Asymptomatic Infarction Research Articles

Cerebrovascular Risk-Factors of Prevalent and Incident Brain Infarcts in the General Population: The AGES-Reykjavik Study.

Studies on the association of cerebrovascular risk factors to magnetic resonance imaging detected brain infarcts have been inconsistent, partly reflecting limits of assessment to infarcts anywhere in the brain, as opposed to specific brain regions. We hypothesized that risk-factors may differ depending on where the infarct is located in subcortical-, cortical-, and cerebellar regions. Participants (n=2662, mean age 74.6±4.8) from the longitudinal population-based AGES (Age, Gene/Environment Susceptibility)-Reykjavik Study underwent brain magnetic resonance imaging at baseline and on average 5.2 years later. We assessed the number and location of brain infarcts (prevalent versus incident). We estimated the risk-ratios of prevalent (PRR) and incident (IRR) infarcts by baseline cerebrovascular risk-factors using Poisson regression. Thirty-one percent of the study participants had prevalent brain infarcts and 21% developed new infarcts over 5 years. Prevalent subcortical infarcts were associated with hypertension (PRR, 2.7 [95% CI, 1.1-6.8]), systolic blood pressure (PRR, 1.2 [95% CI, 1.1-1.4]), and diabetes (PRR, 2.8 [95% CI, 1.9-4.1]); incident subcortical infarcts were associated with systolic (IRR, 1.2 [95% CI, 1.0-1.4]) and diastolic (IRR, 1.3 [95% CI, 1.0-1.6]) blood pressure. Prevalent and incident cortical infarcts were associated with carotid plaques (PRR, 1.8 [95% CI, 1.3-2.5] and IRR, 1.9 [95% CI, 1.3-2.9], respectively), and atrial fibrillation was significantly associated with prevalent cortical infarcts (PRR, 1.8 [95% CI, 1.2-2.7]). Risk-factors for prevalent cerebellar infarcts included hypertension (PRR, 2.45 [95% CI, 1.5-4.0]), carotid plaques (PRR, 1.45 [95% CI, 1.2-1.8]), and migraine with aura (PRR, 1.6 [95% CI, 1.1-2.2]). Incident cerebellar infarcts were only associated with any migraine (IRR, 1.4 [95% CI, 1.0-2.0]). The risk for subcortical infarcts tends to increase with small vessel disease risk-factors such as hypertension and diabetes. Risk for cortical infarcts tends to increase with atherosclerotic/coronary processes and risk for cerebellar infarcts with a more mixed profile of factors. Assessment of risk-factors by location of asymptomatic infarcts found on magnetic resonance imaging may improve the ability to target and optimize preventive therapeutic approaches to prevent stroke.

Genicular Artery Embolization for the Treatment of Symptomatic Knee Osteoarthritis.

Background:Genicular artery embolization (GAE) is a novel therapy to treat patients with symptomatic knee osteoarthritis (OA) by reducing synovial arterial hypervascularity. This study evaluates the safety and efficacy of GAE for the treatment of symptomatic knee OA.Methods:A prospective, single-center, open-label U.S. Food and Drug Administration-approved investigational device exemption study was conducted. Patients enrolled in the study were 40 to 80 years old, with moderate or severe knee OA (Kellgren-Lawrence grade 2, 3, or 4), who previously had failure of conservative therapy. Baseline pain (visual analog scale [VAS]) and symptom scores (Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC]) were assessed. After femoral arterial access was achieved, GAE of 1, 2, or 3 genicular arteries supplying the location of the subject’s pain, as determined by digital subtraction angiography and cone-beam computed tomography, was performed using 100-μm particles. Adverse events and symptoms scores were assessed at 1 week, 1 month, 3 months, 6 months, and 1 year after GAE.Results:Over a 10-month period, 40 subjects were enrolled. The median age was 69 years (range, 49 to 80 years). The median body mass index was 29 kg/m2 (range, 19 to 44 kg/m2). Knee OA severity was grade 2 in 18% of the patients, grade 3 in 43%, and grade 4 in 40%. Technical success was achieved in 100% of the subjects. Transient skin discoloration and transient mild knee pain after the procedure were common and expected. Treatment-related adverse events included a groin hematoma requiring overnight observation in 1 subject, self-resolving focal skin ulceration in 7 subjects, and an asymptomatic small bone infarct on magnetic resonance imaging at 3 months in 2 subjects. The WOMAC total and VAS pain scores decreased by 61% and 67% at 12 months from a median baseline of 52 (of 96) and 8 (of 10), respectively. Twenty-seven patients (68%) had a reduction of ≥50% in both WOMAC total and VAS pain scores.Conclusions:This prospective trial demonstrates that GAE is effective and durable in reducing pain symptoms from moderate or severe knee OA that is refractory to other conservative therapy, with an acceptable safety profile.Level of Evidence:Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Imaging Pattern and the Mechanisms of Postoperative Infarction After Indirect Revascularization in Patients with Moyamoya Disease

To develop preventive strategies against postoperative infarction after indirect revascularization surgery in patients with moyamoya disease (MMD), we evaluated clinical information, with a specific focus on the imaging pattern of postoperative infarction. We retrospectively evaluated 421 surgical procedures performed in 354 (262 pediatric and 159 adult) patients with MMD from April 1991 to March 2021 at our institute. In addition to clinical information, raw images of postoperative infarction were collected and categorized into subtypes by the location of the infarction. Symptomatic and asymptomatic postoperative infarction occurred in 47 and 12 patients (11.1% and 2.6%), respectively, and more than half (51.7%) of these cases of postoperative infarction occurred immediately or the day after the surgery. Cortical infarction around the craniotomy site was the most frequent pattern observed (50/59, 84.8%), and some of these cases seemed to occur under local compression from epidural or subdural hematomas (15/50, 30.0%). Ipsilateral white matter infarctions located in the watershed area (9/59, 15.3%) and contralateral infarctions (3/59, 5.1%) were also observed. Four patients (1.0%) showed sudden occlusions of ipsilateral or contralateral large intracranial arteries immediately after surgery. Postoperative infarction caused permanent neurologic deficits in 7 patients (1.7%), and all included the cortex outside the craniotomy site. Local cortical irritation, hemodynamic fluctuation, and thromboembolic events were suggested as possible mechanisms of postoperative infarction after indirect revascularization in patients with MMD. Minimizing cortical irritation, maintaining adequate cerebral blood flow, and perioperative antiplatelet agents might decrease the incidence of postoperative infarction.

Anti-neutrophil cytoplasmic antibody-associated vasculitis accompanied by type II heparin-induced thrombocytopenia resulting in asymptomatic cerebral infarction: a case report

BackgroundHeparin-induced thrombocytopenia (HIT) involves platelet activation and aggregation caused by heparin or HIT antibodies associated with poor survival outcomes. We report a case of HIT that occurred after hemodialysis was started for rapidly progressive glomerulonephritis (RPGN), which was caused by anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV), and ultimately resulted in asymptomatic cerebral infarction.Case presentationA 76-year-old Japanese man was urgently admitted to our hospital for weight loss and acute kidney injury (serum creatinine: 12 mg/dL). Hemodialysis therapy was started using heparin for anticoagulation. Blood testing revealed elevated titers of myeloperoxidase anti-neutrophil cytoplasmic antibodies, and renal biopsy revealed crescentic glomerulonephritis with broad hyalinization of most of the glomeruli and a pauci-immune staining pattern. These findings fulfilled the diagnostic criteria for microscopic polyangiitis, and the patient was diagnosed with RPGN caused by AAV. Steroid pulse therapy, intermittent pulse intravenous cyclophosphamide, and oral steroid therapy failed to improve the patient’s renal function, and maintenance dialysis was started. However, on day 15, his platelet count had decreased to 47,000/µL, with clotting observed in the hemodialysis catheter. Magnetic resonance imaging of the head identified acute asymptomatic brain infarction in the left occipital lobe, and a positive HIT antibody test result supported a diagnosis of type II HIT. During hemodialysis, the anticoagulant treatment was changed from heparin to argatroban. Platelet counts subsequently normalized, and the patient was discharged. A negative HIT antibody test result was observed on day 622.ConclusionsThere have been several similar reports of AAV and HIT co-existence. However, this is a rare case report on cerebral infarction with AAV and HIT co-existence. Autoimmune diseases are considered risk factors for HIT, and AAV may overlap with other systemic autoimmune diseases. To confirm the relationship between these two diseases, it is necessary to accumulate more information from future cases with AAV and HIT co-existence. If acute thrombocytopenia and clotting events are observed when heparin is used as an anticoagulant, type II HIT should always be considered in any patient due to its potentially fatal thrombotic complications.

Microcatheter Stabilization Technique Using Partially Inflated Balloon for Coil Embolization of Paraclinoid Aneurysms.

PurposeCoil embolization of paraclinoid aneurysms should be simple, safe, and effective considering the benign nature of the aneurysm. Here, we present a microcatheter stabilization technique using a partially inflated balloon for the treatment of paraclinoid aneurysms.Materials and MethodsThis retrospective study included 58 patients who underwent balloon-assisted coiling (BAC) for unruptured paraclinoid aneurysms at a tertiary neuro-intervention center between January 2019 and March 2020. We applied a technique to stabilize the microcatheter’s position using the modified BAC technique in paraclinoid aneurysms showing various projections around the ophthalmic curve of the internal carotid artery. The basic concept of the technique is to place a partially inflated balloon just distal to the aneurysm neck and support the distal curve of the microcatheter using the proximal bottom of the balloon. Immediate radiological outcomes were analyzed, and clinical outcomes were evaluated with modified Rankin Scale (mRS) scores.ResultsThe BAC was successfully performed in 51 of 58 patients (88%). We treated the remaining 7 patients by switching to stent-assisted coiling. We obtained a 37% mean packing density resulting in favorable occlusion in all 58 aneurysms (complete occlusion in 35 and residual neck in 23). There were no intraprocedural thromboembolic or hemorrhagic events except one that revealed an asymptomatic infarction after the procedure (1.7%). Magnetic resonance angiography follow-up was performed in 37 patients at an average of 11.8 months, in which 11 minor recurrences (29.7%) were found. There was no major recurrence nor retreatment. The mRS score was 0 in all patients during a mean follow-up of 17.7 months (range, 12–25 months).ConclusionThe modified balloon-assisted coiling technique using a partially inflated balloon was safe and effective and could serve as an option for treating paraclinoid aneurysms.

Abstract No. 16 Genicular artery embolization for the treatment of knee osteoarthritis: final results from a prospective investigational device exemption trial

Genicular artery embolization (GAE) is a promising therapy to treat patients with symptomatic knee osteoarthritis (OA) by reducing synovial arterial hypervascularity. This study evaluates the safety and efficacy of GAE for the treatment of symptomatic knee OA. A prospective, single-center, open-label FDA-approved IDE study was conducted to evaluate the safety and efficacy of GAE for the treatment of symptomatic knee OA. Included patients were age 40-80 years, with moderate or severe focal knee pain and osteoarthritis on knee radiograph (Kellgren-Lawrence 2-4), had no prior knee surgery, and were not candidates or not willing to undergo total knee replacement surgery. Patients had to have failed conservative therapy, including NSAIDs and/or joint injections. Baseline pain (visual analog scale) and symptom scores (WOMAC) were assessed. Median age was 69 years (range 49-80). Median BMI was 28 (range 18-44). Knee OA severity based on Kellgren-Lawrence scale: 18% with grade 2, 43% with grade 3, and 40% with grade 4. After obtaining femoral arterial access, genicular artery embolization was performed using 100-μm particles (Embozene, Varian) of 1-3 genicular arteries supplying the location of the subject’s pain, as determined by digital subtraction angiography and cone-beam CT. Adverse events and symptoms scores were assessed at 1 week, 1 month, 3 months, 6 months, and 1 year after GAE. Over a 9-month period, 40 patients were treated with GAE. The left knee was treated in 25/40 (62%) subjects, and the right knee was treated in 15/40 (38%) subjects. Medial knee pain was treated in 27/40 (68%) and lateral knee pain was treated in 13/40 (32%). Technical success was achieved in 100% of subjects. Transient skin discoloration and transient mild post-procedure knee pain were common and expected. Treatment-related adverse events included: 1 subject with a groin hematoma requiring overnight observation, 7 subjects with self-resolving focal skin ulceration, and 2 subjects with asymptomatic small bone infarct on MRI at 3 months. WOMAC and pain scores decreased from median of 52 (of 96) and 8/10 at baseline to 21/96 (60% decrease) and 3/10 (63% decrease) at 12 months, respectively. 27/40 (67.5%) and 28/40 (70%) had greater than 50% reduction in WOMAC and pain scores, respectively. This prospective trial demonstrates that GAE is highly effective and durable in reducing symptoms due to moderate to severe knee OA that is refractory to other conservative therapy and has an acceptably low toxicity profile.

Research progress of imaging technologies for ischemic cerebrovascular diseases.

Cerebrovascular diseases mainly affect the blood supply of the brain, which has a high demand for oxygen and glucose for the nerve tissues to perform its nerve functions. Ischemic cerebrovascular disease can not only cause stroke, but is also associated with a high incidence of asymptomatic infarction and minimal bleeding that can lead to cognitive and behavioral changes. These changes ultimately manifest as vascular dementia or cognitive impairment. In clinical settings, ischemic cerebrovascular disease can be classified as a transient ischemic attack, reversible ischemic neurological deficit, progressive stroke, complete stroke, marginal infarction, or lacunar infarction. In this review, the research progress of imaging technologies for ischemic cerebrovascular diseases was reviewed, with an aim to provide evidence for clinical practitioners.

Acute coronary artery thrombosis presenting as asymptomatic ST-elevation myocardial infarction in a patient with COVID-19 pneumonia

A 55-year-old man with no cardiovascular comorbidities was admitted to the intensive care unit (ICU) with severe COVID-19 pneumonia requiring ventilatory support. Blood results showed a white cell count of...

Shuxuetong for Prevention of recurrence in Acute Cerebrovascular events with Embolism (SPACE) trial: rationale and design

BackgroundsEmbolic stroke is one of the main mechanisms of ischaemic stroke. Even if treated with recommended antithrombotic agents, stroke recurrence remains high. The Shuxuetong injection, a purified extract of traditional...

Feasibility and Safety of Paclitaxel-Coated Balloon Angioplasty for the Treatment of Intracranial Symptomatic In-Stent Restenosis.

Objective: Symptomatic in-stent restenosis (sISR) is the major cause of medium- or long-term cerebral infarctions in patients who underwent percutaneous transluminal angioplasty and stenting for severe intracranial atherosclerotic stenosis. This study aims to evaluate the feasibility and safety of paclitaxel-coated balloon (PCB) angioplasty for the treatment of intracranial sISR.Methods: We report 11 cases of PCB angioplasty for intracranial sISR. Lesion locations and number were as follows: intracranial internal carotid artery (n = 4), M1 segment of middle cerebral artery (MCA) (n = 1), V4 segment of vertebral artery (n = 6). The technical success rate, periprocedural complications, and short-term outcome were retrospectively analyzed.Results: All procedures were successfully performed without periprocedural complication. Asymptomatic vessel dissection after PCB inflation occurred in one case. Postprocedural diffusion-weighted imaging (DWI) showed new asymptomatic ipsilateral infarction in one case. All 11 cases did not experience ipsilateral stroke or death within 30 days or ischemic stroke in the territory of the target artery between 31 and 90 days after procedure.Conclusion: This preliminary study indicates that PCB angioplasty is feasible and safe for the treatment of intracranial sISR. Further studies are needed to clarify its efficiency and long-term outcome.

Endovascular Coils as Lung Tumor Fiducial Markers for Real-Time Tumor Tracking in Stereotactic Body Radiotherapy: Comparison of Complication Rates with Transthoracic Fiducial Marker Placement

To evaluate safety of endovascular coil fiducial placement and compare complication rates with transthoracic fiducial placement in patients with peripheral early-stage lung cancer receiving fiducial markers for stereotactic body radiotherapy (SBRT). This retrospective study included consecutive patients who received endovascular coils (n= 416 patients, n= 1,335 coils) or transthoracic fiducials (n= 30 patients, n= 80 fiducials) for SBRT between August 2005 and January 2017. During the first 3 years of the study period, patients preferentially received cylindrical platinum fiducial markers by percutaneous transthoracic placement; only patients with contraindications received endovascular coils. Thereafter, patients received endovascular fiducials as the first-line procedure. Endovascular embolization coils were placed via the femoral vein into subsegmental pulmonary artery branches near the tumor. Complications were scored by SIR criteria. The success rate of endovascular coil placement was 99.8%. One patient developed grade 2 hemoptysis requiring procedure discontinuation. Following placement, 1 patient (0.2%) developed grade 3 cardiac arrhythmia. A total of 36 patients (9%) developed grade 1 complications: mild hemoptysis (n= 4; 1%), small asymptomatic pulmonary infarction or hemorrhage (n= 30; 7%), hypoglycemia (n= 1; 0.2%), and vasovagal episode (n= 1; 0.2%). Following transthoracic marker placement, 4 patients (13%) developed a pneumothorax requiring hospital admission and chest tube (grade 2), 6 patients (20%) developed pneumothorax requiring no intervention (grade 1), 2 patients (7%) experienced asymptomatic pulmonary bleeding, and 1 patient (3%) developed persistent pain. Endovascular coil fiducial placement for lung SBRT is associated with high procedural success rates and lower rates of clinically relevant complications than transthoracic marker placement.

Second Generation Drug-Eluting Stents for Endovascular Treatment of Ostial Vertebral Artery Stenosis: A Single Center Experience.

Objective: To report a single-center experience using drug-eluting balloon mounted stents (DES) for endovascular treatment of atherosclerotic ostial vertebral artery stenosis (OVAS).Background: Posterior circulation is affected in up to 25% of strokes, 20% of them resulting from atherosclerotic OVAS. The optimal management of symptomatic OVAS remains controversial. DES have been introduced to improve restenosis rates.Methods: We retrospectively analyzed prospectively collected data from patients with dominant OVAS who underwent endovascular treatment with second-generation DES placement. Patient demographics, clinical presentation, comorbidities, stenosis severity, stent features, technical success, complications, and imaging follow-up were assessed.Results: Thirty patients were treated, predominantly male (86.6%). Sixteen patients presented with an acute stroke or TIA and fourteen were treated on an elective basis due to symptomatic chronic stenosis and contralateral occlusion. Comorbidities included hyperlipidemia (83%), hypertension (70%) and prior stroke (63.3%). Mean ostial stenosis at presentation was 80 ± 14.8%. Twenty-one patients had contralateral VA involvement. DES deployment was technically successful in all patients using everolimus eluting stents in 30 lesions and zotarolimus eluting stents in two. One technical complication (stent migration) and three (10%) minor peri-procedural complications occurred. Complications included one asymptomatic ischemic infarct in the posterior circulation, one femoral artery thrombosis and one post-procedure altered mental status secondary to contrast induced neurotoxicity. Mean imaging follow-up was 8.8 months. Two (7.6%) patients had in-stent restenosis and underwent retreatment with angioplasty. There were no procedure-related mortalities.Conclusion: Our study confirms the feasibility of deploying DES for the treatment of ostial vertebral artery stenosis with low peri-procedural risk and low medium-term rates of re-stenosis.

Intravenous thrombolysis in acute ischemic stroke due to intracranial artery dissection: a single-center case series and a review of literature.

Efficacy and safety of intravenous thrombolysis (IVT) in acute ischemic stroke (AIS) due to intracranial artery dissection (IAD) are currently not established. We aimed to present a single-center experience on IAD-related AIS treated by IVT. We selected all consecutive patients with IAD-related AIS treated by IVT from a prospectively constructed single-center acute stroke registry from 2003 to 2017. We reviewed demographical, clinical and neuroimaging data and recorded hemorrhagic complications, mortality within 7days and modified Rankin Scale at 3-months. Out of 181 AISs related to cervicocephalic dissections, 10 (5.5%) were due to IAD and five of these patients received IVT. Among these five patients, median age was 62years; hypertension and dyslipidemia were the most frequent vascular risk factors. IAD locations were distal internal carotid artery, middle cerebral artery (M1), anterior cerebral artery (A2), and, in two cases, the basilar artery. All anterior circulation IADs were occlusive or subocclusive, while the two basilar artery IADs caused arterial stenosis. After IVT, there were no subarachnoid or symptomatic intracranial hemorrhages. One patient had an asymptomatic hemorrhagic infarct type 1. Two patients died within 7days from ischemic mass effect. The other three patients had favorable clinical outcomes at 3-months. In this small single-center case series of IAD-related AIS, thrombolysis seemed relatively safe. However, IVT efficacy and the likelihood of arterial recanalization are still uncertain in this context. Further studies are needed to assess the safety and efficacy of IVT in these patients.

Serotonin-Mediated Cardiac Analgesia via Ah-Type Baroreceptor Activation Contributes to Silent Angina and Asymptomatic Infarction

Silent angina is a critical phenomenon in the clinic and is more commonly associated with women patients suffering from myocardial ischemia. Its underlying cause remains mysterious in medicine. With our recent discovery of female-specific Ah-type baroreceptor neurons (BRNs), we hypothesize that cardiac analgesia is due to the direct activation of Ah-type BRNs by elevated levels of circulating serotonin (5-HT) myocardial infarction (MI) patients. Electromyography and the tail-flick reflex were assessed in control and MI-model rats to evaluate 5-HT-mediated BP regulation as well as peripheral and cardiac nociception. 5-HT or a 5-HT receptor agonist was microinjected into the nodose ganglion to confirm the involvement of the afferent pathway of the baroreflex arc. An inward current was observed in identified BRNs by applying a whole-cell patch-clamp technique in conjunction with qRT-PCR to verify the afferent-specific action of 5-HT and the expression of 5-HT receptors. Although the tail-flick reflex and mean arterial pressure were dramatically reduced in female MI rats with elevated serum 5-HT, intrapericardial capsaicin-evoked muscular discharges were significantly inhibited in comparing with those of males, which were mimicked by microinjection of 5-HT or SR57227A into the nodose. Ah-type BRNs displayed robust inward currents at lower concentrations of 5-HT than the C-type or the A-type, with significantly increased expression and cellular distribution of 5-HT3AR but not 5-HT3BR compared to the A- and C-types. Activation of 5-HT3AR in Ah-type BRNs by 5-HT contributes significantly to cardiac analgesia, which may suggest the pathogenic condition that silent angina occurs mainly in female patients.

Introduction of intraoperative neuromonitoring does not necessarily improve overall long-term outcome in elective aneurysm clipping.

Intraoperative neuromonitoring (IOM), particularly of somatosensory-evoked potentials (SSEPs) and motor-evoked potentials (MEPs), evolved as standard of care in a variety of neurosurgical procedures. Case series report a positive impact of IOM for elective microsurgical clipping of unruptured intracranial aneurysms (ECUIA), whereas systematic evaluation of its predictive value is lacking. Therefore, the authors analyzed the neurological outcome of patients undergoing ECUIA before and after IOM introduction to this procedure. The dates of inclusion in the study were 2007-2014. In this period, ECUIA procedures before (n = 136, NIOM-group; 2007-2010) and after introduction of IOM (n = 138, IOM-group; 2011-2014) were included. The cutoff value for SSEP/MEP abnormality was chosen as an amplitude reduction ≥ 50%. SSEP/MEP changes were correlated with neurological outcome. IOM-undetectable deficits (bulbar, vision, ataxia) were not included in risk stratification. There was no significant difference in sex distribution, follow-up period, subarachnoid hemorrhage risk factors, aneurysm diameter, complexity, and location. Age was higher in the IOM-group (57 vs 54 years, p = 0.012). In the IOM group, there were 18 new postoperative deficits (13.0%, 5.8% permanent), 9 hemisyndromes, 2 comas, 4 bulbar symptoms, and 3 visual deficits. In the NIOM group there were 18 new deficits (13.2%; 7.3% permanent, including 7 hemisyndromes). The groups did not significantly differ in the number or nature of postoperative deficits, nor in their recovery rate. In the IOM group, SSEPs and MEPs were available in 99% of cases. Significant changes were noted in 18 cases, 4 of which exhibited postoperative hemisyndrome, and 1 suffered from prolonged comatose state (5 true-positive cases). Twelve patients showed no new detectable deficits (false positives), however 2 of these cases showed asymptomatic infarction. Five patients with new hemisyndrome and 1 comatose patient did not show significant SSEP/MEP alterations (false negatives). Overall sensitivity of SSEP/MEP monitoring was 45.5%, specificity 89.8%, positive predictive value 27.8%, and negative predictive value 95.0%. The assumed positive impact of introducing SSEP/MEP monitoring on overall neurological outcome in ECUIA did not reach significance. This study suggests that from a medicolegal point of view, IOM is not stringently required in all neurovascular procedures. However, future studies should carefully address high-risk patients with complex procedures who might benefit more clearly from IOM than others.

Abstract TP418: Asymptomatic Hemorrhagic Infarction on 24-Hour CT Post Intravenous Recombinant Tissue Plasminogen Activator for Acute Ischemic Stroke Predicts Symptomatic Intracerebral Hemorrhage After Initiation of Antiplatelet Therapy

Background and Purpose: Predictors of symptomatic intracerebral hemorrhage (sICH) after intravenous alteplase in acute ischemic stroke (AIS) are well established however there is limited data on predictors of delayed sICH (d-sICH) (occurring > 36 hours from alteplase) after initiation of antithrombotic therapy in these patients. We hypothesize that asymptomatic hemorrhagic infarction (HI) on 24-hour brain imaging predicts delayed sICH after initiation of antiplatelet therapy. Methods: We included consecutive patients who received intravenous alteplase for AIS over a 12-month period. All patients received brain imaging, either CT or MRI, approximately 24-hours post alteplase. Patients who were deceased or made comfort measures only or with lack of at least 48 hour follow-up, or those with parenchymal hematoma (PH) or sICH prior to antithrombotic therapy initiation were excluded. The primary outcome was delayed sICH defined using the modified SITS-MOST criteria. We compared demographic data, clinical risk factors, NIHSS score, pre-admission antithrombotic usage, and 24-hour imaging characteristics between the two groups (d-sICH vs. no d-sICH) using univariate and multivariable analyses (including variables with p<0.1 on univariable models). Analysis was done using SPSS version 20.0 and p<0.05 was considered significant. Results: We identified 263 patients who met the inclusion criteria; 51.3% were men and the mean age was70.9 years, 8 patients (3.0%) had d-sICH and 60 patients (22.8%) had asymptomatic HI on 24-hour brain imaging (CT or MRI). On univariate analyses, predictors of d-sICH were diabetes [50.0% (4/8) vs. 23.1% (59/255), p = 0.097} and asymptomatic HI on CT [50.0% (4/8) vs. 13.1 (31/236), p=0.016] and a trend for asymptomatic hemorrhage on MRI [60.0% (3/5) vs. 25.0% (42/168), p = 0.11]. In a multivariable model, both diabetes (OR 5.1 95% CI 1.1 - 23.3, p=0.037) and asymptomatic hemorrhage on CT (OR 8.9 95% CI 1.9 - 41.7 p = 0.005) predicted d-sICH. Conclusion: In AIS patient receiving alteplase, asymptomatic HI on 24-hour brain imaging predicts d-sICH after antithrombotic treatment. Future studies are needed to confirm our findings and investigate best timing of initiating antiplatelet therapy and other measures to reduce d-sICH risk.

Dabigatran Treatment of Acute Non-Cardioembolic Ischaemic Stroke: A Randomised Controlled Trial

Background: Transient ischaemic attack (TIA) and minor ischaemic stroke patients are at high risk for recurrent events. Anticoagulants are associated with reduced recurrent ischemic stroke rates, but also increased risk of haemorrhagic transformation (HT). Dabigatran, a novel oral anticoagulant associated with reduced risk of intracranial bleeding compared with warfarin in atrial fibrillation patients, has not been assessed in acute brain ischemia. We hypothesised that HT rates are not increased by dabigatran relative to aspirin after acute ischaemic stroke/TIA. Methods: DAbigatran Treatment of Acute Stroke II (DATAS II) was a prospective, randomised open label, blinded endpoint trial of dabigatran versus aspirin in acute stroke/TIA (clinicatrials.gov NCT02295826). Non-cardio-embolic stroke/TIA patients (NIHSS score ≤9, infarct volume < 25 ml) who did not receive thrombolytic therapy or thrombectomy were randomised 1:1 to dabigatran 150 mg BID (110 mg BID in patients ≥80 or if CrCl <50 ml/min) or aspirin (81 mg OD). Magnetic resonance imaging was performed prior to randomisation and was repeated at day 30, with clinical assessments at 30 and 90 days. Imaging endpoints were ascertained centrally by readers blinded to treatment. The primary endpoint was symptomatic HT within 37 days of randomisation. Secondary endpoints included asymptomatic HT and recurrent cerebral infarcts. Findings: A total of 305 patients, mean age 66±13.21 years, were randomised to dabigatran or aspirin a mean of 40.10±19.44 hours after symptom onset. The qualifying event was a TIA in 21%, and ischaemic stroke in79% of patients. Median NIHSS (IQR) was 1 (0-2), and mean infarct volume 3.2±6.5 ml. No symptomatic HT occurred. Asymptomatic petechial HT developed in 11/142 (7.8%) of dabigatran-assigned patients and 5/142 (3.5%) of aspirin-assigned patients (RR=2.32, 95% CI 0.78, 6.85). Baseline infarct volume predicted incident HT (OR 1.07; 95% CI 1.03-1.12, p=0.0026). Incident covert infarcts on day 30 imaging occurred in 9/142 (6.3%) of dabigatran and 14/142 (9.8%) of aspirin patients (RR=0.62, 95% CI 0.26, 1.48). There were no major bleeding events with either treatment. Interpretation: Dabigatran given to patients with acute minor non-cardioembolic ischaemic stroke/TIA was safe and was associated with a risk of HT similar to aspirin. Trial Registration Number: clinicatrials.gov NCT02295826 Funding Statement: DATAS II was funded by the Canadian Institutes for Health Research (G327075). Declaration of Interests: Dr. Butcher has served as an advisory board consultant and received speaker’s fees and investigatorinitiated grant support from Boehringer-Ingelheim, Bayer, BMS-Pfizer and Servier. Dr. Sharma has served as an advisory board consultant and or received speaker’s fees and investigator-initiated grant support from Boehringer-Ingelheim, Bayer, BMS-Pfizer, Daiichi Sankyo and Servier. Dr. Benavente has served as an advisory board consultant and or received speaker’s fees from Boehringer-Ingelheim, Bayer, BMS-Pfizer and Servier. Dr. Field has served as an advisory board consultant and received speaker’s fees from BoehringerIngelheim, Bayer, BMS-Pfizer and Servier and investigator-initiated grant support from BoehringerIngelheim and Bayer (study medication). Dr. Hill has served as a consultant for Boehringer-Ingelheim. He has received grants to the University of Calgary from Medtronic, Stryker, Boehringer-Ingelheim Canada, Bayer Canada. Dr. Gioia has received speaker honoraria from Bayer, and BMS Pfizer and has served as an advisory board consultant for Bayer, and Servier Inc. Dr. Coutts has served as an advisory board consultant for BMS-Pfizer. Boehringer-Ingelheim is providing study drug for an investigator-initiated study led by Dr. Coutts. Ethics Approval Statement: The trial was approved by research ethics review boards at each institution.

Assessment of asymptomatic ischemic heart disease using stress myocardial perfusion imaging in patients with type 2 diabetes mellitus

BackgroundCoronary artery disease (CAD) is the leading cause of death in patients with type 2 diabetes mellitus (T2DM) and may be asymptomatic. ObjectiveThe objective of this study was to assess the prevalence of asymptomatic myocardial ischemia in patients with T2DM using stress myocardial perfusion imaging. MethodsWe evaluated 97 consecutive patients with T2DM without clinical evidence of CAD presenting to Cardiology and Endocrinology clinics using Tc-99m MIBI gated single-photon emission–computed tomography (SPECT) myocardial perfusion imaging for the presence of asymptomatic CAD. ResultsAbnormal myocardial perfusion was observed in 10 patients (10.3%). Of these, one half of patients had reversible myocardial perfusion defects suggestive of inducible myocardial ischemia. The other half had fixed perfusion defects suggestive of previous silent myocardial infarctions. Small and moderate reversible perfusion defects were observed in 3 and 2 patients, respectively. The fixed perfusion defects observed in 5 patients were medium sized. The presence of asymptomatic ischemia was significantly associated with age and smoking but not with other traditional cardiac risk factors. ConclusionTen percent of patients with T2DM with no clinical evidence of CAD were found to have evidence of asymptomatic ischemia or infarction.

Cilostazol is Effective to Prevent Stroke-Associated Pneumonia in Patients Receiving Tube Feeding.

Stroke-associated pneumonia (SAP) is a frequent complication in acute ischemic stroke (IS) patients, especially those receiving tube feeding (TF). In this retrospective study, we investigated whether or not cilostazol, a pluripotent phosphodiesterase III-specific inhibitor with anti-platelet and vasculogenic effects, can prevent SAP in these patients and reduce their duration of stay in intensive care unit/hospitalization. We recruited 158 IS patients receiving TF. Patients' characteristics (including age, gender, past history), National Institute of Health Stroke Scale and serum albumin level on admission, concomitant medications associated with SAP prevention (including cilostazol), and stroke characteristics (bilateral subcortical white matter lesion, brainstem involvement, large infarction, and asymptomatic hemorrhagic infarction) were compared between the SAP(-) and SAP(+) groups. Cilostazol was more frequently used in the SAP(-) group (20.8% vs. 6.1%, p < 0.05). Duration of intensive care unit was longer in patients with SAP (9 ± 8 vs. 6 ± 6days, p < 0.05). However, the length of stay in an intensive care unit and duration of hospitalization were not reduced due to the prevention of SAP by cilostazol treatment. Cilostazol administration was associated with reduced SAP incidence in acute IS patients receiving TF.

Abstract TP138: The Clinical Features and the Long-Term Outcomes of Carotid Symptomatic Low-Grade Stenosis

Background: Ischemic events caused by carotid artery stenosis are affected not only by stenosis but also by the instability of plaque. In symptomatic low-grade stenosis cases medical treatment is generally performed, but there are cases with repeated recurrence. The purpose of this study is to clarify the clinical features and long-term outcomes in cases of symptomatic low-grade stenosis. Methods: We included seventy-one symptomatic patients with carotid low-grade stenosis (&lt;NASCET 50%) who were admitted to our hospital from 2005 to 2016. The relative plaque signal intensity (rSI) with reference to muscle and expansive remodeling rate (ERR) were measured using carotid MRI. Antiplatelet therapy and treatment for atherosclerosis risk factors were administered in all cases. Carotid endarterectomy (CEA) was performed when ischemic symptoms appeared or the stenosis rate progressed despite medical treatment. Results: The mean stenosis rate, rSI and ERR on admission were 20.4, 1.75 and 1.96, respectively. Seventy percent of cases involved intraplaque hemorrhage and positive remodeling. During a mean of 52-months follow-up, a recurrence of ischemic events was confirmed in 33 cases (46%), from which the duration until recurrence was within 7 days (33%), 3 months (18%), 1 year (18%), 2 years (21%), and over 2 years (15%). Nine cases had impending stroke, 3 of which were associated with major artery occlusion. CEA was performed in 28 cases (39%) for impending stroke (25%), recurrence of ischemic events (46%), asymptomatic infarction (7%), and stenosis rate progression (11%). During a mean of 47-months follow-up after CEA, 2 cases of death (fetal intracerebral hemorrhage, asphyxia) and one case of brain stem lacunar infarction were observed, but an ipsilateral ischemic event was not observed. Conclusion: Most of the symptomatic patients with low-grade stenosis had both intraplaque hemorrhage and positive remodeling. The risk of recurrence and stenosis progression was high. CEA might have had a preventive effect against ischemic events in low-grade stenosis.