Utilizing RNA sequencing to identify gene expression markers of stroke-causing thrombi origin: A pilot study.

INTRODUCTION: Stroke embolic source have an unknown origin in 30-40% of cases. Mechanical thrombectomy for acute large vessel occlusion stroke has provided us with a method to directly retrieve the thrombi from patients for analysis. By collecting stroke-causing thrombi from known sources, we can then use high-throughput RNA sequencing (RNAseq) technology to directly measure the gene expression signatures of these clots. This may allow us to identify genetic markers to predict the cause of cryptogenic embolism. METHODS: This is a prospective study in which RNAseq was used to analyze cerebral thrombi retrieved by mechanical thrombectomy devices in acute ischemic stroke patients. Samples were separated into two groups based on known stroke thrombus etiology, including Carotid group (patients with ipsilateral >70% carotid stenosis) and Atrial fibrillation (AF) group (patients with atrial fibrillation). Gene expression was compared by RNAseq analysis between the groups. RESULTS: From October 2016 to September 2017, 8 thrombi (4 in Carotid group, 4 in Afib group) were included in this study. There were 131 genes that were significantly up- or down-regulated between the two groups defined as a false discovery rate ≤ 0.05 and a fold change ≥ 2. Twenty-six genes were selected as candidate gene biomarkers based on the criteria in the methods section. Candidate genes HSPA1B, which encodes a heatshock protein, and GPRC5B, which encodes a G-protein, showed the greatest fold differences in expression between the two groups. CONCLUSION: This study has shown that RNA sequencing of acute ischemic stroke thrombi is feasible and indentified potential novel biomarkers for identifying stroke-causing thrombi origin, especially in cryptogenic stroke.

Intramyocardial cell-based therapy with Lomecel-B during bidirectional cavopulmonary anastomosis for hypoplastic left heart syndrome: the ELPIS phase I trial.

Aims: Hypoplastic left heart syndrome (HLHS) survival relies on surgical reconstruction of the right ventricle (RV) to provide systemic circulation. This substantially increases the RV load, wall stress, maladaptive remodelling, and dysfunction, which in turn increases the risk of death or transplantation. Methods and results: We conducted a phase 1 open-label multicentre trial to assess the safety and feasibility of Lomecel-B as an adjunct to second-stage HLHS surgical palliation. Lomecel-B, an investigational cell therapy consisting of allogeneic medicinal signalling cells (MSCs), was delivered via intramyocardial injections. The primary endpoint was safety, and measures of RV function for potential efficacy were obtained. Ten patients were treated. None experienced major adverse cardiac events. All were alive and transplant-free at 1-year post-treatment, and experienced growth comparable to healthy historical data. Cardiac magnetic resonance imaging (CMR) suggested improved tricuspid regurgitant fraction (TR RF) via qualitative rater assessment, and via significant quantitative improvements from baseline at 6 and 12 months post-treatment (P < 0.05). Global longitudinal strain (GLS) and RV ejection fraction (EF) showed no declines. To understand potential mechanisms of action, circulating exosomes from intramyocardially transplanted MSCs were examined. Computational modelling identified 54 MSC-specific exosome ribonucleic acids (RNAs) corresponding to changes in TR RF, including miR-215-3p, miR-374b-3p, and RNAs related to cell metabolism and MAPK signalling. Conclusion: Intramyocardially delivered Lomecel-B appears safe in HLHS patients and may favourably affect RV performance. Circulating exosomes of transplanted MSC-specific provide novel insight into bioactivity. Conduct of a controlled phase trial is warranted and is underway.Trial registration number NCT03525418.

Results and insights from a phase I clinical trial of Lomecel-B for Alzheimer's disease.

HYPOTHESIS: We hypothesized that Lomecel-B, an allogeneic medicinal signaling cell (MSC) therapeutic candidate for Alzheimer's disease (AD), is safe and potentially disease-modifying via pleiotropic mechanisms of action. KEY PREDICTIONS: We prospectively tested the predictions that Lomecel-B administration to mild AD patients is safe (primary endpoint) and would provide multiple exploratory indications of potential efficacy in clinical and biomarker domains (prespecified secondary/exploratory endpoints). STRATEGY AND KEY RESULTS: Mild AD patient received a single infusion of low- or high-dose Lomecel-B, or placebo, in a double-blind, randomized, phase I trial. The primary safety endpoint was met. Fluid-based and imaging biomarkers indicated significant improvement in the Lomecel-B arms versus placebo. The low-dose Lomecel-B arm showed significant improvements versus placebo on neurocognitive and other assessments. INTERPRETATION: Our results support the safety of Lomecel-B for AD, suggest clinical potential, and provide mechanistic insights. This early-stage study provides important exploratory information for larger efficacy-powered clinical trials.

Association of hypothyroidism with unruptured cerebral aneurysms: a case-control study.

OBJECTIVE Thyroid disorder has been known to affect vascular function and has been associated with aortic aneurysm formation in some cases; however, the connection has not been well studied. The authors hypothesized that hypothyroidism is associated with the formation of cerebral aneurysms. METHODS The authors performed a retrospective case-control study of consecutive patients who had undergone cerebral angiography at an academic, tertiary care medical center in the period from April 2004 through April 2014. Patients with unruptured aneurysms were identified from among those who had undergone 3-vessel catheter angiography. Age-matched controls without cerebral aneurysms on angiography were also identified from the same database. Patients with previous subarachnoid hemorrhage or intracranial hemorrhage were excluded. History of hypothyroidism and other risk factors were recorded. RESULTS Two hundred forty-three patients with unruptured cerebral aneurysms were identified and age matched with 243 controls. Mean aneurysm size was 9.6 ± 0.8 mm. Hypothyroidism was present in 40 patients (16.5%) and 9 matched controls (3.7%; adjusted OR 3.2, 95% CI 1.3-7.8, p = 0.01). Subgroup analysis showed that men with hypothyroidism had higher odds of an unruptured cerebral aneurysm diagnosis than the women with hypothyroidism, with an adjusted OR of 12.7 (95% CI 1.3-121.9) versus an OR of 2.5 (95% CI 1.0-6.4) on multivariate analysis. CONCLUSIONS Hypothyroidism appears to be independently associated with unruptured cerebral aneurysms, with a higher effect seen in men. Given the known pathophysiological associations between hypothyroidism and vascular dysfunction, this finding warrants further exploration.

Utilizing CT with Maximum Intensity Projection Reconstruction Bypassing CTA Improves Time to Groin Puncture in Large Vessel Occlusion Stroke Thrombectomy.

BACKGROUND AND PURPOSE: Prior to thrombectomy for proximal anterior circulation large vessel occlusion (LVO) stroke, recent trials have utilized CT angiography (CTA) for vascular imaging immediately following noncontrast CT (NCCT) for decision-making, but thin-section NCCT with automated maximum intensity projection (MIP) reconstruction also has high accuracy in demonstrating the site of an occluding thrombus. We hypothesized that performing thin-section NCCT with MIP alone prior to thrombectomy improves the time to groin puncture (GP) compared to performing CTA after NCCT. MATERIALS AND METHODS: We performed a retrospective cohort study of anterior circulation LVO thrombectomy at our tertiary care academic medical center. All stroke patients evaluated with thin-section NCCT (0.625 mm) with automated MIP reconstructions alone and those who had additional CTA were included. We excluded transfer patients, in-hospital strokes, posterior circulation strokes, and patients that were evaluated with stroke imaging other than NCCT or CTA prior to thrombectomy. The study groups were compared for duration from NCCT to GP and total stroke imaging duration. RESULTS: From March 2008 through August 2015, 34 thrombectomy patients met the inclusion/exclusion criteria - 13 in the NCCT and 20 in the NCCT+CTA group. The total stroke imaging duration was shorter in the NCCT group than in the NCCT+CTA group (2 min [1-6] vs. 28 min [23-65]; p < 0.001). The NCCT-only group had a shorter time from NCCT to GP (68 min [32-99] vs. 104 min [79-128]; p = 0.030). CONCLUSION: Avoiding advanced imaging for patients with anterior circulation LVO in whom thin-section NCCT with MIPs reveals a hyperdense sign significantly shortens the imaging-to-GP time.

Dose Comparison Study of Allogeneic Mesenchymal Stem Cells in Patients With Ischemic Cardiomyopathy (The TRIDENT Study).

RATIONALE: Cell dose and concentration play crucial roles in phenotypic responses to cell-based therapy for heart failure. OBJECTIVE: To compare the safety and efficacy of 2 doses of allogeneic bone marrow-derived human mesenchymal stem cells identically delivered in patients with ischemic cardiomyopathy. METHODS AND RESULTS: Thirty patients with ischemic cardiomyopathy received in a blinded manner either 20 million (n=15) or 100 million (n=15) allogeneic human mesenchymal stem cells via transendocardial injection (0.5 cc per injection × 10 injections per patient). Patients were followed for 12 months for safety and efficacy end points. There were no treatment-emergent serious adverse events at 30 days or treatment-related serious adverse events at 12 months. The Major Adverse Cardiac Event rate was 20.0% (95% confidence interval [CI], 6.9% to 50.0%) in 20 million and 13.3% (95% CI, 3.5% to 43.6%) in 100 million (P=0.58). Worsening heart failure rehospitalization was 20.0% (95% CI, 6.9% to 50.0%) in 20 million and 7.1% (95% CI, 1.0% to 40.9%) in 100 million (P=0.27). Whereas scar size reduced to a similar degree in both groups: 20 million by -6.4 g (interquartile range, -13.5 to -3.4 g; P=0.001) and 100 million by -6.1 g (interquartile range, -8.1 to -4.6 g; P=0.0002), the ejection fraction improved only with 100 million by 3.7 U (interquartile range, 1.1 to 6.1; P=0.04). New York Heart Association class improved at 12 months in 35.7% (95% CI, 12.7% to 64.9%) in 20 million and 42.9% (95% CI, 17.7% to 71.1%) in 100 million. Importantly, proBNP (pro-brain natriuretic peptide) increased at 12 months in 20 million by 0.32 log pg/mL (95% CI, 0.02 to 0.62; P=0.039), but not in 100 million (-0.07 log pg/mL; 95% CI, -0.36 to 0.23; P=0.65; between group P=0.07). CONCLUSIONS: Although both cell doses reduced scar size, only the 100 million dose increased ejection fraction. This study highlights the crucial role of cell dose in the responses to cell therapy. Determining optimal dose and delivery is essential to advance the field, decipher mechanism(s) of action and enhance planning of pivotal Phase III trials. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT02013674.

Safety Outcomes Using a Proximal Protection Device in Carotid Stenting of Long Carotid Stenoses.

BACKGROUND: Embolic protection devices can prevent atherosclerotic emboli during carotid stenting. Newer proximal protection devices reverse flow in the internal carotid artery (ICA), leading to reduction in perioperative microemboli. The risk of stroke is high for carotid stenting of ICA lesions with a length >10 mm and/or angiographic string sign. OBJECTIVE: We aimed to evaluate the safety outcomes of proximal embolic protection device usage in this high-risk group. METHODS: This is a retrospective analysis of patients who underwent carotid stenting procedures with proximal embolic protection devices at a tertiary care center. High-risk features for adverse events with carotid stenting were identified. Peri- and postprocedural outcomes were recorded. We further compared outcomes in patients with a carotid stenosis length >10 mm to those with shorter stenosis. RESULTS: From January 2011 to December 2014, we included 27 patients; 96.3% were symptomatic and 3.7% were asymptomatic. There was a stent placement technical success rate of 100%. No major stroke or coronary events were recorded. One minor stroke event developed in one patient. A carotid lesion length >10 mm and/or angiographic string sign was noted in 21/27 patients, with an average lesion length of 14.4 mm. One patient (4.8%) in this group developed a minor stroke event. Neither a coronary nor a major stroke event was recorded in this group. There was no significant difference in the complication rate between the long lesion and the control group. CONCLUSION: In our patient cohort, it was found that a proximal embolic protection device is safe for patients with carotid stenosis, including those with a carotid lesion length >10 mm and/or angiographic string sign.

Large animal canine endovascular ischemic stroke models: A review.

BACKGROUND: Stroke is one of the leading causes of death and long-term disability worldwide. Recent exciting developments in the field with endovascular treatments have shown excellent outcomes in acute ischemic stroke. Prior to translating these treatments to human populations, a large-animal ischemic stroke model is needed. With the advent of new technologies in digital subtraction angiography, less invasive endovascular stroke models have been developed. Canines have gyrencephalic brain similar to human brain and accessible neurovascular anatomy for stroke model creation. Canine stroke model can be widely utilized to understand the disease process of stroke and to develop novel treatment. Less invasive endovascular internal carotid emboli injection and coil embolization methods can be used to simulate transient or permanent middle cerebral artery occlusion. Major restriction includes the extensive collateral circulation of canine cerebral arteries that can limit the stroke size. Transient internal carotid artery occlusion can decrease collateral circulation and increase stroke size to some degree. Additional method of manipulating the extent of collateral circulation needs to be studied. Other types of canine stroke models, including vertebral artery occlusion and basilar artery occlusion, can also be accomplished by endovascular thrombi injection. CONCLUSIONS: We extensively review the literature on endovascular technique of creating canine ischemic stroke models and their application in finding new therapies for ischemic stroke.

Transradial access in acute ischemic stroke intervention.

OBJECTIVE: To describe the feasibility and safety of transradial access (TRA) in the interventional management of acute ischemic stroke (AIS). METHODS: A retrospective review of the local institutional AIS interventional databases of three tertiary academic centers was performed and the use of TRA identified. RESULTS: TRA was attempted in 15 (1.5%) of 1001 patients; it was used in 12 cases due to transfemoral access (TFA) failure and in 3 as the primary strategy. The mean age was 72.3±8.6 and 46% were male. Baseline National Institutes of Health Stroke Scale score was 19.5±8.7, two patients (14%) received intravenous tissue plasminogen activator, and mean time from last known normal to intra-arterial therapy was 17.0±20.1 h. Five patients had anterior circulation occlusive disease and 10 had vertebrobasilar occlusions. TRA was effective in allowing clot engagement in 13 of 15 cases: one patient had a hypoplastic radial artery that precluded sheath advancement and one had chronic innominate artery occlusion that could not be crossed. Mean time to switch from TFA to TRA was 1.9±1.3 h and the mean time from radial puncture to reperfusion was 2.2±1.0 h. Modified Thrombolysis In Cerebral Infarction 2b-3 reperfusion via TRA was achieved in 9 of 15 patients (60%). No radial puncture site complications were noted. At 90 days, two patients (13%) had a good clinical outcome and seven (50%) had died. CONCLUSIONS: Failure of TFA in the endovascular treatment of AIS is uncommon but leads to unacceptable delays in reperfusion and poor outcomes. Standardization of benchmarks for access switch could serve as a guide for neurointerventionalists. TRA is a valid approach for the endovascular treatment of AIS.