Abstract TMP10: A Retrospective Comparison of Medical Eligibility for Acute Ischemic Stroke Clinical Trials Compared with Hospital Enrollment Rates: Greater Cincinnati/Northern Kentucky Population
Introduction: Low rates of enrollment into stroke clinical trials are an ongoing challenge for the stroke research community. We sought to retrospectively describe the association between medical eligibility and recruitment rates for two acute clinical trials. Methods: Within a population of 1.3 million, we screened local hospital admissions in 2010 using ICD-9 discharge codes 430-436, and performed chart review. Within the region are 15 adult acute care hospitals, all of which are covered by the same stroke team for clinical care and trial enrollment. Medical eligibility, the number of eligible patients/total number of patients, was calculated for the IMS-III trial and the CLEAR-ER trials using their inclusion/exclusion criteria. The number of patients enrolled in the trial per month of open enrollment was determined for each hospital. Statistical analysis included paired signed rank test and regression. Results: In 2010, 2035 ischemic strokes (IS) were hospitalized in the region. Regional medical eligibility was 1.7% for IMS III and 4.5% for CLEARER (p=0.001), overall regional hospital enrollment/month was 0.81 for IMS III and 1.84 for CLEAR-ER (p=0.001). Eligibility rates per hospital ranged from 0-9.5%, and recruitment rates per hospital/mo ranged from 0-0.38. Hospital-level eligibility and recruitment rates were significantly correlated (see figure for both trials combined, adjusted r2 = 0.57, p<0.001.) Discussion: Within our population, medical eligibility explained 57% of the variability in hospital-level enrollment rates for two acute IS trials. The use of population-based epidemiology in trial planning may identify optimal trial enrollment criteria, which must be weighed against proper patient selection. Many other factors impact enrollment rates, such as competing trials, which were not considered here. Further evaluation of our population-based eligibility rates in sites outside our region and with additional clinical trials is needed.
A School-Based Neuromuscular Training Program and Sport-Related Injury Incidence: A Prospective Randomized Controlled Clinical Trial
Context: An estimated 40 million school-aged children (age range = 5−18 years) participate annually in sports in the United States, generating approximately 4 million sport-related injuries and requiring 2.6 million emergency department visits at a cost of nearly $2 billion. Objective: To determine the effects of a school-based neuromuscular training (NMT) program on sport-related injury incidence across 3 sports at the high school and middle school levels, focusing particularly on knee and ankle injuries. Design: Randomized controlled clinical trial. Setting: A total of 5 middle schools and 4 high schools in a single-county public school district. Patients or Other Participants: A total of 474 girls (222 middle school, 252 high school; age = 14.0 ± 1.7 years, height = 161.0 ± 8.1 cm, mass = 55.4 ± 12.2 kg) were cluster randomized to an NMT (CORE; n = 259 athletes) or sham (SHAM; n = 215 athletes) intervention group by team within each sport (basketball, soccer, and volleyball). Intervention(s): The CORE intervention consisted of exercises focused on the trunk and lower extremity, whereas the SHAM protocol consisted of resisted running using elastic bands. Each intervention was implemented at the start of the season and continued until the last competition. An athletic trainer evaluated athletes weekly for sport-related injuries. The coach recorded each athlete-exposure (AE), which was defined as 1 athlete participating in 1 coach-directed session (game or practice). Main Outcome Measure(s): Injury rates were calculated overall, by sport, and by competition level. We also calculated rates of specific knee and ankle injuries. A mixed-model approach was used to account for multiple injuries per athlete. Results: Overall, the CORE group reported 107 injuries (rate = 5.34 injuries/1000 AEs), and the SHAM group reported 134 injuries (rate = 8.54 injuries/1000 AEs; F1,578 = 18.65, P < .001). Basketball (rate = 4.99 injuries/1000 AEs) and volleyball (rate = 5.74 injuries/1000 AEs) athletes in the CORE group demonstrated lower injury incidences than basketball (rate = 7.72 injuries/1000 AEs) and volleyball (rate = 11.63 injuries/1000 AEs; F1,275 = 9.46, P = .002 and F1,149 = 11.36, P = .001, respectively) athletes in the SHAM group. The CORE intervention appeared to have a greater protective effect on knee injuries at the middle school level (knee-injury incidence rate = 4.16 injuries/1000 AEs) than the SHAM intervention (knee-injury incidence rate = 7.04 injuries/1000 AEs; F1,261 = 5.36, P = .02). We did not observe differences between groups for ankle injuries (F1,578 = 1.02, P = .31). Conclusions: Participation in an NMT intervention program resulted in a reduced injury incidence relative to participation in a SHAM intervention. This protective benefit of NMT was demonstrated at both the high school and middle school levels.
Effectiveness of Neuromuscular Training Based on the Neuromuscular Risk Profile
Background: The effects of targeted neuromuscular training (TNMT) on movement biomechanics associated with the risk of anterior cruciate ligament (ACL) injuries are currently unknown. Purpose/Hypotheses: To determine the effectiveness of TNMT specifically designed to increase trunk control and hip strength. The hypotheses were that (1) TNMT would decrease biomechanical and neuromuscular factors related to an increased ACL injury risk and (2) TNMT would decrease these biomechanical and neuromuscular factors to a greater extent in athletes identified as being at a high risk for future ACL injuries. Study Design: Controlled laboratory study. Methods: Female athletes who participated in jumping, cutting, and pivoting sports underwent 3-dimensional biomechanical testing before the season and after completing TNMT. During testing, athletes performed 3 different types of tasks: (1) drop vertical jump, (2) single-leg drop, and (3) single-leg cross drop. Analysis of covariance was used to examine the treatment effects of TNMT designed to enhance core and hip strength on biomechanical and neuromuscular characteristics. Differences were also evaluated by risk profile. Differences were considered statistically significant at P < .05. Results: TNMT significantly increased hip external rotation moments and moment impulses, increased peak trunk flexion, and decreased peak trunk extension. Athletes with a high risk before the intervention (risk profile III) had a more significant treatment effect of TNMT than low-risk groups (risk profiles I and II). Conclusion: TNMT significantly improved proximal biomechanics, including increased hip external rotation moments and moment impulses, increased peak trunk flexion, and decreased peak trunk extension. TNMT that focuses exclusively on proximal leg and trunk risk factors is not, however, adequate to induce significant changes in frontal-plane knee loading. Biomechanical changes varied across the risk profile groups, with higher risk groups exhibiting greater improvements in their biomechanics.
Utilization of ACL Injury Biomechanical and Neuromuscular Risk Profile Analysis to Determine the Effectiveness of Neuromuscular Training
Background: The widespread use of anterior cruciate ligament (ACL) injury prevention interventions has not been effective in reducing the injury incidence among female athletes who participate in high-risk sports. Purpose/Hypothesis: The purpose of this study was to determine if biomechanical and neuromuscular factors that contribute to the knee abduction moment (KAM), a predictor of future ACL injuries, could be used to characterize athletes by a distinct factor. Specifically, we hypothesized that a priori selected biomechanical and neuromuscular factors would characterize participants into distinct at-risk profiles. Study Design: Controlled laboratory study. Methods: A total of 624 female athletes who participated in jumping, cutting, and pivoting sports underwent testing before their competitive season. During testing, athletes performed drop-jump tasks from which biomechanical measures were captured. Using data from these tasks, latent profile analysis (LPA) was conducted to identify distinct profiles based on preintervention biomechanical and neuromuscular measures. As a validation, we examined whether the profile membership was a significant predictor of the KAM. Results: LPA using 6 preintervention biomechanical measures selected a priori resulted in 3 distinct profiles, including a low (profile 1), moderate (profile 2), and high (profile 3) risk for ACL injuries. Athletes with profiles 2 and 3 had a significantly higher KAM compared with those with profile 1 ( P < .05). Conclusion: This is the first study to use LPA of biomechanical landing data to create ACL injury risk profiles. Three distinct risk groups were identified based on differences in the peak KAM. Clinical Relevance: These findings demonstrate the existence of discernable groups of athletes that may benefit from injury prevention interventions. Study Registration: ClinicalTrials.gov NCT identifier: NCT01034527.
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.
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.
Early Surgical Treatment for Supratentorial Intracerebral Hemorrhage
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.
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ombined Approach to
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ysis Utilizing
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ptifibatide
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t-PA in Acute Ischemic Stroke
Background and Purpose— Multiple approaches are being studied to enhance the rate of thrombolysis for acute ischemic stroke. Treatment of myocardial infarction with a combination of a reduced-dose fibrinolytic agent and a glycoprotein (GP) IIb/IIIa receptor antagonist has been shown to improve the rate of recanalization versus fibrinolysis alone. The c ombined approach to l ysis utilizing e ptifibatide a nd r ecombinant tissue-type plasminogen activator (rt-PA) (CLEAR) stroke trial assessed the safety of treating acute ischemic stroke patients within 3 hours of symptom onset with this combination. Methods— The CLEAR trial was a National Institutes of Health/National Institute of Neurological Disorders and Stroke–funded multicenter, double-blind, randomized, dose-escalation and safety study. Patients were randomized 3:1 to either low-dose rt-PA (tier 1=0.3 mg/kg, tier 2=0.45 mg/kg) plus eptifibatide (75 μg/kg bolus followed by 0.75 μg/kg per min infusion for 2 hours) or standard-dose rt-PA (0.9 mg/kg). The primary safety end point was the incidence of symptomatic intracerebral hemorrhage within 36 hours. Secondary analyses were performed regarding clinical efficacy. Results— Ninety-four patients (40 in tier 1 and 54 in tier 2) were enrolled. The combination group of the 2 dose tiers (n=69) had a median age of 71 years and a median baseline National Institutes of Health Stroke Scale (NIHSS) score of 14, and the standard-dose rt-PA group (n=25) had a median age of 61 years and a median baseline NIHSS score of 10 ( P =0.01 for NIHSS score). Fifty-two (75%) of the combination treatment group and 24 (96%) of the standard treatment group had a baseline modified Rankin scale score of 0 ( P =0.04). There was 1 (1.4%; 95% CI, 0% to 4.3%) symptomatic intracranial hemorrhage in the combination group and 2 (8.0%; 95% CI, 0% to 19.2%) in the rt-PA–only arm ( P =0.17). During randomization in tier 2, a review by the independent data safety monitoring board demonstrated that the safety profile of combination therapy at the tier 2 doses was such that further enrollment was statistically unlikely to indicate inadequate safety for the combination treatment group, the ultimate outcome of the study. Thus, the study was halted. There was a trend toward increased clinical efficacy of standard-dose rt-PA compared with the combination treatment group. Conclusions— The safety of the combination of reduced-dose rt-PA plus eptifibatide justifies further dose-ranging trials in acute 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.
Natural History of Perihematomal Edema in Patients With Hyperacute Spontaneous Intracerebral Hemorrhage
Background and Purpose— The natural history of perihematomal edema in human hyperacute spontaneous intracerebral hemorrhage (ICH) has not been well described. Methods— This study was a secondary analysis of a previously reported prospective, population-based study of hematoma growth in 142 patients with spontaneous ICH. Patients were first imaged within 3 hours of onset, then 1 and 20 hours later. We excluded patients with anticoagulant use (n=7), underlying aneurysm/vascular malformation (n=9), trauma (n=1), incomplete data (n=20), infratentorial ICH (n=17), and no consent (n=2), leaving an overall study population of 86 patients. From this overall group we further excluded patients with intraventricular extension (n=38), subsequent surgery (n=5), or death (n=2) before 20-hour postbaseline CT. This second, “restricted” analysis group of 41 patients was relatively devoid of clinical or radiological variables likely to confound edema measurement. Absolute and relative edema volumes (edema volume divided by hematoma volume) were descriptively summarized. Correlations between baseline edema volumes and relevant clinical and radiological variables were then performed. Results— Overall, median absolute edema volume increased from 6.93 to 14.4 cm 3 during the first 24 hours after ICH, and median relative edema volume increased from 0.47 to 0.81. In the restricted group, median absolute edema volume was 7.4 cm 3 at baseline and 11.0 cm 3 at 24 hours after ICH, and median relative edema volume increased from 0.55 to 0.81. Baseline relative edema volume was significantly negatively correlated with subsequent change in relative edema volume from baseline to 20-hour CT ( r =0.57, P =0.0002) but was not significantly correlated with other clinical and radiological variables, including hematoma volume or change in hematoma volume. Conclusions— Perihematomal edema volume increases by approximately 75% during the first 24 hours after hyperacute spontaneous ICH. Patients with the least amounts of baseline relative edema volume were most likely to develop significant additional amounts of edema during the first 24 hours after spontaneous ICH.