Epidemiological Surveillance of the Impact of the COVID-19 Pandemic on Stroke Care Using Artificial Intelligence.

BACKGROUND AND PURPOSE: The degree to which the coronavirus disease 2019 (COVID-19) pandemic has affected systems of care, in particular, those for time-sensitive conditions such as stroke, remains poorly quantified. We sought to evaluate the impact of COVID-19 in the overall screening for acute stroke utilizing a commercial clinical artificial intelligence platform. METHODS: Data were derived from the Viz Platform, an artificial intelligence application designed to optimize the workflow of patients with acute stroke. Neuroimaging data on suspected patients with stroke across 97 hospitals in 20 US states were collected in real time and retrospectively analyzed with the number of patients undergoing imaging screening serving as a surrogate for the amount of stroke care. The main outcome measures were the number of computed tomography (CT) angiography, CT perfusion, large vessel occlusions (defined according to the automated software detection), and severe strokes on CT perfusion (defined as those with hypoperfusion volumes >70 mL) normalized as number of patients per day per hospital. Data from the prepandemic (November 4, 2019 to February 29, 2020) and pandemic (March 1 to May 10, 2020) periods were compared at national and state levels. Correlations were made between the inter-period changes in imaging screening, stroke hospitalizations, and thrombectomy procedures using state-specific sampling. RESULTS: A total of 23 223 patients were included. The incidence of large vessel occlusion on CT angiography and severe strokes on CT perfusion were 11.2% (n=2602) and 14.7% (n=1229/8328), respectively. There were significant declines in the overall number of CT angiographies (-22.8%; 1.39-1.07 patients/day per hospital, P<0.001) and CT perfusion (-26.1%; 0.50-0.37 patients/day per hospital, P<0.001) as well as in the incidence of large vessel occlusion (-17.1%; 0.15-0.13 patients/day per hospital, P<0.001) and severe strokes on CT perfusion (-16.7%; 0.12-0.10 patients/day per hospital, P<0.005). The sampled cohort showed similar declines in the rates of large vessel occlusions versus thrombectomy (18.8% versus 19.5%, P=0.9) and comprehensive stroke center hospitalizations (18.8% versus 11.0%, P=0.4). CONCLUSIONS: A significant decline in stroke imaging screening has occurred during the COVID-19 pandemic. This analysis underscores the broader application of artificial intelligence neuroimaging platforms for the real-time monitoring of stroke systems of care.

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.

Severe hemiparesis as a prehospital tool to triage stroke severity: a pilot study to assess diagnostic accuracy and treatment times.

INTRODUCTION: With the publication of the recent trials showing the tremendous benefits of mechanical thrombectomy, opportunities exist to refine prehospital processes to identify patients with larger stroke syndromes. MATERIALS AND METHODS: We retrospectively reviewed consecutive patients who were brought via scene flight from rural parts of the region to our institution, from December 1, 2014 to June 5, 2015, with severe hemiparesis or hemiplegia. We assessed the accuracy of the diagnosis of stroke and the number of patients requiring endovascular therapy. Moreover, we reviewed the times along the pathway of patients who were treated with endovascular therapy. RESULTS: 45 patients were brought via helicopter from the field to our institution. 27 (60%) patients were diagnosed with an ischemic stroke. Of these, 12 (26.7%) were treated with mechanical thrombectomy and 6 (13.3%) with intravenous tissue plasminogen activator alone. An additional three patients required embolization procedures for either a dural arteriovenous fistula or cerebral aneurysm. Thus a total of 15 (33%) patients received an endovascular procedure and 21/45 (46.7%) received an acute treatment. For patients treated with thrombectomy, the median time from first medical contact to groin puncture was 101 min, with 8 of the 12 patients (66.7%) being discharged to home. CONCLUSIONS: We have presented a pilot study showing that severe hemiparesis or hemiplegia may be a reasonable prehospital tool in recognizing patients requiring endovascular treatment. Patients being identified earlier may be treated faster and potentially improve outcomes. Further prospective controlled studies are required to assess the impact on outcomes and cost effectiveness using this methodology.

CODE FAST: a quality improvement initiative to reduce door-to-needle times.

BACKGROUND: Rapid delivery of IV tissue plasminogen activator (tPA) in qualifying patients leads to better clinical outcomes. The American Heart Association has reduced target door-to-needle (DTN) times from 60 to 45 min in the hopes of continued process improvements across institutions. OBJECTIVE: To start a quality improvement project called CODE FAST in order to reduce DTN times at our institution. MATERIALS AND METHODS: We retrospectively reviewed data from our internally maintained database of patients treated with intravenous tPA before and after implementation of the CODE FAST protocol. We assessed demographic information, time of day and times of arrival to first image and delivery of tPA in patients from February 2014 to February 2015. Outcomes were assessed based on discharge to home. Univariate analysis was performed to assess for improvement in DTN times before and after implementation of the protocol. RESULTS: A total of 93 patients (41 pre-CODE FAST and 52 post-CODE FAST) received IV tPA during the study period. Patients were equally matched between the two groups except that in the pre-CODE FAST era patients receiving tPA were younger and more likely to be men. There was a substantial reduction in door-to-imaging time from a median of 16 to 8 min (p<0.0001) and DTN time with a reduction in the median from 62 to 25 min (p<0.0001). In logistic regression modeling, there was a trend towards more discharges to home in patients treated during the CODE FAST era. CONCLUSIONS: We present a quality improvement project that has been overwhelmingly successful in reducing DTN time to <30 min. The template we present may be helpful to other institutions looking to reduce their DTN times and may also reduce costs as we note a trend towards more discharges to home.

Endovascular Therapy in Strokes with ASPECTS 5-7 May Result in Smaller Infarcts and Better Outcomes as Compared to Medical Treatment Alone.

INTRODUCTION: Intra-arterial therapy (IAT) for large vessel occlusion strokes (LVOS) has been increasingly utilized. The benefit of IAT in patients with midrange Alberta Stroke Program Early Computed Tomography Score (ASPECTS) remains to be established. MATERIALS AND METHODS: This was a retrospective analysis of LVOS with ASPECTS 5-7 treated with IAT (n = 86) or medical therapy alone (intravenous tissue plasminogen activator; n = 15) at two centers from 2009 to 2012. Definitions were as follows: symptomatic intracranial hemorrhage = any parenchymal hematoma; successful reperfusion = mTICI ≥2b; good and acceptable outcomes = 90-day mRS 0-2 and 0-3, respectively. Final infarct volumes (FIV) were calculated based on 24-hour CT/MRI scans. RESULTS: Mean age (67 ± 14 vs. 67 ± 19 years) and baseline NIHSS (20 ± 5 vs. 20 ± 6) were similar in the two groups. Successful reperfusion was achieved in 58 (67%) IAT patients. Symptomatic and asymptomatic intracranial hemorrhage occurred in 9 (10%) and 31 (36%) IAT patients, respectively. The proportion of 90-day good and acceptable outcomes was 20 (17/86) and 33% (28/86), respectively. Successful IAT reperfusion was associated with smaller FIV (p = 0.015) and higher rates of good (p = 0.01) and acceptable (p = 0.014) outcomes. There was a strong trend towards a higher hemicraniectomy requirement in medically as compared to endovascularly treated patients (20 vs. 6%; p = 0.06) despite similar in-hospital mortality. The median FIV was significantly lower with IAT versus medical therapy [80 ml (interquartile range, 38-122) vs. 190 ml (121-267); p = 0.015]. CONCLUSIONS: Despite a relatively low probability of achieving functional independence, IAT in LVOS patients with ASPECTS 5-7 appears to result in lower degrees of disability and may lessen the need for hemicraniectomy. Therefore, it may be a reasonable option for patients and families who favor a shift from severe to moderate disability.

Clinical outcomes after thrombectomy for acute ischemic stroke on weekends versus weekdays.

BACKGROUND: The objective of this study was to determine whether clinical outcomes differed in acute ischemic stroke (AIS) patients who underwent thrombectomy on weekends versus weekdays. METHODS: Patients with a primary diagnosis of AIS who underwent thrombectomy were identified from the Nationwide Inpatient Sample from 2005 to 2011 and stratified according to weekend or weekday admission. Logistic regression analysis was performed to identify factors associated with moderate-to-severe disability at hospital discharge in teaching and nonteaching hospitals. RESULTS: Of 12,055 patients with AIS who underwent thrombectomy during the study period, 2862 (23.7%) were admitted on a weekend. In a multivariate logistic regression analysis, factors associated with moderate or severe disability at discharge in nonteaching hospitals were weekend admission (odds ratio [OR], 1.6; 95% confidence interval [CI], 1.0-2.8; P = .04), diagnosis of hypertension (OR, 1.9; 95% CI, 1.0-3.6; P = .05), and Medicare or Medicaid insurance status (OR, 2.1; 95% CI 1.1-4.3; P = .02); factors associated with moderate or severe disability at discharge in teaching hospitals were age >70 years (OR, 1.5; 95% CI, 1.1-2.2; P = .02), pneumonia (OR, 4.7; 95% CI, 2.2-10.2; P < .0001), sepsis (OR, 8.2; 95% CI, 1.2-54.8; P = .03), intracranial hemorrhage (OR, 3.3; 95% CI, 1.8-6.1; P = .0001), and treatment in a Northwest hospital region (OR, 1.7; 95% CI, 1.2-2.4; P = .03). CONCLUSIONS: AIS patients undergoing thrombectomy who were admitted to nonteaching hospitals on weekends were more likely to be discharged with moderate-to-severe disability than those admitted on weekdays. No weekend effect on discharge clinical outcome was seen in teaching hospitals.

Comparison of final infarct volumes in patients who received endovascular therapy or intravenous thrombolysis for acute intracranial large-vessel occlusions.

IMPORTANCE: Studies comparing the efficacy of intra-arterial therapy (IAT) and medical therapy in reducing final infarct volume (FIV) in intracranial large-vessel occlusions (ILVOs) are lacking. OBJECTIVES: To assess whether patients with ILVOs who received IAT have smaller FIVs than patients who received either intravenous tissue plasminogen activator therapy (IVT) or no reperfusion therapy (NRT) and to determine a National Institutes of Health Stroke Scale (NIHSS) threshold score that identifies patients most likely to benefit from IAT. DESIGN: Retrospective cohort study of patients with ILVOs between 2009 and 2011. SETTING: Two large-volume stroke centers. PARTICIPANTS: Adults with anterior circulation ILVOs who presented within 360 minutes from the time last seen as normal. Patients with isolated extracranial occlusions were not included. EXPOSURE: Intra-arterial therapy, IVT, or NRT. MAIN OUTCOMES AND MEASURES: Final infarct volumes, rates of acceptable outcome defined as a modified Rankin Scale score of 0 to 3 at hospital discharge, and NIHSS threshold scores. RESULTS: A total of 203 consecutive patients with ILVOs were evaluated. Baseline characteristics were similar among the 3 groups. The median infarct volume was significantly smaller for the IAT group (42 cm3) than for the IVT group (109 cm3; P = .001) or the NRT group (110 cm3; P < .01). A higher magnitude of infarct volume reduction in more proximal occlusions was noted in the IAT group compared with the IVT and NRT groups combined: internal carotid artery terminus (75 vs 190 cm3; P < .001), M1 middle cerebral artery (39 vs 109 cm3; P = .004), and M2 middle cerebral artery (33 vs 59 cm3; P = .04) occlusions. Patients were stratified based on NIHSS score at presentation (8-13, 14-19, and ≥20). For patients with an NIHSS score of 14 or higher at presentation, IAT significantly reduced FIV (46 cm3 with IAT vs 149 cm3 with IVT or NRT; P < .001) compared with patients with an NIHSS score of 8 to 13 (22 cm3 with IAT vs 44 cm3 with IVT or NRT; P = .40). Patients with an NIHSS score of 14 or higher who received IAT appear to benefit most from IAT. CONCLUSIONS AND RELEVANCE: Our data suggest a greater reduction of FIV with IAT compared with either IVT or NRT. Moreover, patients with an NIHSS score of 14 or higher may be the best candidates for endovascular reperfusion therapy.