxia, fluid and nutritional management, and early integration of rehabilitation into the intensive care unit setting. In this review, we sought to lay down an evidence-based strategy for patients with acute ischemic stroke undergoing emergent endovascular reperfusion.

Presence of the hyperintense acute reperfusion marker on MRI after mechanical thrombectomy for large vessel occlusion is associated with worse early neurological recovery

BACKGROUND

Mechanical thrombectomy has become the accepted treatment for large vessel occlusion in acute ischemic stroke. Unfortunately, a large cohort of patients do not achieve functional independence with treatment, even though the results are more robust than with medical management. The hyperintense acute reperfusion marker (HARM) on MRI is an indication of the breakdown of the blood-brain barrier and reperfusion injury.

OBJECTIVE

To examine the hypothesis that the presence of HARM on MRI correlates with worse neurological recovery after reperfusion therapy.

METHODS

We retrospectively reviewed 35 consecutive patients who between February 24, 2016 and April 23, 2016 underwent MRI to determine the presence of HARM after thrombectomy for anterior circulation large vessel occlusion. Demographic, radiographic imaging, and outcome data were collected. Univariate and binary logistic regression models were performed to assess predictors for improvement of the National Institutes of Health Stroke Scale (NIHSS) score by ≥8 points at 24 hours.

RESULTS

The 35 patients studied had an average age of 64±14 years of age with a median NIHSS score of 15 (IQR 9-20). Eighteen patients (51%) were found to have a HARM-positive MRI. In univariate analysis, patients with HARM were older, had lower reperfusion rates and more postprocedural hemorrhages. In binary logistic regression modeling, the absence of HARM was independently associated with a ≥8-point NIHSS score improvement at 24 hours (OR=7.14, 95% CI 1.22 to 41.67).

CONCLUSIONS

This preliminary analysis shows that the presence of HARM may be linked to worse neurological recovery 24 hours after thrombectomy. Reperfusion injury may affect the number of patients achieving functional independence after treatment.