Abstract WP251: Long Term Outcome Prediction After Ischemic Stroke Using Gene Expression

Objective: Prediction of the long-term outcome in Ischemic Stroke (IS) patients can have a significant impact on design of clinical trials and on patients’ care. We studied gene expression (GE) as a novel biomarker to provide an accurate prediction of 90-day outcome in IS patients.

Methods: RNA from 72 samples from 2 peripheral blood draws (at ≤3 and 24 hrs post IS onset) was analyzed on Affymetrix U133 Plus 2.0 microarrays. These represented samples from 36 CLEAR trial IS patients that had blood drawn within 3 hrs of stroke onset and were then treated with tPA with or without eptifibatide. The samples were split into derivation (n=25) and validation (n=11) sets. We identified the differential GE in blood at 24 hrs and the difference in GE between 24 hrs and 3 hrs post IS that was associated with 90-day post stroke outcome using the model: GE = μ + NIHSS_24hr+mRS_90day+ ε. Good outcome was defined as mRS 0-2; Poor - as mRS 3-5. Logistic regression was used to derive a biomarker classifier.

Results: Using 24 hrs GE, we identified 14 probesets (12 genes) with the highest discriminative power for predicting outcome. The model achieved recall (the probability of correctly identifying the patients with Good outcome) of 0.88 and specificity (the probability of correctly identifying the patients with Poor outcome) of 0.67 in the validation set (The AUC-ROC = 0.88). The biomarker genes were enriched in immune responses such as IL and cytokine signaling. Among the predictors were genes important for stroke and repair after stroke (e.g., MACC1 , GDF11 ). MACC1 has been considered as a potential treatment target for IS with a protective role in hypoxia-induced human brain microvascular endothelial cells. GDF11 plays a role in brain repair after IS. We also determined how the change of GE from 3 hrs to 24 hrs would predict the 90-day outcome. A panel of ten genes was able to predict outcome in the validation set (recall= 1, specificity = 0.67, AUC-ROC=0.88). These included AVPR1A , which mediates platelet aggregation and release of coagulation factors and exacerbates brain inflammatory response to injury.

Conclusion: This pilot study suggests gene expression can be used to predict stroke outcome. Some of the genes may serve as potential therapeutic targets.

Abstract P787: Sexually Dimorphic Gene Expression Molecular Correlates of Improvement in Human Ischemic Stroke

Objective: Ischemic stroke (IS) is sexually dimorphic for risk factors, age, heritability, causes, treatment, and outcome. We identified transcriptional correlates with 90-day outcome that differed between male and female IS subjects.

Methods: RNA from 72 samples from 2 peripheral blood draws (at ≤3 and 24h post IS onset) was analyzed on Affymetrix U133 Plus 2 microarrays. These represented samples from 36 CLEAR trial IS patients treated with tPA with or without eptifibatide after the first blood sample within 3 hours of stroke onset. Changes in gene expression levels (deltaGE) between 3h and 24h were calculated and the association with percent NIH Stroke Scale (NIHSS) improvement from 3h to 90 days (% Improvement) examined. We used mixed-effects linear regression, including Treatment, Age, Sex, Vascular Risk Factors, 3h NIHSS, % Improvement, and a Sex * % Improvement interaction. Sex differences in association of gene expression with % Improvement were determined by examining the Sex * % Improvement interaction term, p<0.005 was considered statistically significant.

Results: 577 genes correlated differently with % Improvement in IS males and females. These included matrix metalloproteinases (MMPs), which play a major role in BBB dysfunction and outcomes post IS. MMP11 , MMP14 and MM17 correlated with % Improvement in opposite direction in males and females. Inflammatory genes like IL-27 , implicated in infarct volume and stroke outcome, and ABC transporters ( ABCC9 ) also had opposite correlation with % Improvement in males and females. Calmodulin 1 ( CAML1 ) was also sexually dimorphic, and a SNP in CALM1 has been implicated in IS risk and blood coagulation in female IS patients. EIF2 signaling, a major protein synthesis pathway was activated in males (adj. p = 1e-8), while suppressed in females (adj. p value = 1e-9). Protein synthesis and associated unfolded protein response cascade have previously been implicated in stroke outcome.

Conclusions: The identified sexually dimorphic gene expression associated with 90-day improvement might relate to sex differences in blood immune and clotting pathways. The findings expand our understanding of the genomic underpinnings associated with stroke outcome and may serve as potential sex-specific treatment targets.

Abstract 182: The CLEAR Trials: A Pooled Analysis of rt-PA plus Eptifibatide for Treatment of Acute Ischemic Stroke

Background: The Combined approach to Lysis utilizing Eptifibatide And Rt-PA in Acute Ischemic Stroke (CLEAR), CLEAR-Enhanced Regimen (CLEAR-ER) and CLEAR-Full Dose Regimen (CLEAR-FDR) trials were phase 2 trials that examined escalating doses of recombinant tissue-type plasminogen activator (rt-PA) combined with eptifibatide in acute ischemic stroke (AIS). We pooled data from these trials and compared outcomes of the escalating doses of rt-PA plus eptifibatide to rt-PA alone.

Methods: The combination arms of the CLEAR trial were: tier 1 - 0.3mg/kg of rt-PA and tier 2 - 0.45mg/kg both combined with eptifibatide 75mcg/kg bolus and 0.75mcg/kg/min for 2 hours. CLEAR-ER combined 0.6mg/kg of rt-PA and 135mcg/kg bolus of eptifibatide and 0.75mcg/kg/min for 2 hours. CLEAR-FDR combined full dose rt-PA (0.9mg/kg) and 135mcg/kg bolus of eptifibatide and 0.75mcg/kg/min for 2 hours. The control groups for both CLEAR and CLEAR-ER received full dose rt-PA only. The primary outcome was 90-day modified Rankin score (mRS) of 0-1 or return to baseline. Logistic regression was used for the analysis.

Results: A total of 247 subjects were available for analysis; 69 from the combination arm of CLEAR (29 in tier 1 and 40 in tier 2), 101 from the combination arm of CLEAR-ER, and 27 from CLEAR-FDR. Fifty rt-PA only subjects (25 from CLEAR and 25 from CLEAR-ER) served as controls. Characteristics and outcomes adjusted for age, sex, race, NIHSS and time to IV rt-PA are shown in the Table.

Conclusion: In the CLEAR trials, eptifibatide added to rt-PA showed a progressive increase in odds of a favorable outcome, without safety concerns. A phase 3 trial of full dose rt-PA plus the eptifibatide dose used in CLEAR-ER and CLEAR-FDR is warranted to establish the efficacy of the combination for improving AIS outcome.

Abstract TMP5: Secondary Analysis of Eptifibatide Plus Full Dose rt-PA in Ischemic Stroke

Background: The Phase 2 Combined approach to Lysis utilizing Eptifibatide And Rt-PA in Acute Ischemic Stroke - Full Dose Regimen (CLEAR-FDR) trial was a single arm trial that demonstrated the safety of full dose (0.9mg/kg) rt-PA plus eptifibatide in AIS patients treated with rt-PA within three hours of symptom onset. Interventional Management of Stroke (IMS) III randomized AIS patients to rt-PA plus endovascular therapy versus standard r-tPA. Albumin in Acute Stroke (ALIAS) Part 2 randomized patients to albumin±rt-PA versus saline±rt-PA. We compared outcomes in CLEAR-FDR patients to propensity score-matched rt-PA only subjects in ALIAS Part 2 and IMS.

Methods: All datasets were restricted to subjects with baseline modified Rankin score (mRS) of 0 or 1. Controls were selected using propensity score matching of CLEAR-FDR subjects and rt-PA only subjects from both IMS III and ALIAS. Age, gender, race, baseline mRS, baseline NIHSS score, and time from stroke onset to rt-PA were included in the logistic model used to generate a propensity score for each subject. The greedy matching algorithm was then used to match 1:3. The primary outcome was 90-day severity-adjusted mRS dichotomization based on baseline NIHSS. Secondary outcomes were 90-day mRS dichotomized as excellent (mRS 0-1); favorable (mRS 0-2); and, nonparametric analysis of the ordinal mRS.

Results: Eighteen CLEAR-FDR subjects were matched with 52 controls. Median age in CLEAR-FDR and control subjects was 67 and 68 years respectively. Median NIHSS in both CLEAR-FDR and control subjects was 11. At 90 days, CLEAR-FDR subjects had a nonsignificant greater proportion of patients with a favorable primary outcome (61% versus 38%; unadjusted RR 1.59; 95%CI 0.96-2.63; P=0.10). Secondary outcomes also favored CLEAR-FDR subjects: excellent outcomes - 67% versus 38% (RR 1.73; 95%CI 1.08-2.79; P=0.04); favorable outcomes - 67% versus 58% (RR 1.16; 95%CI 0.77-1.73; P=0.50); and ordinal Cochran-Mantel-Haenszel, P=0.13.

Conclusion: The outcomes for combination of full dose rt-PA plus eptifibatide showed a consistent direction of effect in favor of the combination over rt-PA alone. A trial to establish the efficacy of rt-PA plus eptifibatide for improving AIS outcomes is warranted and in the planning stages.

ED disposition of the Glasgow Coma Scale 13 to 15 traumatic brain injury patient: analysis of the Transforming Research and Clinical Knowledge in TBI study

OBJECTIVE

Mild traumatic brain injury (mTBI) patients are frequently admitted to high levels of care despite limited evidence suggesting benefit. Such decisions may contribute to the significant cost of caring for mTBI patients. Understanding the factors that drive disposition decision making and how disposition is associated with outcomes is necessary for developing an evidence-base supporting disposition decisions. We evaluated factors associated with emergency department triage of mTBI patients to 1 of 3 levels of care: home, inpatient floor, or intensive care unit (ICU).

METHODS

This multicenter, prospective, cohort study included patients with isolated head trauma, a cranial computed tomography as part of routine care, and a Glasgow Coma Scale (GCS) score of 13 to 15. Data analysis was performed using multinomial logistic regression.

RESULTS

Of the 304 patients included, 167 (55%) were discharged home, 76 (25%) were admitted to the inpatient floor, and 61 (20%) were admitted to the ICU. In the multivariable model, admission to the ICU, compared with floor admission, varied by study site, odds ratio (OR) 0.18 (95% confidence interval [CI], 0.06-0.57); antiplatelet/anticoagulation therapy, OR 7.46 (95% CI, 1.79-31.13); skull fracture, OR 7.60 (95% CI, 2.44-23.73); and lower GCS, OR 2.36 (95% CI, 1.05-5.30). No difference in outcome was observed between the 3 levels of care.

CONCLUSION

Clinical characteristics and local practice patterns contribute to mTBI disposition decisions. Level of care was not associated with outcomes. Intracranial hemorrhage, GCS 13 to 14, skull fracture, and current antiplatelet/anticoagulant therapy influenced disposition decisions.

Abstract T MP72: Temporal Trends in Public Awareness of Stroke Warning Signs and Risk Factors

Introduction: Delay in seeking medical attention after stroke symptom onset is the most common reason for low rates of thrombolytic use for ischemic stroke. This may be related to poor recognition of stroke symptoms or lack of awareness of time-sensitive stroke treatments. We describe public knowledge of stroke warning signs (WS) and risk factors (RF), and changes over time.

Methods: Survey respondents were drawn from our biracial population of 1.3 million using random-digit dialing in 1995, 2000, 2005, and 2011 to reflect the age, race, and gender distribution of stroke patients, based on an ongoing stroke incidence study in the same region. Participants were asked open-ended questions regarding stroke WS and RF. Comparisons over time were made using Armitage test for trend, and multiple logistic regression was used to adjust for covariates.

Results: Over the study period, 8245 surveys were completed. As shown in the figure, knowledge of 3 correct WS improved steadily over time from 5.4% to 22.6% (p<0.001), and knowledge of 3 correct RF has also improved over time from 2.6% to 5.8% (p<0.001), but has remained relatively low. These improvements in knowledge persisted after controlling for differences in age and education between study periods.

Conclusions: Public awareness of stroke WS and RF steadily improved from 1995 to 2011. These findings highlight the success of increasing community awareness of stroke WS and RF. Further research is needed to determine if increased stroke awareness leads to changes in care-seeking health behavior and improved stroke prevention.

Figure 1: Comparison of Knowledge of Stroke Warning Signs and Risk Factors between Survey Years, Greater Cincinnati/Northern Kentucky Population

Abstract T MP17: Reduced Lesion Volume in the rtPA-Epifibatide Group in CLEAR-ER Study

Trial Introduction/Purpose: The C ombined Approach to L ysis Utilizing E ptifibatide and r t-PA in Acute Ischemic Stroke- E nhanced R egimen (CLEAR-ER) trial demonstrated the safety of a reduced-dose rtPA regimen (0.6mg/kg rt-PA over 40 minutes) plus eptifibatide (135mcg/kg bolus followed by a two-hour infusion at 0.75mcg/kg/min), and gave evidence of potential clinical efficacy. The purpose of our study is to examine if differences in lesion volume between the 2 groups further support better clinical outcomes as an additional outcome measure in the CLEAR-ER study.

Methods: Lesion volumes on 24-hour CT (n=117) and MR images (n=2) from subjects with anterior circulation ischemia in the CLEAR-ER Study were calculated using HLW/2 method. Volumes were compared using multiple regression to adjust for baseline mRS, NIHSS, age, and time to IV rtPA administration. Volumes were log transformed for analysis due to the distribution. Geometric means and 95% confidence intervals are shown.

Results: Mean lesion volumes (adjusted and unadjusted) and p value are presented in Table 1.

Discussion: 51.0 % smaller mean adjusted lesion volumes between the combined-treatment and rt-PA-only groups in the CLEAR-ER study supports the clinical benefit observed with combined therapy previously reported. Whereas the findings reported remain hypothesis generating, more conclusive prospective research is needed for confirming the findings of this preliminary analysis.

Abstract T P199: Severity-adjusted Re-analysis of the Phase 2 Clear-er Stroke Trial

Background: The proportion of good outcome (modified Rankin score/mRS ≤1 or return to baseline mRS) in the intervention arm of the randomized Combined Approach to Lysis Utilizing Eptifibatide and rt-PA in Acute Ischemic Stroke-Enhanced Regimen (CLEAR-ER) trial provided evidence for pursuing a phase 3 trial of IV rt-PA plus eptifibatide versus rt-PA alone in acute ischemic stroke (AIS). However, CLEAR-ER had unanticipated imbalances between groups. Using a sliding dichotomy, we compared the rates of good outcome in CLEAR-ER combinations arm to that in the rt-PA arm of the NINDS stroke trials.

Methods: CLEAR-ER was a multi-center, double-blind, randomized study. rt-PA eligible AIS patients were randomized to 0.6mg/kg rt-PA plus eptifibatide (135mcg/kg bolus and 0.75mcg/kg/min two-hour infusion) versus standard rt-PA (0.9mg/kg). For this analysis, as previously suggested for acute stroke trials, good outcome was defined as: 90-day mRS 0 if pretreatment NIHSS scores were 1 to 7; 90-day mRS 0-1 if pretreatment NIHSS scores were 8 to 14; 90-day mRS 0-2 if pretreatment NIHSS scores were >14. As in CLEAR-ER, patients who returned to baseline mRS were considered good outcome. To match CLEAR-ER eligibility criteria, NINDS trial rt-PA arm patients aged 18-85 years with a baseline NIHSS score >5 were used for comparison. Logistic regression was used for analyses.

Results: In the combination therapy arm CLEAR-ER patients, 45% (45 out of 101) had good outcomes compared with 39% (105 out of 266) of the rt-PA arm patients from the NINDS trial (unadjusted odds ratio 1.23, 95%CI 0.77-1.96, p=0.38). After adjusting for baseline NIHSS score, age, gender, pre-existing disability and time to IV rt-PA, the odds ratio was 1.14 (0.69-1.88, p=0.61). When the groups were collapsed by baseline NIH stroke scale <15 versus ≥15, the unadjusted odds ratio was 1.39 (0.88-2.21, p=0.16); after adjustment, the odds ratio was 1.27 (0.75-2.14, p=0.37).

Conclusion: In this exploratory analysis, severity-adjustment confirmed a direction of effect that justifies a well-designed, adequately powered phase 3 trial to determine the efficacy of rt-PA plus eptifibatide for treatment of AIS.

Enrollment in research under exception from informed consent: the Patients' Experiences in Emergency Research (PEER) study

BACKGROUND

Resuscitation research requires an exception from informed consent (EFIC). Despite concerns that patients may find EFIC unacceptable, the views and experiences of patients enrolled in an EFIC study are largely unknown.

METHODS

The Patients' Experience in Emergency Research (PEER) study was nested within the Rapid Anticonvulsant Medication Prior to Arrival Trial (RAMPART) for pre-hospital treatment of status epilepticus. PEER included 61 EFIC enrollees or their surrogates from 5 sites. Interviews used a structured, interactive guide focusing on acceptance of EFIC enrollment in RAMPART and existing regulatory protections. Simple statistics were generated, and textual data were analyzed for common themes.

RESULTS

24 enrolled patients and 37 surrogates were successfully interviewed. 49/60 (82%) were glad they or their family member were included in RAMPART; 54/57 (95%) felt research on emergency seizure treatment is important. 43/59 (73%) found their inclusion under EFIC acceptable; 10 (17%) found it unacceptable, and 6 (10%) were neutral. There were no statistically significant interactions between enrollment attitudes and demographic characteristics, though there were trends toward lower acceptance among interviewees who were non-white, less educated, or had prior research experience. The most common concerns related to lack of consent prior to RAMPART enrollment. Positive responses related to perceived medical benefits, recognition of the impracticality of consent, and wanting doctors to do what needs to be done in emergencies. Many participants had difficulty understanding the trial and EFIC.

CONCLUSIONS

Most subjects had positive views of enrollment, and acceptance generally correlated with results of community consultation studies.

Abstract TP215: Leukocyte RNA Expression Is Altered Prior To Hemorrhagic Transformation In Ischemic Stroke

Background: Hemorrhagic transformation (HT) is a major complication of ischemic stroke that worsens outcomes and increases mortality. In ischemic stroke circulating leukocytes may contribute to blood brain barrier disruption, which is an important component of HT. In this study we sought to determine whether leukocytes express RNA differently in ischemic strokes that latter develop HT, and thus identify molecules and pathways important for the pathogenesis of HT in human stroke.

Methods: Blood samples were collected within 3 hours of ischemic stroke onset prior to thrombolytic therapy. No subjects had HT prior to sample collection. RNA from circulating leukocytes was isolated and processed on Affymetrix U133 Plus2.0 microarrays. Ischemic strokes that developed HT (n=11) were compared to matched ischemic strokes without HT (n=33) and controls (n=14). Genes with a Benjamini Hochberg corrected p-value <0.05 and fold change >

Abstract WP59: IV rt-PA Treatment Response of The STROKE100 Club: Sy stematic Te chnique for Ri sk and Ou tcome Measurements Using Key El ements Totaling 100

Background: Advanced age and high NIHSS are independent predictors of poor AIS outcome. While not excluded from IV rtPA, response is debated in these groups. Patients in the “STROKE 100 Club” (AIS with any combination of age + NIHSS ≥100) have worse outcome without increased sICH. Treatment response has not been evaluated. We evaluated 90 day outcome in the “STROKE 100 Club” with or without rt-PA.

Methods: The UCSD SPOTRIAS prospectively collected database was analyzed for “STROKE 100 Club” patients, and all AIS patients either ≥ 80 years old or with NIHSS ≥ 20. Multivariable regression models were used with treatment group as independent variable. Models were adjusted for pre-specified covariates: pre-stroke mRS, diabetes, and atrial fibrillation.

Results: We identified 82 STROKE 100 Club patients; 24 were untreated, 58 received IV rtPA. IV tPA treated patients were less likely to have prior history of stroke (22.8% vs 54.2%, p=0.0089). No treatment difference was seen in discharge destination, death, or poor outcome (mRS 3-6) at 90 days. In patients either ≥ 80 years old or with NIHSS ≥ 20, no difference was seen in 90 day outcomes between IV tPA and untreated patients, controlling for baseline variables. In patients ≥ 80 years old, poor outcome was associated with higher NIHSS (OR 1.16, 95% CI 1.09-1.24, p<0.0001) and mRS 3-6 (OR 5.28, 95% CI 1.64-16.96, p=0.0052). Higher NIHSS was also associated with death (OR 1.11, 95% CI 1.06-1.16, p<0.0001) and discharge to facility (OR 1.17 95% CI 1.10-1.24, p<0.0001).

Conclusions: Prognosis remains a concern in patients with various permutations of stroke severity and advanced age. Patients ≥80 with higher NIHSS had worse outcome, confirming our prior findings in the STROKE 100 club. Interestingly, IV tPA in the STROKE 100 Club did not lead to worse outcome. IV rtPA remains a safe treatment option for patients in the STROKE 100 club. Ongoing analyses may identify subgroups at greater or lesser benefit of thrombolysis. Planned analyses include assessment in a larger NIH-SPOTRIAS cohort.

Effects of gender on gene expression in the blood of ischemic stroke patients

This study examined the effects of gender on RNA expression after ischemic stroke (IS). RNA obtained from blood of IS patients (n=51; 153 samples at < or =3, 5, and 24 hours) and from matched controls (n=52) were processed on Affymetrix microarrays. Analyses of covariance for stroke versus control samples were performed separately for both genders and the regulated genes for females compared with males. In all, 242, 227, and 338 male-specific genes were regulated at < or =3, 5, and 24 hours after IS, respectively, of which 59 were regulated at all time points. Overall, 774, 3,437, and 571 female-specific stroke genes were regulated at < or =3, 5, and 24 hours, respectively, of which 152 were regulated at all time points. Male-specific stroke genes were associated with integrin, integrin-liked kinase, actin, tight junction, Wnt/β-catenin, RhoA, fibroblast growth factors (FGF), granzyme, and tumor necrosis factor receptor (TNFR)2 signaling. Female-specific stroke genes were associated with p53, high-mobility group box-1, hypoxia inducible factor (HIF)1α, interleukin (IL)1, IL6, IL12, IL18, acute-phase response, T-helper, macrophage, and estrogen signaling. Cell death signaling was overrepresented in both genders, although the molecules and pathways differed. Gender affects gene expression in the blood of IS patients, which likely implies gender differences in immune, inflammatory, and cell death responses to stroke.

Y chromosome gene expression in the blood of male patients with ischemic stroke compared with male controls

BACKGROUND

Sex is suggested to be an important determinant of ischemic stroke risk factors, etiology, and outcome. However, the basis for this remains unclear. The Y chromosome is unique in males. Genes expressed in males on the Y chromosome that are associated with stroke may be important genetic contributors to the unique features of males with ischemic stroke, which would be helpful for explaining sex differences observed between men and women.

OBJECTIVE

We compared Y chromosome gene expression in males with ischemic stroke and male controls.

METHODS

Blood samples were obtained from 40 male patients ≤3, 5, and 24 hours after ischemic stroke and from 41 male controls (July 2003-April 2007). RNA was isolated from blood and was processed using Affymetrix Human U133 Plus 2.0 expression arrays (Affymetrix Inc., Santa Clara, California). Y chromosome genes differentially expressed between male patients with stroke and male control subjects were identified using an ANCOVA adjusted for age and batch. A P < 0.05 and a fold change >1.2 were considered significant.

RESULTS

Seven genes on the Y chromosome were differentially expressed in males with ischemic stroke compared with controls. Five of these genes (VAMP7, CSF2RA, SPRY3, DHRSX, and PLCXD1) are located on pseudoautosomal regions of the human Y chromosome. The other 2 genes (EIF1AY and DDX3Y) are located on the nonrecombining region of the human Y chromosome. The identified genes were associated with immunology, RNA metabolism, vesicle fusion, and angiogenesis.

CONCLUSIONS

Specific genes on the Y chromosome are differentially expressed in blood after ischemic stroke. These genes provide insight into potential molecular contributors to sex differences in ischemic stroke.

Intramuscular versus intravenous therapy for prehospital status epilepticus

BACKGROUND

Early termination of prolonged seizures with intravenous administration of benzodiazepines improves outcomes. For faster and more reliable administration, paramedics increasingly use an intramuscular route.

METHODS

This double-blind, randomized, noninferiority trial compared the efficacy of intramuscular midazolam with that of intravenous lorazepam for children and adults in status epilepticus treated by paramedics. Subjects whose convulsions had persisted for more than 5 minutes and who were still convulsing after paramedics arrived were given the study medication by either intramuscular autoinjector or intravenous infusion. The primary outcome was absence of seizures at the time of arrival in the emergency department without the need for rescue therapy. Secondary outcomes included endotracheal intubation, recurrent seizures, and timing of treatment relative to the cessation of convulsive seizures. This trial tested the hypothesis that intramuscular midazolam was noninferior to intravenous lorazepam by a margin of 10 percentage points.

RESULTS

At the time of arrival in the emergency department, seizures were absent without rescue therapy in 329 of 448 subjects (73.4%) in the intramuscular-midazolam group and in 282 of 445 (63.4%) in the intravenous-lorazepam group (absolute difference, 10 percentage points; 95% confidence interval, 4.0 to 16.1; P<0.001 for both noninferiority and superiority). The two treatment groups were similar with respect to need for endotracheal intubation (14.1% of subjects with intramuscular midazolam and 14.4% with intravenous lorazepam) and recurrence of seizures (11.4% and 10.6%, respectively). Among subjects whose seizures ceased before arrival in the emergency department, the median times to active treatment were 1.2 minutes in the intramuscular-midazolam group and 4.8 minutes in the intravenous-lorazepam group, with corresponding median times from active treatment to cessation of convulsions of 3.3 minutes and 1.6 minutes. Adverse-event rates were similar in the two groups.

CONCLUSIONS

For subjects in status epilepticus, intramuscular midazolam is at least as safe and effective as intravenous lorazepam for prehospital seizure cessation. (Funded by the National Institute of Neurological Disorders and Stroke and others; ClinicalTrials.gov number, ClinicalTrials.gov NCT00809146.).

Abstract 3093: Clinical Factors Associated With Hypotension Within 12 Hours Of Antihypertensive Therapy In Ed Stroke Patients

Background: Extremes of blood pressure (BP) have been associated with poor outcomes in acute stroke. Aggressive antihypertensive therapy in stroke patients with elevated blood pressure (BP) can lead to undesired hypotension. We sought to determine whether any pre-treatment factors are associated with undesired hypotension within 12 hours of initiating antihypertensive therapy in emergency department (ED) patients with neurological emergencies.

Methods: This was a secondary analysis of an observational study conducted at an urban academic ED and two community EDs between November 2007 and March 2009. Patients with signs or symptoms of neurological emergencies treated with antihypertensives in the ED were eligible for enrollment if they were not enrolled in interventional clinical trials. Demographics, medical history, antihypertensive use, and BP measurements were abstracted in duplicate. Discrepant data were adjudicated by a third investigator. Based on American Heart Association guidelines, target BP was defined as a 20% reduction in systolic BP from that recorded immediately prior to treatment. Hypotension was defined as a systolic BP drop of > 40% from the pre-treatment level or systolic BP <100mmHg within 12hours of initiation of antihypertensives. Univariable Cox regression was used to evaluate factors associated with early hypotension.

Results: One hundred patients were enrolled. Median age was 62years (range 36-96), 50 were male and 53 were black. The most common diagnoses were intracerebral hemorrhage (n=36), ischemic stroke (n=35) and hypertensive emergency (n=10). Hypotension occurred in 28 patients within 12hours of initiation of antihypertensive therapy. Median time from first treatment to hypotension was 211 minutes (range 2-629, IQR 98-355). In univariable analysis, lower baseline GCS and higher baseline BP were associated with post-treatment hypotension ( Table ).

Conclusions: In this observational study, hypotension occurred frequently in ED patients with neurological emergencies who received antihypertensives. Since sicker patients with higher BP were more likely to become hypotensive, overly aggressive treatment in these patients may have accounted for the hypotension observed. Larger, future studies should see if these patients are indeed treated more aggressively.

Table.

The X-chromosome has a different pattern of gene expression in women compared with men with ischemic stroke

BACKGROUND AND PURPOSE

Differences in ischemic stroke between men and women have been mainly attributed to hormonal effects. However, sex differences in immune response to ischemia may exist. We hypothesized that differential expression of X-chromosome genes in blood immune cells contribute to differences between men and women with ischemic stroke.

METHODS

RNA levels of 683 X-chromosome genes were measured on Affymetrix U133 Plus2.0 microarrays. Blood samples from patients with ischemic stroke were obtained at ≤ 3 hours, 5 hours, and 24 hours (n=61; 183 samples) after onset and compared with control subjects without symptomatic vascular diseases (n=109). Sex difference in X-chromosome gene expression was determined using analysis of covariance (false discovery rate ≤ 0.05, fold change ≥ 1.2).

RESULTS

At ≤ 3, 5, and 24 hours after stroke, there were 37, 140, and 61 X-chromosome genes, respectively, that changed in women; and 23, 18, and 31 X-chromosome genes that changed in men. Female-specific genes were associated with post-translational modification, small-molecule biochemistry, and cell-cell signaling. Male-specific genes were associated with cellular movement, development, cell-trafficking, and cell death. Altered sex specific X-chromosome gene expression occurred in 2 genes known to be associated with human stroke, including galactosidase A and IDS, mutations of which result in Fabry disease and Hunter syndrome, respectively.

CONCLUSIONS

There are differences in X-chromosome gene expression between men and women with ischemic stroke. Future studies are needed to decipher whether these differences are associated with sexually dimorphic immune response, repair or other mechanisms after stroke, or whether some of them represent risk determinants.

Efficiency of enrollment in a successful phase II acute stroke clinical trial

BACKGROUND

Recruitment challenges are common in acute stroke clinical trials. In a population-based study, we determined eligibility and actual enrollment for a successful, phase II acute stroke clinical trial. We hypothesized that missed opportunities for enrollment of eligible patients occurred frequently, despite the success of the trial.

METHODS

In 2005, acute ischemic stroke (AIS) cases in our region were identified at all 17 local hospitals as part of an epidemiologic study. The Combined Approach to Lysis Utilizing Eptifibatide and Recombinant Tissue Plasminogen Activator (CLEAR) trial assessed the safety of this combination in AIS patients within 3 hours of symptom onset. In 2005, we determined the proportion of AIS patients who were eligible for CLEAR and the proportion that were actually enrolled.

RESULTS

At 8 participating hospitals, 33 (2.8%) of 1175 AIS patients were eligible for CLEAR. Of 33 eligible patients, 18 (54.5%) were approached for enrollment, 4 (12.1%) refused, 1 (3.0%) was not consentable, and 13 (39.4%) were enrolled. Of the 15 not approached for enrollment in the trial, 10 were evaluated by the stroke team; 7 received recombinant tissue plasminogen activator. Enrollment was not associated with night or weekend presentation.

CONCLUSIONS

Although the CLEAR trial was successful in meeting its delineated recruitment goals, our findings suggest enrollment could have been more efficient. Three out of 4 patients approached for enrollment participated in the trial. Eligible patients who were not approached and those treated with recombinant tissue plasminogen activator but not enrolled represent targets for improving enrollment rates.

Signatures of cardioembolic and large-vessel ischemic stroke

OBJECTIVE

The cause of stroke remains unknown or cryptogenic in many patients. We sought to determine whether gene expression signatures in blood can distinguish between cardioembolic and large-vessel causes of stroke, and whether these profiles can predict stroke etiology in the cryptogenic group.

METHODS

A total of 194 samples from 76 acute ischemic stroke patients were analyzed. RNA was isolated from blood and run on Affymetrix U133 Plus2.0 microarrays. Genes that distinguish large-vessel from cardioembolic stroke were determined at 3, 5, and 24 hours following stroke onset. Predictors were evaluated using cross-validation and a separate set of patients with known stroke subtype. The cause of cryptogenic stroke was predicted based on a model developed from strokes of known cause and identified predictors.

RESULTS

A 40-gene profile differentiated cardioembolic stroke from large-vessel stroke with >95% sensitivity and specificity. A separate 37-gene profile differentiated cardioembolic stroke due to atrial fibrillation from nonatrial fibrillation causes with >90% sensitivity and specificity. The identified genes elucidate differences in inflammation between stroke subtypes. When applied to patients with cryptogenic stroke, 17% are predicted to be large-vessel and 41% to be cardioembolic stroke. Of the cryptogenic strokes predicted to be cardioembolic, 27% were predicted to have atrial fibrillation.

INTERPRETATION

Gene expression signatures distinguish cardioembolic from large-vessel causes of ischemic stroke. These gene profiles may add valuable diagnostic information in the management of patients with stroke of unknown etiology though they need to be validated in future independent, large studies.

Gene expression profiling of blood for the prediction of ischemic stroke

BACKGROUND AND PURPOSE

A blood-based biomarker of acute ischemic stroke would be of significant value in clinical practice. This study aimed to (1) replicate in a larger cohort our previous study using gene expression profiling to predict ischemic stroke; and (2) refine prediction of ischemic stroke by including control groups relevant to ischemic stroke.

METHODS

Patients with ischemic stroke (n=70, 199 samples) were compared with control subjects who were healthy (n=38), had vascular risk factors (n=52), and who had myocardial infarction (n=17). Whole blood was drawn ≤3 hours, 5 hours, and 24 hours after stroke onset and from control subjects. RNA was processed on whole genome microarrays. Genes differentially expressed in ischemic stroke were identified and analyzed for predictive ability to discriminate stroke from control subjects.

RESULTS

The 29 probe sets previously reported predicted a new set of ischemic strokes with 93.5% sensitivity and 89.5% specificity. Sixty- and 46-probe sets differentiated control groups from 3-hour and 24-hour ischemic stroke samples, respectively. A 97-probe set correctly classified 86% of ischemic strokes (3 hour+24 hour), 84% of healthy subjects, 96% of vascular risk factor subjects, and 75% with myocardial infarction.

CONCLUSIONS

This study replicated our previously reported gene expression profile in a larger cohort and identified additional genes that discriminate ischemic stroke from relevant control groups. This multigene approach shows potential for a point-of-care test in acute ischemic stroke.

Midazolam versus diazepam for the treatment of status epilepticus in children and young adults: a meta-analysis

BACKGROUND

Rapid treatment of status epilepticus (SE) is associated with better outcomes. Diazepam and midazolam are commonly used, but the optimal agent and administration route is unclear.

OBJECTIVES

The objective was to determine by systematic review if nonintravenous (non-IV) midazolam is as effective as diazepam, by any route, in terminating SE seizures in children and adults. Time to seizure cessation and respiratory complications was examined.

METHODS

We performed a search of PubMed, Web of Knowledge, Embase, Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects, American College of Physicians Journal Club, Cochrane Central Register of Controlled Trials, the Cumulative Index to Nursing and Allied Health Literature, and International Pharmaceutical Abstracts for studies published January 1, 1950, through July 4, 2009. English language quasi-experimental or randomized controlled trials comparing midazolam and diazepam as first-line treatment for SE, and meeting the Consolidated Standards of Reporting Trials (CONSORT)-based quality measures, were eligible. Two reviewers independently screened studies for inclusion and extracted outcomes data. Administration routes were stratified as non-IV (buccal, intranasal, intramuscular, rectal) or IV. Fixed-effects models generated pooled statistics.

RESULTS

Six studies with 774 subjects were included. For seizure cessation, midazolam, by any route, was superior to diazepam, by any route (relative risk [RR] = 1.52; 95% confidence interval [CI] = 1.27 to 1.82). Non-IV midazolam is as effective as IV diazepam (RR = 0.79; 95% CI = 0.19 to 3.36), and buccal midazolam is superior to rectal diazepam in achieving seizure control (RR = 1.54; 95% CI = 1.29 to 1.85). Midazolam was administered faster than diazepam (mean difference = 2.46 minutes; 95% CI = 1.52 to 3.39 minutes) and had similar times between drug administration and seizure cessation. Respiratory complications requiring intervention were similar, regardless of administration route (RR = 1.49; 95% CI = 0.25 to 8.72).

CONCLUSIONS

Non-IV midazolam, compared to non-IV or IV diazepam, is safe and effective in treating SE. Comparison to lorazepam, evaluation in adults, and prospective confirmation of safety and efficacy is needed.

Temporal trends in public awareness of stroke: warning signs, risk factors, and treatment

BACKGROUND AND PURPOSE

Delay in seeking medical attention after stroke symptom onset is the most important reason for low rates of thrombolytic use for ischemic stroke (IS) in the United States. This may be related to poor recognition of stroke symptoms, or to lack of awareness of time-sensitive stroke treatments. We describe public knowledge of t-PA as a treatment for IS, as well as changes over time in knowledge of stroke warning signs (WS) and risk factors (RF).

METHODS

Survey respondents were drawn from our biracial population of 1.3 million using random-digit dialing in 1995, 2000, and 2005 to reflect the age, race, and gender distribution of stroke patients, based on an ongoing stroke incidence study in the same region. They were asked open-ended questions regarding stroke WS, RF, and, in 2005, specific questions regarding t-PA. Comparisons over time were made using chi(2) analysis, and were corrected for multiple comparisons.

RESULTS

Over the 10-year study period, 6209 surveys were completed. Knowledge of WS and RF improved between 1995 and 2000. Between 2000 and 2005, knowledge did not improve significantly; however, there was a significant improvement in knowledge of 3 warning signs (12% in 1995 vs 16% in 2005, P=0.0004). In 2005, only 3.6% of those surveyed were able to independently name t-PA or "clot buster" when asked: "Suppose you were having a stroke. Do you know of any medication your doctor could give you into the vein to increase your chance of recovering from a stroke?"-although 19% claimed to have heard of t-PA once it was mentioned to them.

CONCLUSIONS

Despite numerous national stroke public awareness campaigns, public knowledge of stroke WS and RF has not improved over the last 5 years. In addition, knowledge of t-PA as a treatment for IS is extremely poor. Public awareness messages in the future should focus on the possibility of urgent treatments, in addition to stroke WS and RF, so the public can translate their knowledge into action and present to medical attention more quickly. This may be the highest yield approach to increasing rates of treatment of IS with t-PA.

Gene expression in peripheral blood differs after cardioembolic compared with large-vessel atherosclerotic stroke: biomarkers for the etiology of ischemic stroke

There are no biomarkers that differentiate cardioembolic from large-vessel atherosclerotic stroke, although the treatments differ for each and approximately 30% of strokes and transient ischemic attacks have undetermined etiologies using current clinical criteria. We aimed to define gene expression profiles in blood that differentiate cardioembolic from large-vessel atherosclerotic stroke. Peripheral blood samples were obtained from healthy controls and acute ischemic stroke patients (<3, 5, and 24 h). RNA was purified, labeled, and applied to Affymetrix Human U133 Plus 2.0 Arrays. Expression profiles in the blood of cardioembolic stroke patients are distinctive from those of large-vessel atherosclerotic stroke patients. Seventy-seven genes differ at least 1.5-fold between them, and a minimum number of 23 genes differentiate the two types of stroke with at least 95.2% specificity and 95.2% sensitivity for each. Genes regulated in large-vessel atherosclerotic stroke are expressed in platelets and monocytes and modulate hemostasis. Genes regulated in cardioembolic stroke are expressed in neutrophils and modulate immune responses to infectious stimuli. This new method can be used to predict whether a stroke of unknown etiology was because of cardioembolism or large-vessel atherosclerosis that would lead to different therapy. These results have wide ranging implications for similar disorders.

Emergency Department Arrival Times after Acute Ischemic Stroke During the 1990s

INTRODUCTION

Only 8% of ischemic stroke (IS) patients are eligible for rt-PA, and the largest exclusion criterion is delayed time of presentation to the ED. We sought to investigate whether patients are arriving to the ED more quickly in 1999 than in 1993/94 within our large biracial population of 1.3 million.

METHODS

Using ICD-9 codes 430-436, we ascertained all stroke events that presented to a local ED within our population in 7/93-6/94 and again in 1999. Times were recorded as documented in the medical record.

RESULTS

There were 1,792 IS patients that presented to an ED in 1993/94 and 1,973 in 1999. The percentage of patients with documented times arriving in under 3 h improved slightly in 1999 (26% vs. 23% in 93/94, P = 0.03), however, the percentage arriving in under 2 h did not. Blacks significantly improved in arrivals under 3 h: 26% in 1999 compared to 17% in 1993/94 (P = 0.01), while whites did not (26% vs. 25%, P = 0.29). In 1999, only 9% of patients arrived from 3-8 h after symptom onset, the large majority of times were either estimated, unknown, or >8 h.

DISCUSSION

We found only marginal improvement in arrival times during the 1990s. In our population, blacks improved in early arrival after symptom onset, while whites did not. Very few patients arrive 3-8 h after onset; therefore expansion of the acute treatment time window to 8 h is unlikely to dramatically affect acute treatment of ischemic stroke.

Lack of evidence for an association between hemodynamic variables and hematoma growth in spontaneous intracerebral hemorrhage

BACKGROUND AND PURPOSE

Early hematoma expansion in spontaneous intracerebral hemorrhage (ICH) is associated with worse clinical outcome. We hypothesized that hemodynamic parameters are associated with the increase in hematoma volume owing to their relationship to blood vessel wall stresses.

METHODS

We performed a post hoc analysis of clinical and computed tomography (CT) data from patients enrolled in a prospective observational study of ICH patients presenting within 3 hours from symptom onset. Hematoma volumes were measured at hospital arrival and at 1 and 20 hours from presentation. Blood pressure and heart rate, recorded at 19 time points between presentation and 20 hours, were used to derive hemodynamic variables. Multivariable logistic-regression models were constructed to assess the relation between hemodynamic parameters and hematoma growth, adjusted for clinical covariates.

RESULTS

From the original study, 98 patients underwent baseline and 1-hour CT scans; of these, 65 had 20-hour CT scans. Substantial hematoma growth was observed in 28% within the first hour. Of the 65 patients not undergoing surgery within 20 hours, 37% experienced hematoma growth by 20 hours. Neither baseline or peak hemodynamic parameters nor changes in hemodynamic parameters were significantly associated with hematoma growth at either 1 or 20 hours.

CONCLUSIONS

We found no blood pressure or heart rate parameters, individually or in combination, that were associated with hematoma growth. Our data suggest the influence of hemodynamic parameters on vessel wall stress to be an unlikely target for intervention in reducing the risk of early hematoma growth in ICH.

Community socioeconomic status and prehospital times in acute stroke and transient ischemic attack: do poorer patients have longer delays from 911 call to the emergency department?

BACKGROUND AND PURPOSE

Timely access to medical treatment is critical for patients with acute stroke because acute therapies must be given very quickly after symptom onset. We examined the effect of socioeconomic status on prehospital delays in stroke and transient ischemic attack (TIA) patients within a large, biracial population.

METHODS

By screening all local hospital ICD-9 codes 430 to 436, all stroke and TIA patients were identified during the calendar year of 1999. Cases must have used emergency medical services (EMS), lived at home, had their stroke at home, and had documented times of the 911 call and arrival to the emergency department. Socioeconomic status was estimated using economic data regarding the geocoded home residence census tract.

RESULTS

Only 38% of stroke and TIA patients used EMS. There were 978 cases of stroke and TIA included in this analysis. The mean times were call to arrival on scene 6.5 minutes, on-scene time 14.1 minutes, and transport time 13.1 minutes. Lower community socioeconomic status was associated with all 3 EMS time intervals; however, all time differences were small: the largest difference was 5 minutes.

CONCLUSIONS

Within our population, living in a poorer area does not appear to delay access to acute care for stroke in a clinically significant way. We did find small, statistically significant delays in prehospital times that were associated with poorer communities, black race, and increasing age. However, delays related to public recognition of stroke symptoms, and limited use of 911, are likely much more important than these small delays that occur with EMS systems.

Association of apolipoprotein E4 and haplotypes of the apolipoprotein E gene with lobar intracerebral hemorrhage

BACKGROUND AND PURPOSE

Conflicting reports in the literature exist with regard to the association of apolipoprotein E (apo E) alleles and lobar intracerebral hemorrhage (ICH). We genotyped 12 single-nucleotide polymorphisms in the 5' upstream regulatory, exonic, and intronic regions of the apo E gene and performed genotype and haplotype association analyses.

METHODS

We prospectively enrolled subjects with hemorrhagic stroke and matched them with 2 controls based on age, race, and sex. Each case was reviewed by a physician to determine case status and location of the ICH. Multivariate logistic-regression modeling with backward elimination was used to determine significant risk factors for lobar ICH. Associations at the genotype and haplotype levels and linkage disequilibrium were conducted according to standard statistical methods.

RESULTS

Between May 1997 and December 2002, 315 cases of ICH were recruited, of whom 107 were lobar ICH cases matched to 205 controls. No association was found for apo E2, E3, or E4 with nonlobar ICH. Independent, significant risk factors for lobar ICH included apo E4, untreated hypertension, anticoagulant use, a first-degree relative with ICH, and < or =high school education (compared with >high school education). Treated hypercholesterolemia compared with "no history of hypercholesterolemia" was associated with a decreased risk of lobar ICH. Haplotype association analysis demonstrated a significant association of the apo E gene with lobar ICH among whites (P<0.0001) and blacks (P=0.0024).

CONCLUSIONS

Apo E4 is independently associated with lobar ICH but not nonlobar ICH. Haplotypes of the apo E gene are associated with lobar ICH. Untreated hypertension is a risk factor for lobar ICH.

Incidence and Short-Term Prognosis of Transient Ischemic Attack in a Population-Based Study

Background and Purpose— Transient ischemic attacks (TIAs) have been shown to be a strong predictor of subsequent stroke and death. We present the incidence and short-term prognosis of TIA within a large population with a significant proportion of minorities with out-of-hospital TIA.

Methods— TIA cases were identified between July 1, 1993 and June 30, 1994 from the Greater Cincinnati/Northern Kentucky population of 1.3 million inhabitants by previously published surveillance methods, including inpatient and out-of-hospital events. Incidence rates were adjusted to the 1990 population, and life-table analyses were used for prognosis.

Results— The overall race, age, and gender-adjusted incidence rate for TIA within our population was 83 per 100 000, with age, race, and gender adjusted to the 1990 US population. Blacks and men had significantly higher rates of TIA than whites and women. Risk of stroke after TIA was 14.6% at 3 months, and risk of TIA/stroke/death was 25.2%. Age, race, and sex were not associated with recurrent TIA or subsequent stroke in our population, but age was associated with mortality.

Conclusions— Using our incidence rates for TIA in blacks and whites, we conservatively estimate that ≈240 000 TIAs occurred in 2002 in the United States. Our incidence rate of TIA is slightly higher than previously reported, which may be related to the inclusion of blacks and out-of-hospital events. There are racial and gender-related differences in the incidence of TIA. We found a striking risk of adverse events after TIA; however, there were no racial or gender differences predicting these events. Further study is warranted in interventions to prevent these adverse events after TIA.

A Description of Canadian and United States Physician Reimbursement for Thrombolytic Therapy Administration in Acute Ischemic Stroke

Background and Purpose— Acute ischemic stroke patients are infrequently treated with rtPA, despite its proven effectiveness. Poor physician reimbursement for acute stroke care is one possible explanation for the low frequency of use. We describe the physician reimbursement for thrombolytic therapy for the stroke team physicians serving the Greater Cincinnati/Northern Kentucky region (GCNK), and the Alberta region.

Methods— GCNK: billing logs were accessed for the study period of 7/01–12/02, and cross-matched to stroke call logs. University of Calgary (UC): treatment records of a single physician were reviewed from 4/02–3/04. A telephone survey of Canadian provinces was conducted regarding billing practices.

Results— GCNK: During the study period, 151 patients received rtPA. For treated pts. the average time spent was 2.6 hours, and average reimbursement received was $472 (of those with insurance). The highest reimbursement was received by billing critical care codes. Reimbursement for critical care was similar to or lower than common office procedures for neurologists. UC: during the study period, 131 patients received rtPA. Average reimbursement for rtPA treated patients was $340 US, not including on-call payments. Survey across Canada revealed many provinces with weekend/after hour premium stipends and on-call stipends.

Conclusions— Physician reimbursement for the evaluation and treatment of acute stroke, when compared with other diagnoses commonly treated by neurologists, is relatively low in both the U.S. and Canada. Health policy decision-makers in the US and Canada should be made aware of the importance of providing a more balanced plan to provide medical care to stroke patients.

Combined IV and intra-arterial thrombolysis for acute ischemic stroke

Combined IV and intra-arterial (IA) thrombolysis for acute ischemic stroke may offer advantages over either technique alone. Sixty-two nonrandomized patients with NIH Stroke Scale scores of > or =10 who met standard criteria for IV thrombolysis were treated with an IV/IA approach. Three-month modified Rankin Scale scores were 0 to 2 for 50% of patients, mortality was 18%, and symptomatic intracerebral hemorrhage occurred in 8%. IV/IA thrombolysis appeared safe and effective in this group.

Effect of untreated hypertension on hemorrhagic stroke

BACKGROUND AND PURPOSE

Stroke is the third leading cause of death and the leading cause of disability in the United States. Intracerebral hemorrhage and subarachnoid hemorrhage represent approximately 20% of all stroke cases and have a mortality rate of 40% to 50%. Hypertension is an important risk factor for these subtypes of stroke. We sought to determine whether untreated hypertension carries a different risk from treated hypertension for hemorrhagic stroke.

METHODS

Cases of hemorrhagic stroke in the greater Cincinnati region were identified by screening all area hospital emergency rooms, radiology reports, and International Classification of Diseases 9 codes. Medical records were reviewed for risk factors and medication use. Cases of hemorrhagic stroke were approached for enrollment into the genetic sampling and interview arm. If subjects agreed, the case was matched by age, race, and gender to population-based controls.

RESULTS

Between May 1997 and December 2002, we recruited 549 cases of hemorrhagic stroke, of which 322 were intracerebral hemorrhage and 227 were subarachnoid hemorrhage. Untreated hypertension was found to be a significant risk factor for hemorrhagic stroke (odds ratio [OR]=3.5 [2.3 to 5.2]; P<0.0001) as was treated hypertension (OR=1.4 [1.0 to 1.9]; P=0.03). Insurance status of "self-pay" or Medicaid was a significant risk factor for untreated hypertension (OR=2.7 [1.6 to 4.4]). We estimate that 17% to 28% of hemorrhagic strokes among hypertensive patients would have been prevented if they had been on hypertension treatment.

CONCLUSIONS

Untreated hypertension is highly prevalent and an important risk factor for hemorrhagic stroke. We estimate that among hypertensive subjects, approximately one fourth of hemorrhagic strokes would be prevented if all hypertensive subjects received treatment.

Ischemic stroke subtypes: a population-based study of incidence rates among blacks and whites

BACKGROUND AND PURPOSE

Blacks have an excess burden of stroke compared with whites; however, data comparing ischemic stroke subtypes among the 2 groups are limited and typically involve relative frequencies. The objective of this study is to compare the incidence rates of ischemic stroke subtypes between blacks and whites within a large, representative, biracial population.

METHODS

The Greater Cincinnati/Northern Kentucky Stroke Study is designed to measure incidence rates and trends of all strokes within a well-defined, large, biracial population. Hospitalized cases were ascertained by International Classification of Disease (9th revision; ICD-9) discharge codes. Out-of-hospital events were ascertained by prospective screening of emergency department admission logs, review of coroners' cases, and monitoring all public health and hospital-based primary care clinics. A sampling scheme was used to ascertain events from nursing homes and all other primary care physician offices. All potential cases underwent detailed chart abstraction and confirmed by physician review. Based on all available clinical, laboratory, and radiographic information, ischemic stroke cases were subtyped into the following categories: cardioembolic, large-vessel, small-vessel, other, and stroke of undetermined cause. Race-specific incidence rates were calculated and compared after adjusting for age and gender, and standardizing to the 1990 US population.

RESULTS

Between July 1, 1993, and June 30, 1994, 1956 first-ever ischemic strokes occurred among blacks and whites in the study population. Small-vessel strokes and strokes of undetermined cause were nearly twice as common among blacks. Large-vessel strokes were 40% more common among blacks than whites, and there was a trend toward cardioembolic strokes being more common among blacks.

CONCLUSIONS

The excess burden of ischemic strokes among blacks compared with whites is not uniformly spread across the different subtypes. Large-vessel strokes are more common and cardioembolic stroke are as common among blacks, traditionally thought to be more common among whites.

Stroke in a biracial population: the excess burden of stroke among blacks

BACKGROUND AND PURPOSE

Excess mortality resulting from stroke is an important reason why blacks have higher age-adjusted mortality rates than whites. This observation has 2 possible explanations: Strokes occur more commonly among blacks or blacks have higher mortality rates after stroke. Our population-based epidemiological study is set in the Greater Cincinnati/Northern Kentucky region of 1.31 million people, which is representative of the US white and black populations with regard to many demographic and socioeconomic characteristics.

METHODS

Hospitalized cases were ascertained by International Classification of Diseases (ninth revision) discharge codes, prospective screening of emergency department admission logs, and review of coroner's cases. A sampling scheme was used to ascertain cases in the out-of-hospital setting. All potential cases underwent detailed chart abstraction by study nurses, followed by physician review. Race-specific incidence and case fatality rates were calculated.

RESULTS

We identified 3136 strokes during the study period (January 1, 1993, to June 30, 1994). Stroke incidence rates were higher for blacks at every age, with the greatest risk (2- to 5-fold) seen in young and middle-aged blacks (<65 years of age). Case fatality rates did not differ significantly in blacks compared with whites. Applying the resulting age- and race-specific rates to the US population in 2002, we estimate that 705,000 to 740,000 strokes have occurred in the United States, with a minimum of 616,000 cerebral infarctions, 67,000 intracerebral hemorrhages, and 22,000 subarachnoid hemorrhages.

CONCLUSIONS

Excess stroke-related mortality in blacks is due to higher stroke incidence rates, particularly in the young and middle-aged. This excess burden of stroke incidence among blacks represents one of the most serious public health problems facing the United States.

Eligibility for recombinant tissue plasminogen activator in acute ischemic stroke: a population-based study

BACKGROUND AND PURPOSE

Acute ischemic stroke patients are infrequently treated with recombinant tissue plasminogen activator (rtPA). We present unique population-based data regarding the eligibility of ischemic stroke patients for rtPA treatment.

METHODS

All ischemic strokes presenting to an emergency department (ED) within a biracial population of 1.3 million were identified. The patient was considered eligible for rtPA on the basis of exclusion criteria from the National Institute of Neurological Disorders and Stroke rtPA trial.

RESULTS

Of 2308 ischemic strokes, 1849 presented to an ED. Only 22% of all ischemic strokes in the population arrived in the ED in <3 hours from symptom onset; of these, 209 (51%) were ineligible for rtPA on the basis of mild stroke severity, medical and surgical history, or blood tests.

CONCLUSIONS

In our population in 1993 to 1994, 8% of all ischemic stroke patients presented to an ED within 3 hours and met other eligibility criteria for rtPA. Even if time were not an exclusion for rtPA, only 29% of all ischemic strokes in our population would have otherwise been eligible for rtPA.

The effect of race and gender on patterns of rt-PA use within a population

To date, there have been no population-based data published regarding the influence of the patient's demographic factors on rt-PA use. We present preliminary data regarding the effect of race and gender on patterns of rt-PA use in the pre-FDA approval era, in a population with demographic and socioeconomic characteristics similar to the United States. All ischemic strokes within a biracial population of 1.3 million were identified by review of all primary and secondary hospital ICD-9-CM codes 430-438 from July 1993 to June 1994 at all hospitals in the region. The number of patients treated with rt-PA or placebo as part of the blinded NINDS rt-PA trial, as well as demographic characteristics, were recorded and analyzed. There were a total of 1973 hospitalized ischemic strokes that occurred at a hospital participating in the NINDS rt-PA trial. Patients that received rt-PA were significantly younger than those that did not (mean age 67 v 72, respectively, P = .01). Of the 413 strokes that occurred in African Americans, 2.2% were treated with rt-PA vs. 2.6% of the 1560 non-African Americans. Women (2.0%) and men (3.0%) were equally likely to receive rt-PA. The single academic center was as likely to give rt-PA as the community medical centers. In the Greater Cincinnati/Northern Kentucky population, patterns of rt-PA use in 1993-94 did not appear to vary according to race or gender, or type of medical center. These findings may be in part because of the regionally-based method of stroke care delivery in the area.

Feasibility of neuroprotective agent administration by prehospital personnel in an urban setting

BACKGROUND AND PURPOSE

Studies have demonstrated the importance of early stroke treatment. If a neuroprotective agent (NA) clinical trial is successful, the greatest benefit might be attained with early prehospital administration. This study determined the potential reduction in time to treatment of stroke patients when NAs were administered in the prehospital setting.

METHODS

Twenty-three urban emergency medical services (EMS) agencies participated in this study. Prehospital personnel completed a stroke assessment checklist on any potential stroke victim. The checklist collected clinical inclusion/exclusion criteria for NA administration and event/decision times. Patients meeting the hypothetical clinical inclusion criteria were enrolled into this study. Time data included scene arrival/departure, emergency department (ED) arrival, and estimated time of theoretical NA administration. The reduction in time to stroke treatment was calculated as the difference between the time of ED arrival and the reported time of NA administration. The t test and simple linear regression were used to probe for differences in treatment time reduction between selected subgroups. EMS personnel's ability to obtain informed consent for theoretical NA administration was calculated.

RESULTS

Two hundred twenty-two patients were enrolled in this study; of these, 75 were deemed eligible for hypothetical NA administration and had complete time data. On average, EMS personnel documented the theoretical time of NA administration at 12.04+/-2.07 minutes before arrival at the ED (17.06+/-1.74 minutes when the NA was given on scene [n=43]; 6.65+/-1.14 minutes when the NA was given en route [n=32]).

CONCLUSIONS

Prehospital NA administration can potentially significantly reduce the time to first intervention in stroke patients.

Subarachnoid hemorrhage: a preventable disease with a heritable component

BACKGROUND AND PURPOSE

Subarachnoid hemorrhage (SAH) caused by ruptured intracranial aneurysm affects approximately 16 000 Americans annually, and almost 40% of affected patients die within 30 days despite the best current therapy. Prevention of SAH is therefore of paramount importance. We present a preliminary analysis of risk factors for SAH from our population-based, case-control study.

METHODS

Cases were prospectively collected and matched 2:1 by age, race, and gender to controls using random digit dialing. Personal risk factor history, family history, neuroimaging data, and genetic samples were obtained. Univariate and bivariate analyses were performed and population-attributable risks estimated. Multivariable analysis was performed using conditional logistic regression.

RESULTS

Between June 1997 and February 2000, 107 cases and 197 controls were enrolled. In bivariate analyses, a large proportion of population-attributable risk for SAH could be explained by modifiable risk factors: smoking, hypertension, and heavy alcohol use. In multivariable analysis, current cigarette smoking, history of hypertension, frequent alcohol use, lower body mass index, and a family history of a relative with SAH or intracranial aneurysm were found to be significant, independent risk factors for SAH.

CONCLUSION

Our data confirm previous reports that SAH clusters within some families independent of environmental risk factors, suggesting that SAH has a significant genetic component. Yet, even among families at increased risk of SAH, smoking cessation, treatment of hypertension, and reduced alcohol intake may substantially decrease SAH risk. The independent associations with heavy alcohol use and low body mass index with SAH may be confounded by smoking and require further study.

Recommendations for improving the quality of care through stroke centers and systems: an examination of stroke center identification options: multidisciplinary consensus recommendations from the Advisory Working Group on Stroke Center Identification Options of the American Stroke Association

BACKGROUND AND PURPOSE

The American Stroke Association (ASA) assembled a multidisciplinary group of experts to develop recommendations regarding the potential effectiveness of establishing an identification program for stroke centers and systems. "Identification" refers to the full spectrum of models for assessing and recognizing standards of quality care (self-assessment, verification, certification, and accreditation). A primary consideration is whether stroke center identification might improve patient outcomes.

METHODS

In February 2001, ASA, with the support of the Stroke Council's Executive Committee, decided to embark on an evaluation of the potential impact of stroke center identification. HealthPolicy R&D was selected to prepare a comprehensive report. The investigators reported on models outside the area of stroke, ongoing initiatives within the stroke community (such as Operation Stroke), and state and federal activities designed to improve care for stroke patients. The investigators also conducted interviews with thought leaders in the stroke community, representing a diverse sampling of specialties and affiliations. In October 2001, the Advisory Working Group on Stroke Center Identification developed its consensus recommendations. This group included recognized experts in neurology, emergency medicine, emergency medical services, neurological surgery, neurointensive care, vascular disease, and stroke program planning.

RESULTS

There are a variety of existing identification programs, generally falling within 1 of 4 categories (self-assessment, verification, certification, and accreditation) along a continuum with respect to intensity and scope of review and consumption of resources. Ten programs were evaluated, including Peer Review Organizations, trauma centers, and new efforts by the National Committee on Quality Assurance and the Joint Commission on the Accreditation of Healthcare Organizations to identify providers and disease management programs. The largest body of literature on clinical outcomes associated with identification programs involves trauma centers. Most studies support that trauma centers and systems lead to improved mortality rates and patient outcomes. The Advisory Working Group felt that comparison to the trauma model was most relevant given the need for urgent evaluation and treatment of stroke. The literature in other areas generally supports the positive impact of identification programs, although patient outcomes data have less often been published. In the leadership interviews, participants generally expressed strong support for pursuing some form of voluntary identification program, although concerns were raised that this effort could meet with some resistance.

CONCLUSIONS

Identification of stroke centers and stroke systems competencies is in the best interest of stroke patients in the United States, and ASA should support the development and implementation of such processes. The purpose of a stroke center/systems identification program is to increase the capacity for all hospitals to treat stroke patients according to standards of care, recognizing that levels of involvement will vary according to the resources of hospitals and systems.

Greater Cincinnati/Northern Kentucky Stroke Study: volume of first-ever ischemic stroke among blacks in a population-based study

BACKGROUND AND PURPOSE

The volume of ischemic stroke on CT scans has been studied in a standardized fashion in acute stroke therapy trials with median volumes between 10.5 to 55 cm(3). The volume of first-ever ischemic stroke in the population is not known.

METHODS

The first phase of the population-based Greater Cincinnati/Northern Kentucky Stroke Study identified all ischemic strokes occurring in blacks in the greater Cincinnati region between January and June of 1993. The patients in this phase of the study who had a first-ever ischemic clinical stroke were identified, and the volume of ischemic stroke was measured.

RESULTS

There were 257 verified clinical cases of ischemic stroke, of which 181 had a first-ever ischemic infarct. Imaging was available for 150 of these patients, and 79 had an infarct on the CT or MRI study that was definitely or possibly related to the clinical symptoms. For these patients, volumetric measurements were performed by means of the modified ellipsoid method. The median volume of first-ever ischemic stroke for the 79 patients was 2.5 cm(3) (interquartile range, 0.5 to 8.8 cm(3)). There was a significant relation between location of lesion and infarct size (P<0.001) and between volume and mechanism of stroke (P=0.001).

CONCLUSIONS

The volume of first-ever ischemic stroke among blacks in our population-based study is smaller than has been previously reported in acute stroke therapy trials. The large proportion of small, mild strokes in blacks may be an important reason for the low percentage of patients who meet the inclusion criteria for tissue plasminogen activator. Further study is necessary to see if these results are generalizable to a multiracial population.

Apolipoprotein E phenotype and the efficacy of intravenous tissue plasminogen activator in acute ischemic stroke

We used stored plasma samples from 409 patients in the National Institute of Neurological Diseases and Stroke (NINDS) tissue plasminogen activator (t-PA) Stroke Trial to examine the relationship between an apolipoprotein (Apo) E2 or an Apo E4 phenotype and a favorable outcome 3 months after stroke, the risk of intracerebral hemorrhage, and the response to intravenous t-PA therapy. For the 27 patients with an Apo E2 phenotype who were treated with t-PA, the odds ratio (OR) of a favorable outcome at 3 months was 6.4 [95% confidence interval (CI) 2.7-15.3%] compared to the 161 patients without an Apo E2 phenotype who were treated with placebo. The 190 patients treated with t-PA who did not have an Apo E2 phenotype also had a greater, though less pronounced, likelihood of a favorable outcome (OR 2.0, 95% CI 1.2-3.2%) than patients without an Apo E2 phenotype treated with placebo. For the 31 patients with an Apo E2 phenotype treated with placebo, the OR of a favorable 3 month outcome was 0.8 (95% CI 0.4-1.7%) compared to the 161 patients without an Apo E2 phenotype treated with placebo. This interaction between treatment and Apo E2 status persisted after adjustment for baseline variables previously associated with 3 month outcome, for differences in the baseline variables in the two treatment groups and in the Apo E2-positive and -negative groups, and for a previously reported time-to-treatment x treatment interaction (p = 0.03). Apo E4 phenotype, present in 111 (27%) of the 409 patients, was not related to a favorable 3 month outcome, response to t-PA, 3 month mortality, or risk of intracerebral hemorrhage. We conclude that the efficacy of intravenous t-PA in patients with acute ischemic stroke may be enhanced in patients who have an Apo E2 phenotype, whereas the Apo E2 phenotype alone is not associated with a detectable benefit on stroke outcome at 3 months in patients not given t-PA. In contrast to prior studies of head injury and stroke, we could not detect a relationship between Apo E4 phenotype and clinical outcome.

Combined intravenous and intra-arterial recombinant tissue plasminogen activator in acute ischemic stroke

BACKGROUND AND PURPOSE

A retrospective analysis was performed on 20 consecutive patients who presented with severe acute ischemic stroke and were evaluated for a combined intravenous (IV) and local intra-arterial (IA) recombinant tissue plasminogen activator (rtPA) thrombolytic approach within 3 hours of onset.

METHODS

Twenty consecutive patients with carotid artery distribution strokes were evaluated and treated using a combined IV and IA rtPA approach over a 14-month period (September 1998 to October 1999). rtPA (0.6 mg/kg) was given intravenously (maximum dose 60 mg); 15% of the IV dose was given as bolus, followed by a continuous infusion over 30 minutes. A maximal IA dose, up to 0.3 mg/kg or 24 mg, whichever was less, was given over a maximum of 2 hours. IV treatment was initiated within 3 hours in 19 of 20 patients. All 20 patients underwent angiography, and 16 of 20 patients received local IA rtPA.

RESULTS

The median baseline National Institutes of Health Stroke Scale (NIHSS) score for the 20 patients was 21 (range 11 to 31). The median time from stroke onset to IV treatment was 2 hours and 2 minutes, and median time to initiation of IA treatment was 3 hours and 30 minutes. Ten patients (50%) recovered to a modified Rankin Scale (mRS) of 0 or 1; 3 patients (15%), to an mRS of 2; and 5 patients (25%), to an mRS of 4 or 5. One patient (5%) developed a symptomatic intracerebral hemorrhage and eventually died. One other patient (5%) expired because of complications from the stroke.

CONCLUSIONS

We believe that the greater-than-expected proportion of favorable outcomes in these patients with severe ischemic stroke reflects the short time to initiation of both IV and IA thrombolysis.

Decreased perihematomal edema in thrombolysis-related intracerebral hemorrhage compared with spontaneous intracerebral hemorrhage

BACKGROUND AND PURPOSE

Intracerebral hemorrhage (ICH) is a highly morbid disease process. Perihematomal edema is reported to contribute to clinical deterioration and death. Recent experimental observations indicate that clotting of the intrahematomal blood is the essential prerequisite for hyperacute perihematomal edema formation rather than blood-brain barrier disruption.

METHODS

We compared a series of patients with spontaneous ICH (SICH) to a series of patients with thrombolysis-related ICH (TICH). All patients were imaged within 3 hours of clinical onset. We reviewed relevant neuroimaging features, emphasizing and quantifying perihematomal edema. We then analyzed clinical and radiological differences between the 2 ICH types and determined whether these factors were associated with perihematomal edema.

RESULTS

TICHs contained visible perihematomal edema less than half as often as SICHs (31% versus 69%, P<0.001) and had both lower absolute edema volumes (0 cc [25th, 75th percentiles: 0, 6] versus 6 cc [0, 13], P<0.0001) and relative edema volumes (0.16 [0.10, 0.33] versus 0.55 [0.40, 0.83], P<0.0001). Compared with SICHs, TICHs were 3 times larger in volume (median [25th, 75th percentiles] volume 69 cc [30, 106] versus 21 cc [8, 45], P<0.0001), 4 times more frequently lobar in location (62% versus 15%, P<0.001), 80 times more frequently contained blood-fluid level(s) (86% versus 1%, P<0.001), and were more frequently multifocal (22% versus 0%, P<0.001).

CONCLUSIONS

The striking qualitative and quantitative lack of perihematomal edema observed in the thrombolysis-related ICHs compared with the SICHs provides the first substantial, although indirect, human evidence that intrahematomal blood clotting is a plausible pathogenetic factor in hyperacute perihematomal edema formation.

Incidence rates of first-ever ischemic stroke subtypes among blacks: a population-based study

BACKGROUND AND PURPOSE

The aim of this study was to determine the incidence rates of ischemic stroke subtypes among blacks.

METHODS

Hospitalized and autopsied cases of stroke and transient ischemic attack among the 187 000 blacks in the 5-county region of greater Cincinnati/northern Kentucky From January 1, 1993, through June 30, 1993, were identified. Incidence rates were age- and sex-adjusted to the 1990 US population. Subtype classification was performed after extensive review of all available imaging, laboratory data, clinical information, and past medical history. Case-control comparisons of risk factors were made with age-, race-, and sex-matched control subjects.

RESULTS

Annual incidence rates per 100 000 for first-ever ischemic stroke subtypes among blacks were as follows: uncertain cause, 103 (95% confidence interval [CI], 80 to 126); cardioembolic, 56 (95% CI, 40 to 73); small-vessel infarct, 52 (95% CI, 36 to 68); large vessel, 17 (95% CI, 8 to 26); and other causes, 17 (95% CI, 9 to 26). Of the patients diagnosed with an infarct of uncertain cause, 31% underwent echocardiography, 45% underwent carotid ultrasound, and 48% had neither. Compared with age-, race-, and sex- (proportionally) matched control subjects from the greater Cincinnati/northern Kentucky region, the attributable risk of hypertension for all causes of first-ever ischemic stroke is 27% (95% CI, 7 to 43); for diabetes, 21% (95% CI, 11 to 29); and for coronary artery disease, 9% (95% CI, 2 to 16). For small-vessel ischemic stroke, the attributable risk of hypertension is 68% (95% CI, 31 to 85; odds ratio [OR], 5.0), and the attributable risk of diabetes is 30% (95% CI, 10 to 45; OR, 4.4). For cardioembolic stroke, the attributable risk of diabetes is 25% (95% CI, 4 to 41; OR, 3.1).

CONCLUSIONS

Stroke of uncertain cause is the most common subtype of ischemic stroke among blacks. Cardioembolic stroke and small-vessel stroke are the most important, identifiable causes of first-ever ischemic stroke among blacks. The incidence rates of cardioembolic and large-vessel stroke are likely underestimated because noninvasive testing of the carotid arteries and echocardiography were not consistently obtained in stroke patients at the 18 regional hospitals. Most small-vessel strokes in blacks can be attributed to hypertension and diabetes.

Early surgical treatment for supratentorial intracerebral hemorrhage: a randomized feasibility study

BACKGROUND AND PURPOSE

The safety and the effectiveness of the surgical treatment of spontaneous intracerebral hemorrhage (ICH) remain controversial. To investigate the feasibility of urgent surgical evacuation of ICH, we conducted a small, randomized feasibility study of early surgical treatment versus current nonoperative management in patients with spontaneous supratentorial ICH.

METHODS

Patients with spontaneous supratentorial ICH who presented to 1 university and 2 community hospitals were randomized to surgical treatment or best medical treatment. Principal eligibility criteria were ICH volume >10 cm(3) on baseline CT scan with a focal neurological deficit, Glasgow Coma Scale score >4 at the time of enrollment, randomization and therapy within 24 hours of symptom onset, surgery within 3 hours of randomization, and no evidence for ruptured aneurysm or arteriovenous malformation. The primary end point was the 3-month Glasgow Outcome Scale (GOS). A good outcome was defined as a 3-month GOS score >3.

RESULTS

Twenty patients were randomized over 24 months, 9 to surgical intervention and 11 to medical treatment. The median time from onset of symptoms to presentation at the treating hospitals was 3 hours and 17 minutes, the time from randomization to surgery was 1 hour and 20 minutes, and the time from onset of symptoms to surgery was 8 hours and 35 minutes. The likelihood of a good outcome (primary outcome measure: GOS score >3) for the surgical treatment group (56%) did not differ significantly from the medical treatment group (36%). There was no significant difference in mortality at 3 months. Analysis of the secondary 3-month outcome measures showed a nonsignificant trend toward a better outcome in the surgical treatment group versus the medical treatment group for the median GOS, Barthel Index, and Rankin Scale and a significant difference in the National Institutes of Health Stroke Scale score (4 versus 14; P=0.04).

CONCLUSIONS

Very early surgical treatment for acute ICH is difficult to achieve but feasible at academic medical centers and community hospitals. The trend toward less 3-month morbidity with surgical intervention in patients with spontaneous supratentorial ICH warrants further investigation of very early clot removal in larger randomized clinical trials.