Khan, Muhib

BACKGROUND: Patients presenting with cervical artery dissection (CAD) are at risk for subsequent ischemic events. We aimed to identify characteristics that are associated with increased risk of ischemic stroke after initial presentation of CAD and to evaluate the differential impact of anticoagulant versus antiplatelet therapy in these high-risk individuals. METHODS: This was a preplanned secondary analysis of the STOP-CAD study (Antithrombotic Treatment for Stroke Prevention in Cervical Artery Dissection), a multicenter international retrospective observational study (63 sites from 16 countries in North America, South America, Europe, Asia, and Africa) that included patients with CAD predominantly between January 2015 and June 2022. The primary outcome was subsequent ischemic stroke by day 180 after diagnosis. Clinical and imaging variables were compared between those with versus without subsequent ischemic stroke. Significant factors associated with subsequent stroke risk were identified using stepwise Cox regression. Associations between subsequent ischemic stroke risk and antithrombotic therapy type (anticoagulation versus antiplatelets) among patients with identified risk factors were explored using adjusted Cox regression. RESULTS: In all, 4023 patients (mean age was 47.4 years; 44.5% were women) were included. By day 180, subsequent ischemic stroke occurred in 5.3% of the cohort. In adjusted Cox regression, factors associated with increased risk of subsequent ischemic stroke were prior history of ischemic stroke (adjusted hazard ratio [aHR], 7.31 [95% CI, 1.61–33.13]; P =0.010), presentation within 7 days from first symptoms (aHR, 3.04 [95% CI, 1.04–8.91]; P =0.043), infarct on baseline imaging (aHR, 9.85 [95% CI, 3.65–26.58]; P <0.001), and occlusive dissection (aHR, 2.34 [95% CI, 1.03–5.34]; P =0.043). Only patients with occlusive dissection demonstrated a reduced risk of subsequent ischemic stroke when treated with anticoagulation versus antiplatelets (aHR, 0.36 [95% CI, 0.16–0.80]; P =0.01). CONCLUSIONS: In this post hoc analysis of the STOP-CAD study, several factors associated with subsequent ischemic stroke were identified among patients with CAD. Furthermore, we identified a potential benefit of anticoagulation in patients with CAD with occlusive dissection. These findings require validation by meta-analyses of prior studies to formulate optimal treatment strategies for specific high-risk CAD subgroups.

Background Although intravenous thrombolysis (IVT) is safe and effective in populations with general stroke, its impact on cervical artery dissection–related acute ischemic stroke (CeAD‐AIS) remains unclear. This retrospective study used the National Inpatient Sample to compare outcomes in patients with CeAD‐AIS treated with and without IVT. Methods We included adult patients with concurrent CeAD and AIS diagnoses ( International Classification of Diseases, Tenth Revision [ ICD‐10 ], codes) hospitalized from 2016 to 2019. The primary outcome was home discharge; safety outcomes included inpatient death and intracerebral hemorrhage. We performed survey‐weighted multivariable logistic regressions comparing IVT versus no IVT, followed by interaction analyses to examine effect modifications based on age, medical history, stroke severity, carotid artery involvement, and endovascular treatment. Results Between 2016 and 2019, 1360 (12.1%) of 11 285 patients with CeAD‐AIS received IVT. IVT‐treated patients had higher median National Institutes of Health Stroke Scale scores (median [interquartile range], 8 [4–17] versus 3 [1–11]; P <0.001). Adjusted analyses showed IVT was associated with higher odds of home discharge (adjusted odds ratio [OR], 1.40 [95% CI, 1.01–1.92]; P =0.042), but not with inpatient death (adjusted OR, 1.29 [95% CI, 0.76–2.20]; P =0.347) or intracerebral hemorrhage (adjusted OR, 0.69 [95% CI, 0.32–1.48]; P =0.341). Stroke severity ( P for interaction=0.001) and carotid artery involvement ( P for interaction=0.021) significantly modified IVT's effect on home discharge, with IVT being associated with an increased likelihood of home discharge in patients with moderate to severe strokes (National Institutes of Health Stroke Scale score >4) and carotid artery involvement. Conclusions IVT improves the likelihood of home discharge in patients with CeAD‐AIS without increasing the risk of inpatient death or intracerebral hemorrhage.

Background: CT perfusion (CTP) imaging is an important tool for identifying candidates for mechanical thrombectomy (MT). This modality is increasingly available in regional facilities, but whether pre-transfer perfusion imaging studies may be relied upon for treatment decisions is unclear. We analyzed a cohort of stroke transfers to quantify changes in CTP imaging profiles over time. Methods: A cohort of confirmed ischemic stroke patients who received CTP before and after transfer to a large mid-western comprehensive stroke center (CSC) were identified. We compared perfusion mismatch (MM), core infarct volume (CIV), and favorability of imaging for mechanical thrombectomy (MT) candidacy (defined as the presence of LVO and MM/CIV ratio of >1.8) between studies. Regression models were used to examine predictors of CIV growth including hypoperfusion intensity ratio (HIR) and time between studies. Results: Over a 24-month period, 61 patients met inclusion criteria. Median age was 71 (IQR 60-80), 52% were female, median NIHSS was 14 (IQR 4-19), and most patients had occlusion of the internal carotid and/or middle cerebral arteries (77%). The median time from last known well (LKW) to initial CT was 148 minutes (IQR 71-620) and median time between imaging studies was 149 minutes (IQR 126-194). Median CIV growth was 0 mL (IQR 0-6) and 8% (5/61) had growth ≥25 mL. In linear regression, higher HIR predicted CIV growth (β=24.3, p=0.04), but time from LKW to presentation and time between imaging studies did not. Imaging studies taken at the regional and CSC sites demonstrated excellent agreement in classifying patients as candidates for MT (kappa 0.778 [95% CI: 0.611-0.944]). A favorable regional CTP profile was 93% sensitive for MT delivery at the CSC with a positive predictive value of 63%. Conclusion: In our cohort, CIV growth between facilities was minimal despite relatively long interfacility transport times and was predicted by the regional HIR. A favorable regional imaging profile demonstrated high agreement with the imaging result at the CSC and was strongly associated with MT treatment.

Introduction: The safety and efficacy of intravenous thrombolysis (IVT) in cervical artery dissection-related acute ischemic stroke (CeAD-AIS) remains unclear. We performed a retrospective study of data from the National Inpatient Sample investigating outcomes in CeAD-AIS patients treated with and without IVT. Methods: We included adult patients with CeAD-AIS hospitalized between 2016 to 2019. CeAD-AIS was defined by concurrent CeAD and AIS diagnoses, identified with ICD-10 codes. The primary outcome was home discharge. The safety outcomes were inpatient death and intracerebral hemorrhage (ICH). We used survey-weighted multivariable adjusted logistic regressions comparing the groups (IVT versus no IVT), followed by interaction analyses to examine for effect modifications based on age, medical history, stroke severity, and endovascular treatment. Results: Between 2016-2019, 1,360 (12.1%) of 11,285 CeAD-AIS patients received IVT. Patients treated with IVT- had higher NIH Stroke Scale (NIHSS) scores (median 8 [4-17] versus 3 [1-11]; p < 0.001). In adjusted analyses, treatment with IVT was associated with a greater odds of home discharge (adjusted odds ratio [aOR] 1.49; 95% confidence interval [CI] 1.09-2.05, p = 0.014), but not ICH (aOR 0.90, 95% CI 0.43-1.86, p = 0.773) or inpatient death (aOR 1.22, 95% CI 0.72-2.06, p = 0.454). In interaction analyses, stroke severity significantly interacted with IVT ( p for interaction = 0.001), where IVT was significantly associated with increased likelihood of home discharge in patients with moderate to severe strokes (NIHSS > 4) (aOR 2.28, 95% CI 1.59-3.26, p < 0.001) but not in those with mild stroke (NIHSS 0-4) (aOR 1.03 95% CI 0.62-1.70, p = 0.922). Conclusion: IVT improved the likelihood of home discharge in patients with CeAD-AIS without increasing the risk of inpatient death or ICH.

Background: Emergency medical services (EMS) routing of stroke patients is challenging in rural settings. To address this, the American Stroke Association (ASA) has developed a template severity-based EMS triage algorithm to direct EMS to either the nearest stroke-ready versus the nearest Comprehensive Stroke Center (CSC) hospital, but its real-world impact is uncertain. Methods: This is an interim analysis of a before-and-after quality improvement study examining the impact of implementation of a severity-based EMS stroke destination protocol by three medical control authorities (MCAs) covering 4 rural counties in western Michigan. We defined optimal destination according to the ASA algorithm, which recommends bypass for patients within 24 of last known well if large vessel occlusion suspected and bypass will not delay thrombolysis. Chi square tests were used to compare optimal destination selection before and after implementation among EMS suspected stroke cases originating from the target counties. We also compared the time from EMS scene arrival to ischemic stroke (IS) treatment (thrombolysis or endovascular therapy [EVT]) before and after implementation using Wilcoxon Rank Sum tests. Results: From November 2021 to May 2024, EMS transported 616 suspected stroke cases, 272 (44.2%) of which ultimately received a diagnosis of ischemic stroke (IS) or transient ischemic attack. The protocol was implemented by each MCA in random order at months 21, 23, and 29, resulting in 73 MCA-months before and 17 after implementation, excluding a one-month washout for each MCA. Optimal hospital destinations were selected for 310/499 (62.1%) patients prior to the protocol and 86/117 (73.5%) after (p=0.021). Thrombolytics were administered to 57 patients (48 before and 9 after) and 46 (42 before and 4 after) received EVT. Median times from first EMS contact to needle decreased from 98 (interquartile range [IQR]: 79-107) to 77 (IQR: 75-85) minutes (p=0.012); median times from EMS contact to groin puncture increased nonsignificantly from 165 (IQR: 132-216) to 196 (IQR: 191-228) minutes (p=0.110). Conclusions: Interim analysis of implementation of a rural EMS severity-based triage algorithm for suspected stroke cases resulted in improved destination selection and faster thrombolysis but did not improve EVT treatment times. This analysis will be repeated once follow-up is completed in 7 months.

Introduction: Dynamic vertebral artery insufficiency is a rare vascular phenomenon characterized by insufficient flow of the posterior cerebral circulation induced by dynamic motion of the head. Prior case reports have been limited to vertebral artery occlusion by cervical osteophytes or other structural impingements. Case Report: In this case report, we discuss the unusual case of a 61-year-old female with a history of vertigo, diplopia, nystagmus, and left subclavian stenosis admitted to the hospital for syncope elicited by a left head turn and left shoulder raise. Transcranial Doppler (TCD) ultrasound and angiography showed evidence of dynamic vertebrobasilar insufficiency elicited by a left-head turn. Percutaneous stenting of the left subclavian artery led to the resumption of normal vessel flow as assessed by TCD and the resolution of the patient’s symptoms. Conclusions: This case highlights an unusual cause of dynamic vertebrobasilar insufficiency induced by head turn and/or left shoulder raise due to subclavian stenosis, diagnosed by TCD and angiography, and successfully treated with subclavian artery stenting.