Racial Differences in Atrial Cardiopathy Phenotypes in Ischemic Stroke Patients.

OBJECTIVE: To test the hypothesis that thrombogenic atrial cardiopathy may be relevant to stroke-related racial disparities, we compared atrial cardiopathy phenotypes between Black versus White ischemic stroke patients. METHODS: We assessed markers of atrial cardiopathy in the Greater Cincinnati/Northern Kentucky Stroke Study, a study of stroke incidence in a population of 1.3 million. We obtained ECGs and reports of echocardiograms performed during evaluation of stroke during the 2010/2015 study periods. Patients with atrial fibrillation (AF) or flutter (AFL) were excluded. Investigators blinded to patients' characteristics measured P-wave terminal force in ECG lead V1 (PTFV1), a marker of left atrial fibrosis and impaired inter-atrial conduction, and abstracted left atrial diameter from echocardiogram reports. Linear regression was used to examine the association between race and atrial cardiopathy markers after adjustment for demographics, body mass index, and vascular comorbidities. RESULTS: Among 3,426 ischemic stroke cases in Black or White patients without AF/AFL, 2,391 had a left atrial diameter measurement (mean, 3.65 ±0.70 cm). Black race was associated with smaller left atrial diameter in unadjusted (ß coefficient, -0.11; 95% CI, -0.17 to -0.05) and adjusted (ß, -0.15; 95% CI, -0.21 to -0.09) models. PTFV1 measurements were available in 3,209 patients (mean, 3,434 ±2,525 µV*ms). Black race was associated with greater PTFV1 in unadjusted (ß, 1.59; 95% CI, 1.21 to 1.97) and adjusted (ß, 1.45; 95% CI, 1.00 to 1.80) models. CONCLUSIONS: We found systematic Black-White racial differences in left atrial structure and pathophysiology in a population-based sample of ischemic stroke patients. CLASSIFICATION OF EVIDENCE: This study provides class II evidence that the rate of atrial cardiopathy is greater among Black people with acute stroke compared to White people.

Gastrointestinal Disorders and Risk of First-Ever Ischemic Stroke.

BACKGROUND AND PURPOSE: Recent studies suggest that alteration of the normal gut microbiome contributes to atherosclerotic burden and cardiovascular disease. While many gastrointestinal diseases are known to cause disruption of the normal gut microbiome in humans, the clinical impact of gastrointestinal diseases on subsequent cerebrovascular disease remains unknown. We conducted an exploratory analysis evaluating the relationship between gastrointestinal diseases and ischemic stroke. METHODS: We performed a retrospective cohort study using claims between 2008 and 2015 from a nationally representative 5% sample of Medicare beneficiaries. We included only beneficiaries ≥66 years of age. We used previously validated diagnosis codes to ascertain our primary outcome of ischemic stroke. In an exploratory manner, we categorized gastrointestinal disorders by anatomic location, disease chronicity, and disease mechanism. We used Cox proportional hazards models to examine associations of gastrointestinal disorder categories and ischemic stroke with adjustment for demographics and established vascular risk factors. RESULTS: Among a mean of 1 725 246 beneficiaries in each analysis, several categories of gastrointestinal disorders were associated with an increased risk of ischemic stroke after adjustment for established stroke risk factors. The most notable positive associations included disorders of the stomach (hazard ratio, 1.17 [95% CI, 1.15-1.19]) and functional (1.16 [95% CI, 1.15-1.17]), inflammatory (1.13 [95% CI, 1.12-1.15]), and infectious gastrointestinal disorders (1.13 [95% CI, 1.12-1.15]). In contrast, we found no associations with stroke for diseases of the anus and rectum (0.97 [95% CI, 0.94-1.00]) or neoplastic gastrointestinal disorders (0.97 [95% CI, 0.94-1.00]). CONCLUSIONS: In exploratory analyses, several categories of gastrointestinal disorders were associated with an increased risk of future ischemic stroke after adjustment for demographics and established stroke risk factors.

Use and Removal of Inferior Vena Cava Filters in Patients With Acute Brain Injury.

BACKGROUND: Few data exist regarding the rate of inferior vena cava (IVC) filter retrieval among brain-injured patients. METHODS: We conducted a retrospective cohort study using inpatient claims between 2009 and 2015 from a nationally representative 5% sample of Medicare beneficiaries. We included patients aged ≥65 years who were hospitalized with acute brain injury. The primary outcome was the retrieval of IVC filter at 12 months and the secondary outcomes were the association with 30-day mortality and 12-month freedom from pulmonary embolism (PE). We used Current Procedural Terminology codes to ascertain filter placement and retrieval and International Classification of Diseases, Ninth Revision, Clinical Modification codes to ascertain venous thromboembolism (VTE) diagnoses. We used standard descriptive statistics to calculate the crude rate of filter placement. We used Cox proportional hazards analysis to examine the association between IVC filter placement and mortality and the occurrence of PE after adjustment for demographics, comorbidities, and mechanical ventilation. We used Kaplan-Meier survival statistics to calculate cumulative rates of retrieval 12 months after filter placement. RESULTS: Among 44 641 Medicare beneficiaries, 1068 (2.4%; 95% confidence interval [CI], 2.3%-2.5) received an IVC filter, of whom 452 (42.3%; 95% CI, 39.3%-45.3) had a diagnosis of VTE. After adjusting for demographics, comorbidities, and mechanical ventilation, filter placement was not associated with a reduced risk of mortality (hazard ratio [HR], 1.0; 95% CI, 0.8-1.3) regardless of documented VTE. The occurrence of pulmonary embolism at 12 months was associated with IVC filter placement (HR, 3.19; 95% CI, 1.3-3.3) in the most adjusted model. The cumulative rate of filter retrieval at 12 months was 4.4% (95% CI, 3.1%-6.1%); there was no significant difference in retrieval rates between those with and without VTE. CONCLUSIONS: In a large cohort of Medicare beneficiaries hospitalized with acute brain injury, IVC filter placement was uncommon, but once placed, very few filters were removed. IVC filter placement was not associated with a reduced risk of mortality and did not prevent future PE.

Differences in Diagnostic Evaluation in Women and Men After Acute Ischemic Stroke.

Background Sex differences have been found in stroke risk factors, incidence, treatment, and outcomes. There are conflicting data on whether diagnostic evaluation for stroke may differ between men and women. Methods and Results We performed a retrospective cohort study using inpatient and outpatient claims between 2008 and 2016 from a nationally representative 5% sample of Medicare beneficiaries. We included patients ≥65 years old and hospitalized with ischemic stroke, defined by International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) and ICD-10-CM diagnosis codes. Logistic regression was used to determine the association between female sex and the odds of diagnostic testing and specialist evaluation, adjusted for age, race, and number of Charlson comorbidities. Among 78 822 patients with acute ischemic stroke, 58.3% (95% CI, 57.9-58.6%) were women. Female sex was associated with decreased odds of intracranial vessel imaging (odds ratio [OR]: 0.94; 95% CI, 0.91-0.97), extracranial vessel imaging (OR: 0.89; 95% CI, 0.86-0.92), heart-rhythm monitoring (OR: 0.92; 95% CI, 0.87-0.98), echocardiography (OR: 0.92; 95% CI, 0.89-0.95), evaluation by a neurologist (OR: 0.94; 95% CI, 0.91-0.97), and evaluation by a vascular neurologist (OR: 0.94; 95% CI, 0.90-0.97), after adjustment for age, race, and comorbidities. These findings were unchanged in separate sensitivity analyses excluding patients who died during the index hospitalization or were discharged to hospice and excluding patients with atrial fibrillation diagnosed before their index stroke. Conclusions In a nationally representative cohort of Medicare beneficiaries, we found that women with acute ischemic stroke were less likely to be evaluated by stroke specialists and less likely to undergo standard diagnostic testing compared with men.

Geographic Analysis of Mobile Stroke Unit Treatment in a Dense Urban Area: The New York City METRONOME Registry.

Background Mobile stroke units (MSUs) reduce time to intravenous thrombolysis in acute ischemic stroke. Whether this advantage exists in densely populated urban areas with many proximate hospitals is unclear. Methods and Results We evaluated patients from the METRONOME (Metropolitan New York Mobile Stroke) registry with suspected acute ischemic stroke who were transported by a bi-institutional MSU operating in Manhattan, New York, from October 2016 to September 2017. The comparison group included patients transported to our hospitals via conventional ambulance for acute ischemic stroke during the same hours of MSU operation (Monday to Friday, 9 am to 5 pm). Our exposure was MSU care, and our primary outcome was dispatch-to-thrombolysis time. We estimated mean differences in the primary outcome between both groups, adjusting for clinical, demographic, and geographic factors, including numbers of nearby designated stroke centers and population density. We identified 66 patients treated or transported by MSU and 19 patients transported by conventional ambulance. Patients receiving MSU care had significantly shorter dispatch-to-thrombolysis time than patients receiving conventional care (mean: 61.2 versus 91.6 minutes; P=0.001). Compared with patients receiving conventional care, patients receiving MSU care were significantly more likely to be picked up closer to a higher mean number of designated stroke centers in a 2.0-mile radius (4.8 versus 2.7, P=0.002). In multivariable analysis, MSU care was associated with a mean decrease in dispatch-to-thrombolysis time of 29.7 minutes (95% CI, 6.9-52.5) compared with conventional care. Conclusions In a densely populated urban area with a high number of intermediary stroke centers, MSU care was associated with substantially quicker time to thrombolysis compared with conventional ambulance care.

Rates and Trends of Endotracheal Intubation in Patients With Status Epilepticus.

OBJECTIVE: Among patients with status epilepticus, we sought to determine the rate of endotracheal intubation, identify the physician specialties responsible for endotracheal intubation, and characterize the trend in use of endotracheal intubation over the last 20 years. METHODS: We performed a cross-sectional study using data from 2 sources. First, we used inpatient claims between 2009 and 2015 from a nationally representative 5% sample of Medicare beneficiaries. Patients with status epilepticus were identified using International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) codes, and those who underwent endotracheal intubation were identified based on Current Procedural Terminology codes. Medical specialties of providers performing intubation were identified based on Healthcare Provider Taxonomy Codes. Second, we used claims data from the National Inpatient Sample (NIS) to estimate the annual rates and trends of endotracheal intubation and tracheostomy among patients with status epilepticus from 1995 to 2014. RESULTS: Among 1971 Medicare beneficiaries with status epilepticus, 566 (29%) patients underwent endotracheal intubation. 375 (66%) patients were intubated on admission. The most common medical providers performing intubation in patients with status epilepticus were emergency medicine physicians (50.4%), anesthesiologists (16.4%), and pulmonary medicine physicians (10.1%). Neurologists accounted for 1.7% of all intubations. Among individuals with status epilepticus identified in the NIS, 248 681 (41.7%) were intubated. The proportion of patients intubated increased from 29.5% (95% confidence interval [CI]: 27.8%-31.3%, P = .018) in 1995 to 50.8% (95% CI: 49.6%-52%, P = .012) in 2014. The proportion of patients with status epilepticus who underwent tracheostomy increased from 2.2% (95% CI: 1.7%-2.7%, P = .005) in 1995 to 3.4% (95% CI: 3%-3.9%, P = .004) in 2014. SIGNIFICANCE: Approximately 1 in 3 patients with status epilepticus undergo endotracheal intubation. Over the last 20 years, the proportion of patients with status epilepticus undergoing endotracheal intubation has almost doubled. Neurologists perform a small percentage of these intubations.

Association Between Intravenous Thrombolysis and Anaphylaxis Among Medicare Beneficiaries With Acute Ischemic Stroke.

Background and Purpose- Allergic reactions, including anaphylaxis, can sometimes occur after intravenous thrombolysis in patients with acute ischemic stroke. However, it remains unclear whether patients with stroke who receive thrombolytic agents face a higher risk of anaphylaxis than those who do not receive thrombolytics. Methods- We performed a retrospective cohort study using inpatient and outpatient claims between 2008 and 2015 from a nationally representative 5% sample of Medicare beneficiaries. We included patients who were ≥65 years old and hospitalized with acute ischemic stroke, defined by validated International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis codes. Our exposure was treated with an intravenous thrombolytic agent during the index hospitalization (International Classification of Diseases, Ninth Revision, Clinical Modification code 99.10). Our primary outcome was anaphylaxis, defined using an accepted International Classification of Diseases, Ninth Revision, Clinical Modification code algorithm (989.5, 995.0-4, 995.6x, E905, E905.3, E905.5, or E905.8-9). A secondary outcome was anaphylactic shock (995.0 or 995.6x). Multiple logistic regression was used to evaluate the association between intravenous thrombolysis and anaphylaxis after adjustment for demographics, vascular risk factors, the Charlson comorbidity index, exposure to intravenous contrast dye, treatment with mechanical thrombectomy, and history of allergic reactions. Results- Among 66 989 patients with stroke, the 3176 (4.7%) who underwent intravenous thrombolysis more often had atrial fibrillation (47.7% versus 37.4%) and more often received intravenous contrast dye (44.3% versus 21.9%) but were otherwise similar in terms of demographics and comorbidities. Anaphylaxis developed in 17 (0.54%; 95% CI, 0.31%-0.86%) patients who received intravenous thrombolysis versus 45 (0.07%; 95% CI, 0.05%-0.09%) who did not. After adjustment for demographics, comorbidities, contrast dye, mechanical thrombectomy, and history of allergies, there was a significant association between receipt of intravenous thrombolysis and anaphylaxis (odds ratio, 7.8; 95% CI, 4.3-13.9). We found a similar association for anaphylactic shock. Conclusions- Although a rare occurrence, the risk of anaphylaxis among patients with acute ischemic stroke was significantly higher among those who received intravenous thrombolysis.

Associations between cerebrovascular risk factors and parkinson disease.

OBJECTIVE: To determine whether cerebrovascular risk factors are associated with subsequent diagnoses of Parkinson disease, and whether these associations are similar in magnitude to those with subsequent diagnoses of Alzheimer disease. METHODS: This was a retrospective cohort study using claims data from a 5% random sample of Medicare beneficiaries from 2008 to 2015. The exposures were stroke, atrial fibrillation, coronary disease, hyperlipidemia, hypertension, sleep apnea, diabetes mellitus, heart failure, peripheral vascular disease, chronic kidney disease, chronic obstructive pulmonary disease, valvular heart disease, tobacco use, and alcohol abuse. The primary outcome was a new diagnosis of idiopathic Parkinson disease. The secondary outcome was a new diagnosis of Alzheimer disease. Marginal structural Cox models adjusting for time-dependent confounding were used to characterize the association between exposures and outcomes. We also evaluated the association between cerebrovascular risk factors and subsequent renal colic (negative control). RESULTS: Among 1,035,536 Medicare beneficiaries followed for a mean of 5.2 years, 15,531 (1.5%) participants were diagnosed with Parkinson disease and 81,974 (7.9%) were diagnosed with Alzheimer disease. Most evaluated cerebrovascular risk factors, including prior stroke (hazard ratio = 1.55; 95% confidence interval = 1.39-1.72), were associated with the subsequent diagnosis of Parkinson disease. The magnitudes of these associations were similar, but attenuated, to the associations between cerebrovascular risk factors and Alzheimer disease. Confirming the validity of our analytical model, most cerebrovascular risk factors were not associated with the subsequent diagnosis of renal colic. INTERPRETATION: Cerebrovascular risk factors are associated with Parkinson disease, an effect comparable to their association with Alzheimer disease. ANN NEUROL 2019;86:572-581.

Effect of A Randomized trial of Unruptured Brain Arteriovenous Malformation on Interventional Treatment Rates for Unruptured Arteriovenous Malformations.

BACKGROUND: In 2013, investigators from A Randomized Trial of Unruptured Brain Arteriovenous Malformations (AVM; ARUBA) reported that interventions to obliterate unruptured AVMs caused more morbidity and mortality than medical management. OBJECTIVE: We sought to determine whether interventions for unruptured AVM decreased after publication of ARUBA results. METHODS: We used the Nationwide Readmissions Database to assess trends in interventional AVM management in patients ≥18 years of age from 2010 through 2015. Unruptured brain AVMs were identified using International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) code 747.81 and excluding any patient with a diagnosis of intracranial hemorrhage. Our primary outcome was interventional AVM treatment, identified using ICD-9-CM procedure codes for surgical resection, endovascular therapy, and stereotactic radiosurgery. Join-point regression was used to assess trends in the incidence of interventional AVM management among adults from 2010 through 2015. RESULTS: There was no significant U.S. population level change in unruptured brain AVM intervention rates before versus after ARUBA (p = 0.59), with the incidence of AVM intervention ranging from 8.0 to 9.2 per 10 million U.S. residents before the trial publication to 7.7-8.3 per 10 million afterwards. CONCLUSIONS: In a nationally representative sample, we found no change in rates of interventional unruptured AVM management after publication of the ARUBA trial results.

Temporal Trends in the Use of Acute Recanalization Therapies for Ischemic Stroke in Patients with Cancer.

OBJECTIVE: We sought to characterize the US nationwide temporal trends in recanalization therapy utilization for ischemic stroke among patients with and without cancer. METHODS: We identified all acute ischemic stroke (AIS) hospitalizations in the National Inpatient Sample from January 1, 1998 to September 30, 2015. The primary exposure was solid or hematologic cancer. The primary outcome was use of intravenous thrombolysis. The secondary outcome was use of endovascular therapy (EVT). RESULTS: Among 9,508,804 AIS hospitalizations, 503,510 (5.3%) involved cancer patients. Intravenous thrombolysis use among ischemic stroke patients with cancer increased from .01% (95% confidence interval [CI], .00%-.02%) in 1998 to 4.91% (95% CI, 4.33%-5.48%) in 2015, whereas intravenous thrombolysis use among ischemic stroke patients without cancer increased from .02% (95% CI, .01%-.02%) in 1998 to 7.22% (95% CI, 6.98%-7.45%) in 2015. The demographic- and comorbidity-adjusted odds ratio/year of receiving intravenous thrombolysis was similar in patients with cancer (1.21; 95% CI, 1.20-1.23) versus those without (1.20; 95% CI, 1.19-1.21). EVT use among ischemic stroke patients with cancer increased from .05% (95% CI, .02%-.07%) in 2006 to 1.90% (95% CI, 1.49%-2.31%) in 2015, whereas EVT use among ischemic stroke patients without cancer increased from .09% (95% CI, .00%-.18%) in 2006 to 1.88% (95% CI, 1.68%-2.09%) in 2015. CONCLUSIONS: Among 9.5 million AIS hospitalizations, patients with cancer received intravenous thrombolysis about two thirds as often as patients without cancer. This difference persisted over time despite increased utilization in both groups. EVT utilization was similar between cancer and non-cancer AIS patients.

Association Between Heart Transplantation and Subsequent Risk of Stroke Among Patients With Heart Failure.

Background and Purpose- It is uncertain whether heart transplantation decreases the risk of stroke. The objective of our study was to determine whether heart transplantation is associated with a decreased risk of subsequent stroke among patients with heart failure awaiting transplantation. Methods- We performed a retrospective cohort study using administrative data from New York, California, and Florida between 2005 and 2015. Individuals with heart failure awaiting heart transplantation were identified using previously validated International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis codes for heart failure in combination with code V49.83 for awaiting organ transplant status. Individuals with prior stroke were excluded. Our primary exposure variable was heart transplantation, modeled as a time-varying covariate and defined by procedure code 37.51. The primary outcome was stroke, defined as the composite of ischemic and hemorrhagic stroke. Survival statistics were used to calculate stroke incidence, and Cox proportional hazards analysis was used to determine the association between heart transplantation and stroke while adjusting for demographics, stroke risk factors, Elixhauser comorbidities, and implantation of a left ventricular assist device. Results- We identified 7848 patients with heart failure awaiting heart transplantation, of whom 1068 (13.6%) underwent heart transplantation. During a mean follow-up of 2.7 years, we identified 428 strokes. The annual incidence of stroke was 0.7% (95% CI, 0.5%-1.0%) after heart transplantation versus 2.4% (95% CI, 2.2%-2.6%) among those awaiting heart transplantation. After adjustment for potential confounders, heart transplantation was associated with a lower risk of stroke (hazard ratio, 0.4; 95% CI, 0.2-0.6). Conclusions- Heart transplantation is associated with a decreased risk of stroke among patients with heart failure awaiting transplantation.

Risk of Atrial Fibrillation in Black Versus White Medicare Beneficiaries With Implanted Cardiac Devices.

Background Black individuals in the United States experience higher rates of ischemic stroke than other racial groups but have lower rates of clinically apparent atrial fibrillation ( AF ). It is unclear whether blacks truly have less AF or simply more undiagnosed AF . Methods and Results We performed a retrospective cohort study using inpatient and outpatient claims from 2009 to 2015 for a 5% nationally representative sample of Medicare beneficiaries. We included patients aged ≥66 years with at least 1 documented Current Procedural Terminology code for interrogation of an implantable pacemaker, cardioverter-defibrillator, or loop recorder and no documented history of AF , atrial flutter, or stroke before their first device interrogation. Kaplan-Meier statistics and Cox proportional hazards models were used to examine the association between black race and the composite outcome of AF or atrial flutter while adjusting for age, sex, and vascular risk factors. Among 47 417 eligible patients, the annual incidence of AF /atrial flutter was 12.2 (95% CI , 11.5-13.1) per 100 person-years among blacks and 17.6 (95% CI , 17.4-17.9) per 100 person-years among non-black beneficiaries. After adjustment for confounders, black beneficiaries faced a lower hazard of AF /atrial flutter than non-black beneficiaries (hazard ratio, 0.75; 95% CI , 0.70-0.80). Despite the lower risk of AF , black patients faced a higher hazard of ischemic stroke (hazard ratio, 1.37; 95% CI , 1.22-1.53). Conclusions Among Medicare beneficiaries with implanted cardiac devices capable of detecting atrial rhythm, black patients had a lower incidence of AF despite a higher burden of vascular risk factors and a higher risk of stroke.

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.

Specialty Classifications of Physicians Who Provide Neurocritical Care in the United States.

BACKGROUND: We sought to characterize the specialty classification of US physicians who provide critical care for neurological/neurosurgical disease. METHODS: Using inpatient claims between 2009 and 2015 from a nationally representative 5% sample of Medicare beneficiaries, we selected hospitalizations for neurological/neurosurgical diseases with potential to result in life-threatening manifestations requiring critical care. Using Current Procedural Terminology® codes, we determined the medical specialty of providers submitting critical care claims, and, using National Provider Identifier numbers, we merged in data from the United Council for Neurologic Subspecialties (UCNS) to determine whether the provider was a UCNS diplomate in neurocritical care. We defined providers with a clinical neuroscience background as neurologists, neurosurgeons, and/or UCNS diplomates in neurocritical care. We defined neurocritical care service as a critical care claim with a qualifying neurological/neurosurgical diagnosis in patients with a relevant primary hospital discharge diagnosis and ≥ 3 total critical care claims, excluding claims from the first day of hospitalization since these were mostly emergency-department claims. Our findings were reported using descriptive statistics with exact confidence intervals (CI). RESULTS: Among 1,952,305 Medicare beneficiaries, we identified 99,937 hospitalizations with at least one claim for neurocritical care. In our primary analysis, neurologists accounted for 28.0% (95% CI, 27.5-28.5%) of claims, neurosurgeons for 3.7% (95% CI, 3.5-3.9%), UCNS-certified neurointensivists for 25.8% (95% CI, 25.3-26.3%), and providers with any clinical neuroscience background for 42.8% (95% CI, 42.2-43.3%). The likelihood of management by physicians with a clinical neuroscience background increased proportionally with patients' county-level socioeconomic status and such providers were 3 times more likely to be based at an academic medical center than other physicians who billed for critical care in our sample (odds ratio, 2.9; 95% CI, 1.1-8.1). CONCLUSIONS: Physicians with a dedicated clinical neuroscience background accounted for less than half of neurocritical care service in US Medicare beneficiaries.