Endovascular Thrombectomy in Acute Ischemic Stroke: Outcome in Referred Versus Directly Admitted Patients

Early Versus Late Initiation of Endovascular Therapy in Patients with Severe Cerebral Venous Sinus Thrombosis

BACKGROUND

Endovascular therapy (EVT) for severe cerebral venous sinus thrombosis (CVST) is controversial in terms of indication and clinical benefit. The impact of delay of EVT on functional recovery is unclear. This study aimed to investigate the effect of early versus late initiation of EVT in severe CVST.

METHODS

From prospective EVT and CVST registries, patients with CVST diagnosed between January 2010 and December 2022 were retrospectively identified for this multicenter collaboration. EVT was considered in severe CVST with features prone to a poor prognosis. We compared early (< 24 h) with late (> 24 h) initiation of EVT after the presentation in the emergency department and subsequent CVST diagnosis. Outcome parameters included functional independence (modified Rankin Scale [mRS] score 0-2) at 90 days, mRS score at discharge, in-hospital mortality, and mortality at 3 months.

RESULTS

Of 363 patients with CVST, 45 (12.4%; 31 [early EVT] vs. 14 [late EVT]) were included in this study. We found a higher proportion of patients with functional independence at 3 months among early versus late EVT (66.7% vs. 27.3%; odds ratio [OR] 5.3; 95% confidence interval 1.02-25; p = 0.036). In multivariate logistic regression, late EVT was inversely correlated with functional independence (OR 0.17 [0.04-0.83]; p = 0.011). The mortality rate was 16.7% versus 36.4% (mRS 6 at 3 months, OR 0.34, 95% confidence interval 0.07-1.75; p = 0.217) at 90 days for early versus late EVT.

CONCLUSIONS

We observed a higher rate of functional independence in patients with early EVT. These preliminary findings must be confirmed in subsequent randomized controlled trials evaluating a "time-is-brain" paradigm for EVT in CVST.

Drip and ship and mothership models of mechanical thrombectomy result in similar outcomes in acute ischemic stroke of the anterior circulation

BACKGROUND

Stroke therapy has been transformed in recent years due to the availability of thrombolysis and mechanical thrombectomy (MT). Whether transferring the patient directly to a comprehensive stroke center (CSC, mothership model) is better than taking them to a primary stroke center (PSC) and then to a CSC for MT (drip and ship) is unclear but has important implications. We compared the performance of both models in a district of the Basque country, Spain.

METHODS

This is a retrospective analysis of prospectively collected data of all acute ischemic stroke patients consecutively admitted to the Neurology Department of two institutions and eligible for MT over a 36-month period with anterior circulation large vessel occlusion (LVO). One center applied the mothership model and the other the drip-and-ship. The two models were compared in terms of mortality and functional status assessed by modified Rankin (mRS) scale at 90 days. As a surrogate of the effectiveness of the two models, all times pertinent to stroke therapy were recorded.

RESULTS

A total of 187 patients were evaluated subjected to MT with the drip-and-ship model and 188 with mothership, with a median NIHSS of 15. Prior to MT, 17% of the drip-and-ship patients received thrombolysis and 26% in the mothership. Neither mortality rate nor mRS showed statistically significant differences 90 days after stroke. The time lapse from stroke to MT was optimal in both models; albeit being 10 minutes longer in the drip-and-ship model, it had no impact on patients' outcomes.

CONCLUSIONS

Drip-and-ship and mothership models can provide optimal and similar results in acute stroke patients in terms of mortality and functional status at 90 days. Their coexistence may alleviate the burden of CSC thus facilitating the access of more stroke patients to advanced therapies in an equitable manner.

Drip-and-Ship for Thrombectomy Treatment in Patients With Acute Ischemic Stroke Leads to Inferior Clinical Outcomes in a Stroke Network Covering Vast Rural Areas Compared to Direct Admission to a Comprehensive Stroke Center

Introduction: Organizing regional stroke care considering thrombolysis as well as mechanical thrombectomy (MTE) remains challenging in light of a wide range of regional population distribution. To compare outcomes of patients in a stroke network covering vast rural areas in southwestern Germany who underwent MTE via direct admission to a single comprehensive stroke center [CSC; mothership (MS)] with those of patients transferred from primary stroke centers [PSCs; drip-and-ship (DS)], we undertook this analysis of consecutive stroke patients with MTE.

Materials and Methods: Patients who underwent MTE at the CSC between January 2013 and December 2016 were included in the analysis. The primary outcome measure was 90-day functional independence [modified Rankin score (mRS) 0–2]. Secondary outcome measures included time from stroke onset to recanalization/end of MTE, angiographic outcomes, and mortality rates.

Results: Three hundred and thirty-two consecutive patients were included (MS 222 and DS 110). Median age was 74 in both arms of the study, and there was no significant difference in baseline National Institutes of Health Stroke Scale scores (median MS 15 vs. 16 DS). Intravenous (IV) thrombolysis (IVT) rates differed significantly (55% MS vs. 70% DS, p = 0.008). Time from stroke onset to recanalization/end of MTE was 112 min shorter in the MS group (median 230 vs. 342 min, p < 0.001). Successful recanalization [thrombolysis in cerebral infarction (TICI) 2b-3] was achieved in 72% of patients in the MS group and 73% in the DS group. There was a significant difference in 90-day functional independence (37% MS vs. 24% DS, p = 0.017), whereas no significant differences were observed for mortality rates at 90 days (MS 22% vs. DS 17%, p = 0.306).

Discussion: Our data suggest that patients who had an acute ischemic stroke admitted directly to a CSC may have better 90-day outcomes than those transferred secondarily for thrombectomy from a PSC.

The Maryland Acute Stroke Emergency Medical Services Routing Pilot: Expediting Access to Thrombectomy for Stroke

Background: Mechanical thrombectomy (MT) is the standard of care for acute ischemic stroke caused by large vessel occlusion, but is not available at all stroke centers. Transfers between hospitals lead to treatment delays. Transport directly to a facility capable of MT based on a prehospital stroke severity scale score has been recommended, if transportation time is less than 30 min.

Aims: We hypothesized that an Emergency Medical Services (EMS) routing algorithm for stroke, using the Los Angeles Motor Scale (LAMS) in the field, would improve time from last known well to MT, without causing patients to miss the IV Thrombolysis (IVT) window.

Methods: An EMS algorithm in the Baltimore metro area using the LAMS was implemented. Patients suspected of having an acute stroke were assessed by EMS using the LAMS. Patients scoring 4 or higher and within 20 h from last known well, were transported directly to a Thrombectomy Center, if transport could be completed within 30 min. The algorithm was evaluated retrospectively with prospectively collected data at the Thrombectomy Centers. The primary outcome variables were proportion of patients with suspected stroke rerouted by EMS, proportion of rerouted ischemic stroke patients receiving MT, time to treatment, and whether the IVT window was missed.

Results: A total of 303 patients were rerouted out of 2459 suspected stroke patients over a period of 6 months. Of diverted patients, 47% had acute ischemic stroke. Of these, 48% received an acute stroke treatment: 16.8% IVT, 17.5% MT, and 14% MT+IVT. Thrombectomy occurred 119 min earlier in diverted patients compared to patients transferred from other hospitals (P = 0.006). 55.3% of diverted patients undergoing MT and 38.2% of patients transferred from hospital to hospital were independent at 90 days (modified Rankin score 0–2) (P = 0.148). No patient missed the time window for IVT due to the extra travel time.

Conclusions: In this retrospective analysis of prospectively acquired data, implementation of a pre-hospital clinical screening score to detect patients with suspected acute ischemic stroke due to large vessel occlusion was feasible. Rerouting patients directly to a Thrombectomy Center, based on the EMS algorithm, led to a shorter time to thrombectomy.

Impact of Direct Admission Versus Interfacility Transfer on Endovascular Treatment Outcomes for Acute Ischemic Stroke: Systematic Review and Meta-Analysis

BACKGROUND

Mechanical thrombectomy is a proven treatment for large-vessel ischemic stroke with improved functional outcomes compared with intravenous thrombolytics. Access to thrombectomy-capable sites varies greatly by geography, often necessitating interhospital transfer of patients who first present to hospitals unable to provide thrombectomy. The purpose of this meta-analysis was to examine the impact of interhospital transportation on patient outcomes to better inform recommendations for prehospital protocols.

METHODS

A meta-analysis was performed following systematic literature searches. Outcomes of interest included successful reperfusion, symptomatic intracranial hemorrhage, 90-day modified Rankin Scale score 0-2, 90-day mortality, onset-to-puncture times, and door-to-puncture times.

RESULTS

Pooled analysis comprised >27,000 patients. Door-to-puncture time was 35.6 minutes shorter among transferred patients; however, symptom onset-to-puncture time was 91.6 minutes longer. Rate of reperfusion or symptomatic intracranial hemorrhage as well as 90-day mortality did not differ significantly between transferred and directly admitted patients. While the proportion of patients achieving good functional outcome at 90 days with modified Rankin Scale score 0-2 did not differ by admission type, when modified Rankin Scale score was narrowed to 0-1, direct transport showed 20% greater probability of achieving excellent functional outcome (P < 0.001).

CONCLUSIONS

This meta-analysis represents the largest pooled population examined to date to assess how interfacility transportation to thrombectomy-capable sites affects patient outcomes. Our results indicate that direct admission is a significant predictor of excellent functional outcome. The findings presented here can be used to better inform quality improvement projects to streamline access to facilities providing endovascular mechanical thrombectomy capabilities.

Seasonal patterns and associations in the incidence of acute ischemic stroke requiring mechanical thrombectomy

Background

In order to identify risk periods with an increased demand in technical and human resources, we tried to determine patterns and associations in the incidence of acute ischemic stroke due to embolic large vessel occlusions (eLVO) requiring mechanical thrombectomy (MT).

Methods

We conducted a time series analysis over a 9‐year period (2010–2018) based on observational data in order to detect seasonal patterns in the incidence of MT due to eLVO (n = 2628 patients). In a series of sequential negative binominal regression models, we aimed to detect further associations (e.g., temperature, atmospheric pressure, air pollution).

Results

There was a 6‐month seasonal pattern in the incidence of MT due to eLVO (p = 0.024) peaking in March and September. Colder overall temperature was associated with an increase in MT due to eLVO (average marginal effect [AME], [95% CI]: −0.15 [−0.30–0.0001]; p = 0.05; per °C). A current increase in the average monthly temperature was associated with a higher incidence of MT due to eLVO (0.34 [0.11–0.56]; p = 0.003). Atmospheric pressure was positively correlated with MT due to eLVO (0.38 [0.13–0.64]; p = 0.003; per hectopascal [hPa]). We could detect no causal correlation between air pollutants and MT due to eLVO.

Conclusions

Our data suggest a 6‐month seasonal pattern in the incidence of MT due to eLVO peaking in spring and early autumn. This might be attributed to two different factors: (1) a current temperature rise (comparing the average monthly temperature in consecutive months) and (2) colder overall temperature. These results could help to identify risk periods requiring an adaptation in local infrastructure.

Negative impact of Interhospital Transfer on Clinical Outcomes of Mechanical Thrombectomy for Fast Progressive Stroke

OBJECTIVES

The time-dependence of the clinical outcome of mechanical thrombectomy is higher in the "fast progressor" in whom cerebral ischemia progresses rapidly. The impact of time-consuming interhospital transfer (IT) on the clinical outcome of such patients is unknown. The effect on clinical outcomes of IT of fast progressors was investigated.

METHODS

Among the patients enrolled in the Tokyo/Tama REgistry of Acute endovascular Thrombectomy, fast progressor cerebral ischemia cases were retrospectively investigated. In this study, a fast progressor was defined as a case with an Alberta Stroke Program Early CT Score less than 6 and last known well (LKW) to arterial puncture within 6 h. Patients' background characteristics, treatment progress, and the modified Rankin Scale (mRS) score at 3 months were examined.

RESULTS

Of a total of 1182 patients, 92 (7.8%) were included, with 76 patients in the direct transfer (DT) group, and 16 patients in the IT group. Median LKW to reperfusion was 190 min and 272 min, respectively (P<.001). The number of patients with mRS scores 0-2 at three months was 22 (28.9%) in the DT group and 1 (6.2%) in the IT group. Interhospital transfer was an independent factor associated with worse outcomes (odds ratio 0.08, 95% confidence interval 0.01-0.87, P=.038).

CONCLUSION

This study showed that, among fast progressor patients, the IT group had a worse prognosis than the DT group. To provide good clinical outcomes for fast progressor patients, those who are likely to undergo mechanical thrombectomy should be sent directly to a thrombectomy-capable center.

Pathway Design for Acute Stroke Care in the Era of Endovascular Thrombectomy: A Critical Overview of Optimization Efforts

The efficacy of intravenous thrombolysis and endovascular thrombectomy (EVT) for acute ischemic stroke is highly time dependent. Optimal organization of acute stroke care is therefore important to reduce treatment delays but has become more complex after the introduction of EVT as regular treatment for large vessel occlusions. There is no singular optimal organizational model that can be generalized to different geographic regions worldwide. Current dominant organizational models for EVT include the drip-and-ship- and mothership model. Guidelines recommend routing of suspected patients with stroke to the nearest intravenous thrombolysis capable facility; however, the choice of routing to a certain model should depend on regional stroke service organization and individual patient characteristics. In general, design approaches for organizing stroke care are required, in which 2 key strategies could be considered. The first entails the identification of interventions within existing organizational models for optimizing timely delivery of intravenous thrombolysis and/or EVT. This includes adaptive patient routing toward a comprehensive stroke center, which focuses particularly on prehospital triage tools; bringing intravenous thrombolysis or EVT to the location of the patient; and expediting services and processes along the stroke pathway. The second strategy is to develop analytical or simulation model-based approaches enabling the design and evaluation of organizational models before their implementation. Organizational models for acute stroke care need to take regional and patient characteristics into account and can most efficiently be assessed and optimized through the application of model-based approaches.

Direct admission versus secondary transfer for acute ischemic stroke patients treated with thrombectomy: a systematic review and meta-analysis

BACKGROUND AND PURPOSE

Randomized controlled trials have demonstrated that mechanical thrombectomy (MT) could provide more benefit than standard medical care for acute ischemic stroke (AIS) patients due to emergent large vessel occlusion. However, most primary stroke centers (PSCs) are unable to perform MT, and MT can only be performed in comprehensive stroke centers (CSCs) with on-site interventional neuroradiologic services. Therefore, there is an ongoing debate regarding whether patients with suspected AIS should be directly admitted to CSCs or secondarily transferred to CSCs from PSCs. This meta-analysis was aimed to investigate the two transportation paradigms of direct admission and secondary transfer, which one could provide more benefit for AIS patients treated with MT.

METHODS

We conducted a systematic review and meta-analysis through searching PubMed, Embase and the Cochrane Library database up to March 2020. Primary outcomes are as follows: symptomatic intracerebral hemorrhage (sICH) within 7 days; favorable functional outcome at 3 months; mortality in hospital; mortality at 3 months; and successful recanalization rate.

RESULTS

Our pooled results showed that patients directly admitted to CSCs had higher chances of achieving a favorable functional outcome at 3 months than those secondarily transferred to CSCs (OR = 1.26; 95% CI, 1.12-1.42; P < 0.001). In addition, no significant difference was found between the two transportation paradigms in the rate of sICH (OR = 0.86; 95% CI, 0.62-1.18; P = 0.35), mortality in hospital (OR = 0.84; 95% CI, 0.51-1.39; P = 0.51), mortality at 3 months (OR = 1.01; 95% CI, 0.85-1.21; P = 0.91), and successful recanalization (OR = 1.03; 95% CI, 0.88-1.20; P = 0.74). However, in the 100% bridging thrombolysis usage rate subgroup, our subgroup analysis indicated that no difference was found in any outcome between the two transportation paradigms.

CONCLUSION

Patients with AIS directly admitted to CSCs for MT may be a feasible transportation paradigm for AIS patients. However, more large-scale randomized prospective trials are required to further investigate this issue.

Use, Temporal Trends, and Outcomes of Endovascular Therapy After Interhospital Transfer in the United States

BACKGROUND

The use of endovascular therapy (EVT) in patients with acute ischemic stroke who have large vessel occlusion has rapidly increased in the United States following pivotal trials demonstrating its benefit. Information about the contribution of interhospital transfer in improving access to EVT will help organize regional systems of stroke care.

METHODS

We analyzed trends of transfer-in EVT from a cohort of 1 863 693 patients with ischemic stroke admitted to 2143 Get With The Guidelines-Stroke participating hospitals between January 2012 and December 2017. We further examined the association between arrival mode and in-hospital outcomes by using multivariable logistic regression models.

RESULTS

Of the 37 260 patients who received EVT at 639 hospitals during the study period, 42.9% (15 975) arrived at the EVT-providing hospital after interhospital transfer. Transfer-in EVT cases increased from 256 in the first quarter 2012 to 1422 in the fourth quarter 2017, with sharply accelerated increases following the fourth quarter 2014 ( P<0.001 for change in linear trend). Transfer-in patients were younger and more likely to be of white race, to arrive during off-hours, and to be treated at comprehensive stroke centers. Transfer-in patients had significantly longer last-known-well-to-EVT initiation time (median, 289 minutes versus 213 minutes; absolute standardized difference, 67.33) but were more likely to have door-to-EVT initiation time of ≤90 minutes (65.6% versus 23.6%; absolute standardized difference, 93.18). In-hospital outcomes were worse for transfer-in patients undergoing EVT in unadjusted and in risk-adjusted models. Although the difference in in-hospital mortality disappeared after adjusting for delay in EVT initiation (14.7% versus 13.4%; adjusted odds ratio, 1.01; 95% CI, 0.92-1.11), transfer-in patients were still more likely to develop symptomatic intracranial hemorrhage (7.0% versus 5.7%; adjusted odds ratio, 1.15; 95% CI, 1.02-1.29) and less likely to have either independent ambulation at discharge (33.1% versus 37.1%; adjusted odds ratio, 0.87; 95% CI, 0.80-0.95) or to be discharged to home (24.3% versus 29.1%; adjusted odds ratio, 0.82; 95% CI, 0.76-0.88).

CONCLUSIONS

Interhospital transfer for EVT is increasingly common and is associated with a significant delay in EVT initiation highlighting the need to develop more efficient stroke systems of care. Further evaluation to identify factors that impact EVT outcomes for transfer-in patients is warranted.

Functional Outcome and Safety of Intracranial Thrombectomy After Emergent Extracranial Stenting in Acute Ischemic Stroke Due to Tandem Occlusions

Background and Purpose: Various endovascular approaches to treat acute ischemic stroke caused by extra- intracranial tandem occlusions (TO) exist: percutaneous transluminal angioplasty with or without emergent extracranial carotid stenting (ECS) due to high-grade stenosis preceded or followed by intracranial mechanical and/or aspiration thrombectomy (MT). Which treatment strategy to use is still a matter of debate.

Methods: From our ongoing prospective stroke registry we retrospectively analyzed 1,071 patients with anterior circulation stroke getting endovascular treatment within 6 h of symptom onset. ECS prior to intracranial MT for TO (n = 222) was compared to MT as standard of care (control group; acute intracranial vessel occlusion without concomitant ipsilateral ICA-occlusion or high-grade stenosis [C; n = 849]). Good functional outcome (mRS ≤ 2 at 3 months), mortality rates, frequencies of symptomatic intracranial hemorrhage (sICH) and successful recanalization (Thrombolysis in Cerebral Infarction Score [TICI] 2b or 3) were assessed. In subgroup analyses we tried to detect possible influences of stroke etiology, dual inhibition of platelet aggregation (IPA; clopidogrel [CLO]: n = 83; ticagrelor [TIC]: n = 137; in combination with Aspirin) and intravenous thrombolysis (IVT).

Results: Functional outcome was superior in TO (mRS 0–2: 44.6%) when compared with controls (36.0%; OR [95% CI]: 3.49 [1.59–7.67]; p = 0.002). There was no difference in all-cause mortality at 3 months (TO: 21.6%; C: 27.7%; 0.78 [0.47–1.29]; p = 0.324), in-hospital mortality (0.76 [0.45–1.30]; p = 0.324), sICH (TO: 3.2%; C: 5.0%; 0.70 [0.30–1.59]; p = 0.389), and TICI 2b/3 (TO: 89.1%; C: 88.3%; p = 0.813). In subgroup-analysis, TIC and CLO did not differ in functional outcome (TIC: 45.3%; CLO: 44.6%; 1.04 [0.51–2.09]; p = 0.920) and mortality rates (all-cause mortality: TIC: 23.4%; CLO: 16.9%; 0.75 [0.27–2.13]; p = 0.594). sICH was more frequent in TIC (n = 7 [5.1%]) vs. CLO (n = 0; p = 0.048).

Conclusion: In our pre-selected cohort, ECS prior to intracranial MT in TO allowed for a good functional outcome that was superior compared to a control population. Mortality rates did not differ. Despite a dual IPA in TO, there was no increase in sICH. CLO and TIC for dual IPA did not differ in terms out outcome and mortality rates. A significant increase in sICH was observed after initial loading with TIC.

Impact of landmark endovascular stroke trials on logistical performance measures: a before-and-after evaluation of real-world data from a regional stroke system of care

Background and purpose

Endovascular treatment of large-vessel occlusion stroke often necessitates patient transfer by a twin-track approach: endovascular thrombectomy (ET) in endovascular-capable facilities preceded by intravenous thrombolysis in primary stroke centers. We tested the open hypothesis that recent landmark trials on ET had any significant effect on logistical performance measures among different modes of admission.

Methods

We retrospectively categorized 250 patients who presented at our institution as: (A) primarily admitted or transferred from (B) inner-city and (C) regional hospitals. The period from May 2015 to June 2017 was compared with the preceding period of August 2009 to April 2015 with respect to real-life transfer distances and sectional time metrics from symptom onset to angiographic recanalization.

Results

Onset-to-recanalization time decreased in the primary admission path, whereas delays persisted for inter-hospital transfer: (A: 261 min (210–315) vs 198 (167–264) P<0.0001; B: 257 (214–306) vs 265 (199– 360) P=0.566; and C: 371 (322–415) vs 346 (307–405) P=0.559). Onset-to-recanalization time was negatively correlated with recanalization success (mTICI; r=-0.4195 P<0.0001). The rate of secondarily referred patients (26% vs 48% P=0.0004) and off-hour presentation (36% vs 44% P=0.004) increased, as did the catchment area (C: 52.2 km (30,4–64,5) vs 64.4 (43,2–78,9) P=0.032). Improvement in door-in-door-out time at the referring hospitals (C: 113 min (30) vs 86 (29) P=0.0236) did not translate into reduced total referral times or the accelerated initiation of ET.

Conclusion

Recent landmark trials already led to a considerable streamlining of ET workflow if patients were directly admitted. Prehospital time management and triage seem to be the major determinants of optimization.

Endovascular Thrombectomy in Wake-Up Stroke and Stroke with Unknown Symptom Onset

BACKGROUND AND PURPOSE

Mechanical thrombectomy in acute ischemic stroke within 6 hours of symptom onset is effective and safe. However, in many patients, information on the beginning of symptoms is not available. Patients can be divided into those with wake-up stroke and daytime-unwitnessed stroke. Evidence on outcome and complications after mechanical thrombectomy in wake-up stroke and daytime-unwitnessed stroke is rare. A potential beneficial effect of mechanical thrombectomy in selected patients with wake-up stroke or daytime-unwitnessed stroke is suspected.

MATERIALS AND METHODS

We analyzed 1073 patients with anterior circulation stroke undergoing mechanical thrombectomy between 2010 and 2016. Patients with wake-up stroke and daytime-unwitnessed stroke were compared with controls receiving mechanical thrombectomy as the standard of care. We assessed good functional outcome (mRS ≤ 2 at 3 months), mortality rates, and frequencies of symptomatic intracranial hemorrhage. Subgroup analyses tried to detect influences of patient selection via further imaging modalities (MR imaging, CTP; wake-up stroke [advanced], daytime-unwitnessed stroke [advanced]) on outcome and safety.

RESULTS

There was no significant difference in good functional outcome between patients with wake-up stroke and controls (35.9% versus 38.3%, P = .625). Outcome in patients with daytime-unwitnessed stroke was inferior compared with controls (27.3%, P = .007). Groups did not differ in all-cause mortality at day 90 (P = .224) and the rate of symptomatic intracranial hemorrhage (P = .292). Advanced imaging improved the frequency of good functional outcome (non-wake-up stroke [advanced] versus wake-up stroke [advanced]: OR, 2.92; 95% CI, 1.32-6.45; non-daytime-unwitnessed stroke [advanced] versus daytime-unwitnessed stroke [advanced]: OR, 2.09; 95% CI, 1.03-4.25) with an additional reduction in all-cause mortality (non-daytime-unwitnessed stroke [advanced] versus daytime-unwitnessed stroke [advanced]: OR, 0.42; 95% CI, 0.20-0.88).

CONCLUSIONS

Mechanical thrombectomy in selected patients with wake-up stroke allows a good functional outcome comparable with that of controls. Outcome after mechanical thrombectomy in daytime-unwitnessed stroke seems to be inferior compared with that in controls. Advanced imaging modalities may increase the frequency of good functional outcome in both patients with wake-up stroke and daytime-unwitnessed stroke.

[Clinical diagnosis of proximal occlusion of a major cerebral artery in the very early stage of ischemic stroke]

AIM

To find clinical criteria applied in the first hours of disease for the identification of severe ischemic stroke caused by an occlusion of proximal major arteries.

MATERIAL AND METHODS

The authors have analyzed 133 medical histories of patients with the diagnosis of acute cerebral blood circulation disorder admitted in the first 6 h from onset. All patients underwent CT-angiography or digital subtraction angiography. Occlusion of the inner carotid artery, occlusion of M1-segment of the middle cerebral artery and occlusion of a major artery were considered as proximal occlusion of major cerebral arteries. Neurological status was assessed by the signs of proximal arterial occlusion (PAO).

RESULTS AND CONCLUSION

Checking of 5 PAO symptoms allows the prediction of occlusion location in approximately 80% of cases. Presence of ≥3 out of 5 symptoms is characterized by 70% sensitivity and 90% specificity with regard to the occlusion of the inner carotid artery, M1-segment of the middle cerebral artery and/or a major artery. Predictive value of this model should be verified in a prospective study.

Association of a Primary Stroke Center Protocol for Suspected Stroke by Large-Vessel Occlusion With Efficiency of Care and Patient Outcomes

Importance

While prehospital triage to the closest comprehensive stroke center (CSC) may improve the delivery of care for patients with suspected emergent large-vessel occlusion (ELVO), efficient systems of care must also exist for patients with ELVO who first present to a primary stroke center (PSC).

Objective

To describe the association of a PSC protocol focused on 3 key steps (early CSC notification based on clinical severity, vessel imaging at the PSC, and cloud-based image sharing) with the efficiency of care and the outcomes of patients with suspected ELVO who first present to a PSC.

Design, Setting, and Participants

In this retrospective cohort study, 14 regional PSCs unfamiliar with the management of patients with ELVO were instructed on the use of the following protocol for patients presenting with a Los Angeles Motor Scale score 4 or higher: (1) notify the CSC on arrival, (2) perform computed tomographic angiography concurrently with noncontract computed tomography of the brain and within 30 minutes of arrival, and (3) share imaging data with the CSC using a cloud-based platform. A total of 101 patients were transferred from regional PSCs to the CSC between July 1, 2015, and May 31, 2016, and received mechanical thrombectomy for acute ischemic stroke. The CSC serves approximately 1.7 million people and partners with 14 PSCs located between 6.4 and 73.6 km away. All consecutive patients with internal carotid artery or middle cerebral artery occlusions transferred over an 11-month period were reviewed, and they were divided into 2 groups based on whether the PSC protocol was partially or fully executed.

Main Outcomes and Measures

The primary outcomes were efficiency measures including time from PSC door in to PSC door out, time from PSC door to CSC groin puncture, and 90-day modified Rankin Scale score (range, 0-6; scores of 0-2 indicate a good outcome).

Results

Although 101 patients were transferred, only 70 patients met the inclusion criteria during the study period. The protocol was partially executed for 48 patients (68.6%) (mean age, 77 years [interquartile range, 65-84 years]; 22 of the 48 patients [45.0%] were women) and fully executed for 22 patients (31.4%) (mean age, 76 years [interquartile range, 59-86 years]; 13 of the 22 patients [59.1%] were women). When fully executed, the protocol was associated with a reduction in the median time for PSC arrival to CSC groin puncture (from 151 minutes [95% CI, 141-166 minutes] to 111 minutes [95% CI, 88-130 minutes]; P < .001). This was primarily related to an improvement in the time from PSC door in to door out that reduced from a median time of 104 minutes (95% CI, 82-112 minutes) to a median time of 64 minutes (95% CI, 51-71.0 minutes) (P < .001). When the protocol was fully executed, patients were twice as likely to have a favorable outcome (50% vs 25%, P < .04).

Conclusions and Relevance

When fully implemented, a standardized protocol at PSCs for patients with suspected ELVO consisting of early CSC notification, computed tomographic angiography on arrival to the PSC, and cloud-based image sharing is associated with a reduction in time to groin puncture and improved outcomes.