Background: Racial and ethnic disparities in stroke exist across the continuum of care, including prehospital care. The impact of Mobile Stroke Units (MSUs) on racial disparities in thrombolytic treatment metrics is not reported. Methods: A pre-specified sub-study of ischemic stroke patients enrolled in BEST-MSU was conducted. MSU and standard management (SM) groups were divided into Non-Hispanic White (NHW), Non-Hispanic Black (NHB), and Hispanic (H) cohorts. Other racial groups were excluded (small n). Primary outcome was last seen normal to tPA time . Secondary outcomes included 90-day utility-weighted modified Rankin Scale (uw-mRS), functional independence (mRS 0-1), and mortality. Results: A total of 1420 patients were included: 557 NHW, 586 NHB, and 277 H. NHB and H groups were younger, had lower education, and higher proportions uninsured. In SM, NHB and H patients received slower care and less frequent tPA compared to NHW (Table 1). In contrast, MSU management reduced time to treatment (19 min NHW vs 46.5 min NHB vs 46 min H; p=<0.001) in NHB and H, and led to more frequent tPA (13% more NHW, 11% more NHB, 25% more H) in H. MSU management was associated with better uw-mRS across all groups (Figure 1). More functional independence was seen in NHW and NHB (adjusted OR NHW 1.79 [1.10-2.95] p=0.019; NHB 2.13 [1.38-3.33] p=0.0007). Mortality benefit was seen in H (p=0.03). Conclusion: MSUs overcome known disparities in thrombolytic utilization and treatment metrics in Non-Hispanic Black and Hispanic groups. Further studies are needed to evaluate care inequities that are overcome through integration of a MSU into the prehospital setting.

Background: Mobile stroke units (MSUs) improve outcomes in thrombolytic-eligible ischemic stroke patients. Outcomes of MSU management in patients with intracranial hemorrhage (ICH) have not been reported. Methods: We conducted a retrospective review of ICH patients enrolled in the Benefits of Stroke Treatment Using a Mobile Stroke Unit (BEST-MSU), a prospective multicenter controlled trial comparing MSU with standard EMS management (SM). The primary outcome was utility weighted modified Rankin Scale (uw-mRS) at 90 days; secondary outcomes were hematoma expansion, length of inpatient stay, favorable discharge disposition or 90-day mRS, and mortality. Groups were compared using Chi-square or Fisher’s exact tests for categorical variables, and two sample t-test or Wilcoxon rank sum test for continuous variables. Adjusted analysis was performed to evaluate the relationship between the intervention group and uw-mRS at 90 days. Kaplan-Meier curves and log-rank test were used to compare the survival by 90 days between groups. Results: 201 ICH patients were identified; 102 in the MSU and 99 in the SM groups. MSU patients had more antiplatelet/antithrombotic (AP/AT) use (30.4% vs 15.2%, p=0.016); edema was more frequent in the SM group (72.7% vs 52.0%, p = 0.004). Initial ICH volume was similar between MSU and SM groups (11.50 mL [5.0, 22.0] vs. 9.0 mL [5.0, 20.0], p = 0.62). Anti-hypertensives were given earlier on the MSU (39.0 min [31.00, 45.00] vs 61.0 min [46.50, 75.25], p<0.001), and resulted in shorter time to systolic blood pressure (SBP) < 150mmHg (52 min vs. 121 min, p<0.001). The mean uw-mRS at 90 days was 0.364 ± 0.361 in the MSU and 0.465 ± 0.360 in the SM group (p=0.50, adjusted for AP/AT and edema). There was no difference in hematoma expansion, length of stay, discharge disposition or 90-day mRS. Higher mortality was noted after 5 days post-ictus in the MSU group (26.5% vs. 14.1%, p = 0.04). Conclusion: In ICH patients, MSU management resulted in faster treatment and time to target SBP with similar clinical outcomes except higher late mortality. Further study of the impact of prehospital ICH management including BP reduction and AT/AP reversal are required.

OBJECTIVE:Given the high disease and cost burden of ischemic stroke, evaluating the clinical efficacy and cost-effectiveness of new approaches to prevent and treat ischemic stroke is critical. Effective ischemic stroke management depends on timely administration of thrombolytics after stroke onset. This study evaluates the cost-effectiveness associated with the use of mobile stroke units (MSUs) to expedite tissue plasminogen activator (tPA) administration, as compared with standard management through emergency medical services (EMS). METHODS:This study is a prospective, multicenter, alternating-week, cluster-controlled trial of MSU versus EMS. One-year and life-time cost-effectiveness analyses, using the incremental cost-effectiveness ratio (ICER) method, were performed from the perspective of CMS's Medicare. Quality-adjusted life years (QALYs) estimated using patient-reported EQ-5D-5L data were used as the effectiveness measure. Health care utilizations were converted to costs using average national Medicare reimbursements. ICERs excluding patients with pre-existing disability, and limited to stroke-related costs were also calculated. RESULTS:The first-year ICER for all tPA-eligible patients using total cost differences between MSU and EMS groups was $238,873/QALY; for patients without pre-existing disability was $61,199/QALY. The lifetime ICERs for all tPA-eligible patients and for those without pre-existing disability were $94,710 and $31,259/QALY, respectively. All ICERs were lower when restricted to stroke-related costs and were highly dependent on the number of patients treated per year in an MSU. INTERPRETATION:MSUs' cost-effectiveness is borderline if we consider total first-year costs and outcomes in all tPA-eligible patients. MSUs are cost-effective to highly cost-effective when calculations are based on patients without pre-existing disability, patients' lifetime horizon, stroke-related costs, and more patients treated per year in an MSU. ANN NEUROL 2025;97:209-221.

Introduction: While the goal of IV tissue plasminogen activator (TPA) is to prevent infarction, few data exist on averted stroke. Methods: Secondary analysis of a multicenter trial from 2014-2020 comparing outcomes between patients treated for stroke by mobile stroke unit (MSU) vs standard care (SC). The analytical cohort were patients with suspected stroke treated with IV TPA. The primary outcome was a time-defined averted stroke diagnosis, defined as a final diagnosis of stroke with resolution of presenting symptoms/signs by 24 hours. The secondary outcome was a tissue-defined averted stroke diagnosis, defined as a final diagnosis of stroke with resolution of presenting symptoms/signs by 24 hours and no acute infarction/hemorrhage on imaging. We used multivariable logistic regression to evaluate associations between study exposures (demographics, comorbidities, stroke characteristics) and outcomes. Results: Among 1009 patients with a median last known well-to-TPA time of 87 minutes, 276 patients (27%) had a time-defined averted stroke (31% MSU, 21% SC) and 159 patients (16%) had a tissue-defined averted stroke (18% MSU, 11% SC). Factors independently associated with time-defined averted stroke were younger age (OR, 0.98; 95% CI, 0.96-0.99), female sex (0R, 0.51; 95% CI, 0.36-0.74), hyperlipidemia (OR, 1.81, 95% CI, 1.24-2.64), normal premorbid function (0R, 2.22; 95% CI, 1.37-3.67), lower glucose (OR, 0.996; 95% CI, 0.993-0.999), lower MAP (OR, 0.991; 95% CI, 0.983-0.998), MSU care (OR, 1.77; 95% CI, 1.21-2.62), lower NIH stroke scale (OR, 0.89; 95% CI, 0.86-0.93), and no large vessel occlusion (LVO) (OR, 0.52; 95% CI, 0.32-0.83). For tissue-based averted stroke, younger age, female sex, hyperlipidemia, lower MAP, MSU treatment, lower NIH stroke scale, and no LVO were significantly associated. Conclusion: In a modern acute stroke trial, one-in-four patients treated with TPA for stroke recovered within 24 hours and one-in-six had no demonstrable brain injury on imaging. Younger age, female sex, hyperlipidemia, lower MAP, MSU care, lower stroke severity, and no LVO may increase the odds of averting stroke.

Background The impact of mobile stroke units (MSUs) on outcomes in patients with large vessel occlusions eligible for endovascular thrombectomy (EVT) has yet to be characterized. Methods We completed a prespecified substudy of patients with EVT‐eligible stroke with anterior and posterior circulation large vessel occlusions on computed tomography and/or computed tomography angiography who were enrolled in BEST‐MSU (Benefits of Stroke Treatment using a Mobile Stroke Unit). Primary outcome was 90‐day utility‐weighted modified Rankin scale. Groups were compared using chi‐square or Fisher's exact tests for categorical variables, and 2‐sample t‐tests for continuous variables. Multiple logistic regression was used to assess the effect of MSU on binary outcomes after adjusting for other baseline factors. Results Of 1515 trial patients, 293 had large vessel occlusions eligible for EVT: 168 in the MSU group and 125 in the emergency medical services group. Baseline characteristics were comparable, with the exception of baseline National Institutes of Health Stroke Scale score (MSU median 19 [interquartile range 13, 23] versus emergency medical services 16 [11, 20], P = 0.002) and study site. The mean (±SD) score on the utility‐weighted modified Rankin scale at 90 days was 0.63±0.39 in MSU group and 0.51±0.41 in emergency medical services group (mean difference 0.13, 95% CI [0.03–0.22]). After adjustment, MSU had significantly higher odds of functional independence (odds ratio 2.60 [95% CI, 1.45–4.77], P = 0.002). Secondary outcomes also favored MSU: early neurologic recovery (30% improvement in National Institutes of Health Stroke Scale score at 24 hours) 68% versus 52%; adjusted odds ratio 1.98 [95% CI, 1.19–3.33]; time of tissue plasminogen activator bolus from symptom onset 65.0 minutes [50.5–92.0] versus 96.0 [79.3–130.0], P≤0.001. The groups had similar onset to arterial puncture (169.0 minutes [133.5, 210.0] versus 162.0 [135.0–207.0], P = 0.83). Conclusions In patients with EVT‐eligible large vessel occlusion stroke, MSU management was associated with better clinical outcomes compared with standard emergency medical services management. MSU management sped thrombolysis but did not expedite EVT treatment times. Future MSU processes should include efforts to capitalize on the potential of MSUs to provide earlier EVT.

Objective: Evaluate the impact of a direct-to-angiosuite (DTAS) workflow on Mobile Stroke Units (MSU) in stroke patients with large vessel occlusions (LVO) needing mechanical thrombectomy (MT). Background: MSUs are equipped with CT/CT angiography (CTA), thrombolytics and personnel that can deliver emergency stroke care to patients and reduce time-to-thrombolytic administration and improve clinical outcomes. Although there is no benefit of MSUs on alert-to-puncture times, a reduction in time was seen when CTA was obtained on-board the MSU, which suggests that a DTAS protocol may be a powerful method to reduce delay from alert-to-puncture. Design/Methods: The MSU DTAS group will be comprised of suspected LVO patients having CTA on-board the MSU, alerting of the MT team en route, and bypassing the Emergency Department (ED) with direct transport to the angiosuite. The control group will comprise of the standard Emergency Medical Services (EMS) management group from the BEST-MSU study. In those patients, CTA was done after arrival to the ED and then transported to the angiosuite. Primary outcome will be alert-to-puncture time. Secondary outcomes will include 90-day modified Rankin scale and degree of recanalization. Analysis of the mRS will be a propensity-score based ordinal logistic regression adjusted for baseline predictors to estimate the common odds ratio. Based on pilot data, we estimate we will detect at least a 30-minute reduction in alert-to-puncture time. Results: In a preliminary analysis of the BEST-MSU study, DTAS management resulted in shorter alert-to-puncture (42 minutes) and door-to-puncture times (50 minutes) with similar safety and clinical outcomes compared with standard management. We plan to enroll additional patients to the MSU DTAS pathway and a more detailed and final analysis will be available upon abstract presentation at the AAN conference. Conclusions: A DTAS workflow, triggered by CTA on MSU patients suspected of having LVO, substantially speeds alert-to thrombectomy, and may improve recanalization and clinical outcome. Disclosure: Dr. Tariq has nothing to disclose. Stephanie Parker has nothing to disclose. Dr. Jacob has nothing to disclose. Mengxi Wang has nothing to disclose. Noopur Singh has nothing to disclose. The institution of Jose-Miguel Yamal has received research support from NIH/DoD. Mr. Phan has nothing to disclose. Ms. Bratina has nothing to disclose. Dr. Bowry has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Astrazeneca. Dr. Grotta has received personal compensation in the range of $10,000-$49,999 for serving as a Consultant for Frazer Ltd. Dr. Grotta has received personal compensation in the range of $5,000-$9,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Haemonetics. Dr. Grotta has received personal compensation in the range of $10,000-$49,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Acticor. Dr. Grotta has received personal compensation in the range of $5,000-$9,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Prolong Pharma. The institution of Dr. Grotta has received research support from Genentech. The institution of Dr. Grotta has received research support from CSL Behring. The institution of Dr. Grotta has received research support from Chiesi. Dr. Grotta has received publishing royalties from a publication relating to health care. Dr. Grotta has received publishing royalties from a publication relating to health care. The institution of Dr. Czap has received research support from SVIN. The institution of Dr. Czap has received research support from AAN.

BACKGROUND:Treatment of patients with acute ischemic stroke on mobile stroke units (MSUs) improves outcomes compared with management by standard emergency medical services ambulances and is associated with more patients treated with intravenous tPA (tissue-type plasminogen activator) in the first golden hour after last known normal. We explored the predictors and outcomes of first-hour treatment (FHT) compared with later treatment in an alternating-week cluster-controlled trial of MSUs. METHODS:We analyzed all patients treated with intravenous tPA in the BEST-MSU Study (Benefits of Stroke Treatment Delivered by a Mobile Stroke Unit Compared to Standard Management by Emergency Medical Services). After stratifying by treatment timeframe, we identified factors associated with FHT. We performed adjusted analyses of the association between FHT and clinical outcome and modeled the shape of the relationship between last known normal-to-treatment time and excellent outcome. RESULTS:Among 941 tPA-treated patients, 206 (21.8%) had lytic started within 60 minutes. Treatment on the MSU, older age, male sex, alert by 911, faster arrival on-scene and imaging, more severe stroke, atrial fibrillation, and absence of heart failure and pretreatment antihypertensive treatment were associated with FHT. Compared with later treatment, FHT was associated with higher adjusted odds ratio for 90-day modified Rankin Scale score of 0 to 1 (odds ratio, 1.87 [95% CI, 1.25-2.84]; P=0.003). Among FHT patients, 68% achieved a 90-day modified Rankin Scale of 0 or 1 or returned to their baseline status. FHT was not associated with higher risk of hemorrhage and was associated with reduced risk of treating neurovascular mimics. CONCLUSIONS:FHT almost doubles the odds of excellent clinical outcome without increased risk compared with later treatment, which supports the use of MSUs.

Introduction Mobile Stroke Units (MSUs) speed treatment with tPA, but did not affect time from alert to puncture time for endovascular therapy (EVT) in the Benefits of Stroke Treatment Using a Mobile Stroke Unit (BEST‐MSU), a prospective multicenter controlled trial comparing MSU with standard EMS management. The lack of improvement in EVT treatment time could be because the CTA to identify large vessel occlusions (LVOs), and alerting of the EVT team, were delayed in most MSU patients until after Emergency Department (ED) arrival. The impact of identifying LVOs by imaging on the MSU enabling a direct (from MSU) to angiosuite (DTAS) protocol has yet to be studied. Methods We conducted a pre‐specified substudy of tPA‐eligible stroke patients with LVOs on computed tomography (CT) and/or CT angiography (CTA) who were enrolled into the MSU arm of the BEST‐MSU study. We compared alert to puncture time and other process metrics, mean utility‐weighted modified Rankin Scale (uw‐mRS) and functional independence (mRS 0–2) at 90 days, and rate of early neurologic recovery (30% improvement in NIHSS score) at 24 hours in patients who were managed by DTAS vs post‐ED arrival diagnosis and alerting. Results A total of 169 MSU patients with LVOs were identified; 22 in the DTAS group and 111 in the non DTAS group. Data were not available for 36 LVO patients. Baseline characteristics including age, sex, ethnicity, prestroke mRS, and initial NIHSS were comparable between the groups. 100.0% of patients in the DTAS group vs 90.1% in the non DTAS received tPA (p = 0.264). EVT was performed on 85.0% of patients in the DTAS group vs 77.1% in the non DTAS group (p = 0.634). DTAS group had a faster alert to puncture time (108.00 min [94.75,124.75.] vs 150.50 min [121.25, 179.00], p< 0.001) and door to puncture time (37.00 min [25.50,62.75 vs 86.50 min [62.50,116.00], p< 0.001). The mean score on the uw‐mRS at 90 days was 0.626 ±0.367 in the DTAS group and 0.660 ±0.382 in the non DTAS group and after adjustment for age, baseline NIHSS, premorbid functional status, prior stroke/TIA and site, no significant difference was observed; (p = 0.54). In an unadjusted analysis, early neurologic recovery (72.7% vs 67.6%, (OR = 0.634, 95% CI [0.46,3.82]) and functional independence (50.0% vs 51.4%, p = 1.000) were comparable between DTAS and non DTAS patients. Patients in the DTAS group were less likely to receive general anesthesia (36.4% vs 71.2%, p = 0.004). Rates of recanalization (77.3% vs73,4%, p = 0.947) and post procedural PH‐2 hemorrhage (4.5% vs 0.9%, p = 0.746) were similar in the DTAS and non DTAS group respectively. Conclusions In tPA‐eligible LVO stroke patients, DTAS management resulted in shorter alert to puncture (42 minutes) and door to puncture times (50 minutes) with similar safety and clinical outcomes compared with non DTAS management. MSU DTAS represents an optimized pathway for LVO patients triaged and treated in the field.

Background: Few data exist on acute stroke treatment in patients with pre-existing disability (PD) since they are usually excluded from clinical trials. A recent trial of mobile stroke units (MSUs) demonstrated faster treatment and improved outcomes, and included PD patients. Aim: To determine outcomes with tissue plasminogen activator (tPA), and benefit of MSU versus management by emergency medical services (EMS), for PD patients. Methods: Primary outcomes were utility-weighted modified Rankin Scale (uw-mRS). Linear and logistic regression models compared outcomes in patients with versus without PD, and PD patients treated by MSU versus standard management by EMS. Time metrics, safety, quality of life, and health-care utilization were compared. Results: Of the 1047 tPA-eligible ischemic stroke patients, 254 were with PD (baseline mRS 2-5) and 793 were without PD (baseline mRS 0-1). Although PD patients had worse 90-day uw-mRS, higher mortality, more health-care utilization, and worse quality of life than non-disabled patients, 53% returned to at least their baseline mRS, those treated faster had better outcome, and there was no increased bleeding risk. Comparing PD patients treated by MSU versus EMS, 90-day uw-mRS was 0.42 versus 0.36 (p = 0.07) and 57% versus 46% returned to at least their baseline mRS. There was no interaction between disability status and MSU versus EMS group assignment (p = 0.67) for 90-day uw-mRS. Conclusion: PD did not prevent the benefit of faster treatment with tPA in the BEST-MSU study. Our data support inclusion of PD patients in the MSU management paradigm.

This study was undertaken to examine averted stroke in optimized stroke systems.

Introduction: Stroke is a leading cause of long-term disability in the U.S., and 90% of stroke survivors have residual movement impairment. Inpatient and outpatient rehabilitation is critical for restoring functionality and quality of life among survivors. However, there are few studies evaluating the patterns and predictors of rehabilitation use among stroke survivors. Methods: This study used 947 tPA-eligibe patients from an observational, prospective, multicenter, clinical trial in the U.S., who had complete 1 year follow-up utilization data, collected quarterly as self-reported surveys. We determined the occurrence and length of stay for inpatient rehabilitation, and occurrence and number of visits for outpatient rehabilitation. Logistic and linear regressions were used to examine predictors associated with these occurrences and intensities. Results: The majority of rehabilitation use occurred during the first quarter with 19% and 33% of patients using inpatient and outpatient rehabilitation respectively, and rehabilitation use fell considerably over the rest of the year (Table 1). Higher disability at baseline (mRS≥2 and not living at home) reduced rehabilitation use, and higher disability at discharge increased rehabilitation use. Being uninsured reduced rehabilitation use. Other socio-demographic characteristics (such as age, gender and race-ethnicity), baseline comorbidities, and type and timeliness of therapies after stroke did not have an effect on rehabilitation use. Conclusion: Rehabilitation use is highest during the first 3 months after discharge. Patients with higher discharge disability are more in need of rehabilitation, hence receive it. Patients already disabled at baseline are often excluded, probably due to a combination of rehabilitation entry requirements and perceived lack of potential benefits. Access barriers, such as lack of insurance reduced rehabilitation use suggesting an unmet need among stroke survivors.

Background: Few data exists on acute stroke treatment in patients with pre-existing disability (PD) since they are usually excluded from clinical trials. Methods: A pre-specified subgroup analysis of tPA-eligible patients with PD enrolled in a prospective multicenter trial of Mobile Stroke Units (MSUs) vs standard management by emergency medical services (EMS). All patients had baseline mRS scores. Co-primary outcomes were mean utility-weighted modified Rankin Scale score (uw-mRS) and return to baseline mRS at 90 days. Linear and logistic regression models compared outcomes in patients with vs without PD, and patients with PD treated by MSU vs EMS. Time metrics, safety, quality of life, and health-care utilization were also compared. Results: Of 1047 patients, 254 had baseline mRS >= 2 (159 MSU, 95 EMS; 31% mRS 2, 52% mRS 3, 17% mRS 4). Compared to patients without disability, patients with PD were older, had higher NIHSS, more comorbidities, less often lived at home, were treated slower, and had less thrombectomy. Patients with PD had worse 90-day uw-mRS (0.39 vs 0.80), higher mortality, more health-care utilization and worse quality of life than patients without PD. However, rates of symptomatic intracranial hemorrhage and final diagnoses of stroke mimics were similar between groups, and 52% of patients with PD returned to their baseline mRS. Patients with PD treated within the first hour had better 90-day uw-mRS than those treated later (0.48 vs 0.36, p=0.01). Comparing patients with PD treated by MSU vs EMS, time from last-known-well to tPA bolus was shorter (82 vs 111 min), and 24% vs 0% were treated in the first hour. Among patients with PD, MSU patients had non-significantly better 90-day uw-mRS (0.41 vs 0.35, p=0.09) and higher rate of returning to baseline mRS (56% vs 44%, p=0.09) than EMS patients. There was no interaction between either time to treatment (p=0.24) or MSU vs EMS group assignment (p= 0.42), 90-day uw-mRS, and PD vs no disability status. Conclusion: Although outcomes after stroke are less favorable in patients with vs without PD, in a large, controlled trial, we found no interaction between baseline disability and the benefit of MSU treatment. Our data support the earliest treatment of acute stroke patients regardless of premorbid functional status.

Background: Hematoma enlargement (HE) after intracerebral hemorrhage (ICH) is a therapeutic target for improving outcomes. Hemostatic therapies to prevent HE may be more effective the earlier they are attempted. An understanding of HE in first 1 to 2 hours specifically in the prehospital setting would help guide future treatment interventions in this time frame and setting. Methods: Patients with spontaneous ICH within 4 hours of symptom onset were prospectively evaluated between May 2014 and April 2020 as a prespecified substudy within a multicenter trial of prehospital mobile stroke unit versus standard management. Baseline computed tomography scans obtained <1, 1 to 2, and 2 to 4 hours postsymptom onset on the mobile stroke unit in the prehospital setting were compared with computed tomography scans repeated 1 hour later and at 24 hours in the hospital. HE was defined as >6 mL if baseline ICH volume was <20 mL and 33% increase if baseline volume >20 mL. The association between time from symptom onset to baseline computed tomography (hours) and HE was investigated using Wilcoxon rank-sum test when time was treated as a continuous variable and using Fisher exact test when time was categorized. Kruskal-Wallis and Wilcoxon rank-sum tests evaluated differences in baseline volumes and HE. Univariable and multivariable logistic regression analyses were conducted to identify factors associated with HE and variable selection was performed using cross-validated L1-regularized (Lasso regression). This study adhered to STROBE guidelines (Strengthening the Reporting of Observational Studies in Epidemiology) for cohort studies. Results: One hundred thirty-nine patients were included. There was no difference between baseline ICH volumes obtained <1 hour (n=43) versus 1 to 2 hour (n=51) versus >2 hours (n=45) from symptom onset (median [interquartile range], 13 mL [6-24] versus 14 mL [6-30] versus 12 mL [4-19]; P=0.65). However, within the same 3 time epochs, initial hematoma growth (volume/time from onset) was greater with earlier baseline scanning (median [interquartile range], 17 mL/hour [9-35] versus 9 mL/hour [5-23]) versus 4 mL/hour [2-7]; P<0.001). Forty-nine patients had repeat scans 1 hour after baseline imaging (median, 2.3 hours [interquartile range. 1.9-3.1] after symptom onset). Eight patients (16%) had HE during that 1-hour interval; all of these occurred in patients with baseline imaging within 2 hours of onset (5/18=28% with baseline imaging within 1 hour, 3/18=17% within 1-2 hour, 0/13=0% >2 hours; P=0.02). HE did not occur between the scans repeated at 1 hour and 24 hours. No association between baseline variables and HE was detected in multivariable analyses. Conclusions: HE in the next hour occurs in 28% of ICH patients with baseline imaging within the first hour after symptom onset, and in 17% of those with baseline imaging between 1 and 2 hours. These patients would be a target for ultraearly hemostatic intervention.

BACKGROUND AND PURPOSE:Tissue plasminogen activator (tPA) requires a one-hour infusion after the bolus. The frequency of delay or interruption of the tPA infusion may be useful in weighing the advantages of Tenecteplase (TNKase, TNK) which does not require an infusion.METHODS:Utilizing the Benefits of Stroke Treatment Delivered Using a Mobile Stroke Unit Compared to Standard Management by Emergency Medical Services study database, we calculated the frequency and magnitude of tPA infusion delay or interruption.RESULTS:Of 497 patients treated with tPA on the Houston Mobile Stroke Unit (MSU), 41 (8.3%) had delay or interruption of the infusion for reasons that did not reflect a side effect of, or contraindication to, tPA. Nine received less than 90% of their calculated dose (median 62%, range 28-88%), and eleven had more than a 10% prolongation of their infusion (median 19 min, range 7-210 min). Six patients (1.2%) had infusion stopped for a valid concern for tPA side effect or contraindication.CONCLUSIONS:Interruption or discontinuation of the tPA infusion occurs in 8% of patients treated on a MSU providing an opportunity for more complete and faster treatment with TNK.

Most clinical research stopped during COVID due to possible impact on data quality and personnel safety. We aimed to assess the impact of COVID on acute stroke clinical trial conduct at sites that continued to enroll patients during the pandemic. BEST-MSU is an ongoing study of Mobile Stroke Units (MSU) vs standard management of tPA-eligible acute stroke patients in the pre-hospital setting. MSU personnel include a vascular neurologist via telemedicine, and a nurse, CT technologist, paramedics and emergency medicine technicians on-board. During COVID, consent, 90-day modified Rankin Scale (mRS) and EQ5D were obtained by phone instead of in-person, but other aspects of management were similar to the pre-COVID period. We compared patient demographics, study metrics, and infection of study personnel during intra- vs pre-COVID eras. Five of 6 BEST-MSU sites continued to enroll during COVID. There were no differences in intra- (n = 57) vs pre- (n = 869) COVID enrolled tPA eligible patients' age, sex, race (38.6% vs 38.0% Black), ethnicity (15.8% vs 18.6% Hispanic), or NIHSS (median 11 vs 9). The percent of screened patients enrolled and adjudicated tPA eligible declined from 13.6% to 6.6% (p < .001); study enrollment correlated with local stay-at-home and reopening orders. There were no differences in alert to MSU arrival or arrival to tPA times, but MSU on-scene time was 5 min longer (p = .01). There were no differences in ED door to CT, tPA treatment or thrombectomy puncture times, hospital length of stay, discharge disposition, or remote vs in-person 90-day mRS or EQ5D. One MSU nurse tested positive but did not require hospitalization. Clinical research in the pre-hospital setting can be carried out accurately and safely during a pandemic. tPA eligibility rates declined, but otherwise there were no differences in patient demographics, deterioration of study processes, or serious infection of study staff. Trial registration: NCT02190500.

BACKGROUND: Prehospital tissue plasminogen activator dosing in a mobile stroke unit (MSU) is estimated by the paramedic and nurse. We aimed to determine the accuracy of the estimated weight method compared with the actual weight of patients treated with tissue plasminogen activator on the MSU. METHODS: We prospectively collected the estimated weight used on the MSU for treatment and the first-documented hospital-measured weight (bed scale) within 24 hours of hospital arrival. Median absolute and percent difference in weights were calculated; less than 10% of difference in weights was considered acceptable. To compare the estimated and measured weights, we conducted a Wilcoxon signed rank test and Fisher exact test to explore the association between weight difference of greater than 10% and patient outcomes. RESULTS: Among 337 patients, median estimated and hospital-measured weights were 79.0 kg (interquartile range [IQR], 66.0-94.5) and 78.5 kg (IQR, 65.0-91.7), respectively. The median of the absolute value of the difference in estimated versus measured weight was 2.7 kg (IQR, 0.6-7.6; P < .0001). The median percent difference in weight was 3.6% (IQR, 0.8%-9.4%). The median difference between the tissue plasminogen activator dosage administered on the MSU and the recommended dose based on the actual weight was 1.3 mg (IQR, 0.06-4.8) in absolute value. In 56 patients (16.6% of the entire sample) with overestimation of weight by greater than 10%, there were no symptomatic intracerebral hemorrhages. There was no association between weight difference and discharge modified Rankin score (P = .59). CONCLUSION: Weight estimation on an MSU can lead to similar tissue plasminogen activator dosing for 83.4% of subjects compared with if dosing were determined based on actual weight. Weight overestimation or underestimation had no detected impact on tissue plasminogen activator outcomes.

BACKGROUND:Mobile stroke units (MSUs) are ambulances with staff and a computed tomographic scanner that may enable faster treatment with tissue plasminogen activator (t-PA) than standard management by emergency medical services (EMS). Whether and how much MSUs alter outcomes has not been extensively studied. METHODS:In an observational, prospective, multicenter, alternating-week trial, we assessed outcomes from MSU or EMS management within 4.5 hours after onset of acute stroke symptoms. The primary outcome was the score on the utility-weighted modified Rankin scale (range, 0 to 1, with higher scores indicating better outcomes according to a patient value system, derived from scores on the modified Rankin scale of 0 to 6, with higher scores indicating more disability). The main analysis involved dichotomized scores on the utility-weighted modified Rankin scale (≥0.91 or <0.91, approximating scores on the modified Rankin scale of ≤1 or >1) at 90 days in patients eligible for t-PA. Analyses were also performed in all enrolled patients. RESULTS:We enrolled 1515 patients, of whom 1047 were eligible to receive t-PA; 617 received care by MSU and 430 by EMS. The median time from onset of stroke to administration of t-PA was 72 minutes in the MSU group and 108 minutes in the EMS group. Of patients eligible for t-PA, 97.1% in the MSU group received t-PA, as compared with 79.5% in the EMS group. The mean score on the utility-weighted modified Rankin scale at 90 days in patients eligible for t-PA was 0.72 in the MSU group and 0.66 in the EMS group (adjusted odds ratio for a score of ≥0.91, 2.43; 95% confidence interval [CI], 1.75 to 3.36; P<0.001). Among the patients eligible for t-PA, 55.0% in the MSU group and 44.4% in the EMS group had a score of 0 or 1 on the modified Rankin scale at 90 days. Among all enrolled patients, the mean score on the utility-weighted modified Rankin scale at discharge was 0.57 in the MSU group and 0.51 in the EMS group (adjusted odds ratio for a score of ≥0.91, 1.82; 95% CI, 1.39 to 2.37; P<0.001). Secondary clinical outcomes generally favored MSUs. Mortality at 90 days was 8.9% in the MSU group and 11.9% in the EMS group. CONCLUSIONS:In patients with acute stroke who were eligible for t-PA, utility-weighted disability outcomes at 90 days were better with MSUs than with EMS. (Funded by the Patient-Centered Outcomes Research Institute; BEST-MSU ClinicalTrials.gov number, NCT02190500.).

OBJECTIVES:Studies face challenges with missing 5-level EQ-5D (EQ-5D-5L) data, often because of the need for longitudinal EQ-5D-5L data collection. There is a dearth of validated methodologies for dealing with missing EQ-5D-5L data in the literature. This study, for the first time, examined the possibility of using retrospectively collected EQ-5D-5L data as proxies for the missing data.METHODS:Participants who had prospectively completed a 3rd month postdischarge EQ-5D-5L instrument (in-the-moment collection) were randomly interviewed to respond to a 2nd "retrospective collection" of their 3rd month EQ-5D-5L at 6th, 9th, or 12th month after hospital discharge. A longitudinal single imputation was also used to assess the relative performance of retrospective collection compared with the longitudinal single imputation. Concordances between the in-the-moment, retrospective, and imputed measures were assessed using intraclass correlation coefficients and weighted kappa statistics.RESULTS:Considerable agreement was observed on the basis of weighted kappa (range 0.72-0.95) between the mobility, self-care, and usual activities dimensions of EQ-5D-5L collected in-the-moment and retrospectively. Concordance based on intraclass correlation coefficients was good to excellent (range 0.79-0.81) for utility indices computed, and excellent (range 0.93-0.96) for quality-adjusted life-years computed using in-the-moment compared with retrospective EQ-5D-5L. The longitudinal single imputation did not perform as well as the retrospective collection method.CONCLUSIONS:This study demonstrates that retrospective collection of EQ-5D-5L has high concordance with "in-the-moment" EQ-5D-5L and could be a valid and attractive alternative for data imputation when longitudinally collected EQ-5D-5L data are missing. Future studies examining this method for other disease areas and populations are required to provide more generalizable evidence.

INTRODUCTION:Mobile Stroke Units (MSUs) deliver acute stroke treatment on-scene in coordination with Emergency Medical Services (EMS). One criticism of the MSU approach is the limited range of a single MSU. The Houston MSU is evaluating MSU implementation, and we developed a rendezvous approach as an innovative solution to expand the range and number of patients treated.METHODS:In addition to direct 911 dispatch of our MSU to the scene within our 7-mile catchment area, we empowered more distant EMS units to activate the MSU. We also monitored EMS radio communications to identify possible patients. For these distant patients, the MSU met the EMS unit en route to the stroke center and treated the patient at that intermediate location. The distribution of the distance from MSU base station to site of stroke and time from 911 alert to tissue plasminogen activator (tPA) bolus were compared between patients treated on-scene and by rendezvous using Wilcoxon rank sum test.RESULTS:Over 4 years, 338 acute ischemic stroke patients were treated with tPA on our MSU. Of these, 169 (50%) were treated on-scene after MSU dispatch at a median of 6.4 miles (IQR 6.4 miles) from MSU base station. 169 (50%) were treated by 'rendezvous' pathway with assessment and treatment of stroke a median of 12.4 miles from base (IQR 5.5 miles) (p< 0.0001). Time (min) from MSU alert to tPA bolus did not differ: 36.0 ± 10.0 for on-scene vs 37.0 ± 10.0 with rendezvous (p=0.65). 13% of patients alerted via direct 911 dispatch were treated vs 44% of rendezvous patients.CONCLUSION:Adding a rendezvous approach to an MSU dispatch pathway doubles the range of operations and the number of patients treated by an MSU in an urban area, without incurring delay.