BACKGROUND: The relative value of computed tomography (CT) and magnetic resonance imaging (MRI) in acute ischemic stroke (AIS) is debated. In May 2018, our center transitioned from using CT to MRI as first-line imaging for AIS. This retrospective study aims to assess the effects of this paradigm change on diagnosis and disability outcomes. METHODS: We compared all consecutive patients with confirmed diagnosis of AIS admitted to our center during the MRI-period (May 2018–August 2022) and an identical number of patients from the preceding CT-period (December 2012–April 2018). Univariable and multivariable analyses were performed to evaluate outcomes, including the number and delay of imaging exams, the rate of missed strokes, stroke mimics treated with thrombolysis, undetermined stroke mechanisms, length of hospitalization, and 3-month disability. RESULTS: The median age of the 2972 included patients was 76 years (interquartile range, 65–84), and 46% were female. In the MRI-period, 80% underwent MRI as first acute imaging. The proportion of patients requiring a second acute imaging modality for diagnostic ± revascularization reasons increased from 2.1% to 5% ( P _unadj <0.05), but it decreased in the subacute phase from 79.0% to 60.1% ( P _adj <0.05). In thrombolysis candidates, there was a 2-minute increase in door-to-imaging delay ( P _adj <0.05). The rates of initially missed AIS diagnosis was similar (3.8% versus 4.4%, P _adj =0.32) and thrombolysis in stroke mimics decreased by half (8.6% versus 4.3%; P _adj <0.05). Rates of unidentified stroke mechanism at hospital discharge were similar (22.8% versus 28.1%; P _adj =0.99). The length of hospitalization decreased from 9 (interquartile range, 6–14) to 7 (interquartile range, 4–12) days ( P _adj =0.62). Disability at 3 months was similar (common adjusted odds ratio for favorable Rankin shift, 0.98 [95% CI, 0.71–1.36]; P _adj =0.91), as well as mortality and symptomatic intracranial hemorrhage. CONCLUSIONS: A paradigm shift from CT to MRI as first-line imaging for AIS seems feasible in a comprehensive stroke center, with a minimally increased delay to imaging in thrombolysis candidates. MRI was associated with reduced thrombolysis rates of stroke mimics and subacute neuroimaging needs.

Contrast-associated acute kidney injury (CA-AKI) is a potentially preventable complication after exposure to iodinated contrast media. In patients undergoing endovascular thrombectomy (EVT) for acute ischemic stroke (AIS), the incidence and clinical impact are poorly characterized, and no validated prediction tool is currently available. The aim of this study was to assess the incidence and prognostic significance of CA-AKI in EVT-treated patients with AIS and to develop and validate a predictive score. A retrospective, multicenter cohort study was conducted involving EVT-treated patients across 73 centers in 16 countries (January-December 2023). Inclusion criteria were age ≥18 years, absence of dialysis, availability of preprocedural and 48-hour postprocedural creatinine levels, and available 90-day follow-up (modified Rankin Scale [mRS] score). The primary outcome was CA-AKI, defined by KDIGO (Kidney Disease: Improving Global Outcomes criteria;creatinine increase ≥0.3 mg/dL or ≥1.5 times baseline, within 48 hours). Secondary outcomes were (1) in-hospital mortality, (2) 90-day mRS score, and (3) 90-day severe disability or death (mRS score >3). Logistic models assessing associations with outcomes accounted for within-center clustering by applying robust standard errors. CA-AKI prediction models were developed across imputed data sets using univariable selection (p < 0.20), backward elimination (p < 0.05), and coefficient-based scoring after categorization of continuous predictors, with internal validation by bootstrap to obtain optimism-adjusted estimates. Among 6,638 patients (median age 74 years; 48.7% male), CA-AKI occurred in 326 (4.9%) and was independently associated with in-hospital mortality (adjusted odds ratio [aOR] 2.269; 95% CI 1.615-3.190), higher 90-day mRS scores (adjusted common odds ratio 1.584; 95% CI 1.110-2.258), and 90-day severe disability or death (aOR 1.530; 95% CI 1.057-2.216). A preprocedural risk model including 12 routine clinical variables-sex, ethnicity, arterial hypertension, dyslipidemia, chronic kidney disease, antiplatelet therapy, NIH Stroke Scale score at admission, serum glucose, estimated glomerular filtration rate, hemoglobin, mean arterial pressure, and IV thrombolysis-demonstrated acceptable discrimination (area under the receiver operating characteristic curve 0.710 [95% CI 0.682-0.738]; precision-recall area under the curve 0.13 [95% CI 0.10-0.16]), good calibration (slope 0.870 [95% CI 0.759-0.928]), good overall performance (Brier score 0.045 [95% CI 0.042-0.049]). A second model that included EVT-related variables (e.g., contrast volume) showed similar performances. In this large, international cohort, CA-AKI occurred in approximately 1 in 20 EVT-treated patients with AIS and was independently associated with poor outcomes. A simple preprocedural risk score enables early identification of high-risk individuals and may support preventive strategies.

Introduction: Recent evidence suggests a possible role of non-stenotic carotid atherosclerotic plaques in the etiology of embolic stroke of undetermined source (ESUS). Methods: We conducted a systematic review and meta-analysis of prevalence and characteristics of non-stenotic carotid plaques (NSPs) with high-risk features (complicated NSP) in internal carotid artery in unilateral ESUS in the anterior circulation. We searched MEDLINE and Ovid-Embase databases. High-risk features were intraplaque hemorrhage, thickness ⩾ 3 mm, ulceration, and hypodensity. We assessed the risk of bias (RoB), extracted the data, calculated the pooled prevalence and 95% confidence intervals (CI) using Inverse Variance Weighting method, and Random Effect models. Results: We included 16 studies and 1406 patients with different imaging for NSP assessment (1 ultrasound, 11 computed tomography (CT)-angiography, 4 magnetic resonance (MR) angiography). The RoB was moderate to low in most studies. Definition of complicated NSP differed across studies. The combined prevalence of any complicated NSP was 31% (95% CI = 27–36%) ipsilateral and 14% (95% CI = 9–19%) contralateral to the index stroke, the finding of any high-risk NSP was fourfold higher ipsilateral to the index stroke (OR = 3.63; 95% CI = 2.09–6.33). The prevalence of single high-risk features ipsilateral to ESUS was as follows: 35% (95% CI = 30–41%) for thickness ⩾ 3 mm; 24% (95% CI = 8–39%) for ulceration; 45% (95% CI = −2; 93%) for hypodensity, 16% (95% CI = 5–26%) for intraplaque hemorrhage. Conclusion: Complicated NSPs are present in around a third of all ESUS, and are four times more frequent ipsilaterally to the index stroke. Our results confirm the possible causal role in ESUS and highlight the need for greater diagnostic uniformity of plaque at risk.

The management of anterior circulation tandem lesion stroke remains controversial, given its under-representation in randomized thrombectomy trials and uncertainty regarding optimal extracranial carotid intervention. We aimed to determine whether emergent carotid stenting (eCAS) during endovascular thrombectomy (EVT) for anterior circulation tandem lesions improves 90-day functional outcomes compared with a no-stenting strategy. We conducted an international multicenter longitudinal retrospective cohort study (CERES-TANDEM, NCT06965036) of consecutive adults treated at 49 comprehensive stroke centers in Europe, North America, and Singapore for anterior circulation acute ischemic stroke due to tandem lesions from January 1, 2018, to December 31, 2024. Exclusion criteria were primary hemorrhagic stroke, absence of intracranial occlusion, presentation >24 hours from symptom onset, and age younger than 18 years. We compared 90-day modified Rankin Scale (mRS) scores between participants receiving eCAS and those receiving no stenting during EVT. The primary estimand was mRS shift, analyzed by stabilized inverse probability of treatment weighting (IPTW)-weighted ordinal regression. Additional estimands were direct-effect estimand adjusting for successful recanalization (defined as Thrombolysis in Cerebral Infarction grade 2b or higher) and symptomatic intracranial hemorrhage (sICH) (estimand 2) and stratum estimand restricting to never-crossers (estimand 3). Of 4,053 patients (mean age 70 years, 65.5% female), 2,522 underwent eCAS and 1,531 received no stenting. After IPTW, eCAS was associated with an improved 90-day functional outcome (common odds ratio (OR) 1.31; 95% CI 1.17-1.47;p < 0.001) and higher odds of mRS score 0-1 (OR 1.27; 95% CI 1.08-1.50; p = 0.005) and mRS score 0-2 (OR 1.30; 95% CI 1.13-1.51; p < 0.001), without a significant increase in sICH (OR 1.21; 95% CI 0.93-1.56; p = 0.15). Findings were consistent in direct-effect (common OR 1.17; 95% CI 1.04-1.31; p = 0.008) and stratum (common OR 1.37; 95% CI 1.21-1.55; p < 0.001) estimands. There was no interaction for intracranial occlusion site, IV thrombolysis, sedation technique, EVT approach, or access site. Sensitivity analysis including recanalization in IPTW-weighted estimand 1 framework confirmed the association of eCAS with improved 90-day functional outcomes (common OR 1.14, 95% CI1.02-1.27, p = 0.008). In this large real-world cohort, eCAS during EVT for anterior circulation tandem lesions was associated with superior 90-day functional recovery without increased hemorrhagic risk. These findings support consideration of eCAS in clinical practice and warrant confirmation in randomized trials. Registered in clinicaltrials.gov, NCT06965036. This study provides Class II evidence that in patients with stroke due to anterior circulation tandem lesions, eCAS during EVT improves 90-day functional outcomes compared with EVT alone.