Validation of a cloud-based tele-stroke system reliability in determining national institutes of health stroke scale scores for acute ischemic stroke screening in the emergency department

Background and purpose

The National Institutes of Health Stroke Scale (NIHSS) is the most recommended tool for objectively quantifying the impairment caused by a suspected stroke. Nevertheless, it is mainly used by trained neurologists in the emergency department (ED). To bring forward the NIHSS to the pre-hospital setting, a smartphone-based Telestroke system was developed. It captures the full NIHSS by video, transmits it off-line, and enables assessment by a distant stroke physician. We aimed to compare the reliability of an NIHSS score determined by a neurologist from afar, using the platform with a standard NIHSS assessment performed in the emergency departments.

Methods

A multi-center prospective study was conducted in two centers (Vall d'Hebron, Barcelona, and Rambam, Israel). Patients admitted to the ED with suspected stroke had a neurological exam based on the NIHSS, while being recorded by the system. A skilled neurologist rated the NIHSS according to the videos offline. The results were compared with the NIHSS score given by a neurologist at the bedside.

Results

A total of 95 patients with suspected stroke were included. The overall intraclass correlation coefficient was 0.936 (0.99 in VdH and 0.84 in Rambam), indicating excellent and good reliability, respectively.

Conclusion

Remote stroke assessment based on the NIHSS, using videos segments collected by a dedicated platform, installed on a standard smartphone, is a reliable measurement as compared with the bedside evaluation.

Global impact of COVID-19 on stroke care

Background

The COVID-19 pandemic led to profound changes in the organization of health care systems worldwide.

Aims

We sought to measure the global impact of the COVID-19 pandemic on the volumes for mechanical thrombectomy, stroke, and intracranial hemorrhage hospitalizations over a three-month period at the height of the pandemic (1 March–31 May 2020) compared with two control three-month periods (immediately preceding and one year prior).

Methods

Retrospective, observational, international study, across 6 continents, 40 countries, and 187 comprehensive stroke centers. The diagnoses were identified by their ICD-10 codes and/or classifications in stroke databases at participating centers.

Results

The hospitalization volumes for any stroke, intracranial hemorrhage, and mechanical thrombectomy were 26,699, 4002, and 5191 in the three months immediately before versus 21,576, 3540, and 4533 during the first three pandemic months, representing declines of 19.2% (95%CI, −19.7 to −18.7), 11.5% (95%CI, −12.6 to −10.6), and 12.7% (95%CI, −13.6 to −11.8), respectively. The decreases were noted across centers with high, mid, and low COVID-19 hospitalization burden, and also across high, mid, and low volume stroke/mechanical thrombectomy centers. High-volume COVID-19 centers (−20.5%) had greater declines in mechanical thrombectomy volumes than mid- (−10.1%) and low-volume (−8.7%) centers (p < 0.0001). There was a 1.5% stroke rate across 54,366 COVID-19 hospitalizations. SARS-CoV-2 infection was noted in 3.9% (784/20,250) of all stroke admissions.

Conclusion

The COVID-19 pandemic was associated with a global decline in the volume of overall stroke hospitalizations, mechanical thrombectomy procedures, and intracranial hemorrhage admission volumes. Despite geographic variations, these volume reductions were observed regardless of COVID-19 hospitalization burden and pre-pandemic stroke/mechanical thrombectomy volumes.

Decline in subarachnoid haemorrhage volumes associated with the first wave of the COVID-19 pandemic

Background

During the COVID-19 pandemic, decreased volumes of stroke admissions and mechanical thrombectomy were reported. The study’s objective was to examine whether subarachnoid haemorrhage (SAH) hospitalisations and ruptured aneurysm coiling interventions demonstrated similar declines.

Methods

We conducted a cross-sectional, retrospective, observational study across 6 continents, 37 countries and 140 comprehensive stroke centres. Patients with the diagnosis of SAH, aneurysmal SAH, ruptured aneurysm coiling interventions and COVID-19 were identified by prospective aneurysm databases or by International Classification of Diseases, 10th Revision, codes. The 3-month cumulative volume, monthly volumes for SAH hospitalisations and ruptured aneurysm coiling procedures were compared for the period before (1 year and immediately before) and during the pandemic, defined as 1 March–31 May 2020. The prior 1-year control period (1 March–31 May 2019) was obtained to account for seasonal variation.

Findings

There was a significant decline in SAH hospitalisations, with 2044 admissions in the 3 months immediately before and 1585 admissions during the pandemic, representing a relative decline of 22.5% (95% CI −24.3% to −20.7%, p<0.0001). Embolisation of ruptured aneurysms declined with 1170–1035 procedures, respectively, representing an 11.5% (95%CI −13.5% to −9.8%, p=0.002) relative drop. Subgroup analysis was noted for aneurysmal SAH hospitalisation decline from 834 to 626 hospitalisations, a 24.9% relative decline (95% CI −28.0% to −22.1%, p<0.0001). A relative increase in ruptured aneurysm coiling was noted in low coiling volume hospitals of 41.1% (95% CI 32.3% to 50.6%, p=0.008) despite a decrease in SAH admissions in this tertile.

Interpretation

There was a relative decrease in the volume of SAH hospitalisations, aneurysmal SAH hospitalisations and ruptured aneurysm embolisations during the COVID-19 pandemic. These findings in SAH are consistent with a decrease in other emergencies, such as stroke and myocardial infarction.

Evaluation of Artificial Intelligence-Powered Identification of Large-Vessel Occlusions in a Comprehensive Stroke Center

BACKGROUND AND PURPOSE

Artificial intelligence algorithms have the potential to become an important diagnostic tool to optimize stroke workflow. Viz LVO is a medical product leveraging a convolutional neural network designed to detect large-vessel occlusions on CTA scans and notify the treatment team within minutes via a dedicated mobile application. We aimed to evaluate the detection accuracy of the Viz LVO in real clinical practice at a comprehensive stroke center.

MATERIALS AND METHODS

Viz LVO was installed for this study in a comprehensive stroke center. All consecutive head and neck CTAs performed from January 2018 to March 2019 were scanned by the algorithm for detection of large-vessel occlusions. The system results were compared with the formal reports of senior neuroradiologists used as ground truth for the presence of a large-vessel occlusion.

RESULTS

A total of 1167 CTAs were included in the study. Of these, 404 were stroke protocols. Seventy-five (6.4%) patients had a large-vessel occlusion as ground truth; 61 were detected by the system. Sensitivity was 0.81, negative predictive value was 0.99, and accuracy was 0.94. In the stroke protocol subgroup, 72 (17.8%) of 404 patients had a large-vessel occlusion, with 59 identified by the system, showing a sensitivity of 0.82, negative predictive value of 0.96, and accuracy of 0.89.

CONCLUSIONS

Our experience evaluating Viz LVO shows that the system has the potential for early identification of patients with stroke with large-vessel occlusions, hopefully improving future management and stroke care.

The effect of the COVID-19 pandemic on ED referrals and care for stroke patients: A four-year comparative study

Purpose

To examine the impact of the COVID-19 pandemic on the presentation and care provided to patients with acute ischemic stroke (AIS) at the emergency department (ED).

Method

A retrospective-archive study was conducted between January-April 2020, compared with the parallel months in 2017–2019, in a comprehensive stroke center. We compared the time from symptoms onset to ED arrival, the number of neurologic consultations completed in the ED, patients diagnosed with AIS, patients receiving acute treatment and hospital mortality.

Results

During January-April 2020, we found an increase in the proportion of stroke patients arriving at the ED within 6 h of symptom onset: 68–100% per month during the study period, compared with 28–42% per month in the previous years. The number of patients admitted to the ED with suspected AIS declined by 41%, compared to the parallel period in 2019. An increase was noted in the number of patients diagnosed with AIS who underwent treatment, with the number of s endovascular thrombectomy increasing throughout the examined year.

Conclusion

During the COVID-19 pandemic, we observed a significant decline in the number of AIS patients admitted to the ED. Paradoxically, we have seen an increase in the proportion of patients who arrived shortly after the onset of symptoms and received timely treatment. Future studies might investigate the medical mechanism and ramifications of this phenomenon.

Abstract 94: Artificial Intelligence-Based Application to Detect and Quantify Stroke Symptoms

Assessment of patients suspected to have an acute stroke at the prehospital level or non-stroke centers may be challenging. We aimed to validate a novel Artificial Intelligence (AI) based application (CVAid) for smartphones able to score neurological deficit in acute stroke patients.

Methods: Acute stroke patients, admitted in two different stroke units, and healthy volunteers were studied. A certified stroke neurologist determined NIHSS at bedside. A different user recorded a short neurological exam, using CVAid application. The software processed the video file presenting comprehensive neurological exam per NIHSS test to a remote neurologist on a dedicated tablet. Two different remote neurologists (remote1 and remote2) determined NIHSS reviewing neurological exam in the tablet. CVAid performed also a completely automated AI analysis of facial features, to detect stroke symptoms.

Results: A total of 75 patients were included in the study, 64 (85.3%) stroke patients and 11 (14.7%) healthy volunteers. Correlation between bedside and remote1 NIHSS was r=0. 861 (p<0.001). Correlation between remote1 and remote2 NIHSS was r=0.865 (p=0.001). The CVAId facial recognition system showed an accuracy of 87% in stroke symptom detection, sensitivity 95%, Specificity 80%, false negative 5%, false positive 20%.

Conclusions: An AI based application efficiently allowed remote neurological evaluation of stroke patients. The automated algorithm was able to accurately triage healthy volunteers from patients suffering a stroke. Feeding the machine learning system with additional patients and development of additional automated analysis beyond facial recognition will increase the system accuracy.

A direct aspiration first pass technique for acute stroke therapy: a systematic review and meta-analysis

BACKGROUND AND PURPOSE

A direct aspiration first pass technique (ADAPT), involving the first-line use of a large-bore distal aspiration catheter, is a new strategy in the mechanical thrombectomy of acute ischemic stroke caused by large-vessel occlusion. However, its impact on reperfusion rates, clinical outcomes and complication rates has not been fully examined.

METHODS

We conducted a systematic review of the literature searching multiple databases for reports on thrombectomy of acute stroke with ADAPT and performed meta-analyses of clinical and radiographic outcomes.

RESULTS

We selected 16 articles that included a total of 1378 patients treated with ADAPT. The mean admission National Institutes of Health Stroke Scale score was 17 and pre-treatment intravenous thrombolysis was used in 51% of cases. The successful recanalization (thrombolysis in cerebral ischemia 2b-3) rate was 66% [95% confidence interval (CI), 59-72%] with ADAPT and a rescue stent retriever was used in 31% of cases (95% CI, 24-37%) yielding an overall thrombolysis in cerebral ischemia 2b-3 rate of 89% (95% CI, 85-92%). We found a pooled estimate of 50% (95% CI, 45-54%) for functional independence (modified Rankin Scale score 0-2) at 90 days, 15% (95% CI, 10-21%) for mortality within 90 days and 5% (95% CI, 3-7%) for symptomatic intracranial hemorrhage.

CONCLUSIONS

ADAPT therapy is associated with similar reperfusion rates, clinical outcomes and complication rates compared with thrombectomy with stent retrievers. However, the major limitations of current evidence (i.e. retrospective studies and selection bias) indicate a need for adequately powered, multicenter randomized controlled trials to determine the best strategy.

Patient Outcomes with Stent-Retriever Thrombectomy for Anterior Circulation Stroke: A Meta-Analysis and Review of the Literature

Mechanical thrombectomy with stent retrievers is now the reference therapy for acute ischemic stroke (AIS) in the anterior circulation in association with thrombolysis. We conducted an extensive systematic review and meta-analysis to evaluate the clinical and angiographic outcomes of stent-retriever thrombectomy in patients with acute anterior circulation stroke. Available literature published to date on observational studies and three randomized trials (MR CLEAN, ESCAPE, and EXTEND-IA) involving the stent-retriever device were reviewed. Successful recanalization and favorable clinical outcome were defined by a TICI ≥ 2b and modified Rankin Scale score of ≤ 2 at 90 days following AIS, respectively. A total of 2067 patients harboring an anterior circulation stroke were treated with a stent retriever: 433 patients from 3 randomized trials involving the device and 1634 patients from observational studies. Mean NIH Stroke Scale score on admission was 16.6, and mean time from onset to recanalization was 300 minutes. Successful recanalization was achieved in 82% (95%CI 77-86, 31 studies). The 90 day favorable outcome was achieved in 47% (95%CI 42-5.2, 34 studies) with an overall mortality rate of 17% (95%CI 13-20, 31 studies). Symptomatic intracerebral hemorrhage was identified in 6% (95%CI 4-8, 32 studies). In patients with AIS caused by a proximal intracranial occlusion of the anterior circulation, stent-retriever thrombectomy is safe and restores brain reperfusion in four of five treated patients, allowing favorable clinical outcome in one of two AIS patients with large vessel occlusion.

Early angiographic changes of intra-aneurysmal flow after flow-diverter stent treatment are not predictive of therapeutic success

BACKGROUND AND PURPOSE

Flow-diverter stents (FDS) are new devices for the endovascular treatment of intracranial aneurysms (IAs) promoting progressive aneurysmal thrombosis. To date, the delay of aneurysmal exclusion remains unclear. We evaluated the correlation between angiographic changes in the first 24 hours and 12-month occlusion in aneurysms treated with FDS.

METHODS

We retrospectively analyzed the intra-aneurysmal flow by evaluating the in-flow and out-flow delays on preoperative, immediate postoperative, 24-hour and 12-month follow-up angiography. Dichotomy of in-flow and out-flow within the aneurysm was considered as the time of contrast filling and time of contrast washing relatively to the parent artery. The delay times were compared and correlated with the therapeutic success of FDS at 12 months of follow-up.

RESULTS

Out of 14 treated IAs, in 13 consecutive patients, n = 10 (71%) aneurysms showed complete occlusion at 12 months. Between immediate postoperative and 24-hour control, 10 aneurysms (71%) demonstrated in-flow modification, with eight increasing, two decreasing and four having no change. There were no statistical differences in therapeutic success in relation to the different flow-related profiles of intra-aneurysmal flux.Out-flow modifications were found in 11 aneurysms (79%) between immediate postoperative and 24-hour control, with five increasing, six decreasing and three having no change. Similar to the in-flow changes, there were no statistical differences in therapeutic success relative to the flow-related profiles.

CONCLUSIONS

Early angiographic changes after FDS placement are very frequent, but are not correlated with the 12-month technical success of flow-diversion techniques.

Outcomes of stent retriever thrombectomy in basilar artery occlusion: an observational study and systematic review

BACKGROUND

Basilar artery occlusion (BAO) remains one of the most devastating subtypes of stroke with high mortality and poor outcome. Early recanalisation is the most powerful predictor of favourable outcome in patients with stroke, and may be improved with mechanical thrombectomy using stent retriever devices. However, the benefit in functional outcome and safety of stent retrievers are not yet well known. The aim of this study was to assess efficacy and safety profiles of stent retriever thrombectomy in BAO patients with stroke.

METHODS

We analysed data retrospectively from our consecutive clinical series and conducted a systematic review and meta-analysis of all previous studies of stent retriever thrombectomy in BAO patients with stroke between November 2010 and April 2014.

RESULTS

From March 2010 to March 2013, 22 patients with acute BAO were treated with a Solitaire stent retriever in our series. Favourable outcome was significantly associated with younger age and distal BAO. The literature search identified 15 previous studies involving a total of 312 subjects. In the meta-analysis, including our series data, the recanalisation rate (Thrombolysis In Cerebral Infarction (TICI) score ≥ 2b) reached 81% (95% CI 73% to 87%). The rate of symptomatic intracranial haemorrhage was 4% (95% CI 2% to 8%), favourable outcome (modified Rankin Scale (mRS) ≤ 2 at 3 months) was found in 42% (95% CI 36% to 48%) and mortality rate was 30% (95% CI 25% to 36%).

CONCLUSIONS

Stent retriever thrombectomy is a safe treatment modality for patients with stroke presenting with BAO. Although the stent retrievers showed a good recanalisation rate, there are currently no randomised clinical trials to assess its clinical efficacy in comparison with the reference treatment.

One-Year Angiographic Follow-Up after WEB-SL Endovascular Treatment of Wide-Neck Bifurcation Intracranial Aneurysms

BACKGROUND AND PURPOSE

Endovascular coiling of wide-neck intracranial aneurysms is associated with low rates of initial angiographic occlusion and high rates of recurrence. The WEB intrasaccular device has been developed specifically for this indication. To date, there has been no report of the long-term follow-up of a series of patients with aneurysms treated with this type of device, to our knowledge. Our aim was to evaluate a 1-year follow-up of angiographic results in a prospective single-center series of patients treated with the WEB-Single-Layer (SL) device.

MATERIALS AND METHODS

All patients treated with the WEB-SL device in our center between August 2013 and May 2014 were prospectively included. One-year angiographic outcomes were assessed. Results at follow-up were graded as complete occlusion, neck remnant, or residual aneurysm.

RESULTS

Eight patients with 8 unruptured wide-neck aneurysms were enrolled in this study. Average dome width was 7.5 mm (range, 5.4-10.7 mm), and average neck size was 4.9 mm (range, 2.6-6.5 mm). One-year angiographic follow-up obtained in all aneurysms included 1 complete aneurysm occlusion (12.5%), 6 neck remnants (75%), and 1 aneurysm remnant (12.5%). Of 8 aneurysms, worsening of aneurysm occlusion was observed in 2 (25%) by compression of the WEB device. There was no angiographic recurrence of initially totally occluded aneurysms. No bleeding was observed during the follow-up period.

CONCLUSIONS

Endovascular therapy of intracranial aneurysms with the WEB-SL device allows treatment of wide-neck aneurysms with a high rate of neck remnant at 1 year, at least partially explained by WEB compression. Initial size selection and technologic improvements could be an option for optimization of aneurysm occlusion in WEB-SL treatment.

Endovascular Treatment of Intracranial Aneurysms with the WEB Device: A Systematic Review of Clinical Outcomes

BACKGROUND AND PURPOSE

Despite the improvement in technology, endovascular treatment of bifurcation intracranial wide-neck aneurysms remains challenging, mainly due to the difficulty of maintaining coils within the aneurysm sac without compromising the patency of bifurcation arteries. The Woven EndoBridge (WEB) device is a recent intrasaccular braided device specifically dedicated to treating such aneurysms with a wide neck by disrupting the flow in the aneurysmal neck and promoting progressive aneurysmal thrombosis.

MATERIALS AND METHODS

Using several health data bases, we conducted a systematic review of all published studies of WEB endovascular treatment in intracranial aneurysms from 2010 onward to evaluate its efficacy and safety profile.

RESULTS

The literature search identified 6 relevant studies (7 articles) including wide-neck bifurcation aneurysms in ≥80% of cases. Clinical data supporting the efficacy and safety of the WEB are limited to noncomparative cohort studies with large heterogeneity from a methodologic standpoint. The WEB deployment was feasible with a success rate of 93%-100%. Permanent morbidity (mRS of >1 at last follow-up) and mortality were measured at 2.2%-6.7% and 0%-17%, respectively. The adequate occlusion rate (total occlusion or neck remnant) varied between 65% and 85.4% at midterm follow-up (range, 3.3-27.4 months).

CONCLUSIONS

Endovascular treatment of bifurcation wide-neck aneurysms with the WEB device is feasible and allows an acceptably adequate aneurysm occlusion rate; however, the rate of neck remnants is not negligible. The WEB device needs further clinical and anatomic evaluation with long-term prospective studies, especially of the risk of WEB compression. Prospective controlled studies should be encouraged.

Endovascular treatment of bifurcation intracranial aneurysms with the WEB SL/SLS: 6-month clinical and angiographic results

BACKGROUND

The WEB device is a recent intrasaccular flow disruption technique developed for the treatment of wide-necked intracranial aneurysms. To date, a single report on the WEB Single-Layer (SL) treatment of intracranial aneurysms has been published with 1-months' safety results. The aim of this study is to report our experience and 6-month clinical and angiographic follow-up of endovascular treatment of wide-neck aneurysm with the WEB SL.

METHODS

Ten patients with 10 unruptured wide-necked aneurysms were prospectively enrolled in this study. Feasibility, intraoperative and postoperative complications, and outcomes were recorded. Immediate and 6-month clinical and angiographic results were evaluated.

RESULTS

Failure of WEB SL placement occurred in two cases. Eight aneurysms were successfully treated using one WEB SL without additional treatment. Three middle cerebral artery, four anterior communicating artery, and one basilar artery aneurysms were treated. Average dome width was 7.5 mm (range 5.4-10.7 mm), and average neck size was 4.9 mm (range 2.6-6.5 mm). No periprocedural complication was observed, and morbi-mortality at discharge and 6 months was 0.0%. Angiographic follow-up at 6 months demonstrated complete aneurysm occlusion in 2/8 aneurysms, neck remnant in 5/8 aneurysms, and aneurysm remnant in 1/8 aneurysm.

CONCLUSIONS

From this preliminary study, treatment of bifurcation intracranial aneurysms using WEB SL is feasible. WEB SL treatment seems safe at 6 months; however, the rate of neck remnants is not negligible due to compression of the WEB SL. Further technical improvements may be needed in order to ameliorate the occlusion in the WEB SL treatment.

Endovascular treatment of wide-neck anterior communicating artery aneurysms using WEB-DL and WEB-SL: short-term results in a multicenter study

BACKGROUND AND PURPOSE

Endovascular treatment of wide-neck anterior communicating artery aneurysms can often be challenging. The Woven EndoBridge (WEB) device is a recently developed intrasaccular flow disrupter dedicated to endovascular treatment of intracranial aneurysms. The aim of this study was to investigate the feasibility, safety, and efficacy of the WEB Dual-Layer and WEB Single-Layer devices for the treatment of wide-neck anterior communicating artery aneurysms.

MATERIALS AND METHODS

Patients with anterior communicating artery aneurysms treated with the WEB device between June 2013 and March 2014 in 5 French centers were analyzed. Procedural success, technical complications, clinical outcome at 1 month, and immediate and 3- to 6-month angiographic follow-up results were analyzed.

RESULTS

Ten patients with unruptured anterior communicating artery aneurysms with a mean neck diameter of 5.4 mm were treated with the WEB. Treatment failed in 3 of the 10 aneurysms without further clinical complications. One patient developed a procedural thromboembolic event, and the other 6 had normal neurologic examination findings at 1-month follow-up. Immediate anatomic outcome evaluation showed adequate occlusion (total occlusion or neck remnant) in 6 of 7 patients. Angiographic control was obtained in all patients, including 6 adequate aneurysm occlusions (3 complete occlusions and 3 neck remnants) at short-term follow-up.

CONCLUSIONS

In our small series, treatment of wide-neck anterior communicating artery aneurysms with the WEB device was feasible and safe. However, patient selection based on the aneurysm and initial angiographic findings in the parent artery is important due to the limitations of the WEB device navigation.