Citations

Introduction: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a genetic, progressive microangiopathy caused by mutations in the NOTCH3 gene. Patients often present with migraine and progressive subcortical infarcts resulting in vascular cognitive impairment and death. Currently, there are no disease modifying treatments. Limiting future trials is the lack of an objective construct to classify and monitor severity of disease. The purpose of this study was to gain experience with a novel CADASIL severity grading system. Methods: Neurologists at 5 academic centers retrospectively reviewed charts of those with confirmed CADASIL. Demographic and clinical data were recorded. The CADASIL severity grades were then assigned: 0 (asymptomatic), 1 (migraine alone), 2 (stroke or mild cognitive impairment), 3 (gait impairment or early dementia) and 4 (bedbound) based on available data. Standard descriptive statistical analyses were used. Results: We identified 138 patients; overall mean age of 50.9±13.1 years, 42.8% were men. 15 (10.9%) were grade 0, 50 (36.2%) were grade 1, 41 (44.2%) were grade 2, 12 (8.7%) were grade 3, and none were grade 4. Those with less severe disease tended to be younger, more likely men, had a lower rate of hypertension and diabetes mellitus and were less frequently tobacco users, Table 1. Increasing number of vascular risk factors was associated with higher severity grading. Conclusion: Our study highlights the ability of this severity scale to separate those with CADASIL into an ordinal system. As known in the literature, more advanced phenotypes of CADASIL tend to have more vascular risk factors. Future trials may consider utilizing this ordinal construct to monitor disease progression, response to therapy, or as a screening tool.

Introduction: Embolic stroke of undetermined source (ESUS) is a clinical paradigm that helps to classify and lead investigations into cryptogenic stroke. Diagnostic evaluation of ESUS involves investigating several potential etiologies of stroke. One such etiology includes antiphospholipid syndrome (APLS), a syndrome known to cause hypercoagulability. Clinical characteristics of primary APLS in ESUS have not been described. Methods: This is an IRB approved, retrospective study including patients from 2015-2020 who were seen at Mayo Clinic, were diagnosed with ESUS, and had APLS testing (anti-cardiolipin, beta-2 glycoprotein, or lupus anticoagulant). Baseline characteristics and radiographic features were collected and compared between patients who were and were not diagnosed with APLS, as well as between patients who were and were not APLS antibody positive. Results: Our study included 206 patients. Positive APLS antibody testing was seen in 21 (10%) patients. Of those patients, 8 (4%) received a formal diagnosis of APLS. Compared to controls, patients with positive APLS antibodies as well as those diagnosed with APLS were more likely to have a history of cancer (20 [11%] APLS antibody negative vs 7 [33%] APLS antibody positive p=0.004) (23 [12%] APLS diagnosis negative vs 4 [50%] APLS diagnosis p=0.002). Mean age in primary APLS was greater, 57 years old APLS antibody negative vs 69 years old APLS antibody positive (p<0.001) and 58 years old APLS diagnosis negative vs 75 years old APLS diagnosis (p=0.001) (Table 1). Regressions analyses examining infarct topography and rate of hemorrhagic transformation were non-significant between groups (p>0.1) Conclusion: APLS presenting as ESUS is associated with older age and history of malignancy. We speculate this finding may underscore the need to consider hypercoagulable conditions more broadly in stroke evaluations of older populations. Larger cohorts and longer follow up will be required to validate this observation.

Background Delayed neurological improvement (DNI) is a phenomenon that involves patient improvement in the absence of early neurological change following treatment for acute ischemic stroke. The patient characteristics associated with this condition are largely unexplored. Methods Following the PRISMA guidelines, a systematic review of the English language literature was conducted using PubMed, Embase, Web of science, and Scopus. We calculated pooled odds ratios (ORs), mean differences (MDs), and their corresponding 95% confidence intervals (CIs) to test the association between patient characteristics and achievement of DNI. Results Seven studies, with 3266 patients, were included in our analysis. All studies reported a different definition of DNI, with five studies focusing on rates of good functional outcome at 90 days post-treatment in the absence of early neurological improvement. Use of intravenous thrombolytics was associated with increased rates of DNI (OR 1.96, 95% CI 1.28 to 3.00; p = 0.002). Atrial fibrillation was associated with decreased rates of DNI (OR 0.69, 95% CI 0.57 to 0.82; p < 0.001), as was hypertension (OR 0.66, 95% CI 0.53 to 0.83, p < 0.001), and diabetes mellitus (OR 0.71, 95% CI 0.56 to 0.90; p = 0.005). On average, patients who achieved DNI were 6.30 years younger than their non-DNI counterparts ( MD −6.30, 95% CI −9.19 to −3.41; p < 0.001). There were modest associations between male sex and DNI (OR 1.36, 95% CI 1.01 to 1.74, p = 0.042), and smoking and DNI (OR 1.28, 95% CI 1.03 to 1.59, p = 0.027). Conclusions DNI is a phenomenon that is not presently well understood. Lack of uniformity among definitions of DNI hinders efforts to explore DNI and the factors associated with its occurrence. Future studies should work to establish a consensus definition of DNI to determine its causes and significance more accurately.

Background Wake-up stroke represents a significant challenge in acute treatment and care. Thrombolysis has been extensively studied in the wake-up stroke population. However, mechanical thrombectomy in wake-up stroke exclusively has not been well studied. We performed a systematic review and meta-analysis to assess the clinical and functional outcomes of patients undergoing mechanical thrombectomy for wake-up stroke. Methods We performed a systematic review of the literature using publically accessible databases. Data extraction was completed using Nested Knowledge AutoLit software. Outcomes of interest included modified Rankin Scale (mRS) 0–2, mortality, symptomatic intracerebral hemorrhage (sICH), and thrombolysis in cerebral infarction (TICI) score 2b/3. Statistical analysis was performed using R software version 4.1.2. Results A total of 12 studies were included in our study with a total of 510 patients included. Patients with wake-up stroke were found to have good functional outcome (mRS 0–2) in 46.2% of patients and successful reperfusion (TICI 2b/3) was seen in 83.5% of patients. Mortality was observed in 20.4% of patients with sICH seen in 8.3%. Conclusion Mechanical thrombectomy for patients with wake-up stroke was found to have favorable rates of good functional outcomes and relatively low rates of adverse events.

Background Young patients experience acute ischemic stroke (AIS) at much lower rates than their older counterparts. We performed a systematic review and meta-analysis to assess the question regarding outcomes and clinical characteristics of young stroke patients who underwent mechanical thrombectomy for AIS. Methods Following PRISMA guidelines, a systematic review of the literature was conducted using the databases PubMed, MEDLINE, and Embase. The primary outcome of interest was 90-day modified Rankin Scale (mRS) 0–2. Secondary outcome variables included rate of successful reperfusion (TICI 2b/3), symptomatic intracerebral hemorrhage (sICH), and mortality. Using R software version 4.1.2, we calculated pooled event rates and their corresponding 95% confidence intervals (CI) for all outcomes. Results Our analysis included eight studies with a total of 1903 patients. Definitions of young patients included age ranges of 18–49/50 years, 18–54/55 years, and 18–64/65 years. Functional independence was achieved in 62.0% of the patients, with an overall mortality of 9.0%. Moreover, successful reperfusion was achieved in 82.0% of the patients with sICH rates of 5.7%. There was significant heterogeneity among different analyses, which could not be attributed to the differences of the definition of young patients. Conclusions Following mechanical thrombectomy for AIS, patients aged 18–65 years achieved relatively high rates of functional independence and successful reperfusion and low rates of mortality and sICH. Clinical Perspective In this systematic review and meta-analysis of eight studies, we examined outcomes in young stroke patients, aged 18–65 years old, following mechanical thrombectomy for acute ischemic stroke. We found that young patients achieved high rates of functional independence, high rates of successful reperfusion, and low rates of mortality and symptomatic intracerebral hemorrhage. While there have been several papers examining outcomes following mechanical thrombectomy for acute ischemic stroke in young patients, the results of these studies have yet to be pooled together in a meta-analysis. Our results indicate that young patients have good outcomes following mechanical thrombectomy. Further studies that examine these outcomes are warranted so that a higher-powered analysis can be performed to better informed clinicians regarding outcomes in this patient age-group cohort.

AbstractObjectivesWe aimed to investigate the outcomes of pulmonary vein isolation in athletes.MethodsWe retrospectively identified endurance athletes who underwent catheter ablation at our institution (2004–2018). Endurance athletes were defined as participating in competitive athletics for at least 1500 lifetime hours in sports at the IB or IIA Bethesda classification or higher. Primary endpoints were freedom from atrial arrhythmias at 12, 24, and 36 months after the procedure. Secondary endpoints were defined as qualitative improvement in symptoms allowing athletes to return to their previous level of activity. Athletes were compared with a control group of nonathletes in a 3‐to‐1 matched analysis by age and sex.ResultsA total of 39 endurance athletes who underwent catheter ablation were identified during the study period. At 12 months, there was no difference in treatment outcomes for athletes versus nonathletes (relative risk [RR], 1.06; 95% CI, 0.92–1.22; p = .40). Freedom from atrial arrhythmias was 35% less likely in athletes than nonathletes at 24 months (RR, 0.65; 95% CI, 0.50–0.83; p < .001) and 42% less likely at 36 months (RR, 0.58; 95% CI, 0.41–0.79; p < .001). Overall, 77% of the athletes were able to return to their previous level of activity following catheter ablation.ConclusionEndurance athletes with atrial fibrillation appear to have higher rates of atrial arrhythmia recurrence than nonathletes after catheter ablation, with higher rates of atypical flutter. The majority of athletes were able to return to their previous level of activity after ablation.

AbstractMagnetic resonance imaging (MRI) is a valuable imaging modality for the assessment of both cardiac and non‐cardiac structures. With a growing population of patients with cardiovascular implantable electronic devices (CIEDs), 50%–75% of these patients will need an MRI. MRI‐conditional CIEDs have demonstrated safety of MRI scanning with such devices, yet non‐conditional devices such as hybrid CIEDs which have generator and lead brand mismatch may pose a safety risk. In this retrospective study, we examined the outcomes of patients with hybrid CIEDs undergoing MRI compared to those patients with non‐hybrid CIEDs. A total of 349 patients were included, of which 24 patients (7%) had hybrid CIEDs. The primary endpoint was the safety of MRI for patients with hybrid CIEDs as compared to those with non‐hybrid devices, measured by the rate of adverse events, including death, lead or generator failure needing immediate replacement, loss of capture, new onset arrhythmia, or power‐on reset. Secondary endpoints consisted of pre‐ and post‐MRI changes of decreased P‐wave or R‐wave sensing by ≥50%, changes in pacing lead impedance by ≥50 ohms, increase in pacing thresholds by ≥ 0.5 V at 0.4 ms, and decreasing battery voltage of ≥ 0.04 V. The primary endpoint of any adverse reaction was present in 1 (4.2%) patient with a hybrid device, and consistent of atrial tachyarrhythmia, and in 10 (3.1%) patients with a non‐hybrid device, and consisted of self‐limited atrial and non‐sustained ventricular arrhythmias; this was not statistically significant. No significant differences were found in the secondary endpoints. This study demonstrates that MRI in patients with hybrid CIEDs does not result in increased patient risk or significant device changes when compared to those patients who underwent MRI with non‐hybrid CIEDs.

The zebrafish has emerged as an excellent model for cardiovascular research thanks to its ex-utero and rapid embryonic development, its embryonic transparent nature, and its capacity to survive in the absence of a functional cardiovascular system during the first week of development, which enables functional characterization of mutations that would otherwise induce lethality in traditional murine models. The aim of this project is to identify and characterize novel genes involved in zebrafish cardiovascular development using mutagenic gene trapping, a technique that generates random insertional mutations across the genome. We use the well-defined RP2 gene-breaking transposon system, which not only mutates, but also fluorescently tags the trapped gene product(s) (Clark, Nat Methods, 2011). RP2 also introduces loxP sites into the mutant locus, which can be used for Cre-mediated phenotype rescue by microinjection of Cre recombinase, or by crossing to tissue-specific Cre lines. From over 3000 RP2-injected embryos, 141 fish showed germline transmission. Among them, 51 expressed strong fluorescence in different tissues, including the heart, vessels, notochord, central nervous system (CNS), and eyes. Three cardiovascular lines were selected for phenotypic characterization and functional studies. RP2#C2 strain expressed fluorescence in the heart valves, CNS, eyes and pectoral fin buds. Inverse PCR in RP2#C2 demonstrated a trapped gene at meis4.1a, which encodes a homeobox transcription factor that has not been previously studied in zebrafish. RP2#121 strain expressed strong fluorescence in cardiac and skeletal muscles. RP2#91 strain showed expression in the vasculature and demonstrated a trapped gene at pdgfra. Homozygous RP2#91 mutants showed severe defects in the heart, blood flow, and other body parts including the head and musculature. We are currently creating a panel of tissue-specific Cre lines targeting tissues such as cardiomyocytes, endothelial cells and smooth muscle cells for spatiotemporal rescuing of the mutant phenotype. The generated zebrafish protein-trap lines are invaluable tools to annotate gene function, dissect the molecular mechanisms of cardiovascular development, and potentially serve as disease models.

Abstract There is a significant unmet medical need to develop more effective treatments for cancers of the central and peripheral nervous systems. Glioblastoma multiforme (GBM) is the most common form of brain cancer, and successful long-term treatment has not been realized. Neuroblastomas (NB) arise in the sympathetic nervous system and are the most common extracranial solid tumor of childhood. Survival of children with disseminated, high-risk NB tumors is less than 50%, even with intensive multimodal treatment. To improve treatment outcome, inhibition of murine double minute 2 (MDM2) function in the context of front-line therapy is being explored. MDM2 is a multi-functional protein that plays a critical role in controlling cell growth and migration. MDM2 is a negative regulator of p53 and p73 and, under low stress conditions, sequesters them in the cytoplasm. However, inhibition of MDM2 interactions with p53 and p73 by the MDM2 antagonist nutlin3a can lead to activation of p53/p73-mediated cell-death in tumor cells. The objective of the present study was to evaluate the extent to which blockade of MDM2-p53/p73 interactions by nutlin3a, alone or in combination with front-line therapies, could augment cell death in GBM and NB cells with a variety of molecular profiles. Using the median effect model, we found that temozolomide (TMZ) and nutlin3a were synergistic in increasing cell death in wtp53 U87 and U373 but were predominantly additive in mtp53 U118 cells. Primary patient GBM cells were typically resistant to TMZ relative to established cell lines. However, resistance to TMZ was decreased in the presence of nutlin3a. Further, TMZ and nutlin3a were synergistic in primary GBM10 and GBM43 but not in recurrent primary IU-GBM16, IU-GBM23, IU-GBM27, and IU-GBM32 cells. Moreover, in NB cells with wtp53, nutlin3a and cisplatin were synergistic in MYCN nonamplified SK-N-SH and additive in MYCN amplified IMR5. In mtp53 NB cells, nutlin3a and cisplatin were synergistic in MYCN nonamplified SK-N-FI as well as in MYCN amplified SK-N-DZ. Nutlin3a alone produced dose-related increases in cell death of all GBM and NB cell lines irrespective of p53 status, suggesting that p53-independent mechanisms play a role in inhibition of cell growth produced by blockade of MDM2-mediated signaling. Consistent with this hypothesis, nutlin3a increased p73 protein levels in mtp53 GBM43 cells that were exposed to TMZ. Inhibition of MDM2 function also inhibited repair of TMZ-mediated DNA damage in GBM. In comet assays, nutlin3a+TMZ decreased DNA repair relative to TMZ alone in wtp53 U87 and GBM10 and in mtp53 GBM43 cells. The present results demonstrate that MDM2 is a valid therapeutic target in GBM and NB cells with varying genetic profiles. In conclusion, inhibition of MDM2 signaling by nutlin3a is generally synergistic to additive in combination with front-line chemotherapeutics used to treat cancers of the central and peripheral nervous systems. Citation Format: Harlan E. Shannon, Haiyan Wang, Shanbao Cai, Wei Michael Liu, Lawrence M. Gelbert, Aaron A. Cohen-Gadol, Jann N. Sarkaria, Lindsey D. Mayo, Karen E. Pollok. MDM2 as a therapeutic target: improving upon front-line chemotherapy for nervous system tumors. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3435. doi:10.1158/1538-7445.AM2013-3435