Prediction of blood pressure variability during thrombectomy using supervised machine learning and outcomes of patients with ischemic stroke from large vessel occlusion.

Mechanical thrombectomy (MT) is the standard of care for patients with acute ischemic stroke from large vessel occlusion (AIS-LVO). The association of blood pressure variability (BPV) during MT and outcomes are unknown. We leveraged a supervised machine learning algorithm to predict patient characteristics that are associated with BPV indices. We performed a retrospective review of our comprehensive stroke center's registry of all adult patients undergoing MT between 01/01/2016 and 12/31/2019. The primary outcome was poor functional independence, defined as 90-day modified Rankin Scale (mRS) ≥ 3. We used probit analysis and multivariate logistic regressions to evaluate the association of patients' clinical factors and outcomes. We applied a machine learning algorithm (random forest, RF) to determine predictive factors for the different BPV indices during MT. Evaluation was performed with root-mean-square error (RMSE) and normalized-RMSE (nRMSE) metrics. We analyzed 375 patients with mean age (± standard deviation [SD]) of 65 (15) years. There were 234 (62%) patients with mRS ≥ 3. Univariate probit analysis demonstrated that BPV during MT was associated with poor functional independence. Multivariable logistic regression showed that age, admission National Institutes of Health Stroke Scale (NIHSS), mechanical ventilation, and thrombolysis in cerebral infarction (TICI) score (OR 0.42, 95% CI 0.17-0.98, P = 0.044) were significantly associated with outcome. RF analysis identified that the interval from last-known-well time-to-groin puncture, age, and mechanical ventilation were among important factors significantly associated with BPV. BPV during MT was associated with functional outcome in univariate probit analysis but not in multivariable regression analysis, however, NIHSS and TICI score were. RF algorithm identified risk factors influencing patients' BPV during MT. While awaiting further studies' results, clinicians should still monitor and avoid high BPV during thrombectomy while triaging AIS-LVO candidates quickly to MT.

Black-White Differences in Ischemic Stroke Risk Factor Burden in Young Adults.

BACKGROUND AND PURPOSE: Although the US Black population has a higher incidence of stroke compared with the US White population, few studies have addressed Black-White differences in the contribution of vascular risk factors to the population burden of ischemic stroke in young adults. METHODS: A population-based case-control study of early-onset ischemic stroke, ages 15 to 49 years, was conducted in the Baltimore-Washington DC region between 1992 and 2007. Risk factor data was obtained by in-person interview in both cases and controls. The prevalence, odds ratio, and population-attributable risk percent (PAR%) of smoking, diabetes, and hypertension was determined among Black patients and White patients, stratified by sex. RESULTS: The study included 1044 cases and 1099 controls. Of the cases, 47% were Black patients, 54% were men, and the mean (±SD) age was 41.0 (±6.8) years. For smoking, the population-attributable risk percent were White men 19.7%, White women 32.5%, Black men 10.1%, and Black women 23.8%. For diabetes, the population-attributable risk percent were White men 10.5%, White women 7.4%, Black men 17.2%, and Black women 13.4%. For hypertension, the population-attributable risk percent were White men 17.2%, White women 19.3%, Black men 45.8%, and Black women 26.4%. CONCLUSIONS: Modifiable vascular risk factors account for a large proportion of ischemic stroke in young adults. Cigarette smoking was the strongest contributor to stroke among White patients while hypertension was the strongest contributor to stroke among Black patients. These results support early primary prevention efforts focused on smoking cessation and hypertension detection and treatment.

Black-white Differences in Left Ventricular Hypertrophy Rates Among Young Adults with Ischemic Stroke.

OBJECTIVES: Few studies have addressed Black-White differences in left ventricular hypertrophy (LVH) in young stroke patients without a history of hypertension. METHODS: A case-only cross-sectional analysis performed in 2019 of data from the Stroke Prevention in Young Adults Study, a population-based case-control study of ischemic stroke patients ages 15-49. The main outcomes were hypertension indicators at the time of stroke hospitalization: self-reported history of hypertension, LVH by echocardiography (Echo-LVH) and LVH by electrocardiogram (ECG-LVH). The prevalence of Echo-LVH was further determined in those with and without a history of hypertension. Adjusted odds ratios and 95% confidence intervals comparing blacks and whites were calculated by logistic regression. RESULTS: The study population included 1028 early-onset ischemic stroke patients, 48% Black cases, 54% men, median age 43 years (interquartile range, 38-46 years). Overall, the prevalence of hypertension history, Echo-LVH and ECG-LVH were 41.3%, 34.1% and 17.5%, respectively. Each of the hypertension indicators were more frequent in men than in women and in Black cases than in White cases. Black patients without a history of hypertension had higher rates of Echo-LVH than their white counterparts, 40.3% vs 27.7% (age and obesity adjusted OR 1.8; 95% CI 1.02-3.4) among men and 20.9% vs 7.6% (adjusted OR 2.7; 95% CI 1.2-6.2) among women. CONCLUSIONS: LVH was common in young patients with ischemic stroke, regardless of self-reported history of hypertension. These findings emphasize the need for earlier screening and more effective treatment of hypertension in young adults, particularly in the Black population.

Exploring the Collateral Damage of the COVID-19 Pandemic on Stroke Care: A Statewide Analysis.

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Optimizing the Recognition and Treatment of In-Hospital Stroke: Evaluation of the 2CAN Score.

OBJECTIVES: Stroke-like symptoms may be difficult to appreciate due to the high incidence of stroke mimics (e.g., delirium) in the inpatient population. Many centers have adopted inpatient-specific stroke protocols with the aim of improving time to diagnosis and treatment. We aimed to assess one of these instruments, the "2CAN" score, in our patient population. MATERIALS AND METHODS: A retrospective chart review was conducted for all inpatients for whom our Brain Attack Team (BAT) was called between January 2015 and June 2019. Patients were excluded if they had stroke prior to current admission, were in the emergency department at the time of BAT call, or had incomplete documentation. The 2CAN score was calculated for each patient. RESULTS: The BAT was activated 201 times, and 110 patients met inclusion criteria. Twenty percent of patients had a history of atrial fibrillation, 72% hypertension, and 36% diabetes. Median NIHSS was 14.5 (IQR 5-24). Only 18% of stroke calls occurred within 24 h of hospital admission. The mean 2CAN score was 2.8. Ninety-seven (88%) patients received a final diagnosis of ischemic stroke and 13 (12%) of stroke mimics. There was no difference between 2CAN scores in the stroke and mimic groups (P = 0.91). A 2CAN score of ≥ 2 had sensitivity 83.5%, specificity 23.1%, PPV 89.0%, and NPV 15.8% for stroke. CONCLUSIONS: The 2CAN score was derived and validated in a single academic center as a tool to recognize inpatient stroke. The 2CAN score had good sensitivity and positive predictive value for stroke in our cohort, but poor specificity.

Comparison of Outcomes After Treatment of Large Vessel Occlusion in a Critical Care Resuscitation Unit or a Neurocritical Care Unit.

BACKGROUND: Mechanical thrombectomy (MT) has become first-line treatment for patients with acute ischemic stroke caused by large vessel occlusion (AIS-LVO). Delay in the interhospital transfer (IHT) of patients from referral hospitals to a comprehensive stroke center is associated with worse outcomes. At our academic tertiary care facility in an urban setting, a neurocritical care and emergency neurology unit (NCCU) receives patients with AIS-LVO from outlying medical facilities. When the NCCU is full, patients with AIS-LVO are initially transferred to a critical care resuscitation unit (CCRU). We were interested in quantifying the numbers of AIS-LVO patients treated in those two units and assessing their outcomes. We hypothesized that the CCRU would facilitate an increase in IHTs and provide care comparable to that delivered by the subspecialty NCCU. METHODS: We conducted a retrospective study of the medical center's prospective stroke registry for adult IHT patients undergoing MT between 01/01/2015 and 12/31/2017. Primary outcome was time from consultation and request for transfer to arrival (Consult-Arrival). Other outcomes of interest were functional independence, defined as 90-day modified Rankin Scale (mRS) score ≤ 2, and 90-day all-cause mortality. Multivariable logistic regression was performed to assess association between clinical factors, mortality, and functional independence. RESULTS: We analyzed the records of 128 IHT patients: 87 (68%) were admitted to the CCRU, and 41 (32%) to the NCCU. The two groups had similar baseline characteristics (age, National Institutes of Health Stroke Scale score, Alberta Stroke Program Early Computed Tomography scores [ASPECTS]). The median Consult-Arrival time was shorter for CCRU patients than for the NCCU patients (86 [88‒109] vs 100 [77‒127] [p = 0.031]). The 90-day mortality rates (16 vs 30% [p = 0.052]) and the rates having a mRS score ≤ 2 (31 vs 36% [p = 0.59]) were not statistically different. Multivariable logistic regression showed that each minute of delay in the Consult-Arrival time was associated with 2.3% increase in the likelihood of death (OR 1.023; 95% CI 1.003‒1.04 [p = 0.026]), while high thrombolysis in cerebral infarction score was the only factor that was significantly associated with functional independence at 90 days (OR 2.9; 95% CI 1.4‒6.4 [p = 0.006]). CONCLUSION: The CCRU increased AIS-LVO patients' access to definitive care and reduced their transfer time from outlying medical facilities while achieving outcomes similar to those attained by patients treated in the subspecialty NCCU. We conclude that a resuscitation unit can complement the NCCU to care for patients in the hyperacute phase of AIS-LVO.

Transport Blood Pressures and Outcomes in Stroke Patients Requiring Thrombectomy.

OBJECTIVE: Mechanical thrombectomy is the treatment of choice for acute ischemic strokes from large vessel occlusions. Absolute blood pressure and blood pressure variability (BPV) may affect patients' outcome. We hypothesized that patients' outcomes were not associated with BPV during transport between hospitals in the era of effective thrombectomy. METHODS: We performed a retrospective observational review of adult patients admitted to our comprehensive stroke center who underwent mechanical thrombectomy between January 1, 2015, and December 31, 2018. Data were collected from our stroke registry and transportation records. Outcomes were defined as 90-day modified Rankin Scale (mRS) ≤2 and any acute kidney injury (AKI) during hospitalization. RESULTS: We analyzed 134 eligible patients. The mean age was 66 years (standard deviation = 14 years). Forty percent achieved mRS ≤2, and 16% had an AKI. BPV and maximum systolic blood pressures during transport were examined as variables to determine outcome. We found BPV was similar between patients with good and bad functional independence. Furthermore, the maximum systolic blood pressure during transport (odds ratio = 0.98; 95% confidence interval, 0.96-0.99; P = .038), not BPV, was associated with a lower likelihood of mRS ≤2. No similar correlation of analyzed blood pressure variables could be found for AKI as an outcome. CONCLUSION: The maximum systolic blood pressure was associated with worse functional outcomes in stroke patients transported for thrombectomy. Prehospital clinicians should be cognizant of high blood pressure among patients with acute ischemic stroke from large vessel occlusion during transport and treat accordingly.

Relationship of thrombus length to number of stent retrievals, revascularization, and outcomes in acute ischemic stroke.

PURPOSE: To study the relationship between intracranial thrombus length and number of stent retrievals, revascularization rates, and functional outcomes in stroke. MATERIALS AND METHODS: Retrospective data were collected from consecutive cases of stroke treated with endovascular procedures at a single institution from April 2012-September 2013. Thrombus length was measured in the anterior cerebral circulation. Demographic and clinical details; involved vessels; and procedural details, including the number of devices used and number of retrievals used for each device, were recorded. Revascularization rates and 90-day functional outcomes were recorded. RESULTS: Data regarding the length of thrombus in the anterior cerebral circulation were available for 28 patients. There was no significant association between thrombus length and number of stent retrievals (P = .3780), final thrombolysis in cerebral infarction (TICI) score (P = .4835), or 90-day modified Rankin Scale score (P = .4146). There was a significant difference (P = .0280) between number of retrievals and final TICI score, with lower number of retrieval passes corresponding to higher final TICI scores. CONCLUSIONS: The data suggest no relationship between thrombus length and number of stent retrievals, final TICI score, or functional neurologic outcomes at 90 days in stent retrieval thrombectomy for acute ischemic stroke. These results do not support a predictive value for thrombus length quantification in the evaluation of stroke.

Mildly elevated INR is associated with worse outcomes following mechanical thrombectomy for acute ischemic stroke.

BACKGROUND: Elevated International Normalized Ratio (INR) is a marker of coagulopathy, but its impact on outcomes following mechanical thrombectomy (MT) in patients with stroke is unclear. This study investigates the impact of mild INR elevations on clinical outcomes following MT. METHODS: In this retrospective cohort study, consecutive patients with stroke treated with MT were identified from 2015 to 2020 at a Comprehensive Stroke Center. Demographic information, past medical history, INR, National Institutes of Health Stroke Scale score, use of tissue plasminogen activator, and last known normal to arteriotomy time were recorded. Outcome measures included modified Thrombolysis in Cerebral Infarction (mTICI) score, modified Rankin Scale (mRS) score at 90 days, and intracerebral hemorrhage (ICH). Patients were divided into two groups: normal INR (0.8-1.1) and mildly elevated INR (1.2-1.7). RESULTS: A total of 489 patients were included for analysis, of which 349 had normal INR and 140 had mildly elevated INR. After multivariable adjustments, mildly elevated INR was associated with lower odds of excellent outcomes (mRS 0-1, OR 0.24, p=0.009), lower odds of functional independence (mRS 0-2, OR 0.38, p=0.038), and higher odds of 90-day mortality (OR 3.45, p=0.018). Elevated INR was not associated with a higher likelihood of ICH, and there were no differences in rates of HI1, HI2, PH1, or PH2 hemorrhagic transformations; however, elevated INR was associated with significantly higher odds of 90-day mortality in patients with ICH (OR 6.22, p=0.024). This effect size was larger than in patients without ICH (OR 3.38, p<0.001). CONCLUSION: In patients with stroke treated with MT, mildly elevated INR is associated with worse clinical outcomes after recanalization and may worsen the mortality risk of hemorrhagic transformations.

Stroke, Smoking and Vaping: The No-Good, the Bad and the Ugly.

Both stroke and smoking continue to be major public health crises in the United States, with stroke being the third and fourth leading cause of death among women and men, respectively. The goal of this review will be to provide clinicians a succinct overview regarding the epidemiology, economics, and biology of stroke in the setting of smoking and electronic cigarette use. Special attention will be given to the escalating public health crisis of electronic cigarette use, emphasizing mechanistic relationships of stroke and lung injury. Readers will be made aware of the need for continued scientific advancement and study regarding these relationships, as well as the need for improved governmental and public health efforts to curb these ongoing public health crises.

The Maryland Acute Stroke Emergency Medical Services Routing Pilot: Expediting Access to Thrombectomy for Stroke.

Background: Mechanical thrombectomy (MT) is the standard of care for acute ischemic stroke caused by large vessel occlusion, but is not available at all stroke centers. Transfers between hospitals lead to treatment delays. Transport directly to a facility capable of MT based on a prehospital stroke severity scale score has been recommended, if transportation time is less than 30 min. Aims: We hypothesized that an Emergency Medical Services (EMS) routing algorithm for stroke, using the Los Angeles Motor Scale (LAMS) in the field, would improve time from last known well to MT, without causing patients to miss the IV Thrombolysis (IVT) window. Methods: An EMS algorithm in the Baltimore metro area using the LAMS was implemented. Patients suspected of having an acute stroke were assessed by EMS using the LAMS. Patients scoring 4 or higher and within 20 h from last known well, were transported directly to a Thrombectomy Center, if transport could be completed within 30 min. The algorithm was evaluated retrospectively with prospectively collected data at the Thrombectomy Centers. The primary outcome variables were proportion of patients with suspected stroke rerouted by EMS, proportion of rerouted ischemic stroke patients receiving MT, time to treatment, and whether the IVT window was missed. Results: A total of 303 patients were rerouted out of 2459 suspected stroke patients over a period of 6 months. Of diverted patients, 47% had acute ischemic stroke. Of these, 48% received an acute stroke treatment: 16.8% IVT, 17.5% MT, and 14% MT+IVT. Thrombectomy occurred 119 min earlier in diverted patients compared to patients transferred from other hospitals (P = 0.006). 55.3% of diverted patients undergoing MT and 38.2% of patients transferred from hospital to hospital were independent at 90 days (modified Rankin score 0-2) (P = 0.148). No patient missed the time window for IVT due to the extra travel time. Conclusions: In this retrospective analysis of prospectively acquired data, implementation of a pre-hospital clinical screening score to detect patients with suspected acute ischemic stroke due to large vessel occlusion was feasible. Rerouting patients directly to a Thrombectomy Center, based on the EMS algorithm, led to a shorter time to thrombectomy.

Telemedicine for acute stroke: triumphs and pitfalls.

BACKGROUND AND PURPOSE: Telemedicine is emerging as a potential timesaving, efficient means for evaluating patients experiencing acute stroke. In areas where local stroke care specialists are not available, telemedicine can link an emergency department physician with a specialist in a stroke treatment center. This consultation provides an opportunity for administration of thrombolytic drugs within the short therapeutic time window associated with ischemic stroke. Here, we describe our stroke treatment center experiences and report safe administration of recombinant tissue plasminogen activator (rtPA) during telemedicine consultation. METHODS: The University of Maryland Medical Center uses a triplexed integrated services digital network line providing a 30--frames-per-second video link to St Mary's Hospital >100 miles away. The system uses a pan, tilt, and zoom camera with remote site control, allowing 2-way, real-time, audiovisual communication and CT image transfer. We retrospectively reviewed all acute stroke consultations provided to St Mary's Hospital between 1999 and 2001. RESULTS: We reviewed 50 consultations. Of the 50, 23 were attempted through telemedicine linkage, and 27 were by traditional telephone conversation, followed by transfer. Of the 23 telemedicine consultations, 2 were aborted because of technical difficulties. Of the patients evaluated by traditional means, 1 of 27 (3.8%) received intravenous rtPA; 5 of 21 (23.8%) received rtPA after telemedicine consultation. No patients experienced complications. CONCLUSIONS: Telemedicine consultation provided treatment options not previously available at the remote hospital. Administration of rtPA during telemedicine consultation was feasible and safe, and the system was well received. Lack of reimbursement for telemedicine services will hinder widespread adaptation of this promising technology for remote acute stroke treatment.

Antithrombotic therapy and outcomes of cervical arterial dissection in the trauma patient: a case series.

BACKGROUND: The use of antithrombotic therapy (anticoagulants and/or antiplatelets) in the setting of traumatic cervical arterial dissection (CAD) for the prevention of stroke remains controversial. This issue is further complicated by the frequent co-existence of intracranial hemorrhage (ICH) and other intracranial injuries, and also the wide variability in treatment due to a lack of evidence-based guidance. To address these controversies, a registry in a major Level I trauma center was created. The purpose of this investigation was to compare the safety of antithrombotic therapy in post-traumatic CAD. Analysis from the first year is presented. METHODS: All cervical dissections from the year 2005 were identified in patients at least 18 years of age by diagnosis code from radiology and trauma databases. Presence of arterial injury and grade, and other intracranial disease or injury such as stroke was diagnosed by a trauma radiologist and adjudicated by a neuroradiologist. RESULTS: Fifty-five patients with cervical artery dissection were identified. Fourteen patients presented with a total of 20 acute, post-traumatic intracranial hemorrhages (ICH). Seven of the 14 patients with ICH were treated with antithrombotic therapy, and none extended their intracranial hemorrhages. Of the 41 patients without pre-existing ICH, 28 were treated with antithrombotic therapy and only one developed an interval hematoma. Among all 55 cases, two patients developed an acute ischemic stroke in the territory of the dissected artery after admission; both patients were in the untreated group. CONCLUSION: In so far as antithrombotic therapy may offer benefit in preventing early ischemic stroke following cervical artery dissection, these data suggest withholding antiplatelet or other antithrombotics following trauma may not be warranted, even in the setting of intracranial hemorrhage. From a safety perspective, this registry-based case series indicates antithrombotic management of arterial injury did not contribute to development or progression of ICH, even in patients with pre-existing ICH. This data suggest that instituting early antithrombotic therapy presents a low risk of ICH or hemorrhage extension among traumatic cervical dissection patients.