Citations

Introduction: The selection of acute ischemic stroke patients relies on the interpretation of radiological studies, commonly including noncontrast CT (ASPECTS score), CTA, and in some circumstances, CT perfusion (CTP) scans. Hypothesis: The interrater reliability between readers of noncontrast head CT will be moderate and not as good as that between readers of CT perfusion scans. Methods: Retrospective study of consecutive ischemic stroke patients who were considered for endovascular stroke therapy at an academic medical center from April 2010 - November 2014. All patients underwent CT, CTA, and CTP. Images were independently reviewed by four readers (A, B, C, D) in total (2 experienced neuroradiologists, one experienced neurointensivist, and one neuroradiology fellow). Each rated half of the cohort. All readers performed online training in ASPECTS. Moderate-to-good collateral circulation was defined as filling of 50% or more of the middle cerebral artery pial arterial territory on CTA, as in ESCAPE trial. An “acceptable core” on CTP was defined as in EXTEND-IA trial with core volume < 70 mL, mismatch ratio >1.2, and absolute mismatch volume >10 mL but was qualitatively estimated. Interrater agreement was assessed for total ASPECTS, dichotomized ASPECTS (≥6 vs <6), evaluation of collaterals, and evaluation of core. Agreement was assessed using kappa statistic, which was weighted for the total ASPECTS analysis. Results: Our cohort included 119 patients with acute stroke and large vessel occlusion. Interrater agreement for total ASPECTS was very good between readers C and D (' 0.70) and good between A and B (' 0.55). For dichotomized ASPECTS, agreement was fair-to-good (' 0.30 for C/D; ' 0.41 for A/B). Agreement for grading collaterals on CTA was good to very good (' 0.64 for C /D; ' 0.54 for A/B). Agreement for rating core on CTP was very good (' 0.78 for C/D; ' 0.62 for A/D). Conclusions: Interrater reliability is good to very good for total ASPECTS score, dichotomous grading of collaterals on CTA, and subjective estimation of core size on CTP. Agreement is only fair to good for dichotomized ASPECTS.

Objectives: Limited information is available on the prevalence of cardiorespiratory arrest (CA) and its predisposing factors in patients with acute ischemic stroke. We analyzed/evaluated clinical characteristics, risk factors, access to care, and survival in stroke patients who developed a cardiac arrest. Methods: This is a multicenter cohort study including consecutive patients with acute ischemic stroke admitted to regional stroke centers participating in the Registry of the Canadian Stroke Network from July 2003 to March 2008. Patients with DNR order on admission were excluded. CA was defined as cardiac or respiratory arrest within 30 days of admission documented by a physician and identified from resuscitation records. The main outcome measures were the 30-day and 1-year survival among patients with CA vs. no CA. We also assessed the association between medical complications during hospitalization and CA. Results: Overall, 9,019 patients with acute ischemic stroke were included. Cardiac arrest was observed in 352 patients (3.9%). In patients with CA, 30-day survival (17.9% vs. 90.7%, P<0.001) and 1-year survival (4.5% vs. 80.1, p<0.001) were significantly lower. Less than 1% of stroke patients with CA were discharged home (vs. 47.3%; p<0.0001). Other outcome measures are summarized in Table 1. On multivariable analyses, older age, more severe stroke, previous history of myocardial infarction, congestive heart failure, atrial fibrillation, and diabetes were associated with CA. Conclusions: Cardiac arrest affects less than 5% of patients admitted with an acute ischemic stroke and is associated with poor outcomes. Less than 1% of patients were independent or discharged home.

Background: Current guidelines recommend that initial management of patients with an intracerebral hemorrhage (ICH) occur in a neuroscience intensive care unit (ICU). However, some patients can be safely managed without ICU care. We evaluated factors that may predict the need for ICU level of care. Methods: We reviewed the medical records of all adult patients with supratentorial ICH presenting within 72 hours of symptom onset seen from 2009-2012. Patients admitted for palliative care or ICH due to a known structural lesion were excluded. Criteria defining need for ICU level of care were: need for intubation/mechanical ventilation, hyperosmolar therapy, neurosurgical procedure, prolonged ICU admission, or significant clinical deterioration. A univariate and multivariable logistic regression analysis was performed on patient demographics, medical comorbidities, time to presentation, vital signs, GCS/FOUR score, medications, laboratory studies, and imaging to identify independent predictors of the need for ICU admission. Results: 229 patients met inclusion criteria. Based on our triage criteria, 128 patients (56%) required ICU level of care. Multivariable analysis identified five factors that best predicted the need for ICU admission: younger age, shorter time to presentation, lower FOUR score, larger hemorrhage volume, and use of anticoagulants at presentation (table). Intraventricular hemorrhage and GCS score were not significant predictors on the multivariable analysis. Conclusion: Age, time to presentation, FOUR score, hemorrhage volume, and use of anticoagulants predict the need for ICU care after ICH. These variables will be used to develop a formula to aid clinicians in appropriate initial triage of patients with ICH.

Objective: Using the Nationwide Inpatient Sample (NIS), we determined morbidity, mortality and trends in ischemic and hemorrhagic stroke complications in patients receiving Extracorporeal Membranous Oxygenation (ECMO). Materials and Methods: Using the NIS from 2001-2011, patients receiving ECMO were identified. We analyzed their ischemic and hemorrhagic stroke complication rates and compared discharge status between these patients and those without cerebrovascular complications. Morbidity was defined as discharge to a long-term facility. Ischemic and hemorrhagic stroke rates were compared between two time periods (2001-2006 and 2007-2011). Continuous variables were compared with a student’s t-test and categorical variables were compared with the chi-squared test. Results: A total of 23,950 ECMO patients were included in this study of which 22108 patients (92.3%) had no cerebrovascular complications, 980 patients (4.1%) had ischemic stroke and 862 patients (3.6%) had hemorrhagic stroke. Of those without cerebrovascular complications there was a 49.9% mortality rate and a 6.8% morbidity rate. Patients with ischemic stroke had a mortality rate of 44.3% (P=0.0006) and a morbidity rate of 14.6% (P<0.0001). Patients with hemorrhagic stroke had a mortality rate of 59.7% (P<0.0001) and a morbidity rate of 9.5% (P=0.002). The proportion of patients with ischemic stroke increased from 2.8% in 2001-2006 to 5.1% in 2007-2011 (P<0.0001) and patients with hemorrhagic stroke increased from 2.4% in 2001-2006 to 4.5% in 2007-2011(P<0.0001). Conclusion: ECMO patients complicated with ischemic and hemorrhagic stroke had higher morbidity than those with no cerebrovascular complications. Patients with hemorrhagic stroke had a 10% worsened mortality rate than those with no cerebrovascular complications. The proportion of ECMO patients with cerebrovascular complications has nearly doubled between 2001-2011.

Background and Purpose: Strict maintenance of normovolemia is standard of care in treatment of aneurysmal subarachnoid hemorrhage (aSAH) and induced hypervolemia is used to treat delayed cerebral ischemia (DCI) from vasospasm. Fluid-related complications are not uncommon. We tested the hypothesis that fluid balance affected clinical outcomes in aSAH. Methods: We reviewed 307 patients with aSAH admitted to the Neuroscience Intensive Care Unit (NICU) from October 2001 to June 2011. We collected data on fluid balance during NICU stay, clinical and radiographic evidence of vasospasm, cardiopulmonary complications, and functional outcomes by modified Rankin scale (mRS) upon follow-up (mean 8 ± 8 months). Poor functional outcome was defined as mRS 3-6. Associations of variables of interest with outcome were assessed using univariable and multivariable logistic regression. Propensity scores were estimated to account for imbalances between patients with positive versus negative fluid balance and were included in multivariable models. Results: Average net fluid balance was 1153 ± 5586 mL. Results of univariate analysis are shown on the Table. On multivariate analysis, WFNS grade at nadir (p<0.001, OR=3.09, 95%CI 2.38-4.02) and positive fluid balance per liter increase (p=0.0005, OR=1.12, 95%CI 1.05-1.20) were associated with poor functional outcome. For every liter increase in positive net fluid balance, there was a 12% increased risk of a poor functional outcome on adjusted analysis (Area under ROC Curve 0.868). The association between positive net fluid balance and poor functional outcomes was confirmed using propensity score analysis to control for multiple confounding variables. Conclusions: Greater positive net fluid balance is independently associated with poorer functional outcome in patients with aSAH. This association does not appear to be solely explained by an excess of cardiopulmonary complications.

Objective: To determine trends in tPA utilization, treatment outcomes and predictors of mortality for pediatric patients with acute ischemic stroke. Materials and Methods: Using the Nationwide Inpatient Sample (NIS) from 2001-2010, pediatric patients (age < 18 years) with the primary diagnosis of ischemic stroke were identified. We studied time trends of utilization of intravenous rtPA and outcomes after thrombolysis. We also analyzed the associations of demographic factors, comorbidities, and complications of acute ischemic stroke with in-hospital mortality. Results: A total of 7,379 patients were included in this study. In-hospital mortality was 4.5%. The co-morbidities associated with the highest rates of in-hospital mortality were mitochondrial disorders (19.5%, P<0.0001) and hypercoagulable states (10.9%, p<0.0001). The main complications associated with increased mortality were intracranial hemorrhage (19.9%, p<0.0001), sepsis (13.2%, p<0.0001) and pneumonia (9.3%, p=0.0007). tPA utilization rate was 1.3% (99 patients). tPA utilization increased from 0.9% of patients in 2001-2005 to 1.9% of patients in 2006-2010 (P<0.0001). While patients who received tPA did not have higher mortality rates than non-tPA patients (0.0% versus 5.5%, P=0.06), there was an increased discharge-to-long-term-facilities rate in the tPA group (50.8% versus 12.1%, P<0.0001). Conclusion: Acute ischemic stroke in the pediatric population is associated with a higher mortality rate when related to mitochondriopathies or hypercoagulability. Patients suffering complications such as intracranial hemorrhage, sepsis and pneumonia have higher mortality. rtPA utilization is increasing in pediatric patients with acute ischemic stroke. Pediatric patients receiving tPA have a low risk of fatal hemorrhage. Although patients receiving rtPA have higher rates of morbidity, this may be related to worse stroke severity in these cases.

Background and Purpose- IV rt-PA has become a widely accepted treatment for a select group of patients with acute ischemic stroke. Quantifying the costs of hospitalization is important for understanding the economic impact of these patients on the hospitals that care for them. We evaluated recent data to determine costs associated with hospitalization for acute ischemic stroke patients treated with intravenous thrombolysis, including subgroup analysis to determine the effects of age and discharge status on hospital costs. Methods- Using the National Inpatient Sample, we evaluated the costs for hospitalization for patients treated with intravenous thrombolysis for acute ischemic stroke in the United States from 2001-2008. The primary endpoint examined in this study was total hospital costs, and these were correlated with clinical outcome. Costs were compared with 2008 Medicare reimbursement for intravenous thrombolysis without complication, and intravenous thrombolysis with major complication. Results- A total of 63472 patients received intravenous thrombolysis for acute ischemic stroke. 24094 patients were <65 years old and 40780 patients were ≥65 years old. Median hospital costs in 2008 dollars were $14102 (IQR $9987-$20819) for patients with good outcome, $18856 (IQR $13145-$30423) for patients with severe disability, and $19129 (IQR $11966-$30781) for patients with mortality. Average 2008 Medicare payments were $10,098 for intravenous thrombolysis without complication and $13,835 for intravenous thrombolysis with major complication. Conclusions- Our study of the NIS shows that hospitalization costs in the United States for ischemic stroke patients treated with intravenous thrombolysis are rather high. Medicare payments have not been adequate reimbursement for these hospitalizations. Hopefully, future reconciliation of costs with payments will be feasible, so that hospitals can afford to provide proper care for ischemic stroke patients treated with intravenous thrombolysis.

Background and Objective Hyperdense middle cerebral artery (HDMCA) sign is an early sign seen on CT head after acute ischemic stroke indicating acute arterial thrombosis. We aimed to measure HDMCA sign objectively. Methods We conducted a retrospective analysis of prospectively collected data from 151 cases of acute ischemic stroke eligible for IV rt-PA by time criteria, admitted to Mayo Clinic from March, 2002 through June, 2011. Admission CT Head was studied to identify HDMCA sign. All patients had either 24 hour CT head or MRI head to confirm the stroke in the same vessel territory. MCA was measured in Hounsfield units and was compared to the contralateral MCA. Receiver Operating Characteristic (ROC) curve analysis was performed to calculate sensitivity and specificity. Results Mean admission NIHSS score was 11±7. HDMCA sign was seen in 93 (62%) patients. ROC curve analysis for ipsilateral MCA Hounsfield units had an area under the curve 0.88 (p<0.001, CI 0.83-0.94) which showed 50 HU or more had 48% sensitivity and 98% specificity. Ratio of ipsilateral to contralateral MCA HU had an area under the curve 0.94 (p<0.001, CI 0.90-0.98) which showed ratio of 1.23 had 67% sensitivity and 98% specificity. A combination of either ipsilateral HU more than equal to 50 or a ratio of ipsilateral to contralateral MCA HU more than equal to 1.23 had 77% sensitivity, 95% specificity, 96% positive predictive value and 72% negative predictive value. Conclusion A combination of ipsilateral HU more than equal to 50 or a ratio of ipsilateral to contralateral MCA HU more than equal to 1.23 can objectively identify HDMCA sign with good sensitivity and high specificity.

Background and Objective Hyperdense MCA (HDMCA) sign is an early sign seen on CT head after acute ischemic stroke indicating acute arterial thrombosis. It has been reported as a predictor of stroke morbidity and mortality. The relationship of size of hyperdense middle cerebral artery (MCA) sign with stroke volume and functional outcome has not been sufficiently studied. Methods We did a retrospective analysis of prospectively collected data from 206 cases of acute ischemic stroke eligible for IV rt-PA by time criteria, admitted to Mayo Clinic from March, 2002 through June, 2011. Admission CT Head was studied to identify HDMCA sign which was further subcategorized according to size. CT head at 24 hours after intravenous tissue plasminogen activator was used to calculate Alberta Stroke Program Early CT Score (ASPECTS) to measure ischemic damage area. Functional outcome was assessed using the modified Rankin score at 3 months and dichotomized into less than equal to 2 (good outcome) and more than 2 (bad outcome). Univariate analysis including t-test, Chi-square, and Fisher Exact test was used when appropriate. Results Mean admission NIHSS score was 11±7. HDMCA sign was seen in 99 (48%) patients: 100% MCA occlusion (7) 76-100% M1 (17), 50-75% M1 (17), less than 50% M1 (6), MCA dot sign (23), sylvian dot sign (21) and sylvian MCA sign, defined as any sylvian MCA occlusion bigger than a dot (8). Univariate analysis showed statistically significant associations between our HDMCA classification and ASPECTS at 24 hours (p<0.001) and modified Rankin score at 3 months (p<0.001). Smaller infarctions (ASPECTS >8) were observed more often with lower MCA clot burden; MCA dot (48%), less than 50% MCA (80%), sylvian dot (57%) and sylvian MCA (38%), 50-75% M1 (6%), 75-100% M1 (0%) and 100% MCA (0%). Good outcome (mRS≤2 at 3 months) was seen more often with lower MCA clot burden; MCA dot (52%), less than 50% MCA (67%), sylvian dot (67%) and sylvian MCA (63%). Conversely, larger HDMCA size was associated with poor outcome (mRS>2); 50-75% M1 (100%), 75-100% (88%) and 100% MCA (100%). Conclusion The size of the HDMCA sign size is an important predictor of ischemic stroke mortality and morbidity. HDMCA should be measured upon admission as it may help refine prognostication and identify patients who could benefit from endovascular rescue therapy after intravenous thrombolysis.

Background: Whether a significant proportion of cryptogenic stroke (CS) is caused by under-detected paroxysmal atrial fibrillation (PAF) is not known. Prolonged ambulatory cardiac monitoring may detect episodes of PAF in patients with stroke of unknown cause (cryptogenic stroke, CS). However, it is unclear whether PAF is more common in patients wtih CS compared with patients with stroke of known cause (SKC). We performed a case control study to compare the rates of detection of PAF in CS vs SKC using prolonged ambulatory cardiac rhythm monitoring. Methods and Results: We prospectively enrolled 132 patients within 3 months of a stroke (66 with CS and 66 with SKC) to undergo 3-week ambulatory cardiac rhythm monitoring using the CardioNet MCOT system. Stroke group was assigned by consensus between two vascular neurologists upon enrollment based on the Causative Classification of Stroke system. Primary endpoint was detection of PAF of any duration independently confirmed by two cardiologists blinded to the stroke group. The groups were well balanced except that patients with CS tended to be older and to have less hypertension and diabetes. Four patients (2 in each group) were excluded because of insufficient stroke evaluation or early discontinuation of monitoring. Episodes of PAF were detected in 16/64 (25%) patients with CS and 9/64 (14%) patients with SKC (p=0.12). Only 5 patients had episodes of PAF lasting > 30 seconds (3 with CS and 2 with SKC). Six of the 9 patients from the SKC group with PAF had small subcortical infarctions; the other 3 had cortical strokes ascribed to artery-to-artery embolism (2 with complex aortic plaques, 1 with severe vertebrobasilar stenosis). In patients under age 65, episodes of PAF were more common in the CS group (22% vs 3; p=0.07) while in patients age 65 or older the rates of detection were very similar (29% in CS vs 28% in SKC; p=0.9). Conclusions: Very short episodes of PAF are relatively common in patients with CS and with SKC, and their pathogenic significance is unclear. However, considering only patients under 65, a greater proportion of cryptogenic stroke patients had PAF, suggesting it might be pathogenic.