Abstract TP3: Seizures As Stroke Mimics In Ultra-early Treatment On A Mobile Stroke Unit: A Pilot Study

Background: Stroke mimics are often difficult to distinguish from true ischemic and hemorrhagic cerebrovascular accidents, and present a challenge for appropriate delivery of rapid stroke treatment. This is particularly true in ultra-early stroke care with Mobile Stroke Units (MSU), which administer tPA in the field, within minutes of symptom onset. We sought to evaluate and characterize stroke mimics during prehospital care with an MSU at a Comprehensive Stroke Center.

Methods: The study compared patient and stroke characteristics, neurologic evaluation, and treatment between confirmed strokes and stroke mimics treated during a one-year pilot period on the MSU at a large urban medical center. Variables included patient demographics, NIHSS score, tPA administration, final diagnosis, and discharge disposition.

Results: Between Jan. 15, 2016 and Jan. 9, 2017, 47 patients received prehospital management on the MSU, and 44 were admitted to UC hospital and had an available final diagnosis. Of these, 12 (27%) were stroke mimics. Mimics were younger [median age 60 (IQR 54-71) years, mimics vs. 68 (IQR 60-77) years, strokes], and were more often female (58%, mimics vs. 47%, strokes). Initial NIHSS score was lower for confirmed strokes [median 3 (IQR 2-10) strokes, vs. 6 (IQR 4-12) mimics], but severe strokes with a NIHSS score >17, were more common in strokes (16%, strokes vs. 0%, mimics). Of mimics, 6 (50%) were seizures, 2 (17%) migraine, 2 (17%) conversion, 1 (8%) encephalopathy, and 1 (8%) delirium. Thirteen (30%) of all patients were treated with IV tPA on the MSU, of whom 4 (31%) were mimics. Of mimics given tPA, 2 were seizures, 1 migraine and 1 conversion. Mimics were more likely to be discharged to home (64%, mimics vs. 46%, strokes) while strokes more likely received rehabilitation (23%, strokes vs. 9%, mimics).

Conclusions: One third of patients treated on the MSU were stroke mimics, and among these the most common diagnosis was seizures. These results suggest vigilance is warranted for seizure, as well as further study of rapid EEG technologies to guide appropriate treatment for presentations that appear to be stroke, including antiepileptic drugs, in ultra-early MSU care of suspected CVA.

Abstract P132: Successful Conduct of an Acute Stroke Clinical Trial During COVID

Introduction: 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 study conduct at sites that continued to enroll patients during the pandemic.

Methods: 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 tech, and medics on board using appropriate PPE. During COVID, consent, 90 d mRS and EQ5D could be obtained by phone instead of in person, otherwise management was the same. We compared patient demographics, study metrics, and infection of study personnel during intra- vs pre-COVID eras.

Results: Four of 6 BEST-MSU sites continued to enroll during COVID. There was no difference in intra- (n= 41) vs pre- (n= 763) COVID enrolled tPA eligible patients’ age, sex, race (45% vs 41% Black), ethnicity (23% vs 19% Hispanic), or NIHSS (12 vs 12). MSU alert frequency did not change, but percent of screened patients enrolled and treated with tPA declined to 12% from 23% (p<.001); enrollment correlated with local stay at home and reopening (fig). There was no difference in alert to MSU arrival or arrival to tPA times, but on-scene time was 2 min longer (p=.04). There was no difference in ED door to CT, tPA, or EVT times, hospital LOS, discharge disposition, or 90d mRS or EQ5D accuracy. One MSU nurse tested positive but did not require medical care.

Conclusion: Clinical research in the pre-hospital setting can be carried out accurately and safely during a pandemic. Study enrollment and tPA treatment rates declined, but otherwise there was no difference in patient demographics, deterioration of study processes, or serious infection of study staff.

Successful conduct of an acute stroke clinical trial during COVID

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

Emergency Department Door-to-Puncture Time Since 2014

Background and Purpose- The impact of a mobile stroke unit (MSU) on access to intraarterial thrombectomy (IAT) is a prespecified BEST-MSU substudy (Benefits of Stroke Treatment Delivered Using a Mobile Stroke Unit Compared to Standard Management by Emergency Medical Services). On the MSU, IAT decision-making steps, such as computed tomography, neurological exam, and tPA (tissue-type plasminogen activator) treatment are completed before emergency department arrival. We hypothesized that such pre-ED assessment of potential IAT patients on an MSU improves the time from ED arrival to skin puncture time (door-to-puncture-time, DTPT). Methods- BEST-MSU is a prospective comparative effectiveness study of MSU versus standard management by emergency medical services (EMS). We compared ED DTPT among the following groups of MSU and EMS patients: all IAT patients, IAT patients post-tPA, and IAT patients post-tPA meeting thrombolytic adjudication criteria over the first 4 years of the study. Results- From August 2014 to July 2018, a total of 161 patients underwent IAT. Ninety-four patients presented to the ED via the MSU and 67 by EMS. One hundred forty patients received tPA before IAT, 85 in the MSU arm, and 55 in the EMS arm. One hundred twenty-six patients received tPA within thrombolytic adjudication criteria: 76 MSU and 50 EMS. DTPT in minutes was shorter for MSU patients (all IAT MSU versus EMS 89 versus 99, P=0.01; IAT post-tPA MSU versus EMS 93 versus 100, P=0.03; and IAT post-tPA within adjudicated criteria MSU versus EMS 93 versus 99.5, P=0.03). From 2014 to 2018, DTPT decreased at a faster rate for EMS compared with MSU-managed patients, improving by about an hour. Conclusions- Pre-ED IAT evaluation on an MSU results in faster DTPT compared with arrival by EMS. Since 2014, dramatic improvement in ED IAT metrics has attenuated this difference. However, DTPT in all groups indicates substantial room for improvement.

Abstract TMP11: Emergency Room Door-to-Puncture Time Since 2015: Observations From the BEST-MSU Study

Introduction: The impact of a Mobile stroke unit (MSU) on access to Endovascular Thrombectomy (ET) is a pre-specified BEST-MSU sub-study. On the MSU, ET decision-making steps such as CT, neurologic exam, and tPA treatment are completed prior to Emergency Room (ER) arrival. We hypothesized that such pre-ER assessment of potential ET patients on a MSU improves metrics.

Methods: BEST-MSU is a prospective comparative effectiveness study of MSU vs Standard Management by Emergency Medical Services (SM). We compared ER door-to-puncture-time (mins, DTPT) among the following groups of MSU and SM patients: all ET patients (ETP), ET patients post-tPA (ETT), and ET patients post-tPA meeting thrombolytic adjudication criteria (ETTA) over the first four years of the study.

Results: There were 161 ETP (67 SM, 94 MSU), 140 ETT (55 SM, 85 MSU), and 126 ETTA (50 SM, 76 MSU) patients. DTPT was shorter for MSU patients (ETP 89 vs 99, p=0.01; ETT 93 vs 100, p=0.03; ETTA 93 vs 99.5, p=0.03). From 2015 to 2018, DTPT decreased at a faster rate for SM compared with MSU-managed patients, improving by about an hour (Figure).

Conclusion: Pre-ER ET evaluation on a MSU results in faster DTPT. Since 2015, dramatic improvement in ER ET metrics has attenuated this difference. However, DTPT of 90-100 mins in all groups indicates substantial room for improvement.

Mobile Stroke Unit Reduces Time to Image Acquisition and Reporting

Timely administration of thrombolytic therapy is critical to maximizing the likelihood of favorable outcomes in patients with acute ischemic stroke. Although emergency medical service activation overall improves the timeliness of acute stroke treatment, the time from emergency medical service dispatch to hospital arrival unavoidably decreases the timeliness of thrombolytic administration. Our mobile stroke unit, a new-generation ambulance with on-board CT scanning capability, reduces key imaging time metrics and facilitates in-the-field delivery of IV thrombolytic therapy.

Abstract WP234: Improved Response, Neurologic Evaluation, and Treatment Timing With a Mobile Stroke Unit in a Large Urban Population

Background: The University of Colorado Mobile Stroke Unit (UC MSU) began clinical operation in January 2016, providing ambulance-mounted CT scanning and tele-stroke neurologic assessment in the Denver, CO, metropolitan area. As one of the first U.S. tertiary stroke centers to utilize a mobile stroke protocol we sought to evaluate characteristics of response, neurologic evaluation, and treatment of the MSU.

Methods: The study assessed patient, stroke, ambulance response, neurologic evaluation, and treatment characteristics of the UC MSU for its initial year in service. Variables included time from stroke alert (MSU dispatch) to brain CT in the field, treatment decision, tPA administration, and transport to a hospital stroke center. Time intervals from last seen normal were calculated for all patients. Study variables were compared for patients treated with thrombolysis on the MSU, and those who were not; and with reported times for other MSUs, and hospitals.

Results: Between Jan. 15, 2016 and Jan. 9, 2017, 47 individuals received prehospital management with the UC MSU. Median age was 67 years (IQR 58-77), and 51% were female. Median initial NIH Stroke Scale score was 5 (IQR 2-11), and 36% were moderate to severe (NIHSS ≥8). Thirteen (28%) of patients were treated with IV tPA on the MSU. Median times from stroke alert to MSU arrival on the scene and first CT were 7 minutes (IQR 5-8), and 20 minutes (IQR 18-24), respectively. Median time to tPA administration was 39 minutes (IQR 35-45) from stroke alert, and 52 minutes (IQR 48-77) from the last time the patient was seen normal. Times from stroke alert and last seen normal to arrival at a stroke hospital were a median of 51 minutes (IQR 45-54) and 71 minutes (IQR 56-118), respectively.

Conclusions: In this study of the initial year of an urban MSU’s operation, time intervals from stroke alert to initial brain CT imaging, neurologic evaluation and administration of thrombolysis were found to be substantially reduced compared to conventional, hospital-based stroke protocols, and some earlier MSUs. Intervals from last seen normal to these procedure time points were similarly reduced. These results suggest prehospital management with an MSU has potential to aid the goal of earlier thrombolysis after ischemic stroke symptom onset.

Abstract TMP72: Technological Innovation in a Mobile Stroke Treatment Unit

Background: University of Colorado Hospital, under the UCHealth system, developed a Mobile Stroke Unit (UCHealth MSU) which began clinical operation in January 2016 and added a second operational location in August 2016. As one of the first centers to institute ambulance-mounted brain imaging and neurologic evaluation and treatment in the field for acute stroke in the U.S., it was necessary to design unique, dynamic IT systems for operationalizing the MSU. These include high speed cellular, HIPAA-compliant cloud based environments and remote access to patient electronic medical records (EMR) and a reliable means for rapid image transfer. Here we describe novel technologies engineered and incorporated into the UCHealth MSU.

Methods: Technological data-handling aspects of the UCHealth MSU were reviewed. Functions evaluated included wireless connectivity while in transit, EMR capability in the field, computed tomography (CT) scanning and image transfer, and communications for tele-stroke neurologic assessment.

Results: The UCHealth MSU began clinical operation in January 2016, Wireless communications were designed with redundancy to avoid dropped signals during data transfer. Two IP destinations were assigned for videoconferencing and EMR data transfer, with split-tunnel architecture to direct traffic to each. Placement of the MSU antenna inside the unit reduced interference from home and business Wi-Fi routers encountered. Brain imaging acquired in the ambulance CT scanner is transferred initially to an onboard laptop, then via Citrix Receiver to a hospital-based server and can be visualized by the stroke neurologist, neuroradiologist and all other care providers. Picture Archiving Communications System (PACS) and Radiology Information System (RIS) are two of the XenApps used by CT technologists.

Conclusions: Technological hurdles associated with remote imaging, assessment, and treatment, are critical to overcome if time-saving benefits of mobile stroke protocols are to be recognized. Innovative and unique techniques developed to accommodate wireless communication and image transfer from the field in the UCHealth MSU may aid start-up of similar units elsewhere and serve as a framework to further improve this technology.

Recombinant human platelet-activating factor acetylhydrolase reduces the frequency of diabetes in the diabetes-prone BB rat

Platelet-activating factor (PAF) has been implicated in the development of type 1 diabetes. Our previous studies have suggested that PAF inhibitors reduce insulitis and the frequency of diabetes in BB rats. In this study, serum PAF levels were reduced to address the hypothesis that PAF is important for the development of insulitis. From the age of 35 days on, DP-BB rats were treated with human recombinant PAF acetylhydrolase (rPAF-AH), which efficiently inactivates PAF. Our data indicate that intraperitoneal injections of rPAF-AH reduce the incidence of diabetes in the DP-BB rat. Daily intraperitoneal injections of 6.0 mg/kg body wt rPAF-AH reduced the frequency of diabetes in saline-injected rats from 90% (27/30) to 57% (17/30) (P = 0.004). As found by morphometric analysis on pancreatic islets, DP-BB rats protected from diabetes had less severe degrees of insulitis in a dose-dependent manner. DP-BB rats protected by rPAF-AH also had a higher percentage of insulin-positive cells in pancreas sections compared with those from diabetic animals. We therefore speculated that the beta-cells were protected from insulitis by rPAF-AH.

Anti-inflammatory properties of a platelet-activating factor acetylhydrolase

Platelet-activating factor (PAF) is a potent pro-inflammatory phospholipid that activates cells involved in inflammation. The biological activity of PAF depends on its structural features, namely an ether linkage at the sn-1 position and an acetate group at the sn-2 position. The actions of PAF are abolished by hydrolysis of the acetyl residue, a reaction catalysed by PAF acetylhydrolase. There are at least two forms of this enzyme--one intracellular and another that circulates in plasma and is likely to regulate inflammation. Here we report the molecular cloning and characterization of the human plasma PAF acetylhydrolase. The unique sequence contains a Gly-Xaa-Ser-Xaa-Gly motif commonly found in lipases. Recombinant PAF acetylhydrolase has the substrate specificity and lipoprotein association of the native enzyme, and blocks inflammation in vivo: it markedly decreases vascular leakage in pleurisy and paw oedema, suggesting that PAF acetylhydrolase might be a useful therapy for severe acute inflammation.