False-Negative Initial Magnetic Resonance Imaging in Acute Posterior Circulation Stroke: A Case Report Describing Locked-in Syndrome.

Locked-in syndrome is defined as quadriplegia and anarthria with the preservation of consciousness. Typically, locked-in syndrome is caused by an insult to the ventral pons secondary to trauma or vascular disease. Presented herein is a case of a locked-in syndrome with an initial MRI with no restricted diffusion and clinical deterioration over the course of four days. Repeat interval MRI demonstrated bilateral pontine ischemia.

Association Between Left Ventricular Ejection Fraction, Wall Motion Abnormality, and Embolic Stroke of Undetermined Source.

Background It is uncertain whether there is an association between left ventricular (LV) ejection fraction ( LVEF ) or LV wall motion abnormality and embolic stroke of undetermined source ( ESUS ). Methods and Results We performed a retrospective, cross-sectional study of patients with acute ischemic stroke enrolled in the CAESAR (Cornell Acute Stroke Academic Registry) from 2011 to 2016. We restricted this study to patients with ESUS and, as controls, those with small- and large-artery ischemic strokes. LVEF had to be above 35% to be considered ESUS . In a secondary analysis, we excluded patients with ESUS who had any evidence of ipsilateral carotid atherosclerosis. Multiple logistic regression was used to evaluate whether LVEF or LV wall motion abnormality was associated with ESUS . We performed a confirmatory study at another tertiary-care center. We identified 885 patients with ESUS (n=503) or small- or large-artery strokes (n=382). Among the entire cohort, LVEF was not associated with ESUS (odds ratio per 5% decrement in LVEF , 1.0; 95% CI, 1.0-1.1) and LV wall motion abnormality was not associated with ESUS (odds ratio, 0.9; 95% CI, 0.5-1.6). The results were identical in our confirmatory study. In our secondary analysis excluding ESUS patients with any evidence of ipsilateral carotid atherosclerosis, there was an association between LVEF and ESUS (odds ratio per 5% decrement in LVEF , 1.2; 95% CI, 1.0-1.5; P=0.04). Conclusions Among the entire cohort, no association existed between LVEF or LV wall motion abnormality and ESUS ; however, after excluding ESUS patients with any evidence of ipsilateral carotid atherosclerosis, lower LVEF appeared to be associated with ESUS .

Cardiac Biomarkers Predict Large Vessel Occlusion in Patients with Ischemic Stroke.

BACKGROUND AND PURPOSE: Cardiac biomarkers may help identify stroke mechanisms and may aid in improving stroke prevention strategies. There is limited data on the association between these biomarkers and acute ischemic stroke (AIS) caused by large vessel occlusion (LVO). We hypothesized that cardiac biomarkers (cardiac troponin and left atrial diameter [LAD]) would be associated with the presence of LVO. METHODS: Data were abstracted from a single center prospective AIS database over 18 months and included all patients with AIS with CT angiography of the head and neck. The presence of LVO was defined as proximal LVO of the internal carotid artery terminus, middle cerebral artery (M1 or proximal M2), or basilar artery. Univariate analyses and predefined multivariable models were performed to determine the association between cardiac biomarkers (positive troponin [troponin ≥0.1 ng/mL] and LAD on transthoracic echocardiogram) and LVO adjusting for demographic factors (age and sex), risk factors (hypertension, diabetes, hyperlipidemia, history of stroke, congestive heart failure, coronary heart disease, and smoking), and atrial fibrillation (AF). RESULTS: We identified 1234 patients admitted with AIS; 886 patients (71.8%) had vascular imaging to detect LVO. Of those with imaging available, 374 patients (42.2%) had LVO and 207 patients (23.4%) underwent thrombectomy. There was an association between positive troponin and LVO after adjusting for age, sex and other risk factors (adjusted OR 1.69 [1.08-2.63], P = .022) and this association persisted after including AF in the model (adjusted OR 1.60 [1.02-2.53], P = 0.043). There was an association between LAD and LVO after adjusting for age, sex, and risk factors (adjusted OR per mm 1.03 [1.01-1.05], P = 0.013) but this association was not present when AF was added to the model (adjusted OR 1.01 [0.99-1.04], P = .346). Sensitivity analyses using thrombectomy as an outcome yielded similar findings. CONCLUSIONS: Cardiac biomarkers, particularly serum troponin levels, are associated with acute LVO in patients with ischemic stroke. Prospective studies are ongoing to confirm this association and to test whether anticoagulation reduces the risk of recurrent embolism in this patient population.

National Trends in Hospitalizations for Stroke Associated With Infective Endocarditis and Opioid Use Between 1993 and 2015.

Background and Purpose- There has been a recent sharp rise in opioid-related deaths in the United States. Intravenous opioid use can lead to infective endocarditis (IE) which can result in stroke. There are scant data on recent trends in this neurological complication of opioid abuse. We hypothesized that increasing opioid abuse has led to a higher incidence of stroke associated with IE and opioid use. Methods- We used the 1993 to 2015 releases of the National Inpatient Sample and validated International Classification of Diseases, Ninth Revision, Clinical Modification codes ( ICD-9-CM) to identify hospitalizations with the combination of opioid abuse, IE, and stroke (defined as ischemic stroke, intracerebral hemorrhage, or subarachnoid hemorrhage). Survey weights provided by the National Inpatient Sample were used to calculate nationally representative estimates and population estimates from the United States. Census data were used to calculate annual hospitalization rates per 10 million person-years. Joinpoint regression was used to assess trends. Results- From 1993 through 2015, there were 5283 hospitalizations with stroke associated with IE and opioid use. Across this period, the rate of such hospitalizations increased from 2.4 (95% CI, 0.5-4.3) to 18.8 (95% CI, 14.4-23.3) per 10 million US residents. Joinpoint regression detected 2 segments: no significant change in the hospitalization rate was apparent from 1993 to 2008 (annual percentage change, 1.9%; 95% CI, -2.2% to 6.1%), and then rates significantly increased from 2008 to 2015 (annual percentage change, 20.3%; 95% CI, 10.5%-30.9%), most dramatically in non-Hispanic white patients in the Northeastern and Southern United States. Conclusions- US hospitalization rates for stroke associated with IE and opioid use were stable for ≈2 decades but then sharply increased starting in 2008, coinciding with the emergence of the opioid epidemic.

Clinical Impact of Thrombophilia Screening in Young Adults with Ischemic Stroke.

OBJECTIVE: We evaluated the ability of genetic and serological testing to diagnose clinically relevant thrombophilias in young adults with ischemic stroke. METHODS: We performed a retrospective cohort study of patients aged 18-65 years diagnosed with acute ischemic stroke at a comprehensive stroke center between 2011 and 2015 with laboratory testing for thrombophilia. The primary outcome was any positive thrombophilia screening test. The secondary outcome was a change in clinical management based on thrombophilia testing results. Logistic regression was used to assess whether the prespecified risk factors of age, sex, prior venous thromboembolism, family history of stroke, stroke subtype, and presence of patent foramen ovale were associated with outcomes. RESULTS: Among 196 young ischemic stroke patients, at least 1 positive thrombophilia test was identified in 85 patients (43%; 95% CI, 36%-51%) and 16 (8%; 95% CI, 5%-13%) had a resultant change in management. Among 111 patients with cryptogenic strokes, 49 (44%) had an abnormal thrombophilia test and 9 (8%) had a change in management. After excluding cases of isolated hyperhomocysteinemia or methylenetetrahydrofolate reductase or Factor V Leiden gene mutation heterozygosity, the proportion of patients with an abnormal thrombophilia screen decreased to 24%. Prespecified risk factors were not significantly associated with positive thrombophilia testing or a change in management. CONCLUSIONS: Two-of-five young patients with ischemic stroke who underwent thrombophilia screening at our institution had at least 1 positive test but only one-in-twelve had a resultant change in clinical management. Neither cryptogenic stroke subtype nor other studied clinical factors were associated with a prothrombotic state.

Troponin Improves the Yield of Transthoracic Echocardiography in Ischemic Stroke Patients of Determined Stroke Subtype.

Background and Purpose- Transthoracic echocardiography (TTE) is widely used in the ischemic stroke setting. In this study, we aim to investigate the yield of TTE in patients with ischemic stroke and known subtype and whether the admission troponin level improves the yield of TTE. Methods- Data were abstracted from a single-center prospective ischemic stroke database for 18 months and included all patients with ischemic stroke whose etiologic subtype could be obtained without the need of TTE. Unadjusted and adjusted regression models were built to determine whether positive cardiac troponin levels (≥0.1 ng/mL) improve the yield of TTE, adjusting for demographic and clinical characteristics. Results- We identified 578 patients who met the inclusion criteria. TTE changed clinical management in 64 patients (11.1%), but intracardiac thrombus was detected in only 4 patients (0.7%). In multivariable models, there was an association between TTE changing management and positive serum troponin level (adjusted odds ratio, 4.26; 95% CI, 2.17-8.34; P<0.001). Conclusions- In patients with ischemic stroke, TTE might lead to a change in clinical management in ≈1 of 10 patients with known stroke subtype before TTE but changed acute treatment decisions in <1 percent of patients. Serum troponin levels improved the yield of TTE in these patients.

Population-Based Assessment of the Long-Term Risk of Seizures in Survivors of Stroke.

BACKGROUND AND PURPOSE: We sought to determine the long-term risk of seizures after stroke according to age, sex, race, and stroke subtype. METHODS: We performed a retrospective cohort study using administrative claims from 2 complementary patient data sets. First, we analyzed data from all emergency department visits and hospitalizations in California, Florida, and New York from 2005 to 2013. Second, we evaluated inpatient and outpatient claims from a nationally representative 5% random sample of Medicare beneficiaries. Our cohort consisted of all adults at the time of acute stroke hospitalization without a prior history of seizures. Our outcome was seizure occurring after hospital discharge for stroke. Poisson regression and demographic data were used to calculate age-, sex-, and race-standardized incidence rate ratios (IRR). RESULTS: Among 777 276 patients in the multistate cohort, the annual incidence of seizures was 1.68% (95% confidence interval [CI], 1.67%-1.70%) after stroke versus 0.15% (95% CI, 0.15%-0.15%) among the general population (IRR, 7.3; 95% CI, 7.3-7.4). By 8 years, the cumulative rate of any emergency department visit or hospitalization for seizure was 9.27% (95% CI, 9.16%-9.38%) after stroke versus 1.21% (95% CI, 1.21%-1.22%) in the general population. Stroke was more strongly associated with a subsequent seizure among patients <65 years of age (IRR, 12.0; 95% CI, 11.9-12.2) than in patients ≥65 years of age (IRR, 5.5; 95% CI, 5.4-5.5) and in the multistate analysis, the association between stroke and seizure was stronger among nonwhite patients (IRR, 11.0; 95% CI, 10.8-11.2) than among white patients (IRR, 7.3; 95% CI, 7.2-7.4). Risks were especially elevated after intracerebral hemorrhage (IRR, 13.3; 95% CI, 13.0-13.6) and subarachnoid hemorrhage (IRR, 13.2; 95% CI, 12.8-13.7). Our study of Medicare beneficiaries confirmed these findings. CONCLUSIONS: Almost 10% of patients with stroke will develop seizures within a decade. Hemorrhagic stroke, nonwhite race, and younger age seem to confer the greatest risk of developing seizures.

Clinical Information Systems Integration in New York City's First Mobile Stroke Unit.

BACKGROUND: Mobile stroke units (MSUs) reduce time to thrombolytic therapy in acute ischemic stroke. These units are widely used, but the clinical information systems underlying MSU operations are understudied. OBJECTIVE: The first MSU on the East Coast of the United States was established at New York Presbyterian Hospital (NYP) in October 2016. We describe our program's 7-month pilot, focusing on the integration of our hospital's clinical information systems into our MSU to support patient care and research efforts. METHODS: NYP's MSU was staffed by two paramedics, one radiology technologist, and a vascular neurologist. The unit was equipped with four laptop computers and networking infrastructure enabling all staff to access the hospital intranet and clinical applications during operating hours. A telephone-based registration procedure registered patients from the field into our admit/discharge/transfer system, which interfaced with the institutional electronic health record (EHR). We developed and implemented a computerized physician order entry set in our EHR with prefilled values to permit quick ordering of medications, imaging, and laboratory testing. We also developed and implemented a structured clinician note to facilitate care documentation and clinical data extraction. RESULTS: Our MSU began operating on October 3, 2016. As of April 27, 2017, the MSU transported 49 patients, of whom 16 received tissue plasminogen activator (t-PA). Zero technical problems impacting patient care were reported around registration, order entry, or intranet access. Two onboard network failures occurred, resulting in computed tomography scanner malfunctions, although no patients became ineligible for time-sensitive treatment as a result. Thirteen (26.5%) clinical notes contained at least one incomplete time field. CONCLUSION: The main technical challenges encountered during the integration of our hospital's clinical information systems into our MSU were onboard network failures and incomplete clinical documentation. Future studies are necessary to determine whether such integrative efforts improve MSU care quality, and which enhancements to information systems will optimize clinical care and research efforts.

Modeling the Impact of Interhospital Transfer Network Design on Stroke Outcomes in a Large City.

BACKGROUND AND PURPOSE: We sought to model the effects of interhospital transfer network design on endovascular therapy eligibility and clinical outcomes of stroke because of large-vessel occlusion for the residents of a large city. METHODS: We modeled 3 transfer network designs for New York City. In model A, patients were transferred from spoke hospitals to the closest hub hospitals with endovascular capabilities irrespective of hospital affiliation. In model B, which was considered the base case, patients were transferred to the closest affiliated hub hospitals. In model C, patients were transferred to the closest affiliated hospitals, and transfer times were adjusted to reflect full implementation of streamlined transfer protocols. Using Monte Carlo methods, we simulated the distributions of endovascular therapy eligibility and good functional outcomes (modified Rankin Scale score, 0-2) in these models. RESULTS: In our models, 200 patients (interquartile range [IQR], 168-227) with a stroke amenable to endovascular therapy present to New York City spoke hospitals each year. Transferring patients to the closest hub hospital irrespective of affiliation (model A) resulted in 4 (IQR, 1-9) additional patients being eligible for endovascular therapy and an additional 1 (IQR, 0-2) patient achieving functional independence. Transferring patients only to affiliated hospitals while simulating full implementation of streamlined transfer protocols (model C) resulted in 17 (IQR, 3-41) additional patients being eligible for endovascular therapy and 3 (IQR, 1-8) additional patients achieving functional independence. CONCLUSIONS: Optimizing acute stroke transfer networks resulted in clinically small changes in population-level stroke outcomes in a dense, urban area.

Left Atrial Enlargement and Anticoagulation Status in Patients with Acute Ischemic Stroke and Atrial Fibrillation.

BACKGROUND: Despite anticoagulation therapy, ischemic stroke risk in atrial fibrillation (AF) remains substantial. We hypothesize that left atrial enlargement (LAE) is more prevalent in AF patients admitted with ischemic stroke who are therapeutic, as opposed to nontherapeutic, on anticoagulation. METHODS: We included consecutive patients with AF admitted with ischemic stroke between April 1, 2015, and December 31, 2016. Patients were divided into two groups based on whether they were therapeutic (warfarin with an international normalized ratio ≥ 2.0 or non-vitamin K oral anticoagulant with uninterrupted use in the prior 2 weeks) versus nontherapeutic on anticoagulation. Univariable and multivariable models were used to estimate associations between therapeutic anticoagulation and clinical factors, including CHADS2 score and LAE (none/mild versus moderate/severe). RESULTS: We identified 225 patients during the study period; 52 (23.1%) were therapeutic on anticoagulation. Patients therapeutic on anticoagulation were more likely to have a larger left atrial diameter in millimeters (45.6 ± 9.2 versus 42.3 ± 8.6, P = .032) and a higher CHADS2 score (2.9 ± 1.1 versus 2.4 ± 1.1, P = .03). After adjusting for the CHADS2 score, patients who had a stroke despite therapeutic anticoagulation were more likely to have moderate to severe LAE (odds ratio, 2.05; 95% confidence interval, 1.01-4.16). CONCLUSION: LAE is associated with anticoagulation failure in AF patients admitted with an ischemic stroke. This provides indirect evidence that LAE may portend failure of anticoagulation therapy in patients with AF; further studies are needed to delineate the significance of this association and improve stroke prevention strategies.

Early Elevated Troponin Levels After Ischemic Stroke Suggests a Cardioembolic Source.

BACKGROUND AND PURPOSE: Elevated cardiac troponin is a marker of cardiac disease and has been recently shown to be associated with embolic stroke risk. We hypothesize that early elevated troponin levels in the acute stroke setting are more prevalent in patients with embolic stroke subtypes (cardioembolic and embolic stroke of unknown source) as opposed to noncardioembolic subtypes (large-vessel disease, small-vessel disease, and other). METHODS: We abstracted data from our prospective ischemic stroke database and included all patients with ischemic stroke during an 18-month period. Per our laboratory, we defined positive troponin as ≥0.1 ng/mL and intermediate as ≥0.06 ng/mL and <0.1 ng/mL. Unadjusted and adjusted regression models were built to determine the association between stroke subtype (embolic stroke of unknown source and cardioembolic subtypes) and positive and intermediate troponin levels, adjusting for key confounders, including demographics (age and sex), clinical characteristics (hypertension, hyperlipidemia, diabetes mellitus, renal function, coronary heart disease, congestive heart failure, current smoking, and National Institutes of Health Stroke Scale score), cardiac variables (left atrial diameter, wall-motion abnormalities, ejection fraction, and PR interval on ECG), and insular involvement of infarct. RESULTS: We identified 1234 patients, of whom 1129 had admission troponin levels available; 10.0% (113/1129) of these had a positive troponin. In fully adjusted models, there was an association between troponin positivity and embolic stroke of unknown source subtype (adjusted odds ratio, 4.46; 95% confidence interval, 1.03-7.97; P=0.003) and cardioembolic stroke subtype (odds ratio, 5.00; 95% confidence interval, 1.83-13.63; P=0.002). CONCLUSIONS: We found that early positive troponin after ischemic stroke may be independently associated with a cardiac embolic source. Future studies are needed to confirm our findings using high-sensitivity troponin assays and to test optimal secondary prevention strategies in patients with embolic stroke of unknown source and positive troponin.

Association Between Troponin Levels and Embolic Stroke of Undetermined Source.

BACKGROUND: Our aim was to determine whether patients with embolic strokes of undetermined source (ESUS) have higher rates of elevated troponin than patients with noncardioembolic strokes. METHODS AND RESULTS: CAESAR (The Cornell Acute Stroke Academic Registry) prospectively enrolled all adults with acute stroke from 2011 to 2014. Two neurologists used standard definitions to retrospectively ascertain the etiology of stroke, with a third resolving disagreements. In this analysis we included patients with ESUS and, as controls, patients with small- and large-artery strokes; only patients with a troponin measured within 24 hours of stroke onset were included. A troponin elevation was defined as a value exceeding our laboratory's upper limit (0.04 ng/mL) without a clinically recognized acute ST-segment elevation myocardial infarction. Multiple logistic regression was used to evaluate the association between troponin elevation and ESUS after adjustment for demographics, stroke severity, insular infarction, and vascular risk factors. In a sensitivity analysis we excluded patients diagnosed with atrial fibrillation after discharge. Among 512 patients, 243 (47.5%) had ESUS, and 269 (52.5%) had small- or large-artery stroke. In multivariable analysis an elevated troponin was independently associated with ESUS (odds ratio 3.3; 95% confidence interval 1.2, 8.8). This result was unchanged after excluding patients diagnosed with atrial fibrillation after discharge (odds ratio 3.4; 95% confidence interval 1.3, 9.1), and the association remained significant when troponin was considered a continuous variable (odds ratio for log[troponin], 1.4; 95% confidence interval 1.1, 1.7). CONCLUSIONS: Elevations in cardiac troponin are more common in patients with ESUS than in those with noncardioembolic strokes.

Safety Outcomes After Thrombolysis for Acute Ischemic Stroke in Patients With Recent Stroke.

BACKGROUND AND PURPOSE: It is uncertain whether previous ischemic stroke within 3 months of receiving intravenous thrombolysis (tPA [tissue-type plasminogen activator]) for acute ischemic stroke (AIS) is associated with an increased risk of adverse outcomes. METHODS: Using administrative claims data, we identified adults with AIS who received intravenous tPA at California, New York, and Florida hospitals from 2005 to 2013. Our primary outcome was intracerebral hemorrhage, and our secondary outcomes were unfavorable discharge disposition and inpatient mortality. We used logistic regression to compare rates of outcomes in patients with and without previous ischemic stroke within 3 months of intravenous tPA for AIS. RESULTS: We identified 36 599 AIS patients treated with intravenous tPA, of whom 568 (1.6%) had a previous ischemic stroke in the past 3 months. Of all patients who received intravenous tPA, the rate of intracerebral hemorrhage was 4.9% (95% confidence interval [CI], 4.7%-5.1%), and death occurred in 10.7% (95% CI, 10.4%-11.0%). After adjusting for demographics, vascular risk factors, and the Elixhauser Comorbidity Index, previous ischemic stroke within 3 months of thrombolysis for AIS was not associated with an increased risk of intracerebral hemorrhage (odds ratio, 0.9; 95% CI, 0.6-1.4; P=0.62), but was associated with an increased risk of death (odds ratio, 1.5; 95% CI, 1.2-1.9; P=0.001) and unfavorable discharge disposition (odds ratio, 1.3; 95% CI, 1.0-1.7; P=0.04). CONCLUSIONS: Among patients who receive intravenous tPA for AIS, recent ischemic stroke is not associated with an increased risk of intracerebral hemorrhage but is associated with a higher risk of death and unfavorable discharge disposition.

Rates of Spinal Cord Infarction After Repair of Aortic Aneurysm or Dissection.

BACKGROUND AND PURPOSE: The rate of spinal cord infarction (SCI) after surgical or endovascular repair of an aortic aneurysm or dissection is unclear. METHODS: Using administrative claims data, we identified adult patients discharged from nonfederal acute care hospitals in California, New York, and Florida who underwent surgical or endovascular repair of an aortic aneurysm or dissection between 2005 and 2013. Patients with SCI diagnosed before the aortic repair were excluded. Our primary outcome was an SCI during the index hospitalization for aortic repair. Descriptive statistics were used to estimate crude rates of SCI. Analyses were stratified by whether the aneurysm or dissection had ruptured and by type of repair (surgical versus endovascular). RESULTS: We identified 91 212 patients who had repair of an aortic aneurysm or dissection. SCI occurred in 235 cases (0.26%; 95% confidence interval [CI], 0.22%-0.29%). In patients with ruptured aneurysm or dissection, the rate of SCI was 0.74% (95% CI, 0.60%-0.88%) compared with 0.16% (95% CI, 0.13%-0.19%) with unruptured aneurysm. In secondary analyses, rates of SCI were similar after endovascular repair (0.91%; 95% CI, 0.62%-1.19%) compared with surgical repair (0.68%; 95% CI, 0.53%-0.83%; P=0.147) of ruptured aortic aneurysm or dissection; however, rates of SCI were higher after surgical repair (0.20%; 95% CI, 0.15%-0.25%) versus endovascular repair (0.11%; 95% CI, 0.08%-0.14%; P<0.001) of unruptured aneurysm. CONCLUSIONS: SCI occurs in ≈1 in 130 patients undergoing aortic dissection or ruptured aortic aneurysm repair and in 1 in 600 patients undergoing unruptured aortic aneurysm repair.

Risk of Pulmonary Embolism After Cerebral Venous Thrombosis.

BACKGROUND AND PURPOSE: Cerebral vein thrombosis (CVT) is a type of venous thromboembolism. Whether the risk of pulmonary embolism (PE) after CVT is similar to the risk after deep venous thrombosis (DVT) is unknown. METHODS: We performed a retrospective cohort study using administrative data from all emergency department visits and hospitalizations in California, New York, and Florida from 2005 to 2013. We identified patients with CVT or DVT and the outcome of PE using previously validated International Classification of Diseases, Ninth Revision, Clinical Modification codes. Kaplan-Meier survival statistics and Cox proportional hazards models were used to compare the risk of PE after CVT versus PE after DVT. RESULTS: We identified 4754 patients with CVT and 241 276 with DVT. During a mean follow-up of 3.4 (±2.4) years, 138 patients with CVT and 23 063 with DVT developed PE. CVT patients were younger, more often female, and had fewer risk factors for thromboembolism than patients with DVT. During the index hospitalization, the rate of PE was 1.4% (95% confidence interval [CI], 1.1%-1.8%) in patients with CVT and 6.6% (95% CI, 6.5%-6.7%) in patients with DVT. By 5 years, the cumulative rate of PE after CVT was 3.4% (95% CI, 2.9%-4.0%) compared with 10.9% (95% CI, 10.8%-11.0%; P<0.001) after DVT. CVT was associated with a lower adjusted hazard of PE than DVT (hazard ratio, 0.26; 95% CI, 0.22-0.31). CONCLUSION: The risk of PE after CVT was significantly lower than the risk after DVT. Among patients with CVT, the greatest risk for PE was during the index hospitalization.

Cryptogenic Stroke and Nonstenosing Intracranial Calcified Atherosclerosis.

OBJECTIVE: Because some cryptogenic strokes may result from large-artery atherosclerosis that goes unrecognized as it causes <50% luminal stenosis, we compared the prevalence of nonstenosing intracranial atherosclerotic plaques ipsilateral to cryptogenic cerebral infarcts versus the unaffected side using imaging biomarkers of calcium burden. METHODS: In a prospective stroke registry, we identified patients with cerebral infarction limited to the territory of one internal carotid artery (ICA). We included patients with stroke of undetermined etiology and, as controls, patients with cardioembolic stroke. We used noncontrast computed tomography to measure calcification in both intracranial ICAs, including qualitative calcium scoring and quantitative scoring utilizing the Agatston-Janowitz (AJ) calcium scoring. Within subjects, the Wilcoxon signed-rank sum test for nonparametric paired data was used to compare the calcium burden in the ICA upstream of the infarction versus the ICA on the unaffected side. RESULTS: We obtained 440 calcium measures from 110 ICAs in 55 patients. Among 34 patients with stroke of undetermined etiology, we found greater calcium in the ICA ipsilateral to the infarction (mean Modified Woodcock Visual Scale score, 6.7 ± 4.6) compared with the contralateral side (5.4 ± 4.1) (P = .005). Among 21 patients with cardioembolic stroke, we found no difference in calcium burden ipsilateral to the infarction (6.7 ± 5.9) versus the contralateral side (7.3 ± 6.3) (P = .13). The results were similar using quantitative calcium measurements, including the AJ calcium scores. CONCLUSION: In patients with strokes of undetermined etiology, the burden of calcified intracranial large-artery plaque was associated with downstream cerebral infarction.

Risk of Intracerebral Hemorrhage after Emergency Department Discharges for Hypertension.

BACKGROUND: Recent literature suggests that acute rises in blood pressure may precede intracerebral hemorrhage. We therefore hypothesized that patients discharged from the emergency department with hypertension face an increased risk of intracerebral hemorrhage in subsequent weeks. METHODS: Using administrative claims data from California, New York, and Florida, we identified all patients discharged from the emergency department from 2005 to 2011 with a primary diagnosis of hypertension (ICD-9-CM codes 401-405). We excluded patients if they were hospitalized from the emergency department or had prior histories of cerebrovascular disease at the index visit with hypertension. We used the Mantel-Haenszel estimator for matched data to compare each patient's odds of intracerebral hemorrhage during days 8-38 after emergency department discharge to the same patient's odds during days 373-403 after discharge. This cohort-crossover design with a 1-week washout period enabled individual patients to serve as their own controls, thereby minimizing confounding bias. RESULTS: Among the 552,569 patients discharged from the emergency department with a primary diagnosis of hypertension, 93 (.017%) were diagnosed with intracerebral hemorrhage during days 8-38 after discharge compared to 70 (.013%) during days 373-403 (odds ratio 1.33, 95% confidence interval .96-1.84). The odds of intracerebral hemorrhage were increased in certain subgroups of patients (≥60 years of age and those with secondary discharge diagnoses besides hypertension), but absolute risks were low in all subgroups. CONCLUSIONS: Patients with emergency department discharges for hypertension do not face a substantially increased short-term risk of intracerebral hemorrhage after discharge.

Risk of Stroke After the International Classification of Diseases-Ninth Revision Discharge Code Diagnosis of Hypertensive Encephalopathy.

BACKGROUND AND PURPOSE: Although chronic hypertension is a well-established risk factor for stroke, little is known about stroke risk after hypertensive encephalopathy (HE), when neurologic sequelae of hypertension become evident. Therefore, we evaluated the risk of stroke after a diagnosis of HE. METHODS: We identified all patients discharged from California, New York, and Florida emergency departments and acute care hospitals between 2005 and 2012 with a primary International Classification of Diseases, Ninth Edition, Clinical Modification discharge diagnosis of HE (437.2). Patients discharged with a primary diagnosis of seizure (345.x) served as negative controls, whereas patients with a primary diagnosis of transient ischemic attack (435.x) were positive controls. Our primary outcome was the composite of subsequent ischemic stroke or intracerebral hemorrhage. Kaplan-Meier survival statistics were used to calculate cumulative outcome rates, and Cox proportional hazard analysis was used to examine the association between index disease types and outcomes while adjusting for vascular risk factors. RESULTS: We identified 8233 patients with HE, 191 091 with seizure, and 308 680 with transient ischemic attack. The 1-year cumulative rate of ischemic stroke or intracerebral hemorrhage after HE was 4.90% (95% confidence interval [CI], 4.45-5.40) when compared with 0.92% (95% CI, 0.88-0.97) after seizure and 4.49% (95% CI, 4.42-4.57) after transient ischemic attack. The risk of intracerebral hemorrhage was significantly elevated in those with HE (hazard ratio, 2.0; 95% CI, 1.7-2.5) but not in those with transient ischemic attack (hazard ratio, 1.0; 95% CI, 0.9-1.1), when compared with seizure patients. CONCLUSIONS: Patients discharged with a diagnosis of HE face a high risk of future cerebrovascular events, particularly intracerebral hemorrhage.

Risk of Ischemic Stroke after Intracranial Hemorrhage in Patients with Atrial Fibrillation.

BACKGROUND: We aimed to estimate the risk of ischemic stroke after intracranial hemorrhage in patients with atrial fibrillation. MATERIALS AND METHODS: Using discharge data from all nonfederal acute care hospitals and emergency departments in California, Florida, and New York from 2005 to 2012, we identified patients at the time of a first-recorded encounter with a diagnosis of atrial fibrillation. Ischemic stroke and intracranial hemorrhage were identified using validated diagnosis codes. Kaplan-Meier survival statistics and Cox proportional hazard analyses were used to evaluate cumulative rates of ischemic stroke and the relationship between incident intracranial hemorrhage and subsequent stroke. RESULTS: Among 2,084,735 patients with atrial fibrillation, 50,468 (2.4%) developed intracranial hemorrhage and 89,594 (4.3%) developed ischemic stroke during a mean follow-up period of 3.2 years. The 1-year cumulative rate of stroke was 8.1% (95% CI, 7.5-8.7%) after intracerebral hemorrhage, 3.9% (95% CI, 3.5-4.3%) after subdural hemorrhage, and 2.0% (95% CI, 2.0-2.1%) in those without intracranial hemorrhage. After adjustment for the CHA2DS2-VASc score, stroke risk was elevated after both intracerebral hemorrhage (hazard ratio [HR], 2.8; 95% CI, 2.6-2.9) and subdural hemorrhage (HR, 1.6; 95% CI, 1.5-1.7). Cumulative 1-year rates of stroke ranged from 0.9% in those with subdural hemorrhage and a CHA2DS2-VASc score of 0, to 33.3% in those with intracerebral hemorrhage and a CHA2DS2-VASc score of 9. CONCLUSIONS: In a large, heterogeneous cohort, patients with atrial fibrillation faced a substantially heightened risk of ischemic stroke after intracranial hemorrhage. The risk was most marked in those with intracerebral hemorrhage and high CHA2DS2-VASc scores.