Mojdeh Nasiri

Clinical Predictors of Accurate Prehospital Stroke Recognition

Background and Purpose— Prehospital activation of in-hospital stroke response hastens treatment but depends on accurate emergency medical services (EMS) stroke recognition. We sought to measure EMS stroke recognition accuracy and identify clinical factors associated with correct stroke identification. Methods— Using EMS and hospital records, we assembled a cohort of EMS-transported suspect, confirmed, or missed ischemic stroke or transient ischemic attack cases. The sensitivity and positive predictive value (PPV) for EMS stroke recognition were calculated using the hospital discharge diagnosis as the gold standard. We used multivariable logistic regression analysis to determine the association between Cincinnati Prehospital Stroke Scale use and EMS stroke recognition. Results— During a 12-month period, 441 EMS-transported patients were enrolled; of which, 371 (84.1%) were EMS-suspected strokes and 70 (15.9%) were EMS-missed strokes. Overall, 264 cases (59.9%) were confirmed as either ischemic stroke (n=186) or transient ischemic attack (n=78). The sensitivity of EMS stroke recognition was 73.5% (95% confidence interval, 67.7–78.7), and PPV was 52.3% (95% confidence interval, 47.1–57.5). Sensitivity (84.7% versus 30.9%; P<0.0001) and PPV (56.2% versus 30.4%; P=0.0004) were higher among cases with Cincinnati Prehospital Stroke Scale documentation. In multivariate analysis, Cincinnati Prehospital Stroke Scale documentation was independently associated with EMS sensitivity (odds ratio, 12.0; 95% confidence interval, 5.7–25.5) and PPV (odds ratio, 2.5; 95% confidence interval, 1.3–4.7). Conclusions— EMS providers recognized 3 quarters of the patients with ischemic stroke and transient ischemic attack; however, half of EMS-suspected strokes were false positives. Documentation of a Cincinnati Prehospital Stroke Scale was associated with higher EMS stroke recognition sensitivity and PPV.

The Quality of Prehospital Ischemic Stroke Care: Compliance with Guidelines and Impact on In-hospital Stroke Response

BACKGROUND A number of emergency medical services (EMSs) performance measures for stroke have been proposed to promote early stroke recognition and rapid transportation to definitive care. This study examined performance measure compliance among EMS-transported stroke patients and the relationship between compliance and in-hospital stroke response. METHODS Eight quality indicators were derived from American Stroke Association guidelines. A prospective cohort of consecutive, EMS-transported patients discharged from 2 large Midwestern stroke centers with a diagnosis of acute ischemic stroke was identified. Data were abstracted from hospital and EMS records. Compliance with 8 prehospital quality indicators was calculated. Univariate and multivariable logistic regression analysis were performed to measure the association between prehospital compliance and a binary outcome of door-to-computed tomography (CT) time less than or equal to 25 minutes. RESULTS Over the 12 month study period, 186 EMS-transported ischemic stroke patients were identified. Compliance was highest for prehospital documentation of a glucose level (86.0%) and stroke screen (78.5%) and lowest for on-scene time less than or equal to 15 minutes (46.8%), hospital prenotification (56.5%), and transportation at highest priority (55.4%). After adjustment for age, time from symptom onset, and stroke severity, transportation at highest priority (odds ratio [OR], 13.45) and hospital prenotification (OR, 3.75) were both associated with significantly faster door-to-CT time. No prehospital quality metric was associated with tissue-plasminogen activator delivery. CONCLUSIONS EMS transportation at highest priority and hospital prenotification were associated with faster in-hospital stroke response and represent logical targets for EMS quality improvement efforts.

A Simple Risk Index and Thrombolytic Treatment Response in Acute Ischemic Stroke

IMPORTANCE The Stroke Prognostication using Age and the NIH Stroke Scale index, created by combining age in years plus a National Institutes of Health (NIH) Stroke Scale score of 100 or higher (and hereafter referred to as the SPAN-100 index), is a simple risk score for estimating clinical outcomes for patients with acute ischemic stroke (AIS). The association between this index and response to intravenous thrombolysis for AIS has not been properly evaluated. OBJECTIVE To assess the relationship between SPAN-100 index status and outcome following treatment with intravenous thrombolysis for AIS. DESIGN, SETTING, AND PARTICIPANTS Using the Virtual International Stroke Trials Archive (VISTA) database, an international repository of clinical trials data, we assessed the SPAN-100 index among 7093 patients with AIS who participated in 4 clinical trials from 2000 to 2006. The SPAN-100 index is considered positive if the sum of the age and the NIH Stroke Scale (a 15-item neurological examination scale with scores ranging from 0 to 42, with higher scores indicating more severe strokes) score is greater than or equal to 100. Multivariable logistic regression analyses were used to determine the independent association between SPAN-100 index status and 90-day outcomes. MAIN OUTCOMES AND MEASURES The primary outcome was a composite of severe disability or death measured 90 days after stroke, and the secondary outcomes were death alone and a composite of no disability/modest disability. RESULTS Of 7093 patients, 743 (10.5%) were SPAN-100 positive, and 2731 (38.5%) received intravenous thrombolysis. Compared with SPAN-100-negative patients, SPAN-100-positive patients were more likely to experience a catastrophic outcome (adjusted odds ratio [AOR], 9.03 [95% CI, 6.68-12.21]) or death alone (AOR, 5.03 [95% CI, 4.06-6.23]) and less likely to experience a favorable outcome (AOR, 0.08 [95% CI, 0.06-0.13]). However, there was an interaction between SPAN-100 index status and thrombolysis treatment (P < .001) revealing a reduction in the likelihood of severe disability/death with thrombolytic treatment for SPAN-100-positive (AOR, 0.46 [95% CI, 0.29-0.71]) but not SPAN-100-negative patients (AOR, 0.96 [95% CI, 0.85-1.07]). Similar interactions between SPAN-100 index status and thrombolysis treatment were observed for the 2 secondary outcomes. CONCLUSION AND RELEVANCE Compared with the SPAN-100-negative patients with AIS, the SPAN-100-positive patients with AIS seem to have poorer 3-month outcomes but may derive greater benefit when treated with intravenous thrombolysis. The SPAN-100-positive patients are often excluded from AIS clinical trials but should probably not be denied thrombolysis treatment on the basis of such a profile alone.

Role of cholesterol crystals in atherosclerosis is unmasked by altering tissue preparation methods.

Standard tissue preparation for light and scanning electron microscopy (SEM) uses ethanol as a dehydrating agent but that can also dissolve cholesterol crystals (CC) leaving behind empty tissue imprints or “clefts”. Cholesterol crystals may contribute to plaque rupture by their sharp tips that can tear membranes and trigger inflammation. Therefore, use of ethanol in tissue processing can mask the pathological role of CC. Here we evaluated the amount of cholesterol dissolved from CC with single and complete series of standard graded ethanol concentrations (25−100%) used in tissue preparation. Also, solubility of CC in ethanol at physiological levels was measured. Furthermore, we compared the effect of ethanol on CC in fresh human atherosclerotic plaques to matched segments dehydrated using vacuum (−1 atm, 12h). Tissue crystal density ranging from 0 to +3 was measured semi‐quantitatively by SEM. For CC exposed to 25% and 100% ethanol for 10 min each, 0.38% and 95% of CC were dissolved respectively. Also, increase in CC solubility was significant at physiological levels of ethanol (0.16%) compared to water (43.4 ± 18.0 ng/mL vs. 30.9 ± 13.9 ng/mL; p < 0.05). We speculate that this could represent a potential mechanism of cardio‐protective effects of alcohol consumption. In atherosclerotic plaques, CC density was lower in ethanol vs. saline treatment (+1.2 vs. +2.8; P < 0.01) with visible dissolving noted by SEM. Ethanol has been used for centuries in tissue preparation for microscopy. Here we demonstrate how current tissue preparation methods greatly alter histological findings with SEM by masking the potential mechanism of plaque rupture. Microsc. Res. Tech. 78:969–974, 2015.

Observed long-term mortality after 18,000 person-years among survivors in a large regional drowning registry

AIM Long-term outcomes beyond one year after non-fatal drowning are uncharacterized. We estimated long-term mortality and identified prognostic factors in a large, population-based cohort. METHODS Population-based prospective cohort study (1974-1996) of Western Washington Drowning Registry (WWDR) subjects surviving the index drowning through hospital discharge. Primary outcome was all-cause mortality through 2012. We tabulated Utstein-style exposure variables, estimated Kaplan-Meier curves, and identified prognostic factors with Cox proportional hazard modeling. We also compared 5-, 10-, and 15-year mortality estimates of the primary cohort to age-specific mortality estimates from United States Life Tables. RESULTS Of 2824 WWDR cases, 776 subjects (5[IQR 2-17] years, 68% male) were included. Only 63 (8%) non-fatal drowning subjects died during 18,331 person-years of follow-up. Long-term mortality differed by Utstein variables (age, precipitating alcohol use, submersion interval, GCS, CPR, intubation, defibrillation, initial vital signs, neurologic status at hospital discharge) and inpatient markers of illness severity (mechanical ventilation, vasopressor use, seizure, pneumothorax). Survival differed by age (HR 1.04;95%CI 1.03-1.05), drowning-related cardiac arrest (HR 3.47;95%CI 1.97-6.13), and neurologic impairment at hospital discharge (HR 5.10;95% CI 2.70-9.62). In adjusted analysis, age (HR 1.05;95%CI 1.03-1.06) and severe neurologic impairment at discharge (HR 2.31;95%CI 1.01-5.28) were associated with long-term mortality. Subjects aged 5-15 years had higher mortality risks than those calculated from Life Tables. CONCLUSION Most drownings were fatal, but survivors of non-fatal drowning had low risk of subsequent long-term mortality similar to the general population that was independently associated with age and neurologic status at hospital discharge.

Role of Registries and Community Models in Developed Countries

Historically, stroke registries and other community-based databanks have played a prominent role in providing comprehensive descriptions of the epidemiology of acute stroke, including data on demographics, risk factors, clinical features, and short-term outcomes. Recently stroke registries have expanded beyond this descriptive epidemiological perspective to collect data on the quality of stroke care. The information collected in these quality-based registries allows for the tracking of best practices and the provision of evidence-based care through the monitoring of quality metrics. This chapter provides a brief summary of the broad objectives of these quality-based stroke registries and reviews the principal characteristics of several leading international registries in the developed world, including those from Sweden, the UK, Germany, the USA, Canada, European Union, and Australia. The registries cover a wide variety of different systems of care and have a wide geographical range (from regional or state-level to true national level registries).