Dumitrascu, Oana M.

Background Evidence to guide the optimal timing of antiplatelet and oral anticoagulants (OACs) therapy after hemorrhagic infarction (HI) versus parenchymal hematoma (PH) is limited and inconsistent, leading to substantial variation in practice. This study's goal was to study the practice pattern and compare clinical outcomes associated with early‐versus‐delayed initiation of antiplatelet/OACs after hemorrhagic transformation (HT). Methods This multicenter, retrospective, cross‐sectional study included patients with acute ischemic stroke and HT. Patients with an HI or PH were categorized by HT to antithrombotic initiation time, and their outcomes—30‐day HT exacerbation, composite outcomes of recurrent stroke/systemic emboli, 90‐day vascular death, and functional outcomes—were compared. Results Of 748 patients, 496 received antiplatelets, and 252 received OACs after HT. The median HT‐to‐antiplatelet time was significantly shorter after HI than PH (1 [interquartile range, 0–2] versus 3 [interquartile range, 1–5] days; P <0.001). There were no statistically significant differences in HT exacerbation and composite outcomes (30‐day), as well as vascular death and unfavorable functional outcomes (90‐day), between patients who received same‐day, early (HI, <1 day; PH, <3 days), or late (HI, >1 day; PH, >3 days) antiplatelets after either HI or PH. Among patients on OACs, those with HI had shorter median HT‐to‐OAC time than PH (7 [interquartile range, 2–15] versus 15 [interquartile range, 7–32] days; P <0.001). Although HT exacerbation rates (30‐day) were comparable between early (HI, <7 days; PH, <15 days) and late (HI, >7 days; PH, >15 days) OAC initiation after either HI or PH, late initiation after PH was accompanied by higher rates of composite outcomes (30‐day) than early initiation (20.7% versus 3%; P =0.044). Regression models adjusted for demographics, National Institutes of Health Stroke Scale, and stroke severity showed no statistically significant association between early initiation of antiplatelets or OACs with HT exacerbation risk. Conclusions Our study found no statistically significant difference in HT exacerbation between early and late initiation of antiplatelets or OACs among patients with HI/PH, while prolonged delay among patients with PH were accompanied by increased systemic thromboembolic events. Although these findings offer preliminary clinical insight, prospective studies are needed.

Objectives: This study aims to identify retinal biomarkers of NOTCH3 mutation carriers using optical coherence tomography (OCT) data from the UK Biobank. Methods: We conducted a cross-sectional, matched case-control study of individuals with or without NOTCH3 mutation from the UK Biobank between 2006 and 2010. All participants had macular OCT scan and cognitive assessment. Cases were identified based on pathogenic/likely pathogenic NOTCH3 mutations and 1:1 matched with controls based on age, sex, hypertension, diabetes mellitus, and cigarette smoking status. Baseline characteristics and cognitive test scores were compared using χ 2 or Mann-Whitney U test appropriately. Macular thickness at central, inner, and outer subfields and at each retinal layer was compared using Wilcoxon signed-rank test. Results: Our analysis included 134 participants (67 cases, 67 controls) with a mean age of 54 ± 9 years. NOCTH3 mutation carriers performed worse in prospective memory ( P =0.043), verbal and numerical reasoning ( P =0.178), visual memory ( P =0.227), and processing speed ( P =0.101) than matched controls. There were no differences in visual acuity between the 2 groups. NOTCH3 mutation carriers had significantly thinner macular inner subfield at the superior ( P =0.006), temporal ( P =0.008), and nasal ( P =0.034) quadrants, and significantly thinner macular RNFL ( P =0.008) compared with age-, sex-, and vascular risk factor-matched controls. Conclusion: The presence of NOTCH3 mutation is associated with reduced thickness in the inner macular subfield and macular RFNL. These retinal changes may reflect early pericyte dysfunction and microvascular ischemia. Longitudinal studies are needed to assess the temporal relationship between these retinal changes, cerebrovascular disease progression, and clinical severity of disease.

Abstract Background Sensitive, accessible biomarkers of the pathologies underlying Alzheimer's disease and related dementias (ADRD) are critical for accurate diagnosis, deeper understanding of disease mechanisms, and development of new therapies with validated target engagement. The retina is connected to the brain via the optic nerve, which may facilitate the transmission and spread of amyloid beta (Aβ) and tau species. In postmortem studies, retinal Aβ deposits have been associated with neuritic Aβ‐plaque and neurofibrillary tangle burden, particularly in the entorhinal and temporal cortices. The goal of the current study was to evaluate associations between retinal perivascular amyloid and cognition, as well as to explore effect modification by hippocampal volumetry. Method Participants, aged ≥40 years, underwent retinal imaging, brain MRI, FDG‐PET, and a comprehensive neuropsychological assessment. Retinal amyloid imaging was conducted following curcumin ingestion and pupil dilation using a confocal scanning laser ophthalmoscope. Perivascular Aβ plaque counts were quantified in the superotemporal peripheral region following manual identification and tracking of retinal arteries and veins. Associations between retinal perivascular Aβ plaque counts with cognitive domains were evaluated using linear regression models adjusted for age, sex, and estimated premorbid functioning. Where significant associations were detected ( p ‐value<0.05), effect modification by hippocampal volumetry was examined with additional adjustment for intracranial volume. Result The sample included 26 participants (mean age 65±7 years, 50% female). Higher amyloid plaque counts in the perivascular secondary small and tertiary branches and in the periarteriolar tertiary branch were associated with poorer verbal and visual memory (Table 1). Significant interactions were observed between amyloid plaque count in the perivascular secondary small branch (β(95% Confidence Interval) = 0.397(0.037‐0.756), p = 0.033) and periarteriolar tertiary branch (β(95% Confidence Interval) = 0.756(0.165–1.346), p = 0.017) with hippocampal volumetry for visual memory. Conclusion Our pilot study provides preliminary evidence that perivascular Aβ accumulation in smaller vessels of the superotemporal retina may be a marker of memory impairment that may interact synergistically with hippocampal atrophy. Longitudinal studies consisting of multimodal ophthalmic assessments, brain imaging, ADRD biofluid markers, and cognitive testing will be necessary to capture the temporal sequence of retinal pathological changes and their associations with those in the brain.

Abstract Background The interplay between vascular dysfunction and brain amyloidosis in driving Alzheimer's disease (AD) pathogenesis and cognitive decline is increasingly recognized. The retina, sharing an embryonic origin with the brain, offers an accessible CNS organ for high‐resolution, noninvasive imaging of AD‐related vascular pathology. However, the exact nature of retinal vascular damage in AD—especially in early disease stages—and its relationship with cerebral amyloid angiopathy (CAA) and cognitive impairment remain understudied. Method We examined vascular abnormalities in retinas of MCI and AD via histopathology and in‐vivo imaging studies. Postmortem retinas from 53–62 individuals (CN: 22; MCI/AD: 31–40) underwent immunohistochemistry for pericyte integrity, vascular Aβ42/40, and endothelial TJ proteins, with dysregulated proteins quantified by mass spectrometry in 12 additional AD/CN cases. Retinal curcumin‐amyloid imaging by scanning‐laser ophthalmoscope in 28–34 live participants (CN[MOCA>26]: 8–15; MCI/AD[MOCA≤26]: 13–19) assessed peri‐arteriolar/venular amyloid plaques (APs). Perivascular AP burden was correlated with MRI measures (hippocampal volume, WMH lesions) and cognitive/neuropsychiatric parameters. Result Retinal pericyte loss, reflected by PDGFRβ deficiency and apoptosis, was evident in MCI and AD patients and correlated with vascular Aβ42/40 accumulation and CAA severity (r=0.68–0.84; p <0.01–0.0001). Retinal endothelial ZO‐1 and claudin‐5 levels were significantly reduced, correlating with arteriolar Aβ40 deposition, suggesting impaired retinal Aβ clearance. Retinal capillary claudin‐5 and arteriolar Aβ40 strongly associated with CAA (r=0.75–0.77, p <0.0001), while ZO‐1 moderately correlated with brain amyloidosis/tauopathy, CAA, and cognitive decline (r=0.43–0.57, p <0.01–0.001). Both histological and in‐vivo imaging studies revealed greater Aβ deposition in retinal arterioles, particularly in secondary and tertiary branches, compared to venules or capillaries ( p <0.01–0.0001). Retinal perivascular APs in secondary/tertiary branches imaged in living patients correlated with cognitive impairment (global CDR, MOCA), hippocampal atrophy, and WMH lesions (r=0.51–0.66, p <0.05–0.001). Perivascular APs in the secondary (β=0.397, p = 0.033) and tertiary (β=0.756, p = 0.017) arteriolar branches showed significant interactions with hippocampal volumetry for visual memory. Conclusion Retinal arteriolar Aβ accumulation, pericyte loss, and TJ dysfunction contribute to early AD vascular pathology. If validated in larger cohorts, these findings support retinal vascular biomarkers as tools for predicting cognitive decline, monitoring AD progression, and assessing CAA severity.

Introduction Hypoplastic left heart syndrome and Fontan procedure predispose to cardiac thrombus formation in the venous pathways due to the unique hemodynamic and hematologic disturbances inherent to the Fontan circulation. Systemic venous blood is routed passively to the pulmonary arteries without a subpulmonary pump, resulting in chronic low‐velocity flow, elevated central venous pressure, and venous stasis—all elements of Virchow's triad that favor clot formation 1 . Additionally, these patients exhibit reduced levels of protein C, coagulation factors II, V, VII, and X, plasminogen, and antithrombin III, along with increased levels of factor VIII 2,3 . Once a thrombotic event occurs, the rationale for lifelong anticoagulation is compelling. We report a case of an adult man that underwent Fontan palliation in infancy, with acute cerebral and renal infarcts, and discuss stroke and systemic embolism prevention. Case presentation A 22‐year‐old male with history of hypoplastic left heart syndrome status post Fontan procedure in infancy with congestive splenomegaly and liver disease presented with acute abdominal pain and was found to have bilateral renal infarcts. Anticoagulation was not initiated acutely and within 24 hours he developed left face and arm weakness, dysarthria and mild aphasia. Intravenous Tenecteplase was administered within 1 hour of symptom onset and was followed by symptoms’ complete resolution within 30 minutes of administration. Brain MRI confirmed scattered cerebral infarcts in the bilateral middle cerebral artery territories. Transthoracic echocardiogram showed atrial level shunting, expected due to fenestrated IVC to left atrium from prior Fontan procedure, and no evidence of atrial or ventricular thrombus. Due to the patient having evidence of multiple infarcts in multiple vascular beds within the brain and kidneys, an extensive hypercoagulable workup was undertaken which was unremarkable. The patient's stroke etiology was presumed to be cardioembolic from his altered cardiac anatomy with susceptibility to form venous thrombi and known surgically‐induced atrial level shunt. Low intensity heparin drip without bolus was started initially, and was transitioned to therapeutic apixaban upon discharge with proposed life long anticoagulation. Conclusions Subjects with hypoplastic heart syndrome display persistent unfavorable hemodynamics and procoagulant state after Fontan procedure. Either antiplatelet or anticoagulants are recommended after performing risk stratification. In high‐risk patients (recent thromboembolic event or stent, recurrent atrial arrhythmias, mechanical valve), therapeutic anticoagulation with either warfarin or direct oral anticoagulant is indicated, given increased vulnerability to recurrent events 1 . In intermediate‐risk subjects, antiplatelet or prophylactic doses of anticoagulation is indicated, whereas in low‐risk patients, antiplatelet agent is preferred.

Background Intracranial occlusions in embolic stroke of undetermined source are histopathologically similar to cardiac sources of embolism. Whether patients with embolic stroke of undetermined source and intracranial occlusion benefit from anticoagulation is unknown. Methods A multicenter retrospective cohort of adults with cryptogenic stroke was queried for patients with proximal or medium/distal vessel occlusion. The primary outcome was recurrent ischemic stroke, which was assessed in unadjusted and adjusted Cox proportional hazards models and repeated following 1:1 propensity score matching and biweight kernel density matching. Results Of the 2328 patients who were followed over a median of 1.31 years (interquartile range, 0.34–2.85), 999 (42.6%) had an intracranial occlusion. When compared with patients without an intracranial occlusion, those with an occlusion had fewer atherosclerotic vascular risk factors, more severe symptoms, and less severe cerebral microvascular disease. The rate of recurrent stroke was similar between patients with versus without an intracranial occlusion (6.8%/year [95% CI, 5.7–8.2] versus 7.0%/year [95% CI 6.0–8.1]; adjusted hazard ratio [HR], 1.09 [95% CI, 0.77–1.55]). There was no association between occlusion and recurrent stroke in the adjusted propensity score matching (HR, 1.01 [95% CI, 0.64–1.59]) or kernel density models (HR, 0.95 [95% CI, 0.62–1.45]). There was no interaction between occlusion and treatment with anticoagulation, sex, age, or high‐risk sources of embolism for the primary outcome in the unmatched and matched analyses. Conclusions Intracranial occlusion in patients with embolic stroke of undetermined source is not associated with a greater risk of recurrence when compared with patients without an intracranial occlusion. There was no difference in rate of recurrent stroke with anticoagulation when stratified by presence or absence of occlusion.

BACKGROUND: This individual participant data meta-analysis aimed to determine whether time to treatment influences the effect of intraarterial thrombolysis (IAT), intravenous thrombolysis, and conservative standard therapy on visual outcomes in nonarteritic central retinal artery occlusion. METHODS: We searched MEDLINE, CENTRAL, and Embase up to June 2023 for studies reporting treatment modality and peri-treatment best-corrected visual acuity (BCVA) for ≥5 participants, excluding patients with nonsevere vision loss (BCVA <1.0 logarithm of the minimum angle of resolution [logMAR]) or treated after 24 hours of symptom onset. The primary outcome was recovery from severe vision loss (final BCVA <1.0 logMAR). We used mixed-effect models and local polynomial regression to investigate nonlinear relationships between time to treatment and recovery from severe vision loss. RESULTS: Of 4074 screened studies, individual participant data were sought from 52, with 35 contributing individual participant data for 1038 participants. In total, 783 patients met inclusion criteria (age, 64.8±13.3 years; 35.5% female; baseline BCVA, 2.3±0.5 logMAR). For every hour decrease in time to treatment, thrombolysis was associated with greater improvement in BCVA (intraarterial, 0.02 logMAR [95% CI, 0–0.04]; intravenous, 0.04 logMAR [95% CI, 0.00–0.07]) than conservative standard therapy (0.01 logMAR [95% CI, 0–0.02]). A nonlinear relationship was detected for intraarterial thrombolysis with a changepoint at 8 hours (95% CI, 6.7–9.4). Thrombolysis was associated with increased recovery from severe vision loss compared with conservative standard therapy (intraarterial within 6 hours: odds ratio, 2.72 [95% CI, 1.02–7.28], 27.2% versus 12.0%; intravenous within 4.5 hours: odds ratio, 3.32 [95% CI, 1.24–8.92], 28.8% versus 11.1%). Findings were consistent in subgroup analysis restricted to patients receiving recombinant tissue-type plasminogen activator. Monte-Carlo simulations showed that a randomized controlled trial would require 95 participants per group to achieve 80% power to detect an odds ratio of 3.0 for recovery from severe vision loss. CONCLUSIONS: Early intervention in nonarteritic central retinal artery occlusion is associated with improvement in visual recovery, with intraarterial thrombolysis and intravenous thrombolysis outperforming nonthrombolytic treatments. These findings warrant confirmation in sufficiently powered randomized controlled trials.

Background Prompt diagnosis of acute central retinal artery occlusion (CRAO) is crucial for therapeutic management and stroke prevention. However, most stroke centers lack onsite ophthalmic expertise before considering fibrinolytic treatment. This study aimed to develop, train, and test a deep learning system to detect hyperacute CRAO on retinal fundus photographs within the critical 4.5‐hour treatment window and up to 24 hours after visual loss to aid in secondary stroke prevention. Methods Our retrospective, cross‐sectional study included 1322 color fundus photographs from 771 patients with acute visual loss due to CRAO, central retinal vein occlusion, nonarteritic anterior ischemic optic neuropathy, and healthy controls. Photographs were collected from 9 expert neuro‐ophthalmology centers in 6 countries, including 3 randomized clinical trials. Training included 1039 photographs (517 patients), followed by testing on 2 data sets: (1) hyperacute CRAO (54 photographs, 54 patients) and (2) CRAO within 24 hours after visual loss (110 photographs, 109 patients). Results The deep learning system achieved an area under the receiver operating characteristic curve of 0.96 (95% confidence interval (CI), 0.95–0.98), a sensitivity of 92.6% (95% CI, 87.0–98.0), and a specificity of 85.0% (95% CI, 81.8–92.8) for detecting CRAO at hyperacute stage, with similar results within 24 hours. The deep learning system outperformed stroke neurologists on a subset of hyperacute testing data set (120 photographs, 120 patients). Conclusions A deep learning system can accurately detect hyperacute CRAO on retinal photographs within a time window compatible with urgent fibrinolysis. If further validated, such systems could improve patient selection for fibrinolytic trials and optimize secondary stroke prevention. Registration URL: https://www.clinicaltrials.gov ; Unique identifier: NCT06390579.

AbstractINTRODUCTIONGiven the close interactions between the retina and the brain, retinal amyloid imaging may serve as a diagnostic and prognostic tool for Alzheimer's disease and related dementias. This retrospective study investigated multivariable associations between retinal perivascular amyloid and cognitive domains.METHODSIntegrated analysis of retinal perivascular amyloid imaging, neuropsychological assessment, and brain magnetic resonance imaging in adults with and without cognitive impairment (N = 26; mean age: 65 ± 7 years; 50% female). Correlations between perivascular amyloid plaque burden and cognitive domains were evaluated with linear regression and interactions with hippocampal volumetry were explored.RESULTSHigher perivascular and periarteriolar amyloid plaque count in the secondary small and tertiary branches were associated with poorer verbal and visual memory in this cohort (p = 0.005–0.009). Higher perivascular amyloid burden interacted with hippocampal atrophy to worsen visual memory (p = 0.033).DISCUSSIONRetinal perivascular amyloid may serve as a non‐invasive marker for cognitive impairment and may shed insight into pathological changes in the brain.Highlights In vivo retinal perivascular amyloid plaque counts are associated with poorer memory. Retinal perivascular amyloid interacted with hippocampal atrophy to worsen memory. Retinal amyloid imaging is a potential biomarker for neurodegenerative diseases.