scholarly journals Toward noninvasive assessment of stroke risk in pediatric cerebrovascular disease

2021 ◽  
Author(s):  
John D. Horn ◽  
Michael J. Johnson ◽  
Zbigniew A. Starosolski ◽  
Avner Meoded ◽  
Dianna M. Milewicz ◽  
...  
Keyword(s):  
Cerebrovascular Disease ◽  
Stroke Risk ◽  
Thrombus Formation ◽  
Recurrent Stroke ◽  
Navier Stokes ◽  
Patient Specific ◽  
Analysis Framework ◽  
Flow Simulations ◽  
Disease Stabilization

Background and Purpose: Moyamoya disease (MMD) is a progressive steno-occlusive cerebrovascular disease leading to recurrent stroke. There is a lack of reliable biomarkers to identify unilateral stroke MMD patients who are likely to progress to bilateral disease and experience subsequent contralateral stroke(s). We hypothesized that local hemodynamics are predictive of future stroke and set out to noninvasively assess this stroke risk in pediatric MMD patients. Methods: MR and X-ray angiography imaging were utilized to reconstruct patient-specific models of the circle of Willis of 6 pediatric MMD patients who had previous strokes, along with a control subject. Blood flow simulations were performed by using a Navier-Stokes solver within an isogeometric analysis framework. Vascular regions with a wall shear rate (WSR) above the coagulation limit (> 5000 s-1) were identified to have a higher probability of thrombus formation, potentially leading to ischemic stroke(s). Two metrics, namely, ″critical WSR coverage″ and ″WSR score″, were derived to assess contralateral stroke risk and compared with clinical follow-up data. Results: In two patients that suffered a contralateral stroke within two months of the primary stroke, critical WSR coverages exceeding 50% of vessel surface and WSR scores greater than 6x the control were present in multiple contralateral vessels. These metrics were not as conclusive in two additional patients with 3-to-5-year gaps between primary and contralateral strokes. However, a longitudinal study of one of these two cases, where a subsequent timepoint was analyzed, accurately predicted disease stabilization on the primary stroke side and an elevated contralateral stroke risk, thus indicating that post-stroke follow-up at regular intervals might be warranted for secondary stroke prevention. Conclusions: WSR-based metrics could be predictive of future stroke risk after an initial stroke in MMD patients. In addition, more accurate predictions may be possible by performing patient-specific hemodynamic analysis at multiple timepoints during patient follow-up to monitor changes in the WSR-based metrics.

scholarly journals Prognosis of carotid dissecting aneurysms

Neurology ◽  
2017 ◽  
Vol 88 (7) ◽  
pp. 646-652 ◽  
Author(s):  
Susanna C. Larsson ◽  
Alice King ◽  
Jeremy Madigan ◽  
Christopher Levi ◽  
John W. Norris ◽  
...  
Keyword(s):  
Natural History ◽  
Stroke Risk ◽  
Recurrent Stroke ◽  
Anticoagulation Therapy ◽  
Artery Dissection ◽  
Cervical Artery Dissection ◽  
Cervical Artery ◽  
History Of ◽  
Age And Sex

Objective:To determine the natural history of dissecting aneurysm (DA) and whether DA is associated with an increased recurrent stroke risk and whether type of antithrombotic drugs (antiplatelets vs anticoagulants) modifies the persistence or development of DA.Methods:We included 264 patients with extracranial cervical artery dissection (CAD) from the Cervical Artery Dissection in Stroke Study (CADISS), a multicenter prospective study that compared antiplatelet with anticoagulation therapy. Logistic regression was used to estimate age- and sex-adjusted odds ratios. We conducted a systematic review of published studies assessing the natural history of DA and stroke risk in patients with non-surgically-treated extracranial CAD with DA.Results:In CADISS, DA was present in 24 of 264 patients at baseline. In 36 of 248 patients with follow-up neuroimaging at 3 months, 12 of the 24 baseline DAs persisted, and 24 new DA had developed. There was no association between treatment allocation (antiplatelets vs anticoagulants) and whether DA at baseline persisted at follow-up or whether new DA developed. During 12 months of follow-up, stroke occurred in 1 of 48 patients with DA and in 7 of 216 patients without DA (age- and sex-adjusted odds ratio 0.84; 95% confidence interval 0.10–7.31; p = 0.88). Published studies, mainly retrospective, showed a similarly low risk of stroke and no evidence of an increased stroke rate in patients with DA.Conclusions:The results of CADISS provide evidence suggesting that DAs may have benign prognosis and therefore medical treatment should be considered.

Abstract WP1: High-Frequency Optical Coherence Tomography for Cerebrovascular Disease

Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Ajit S Puri ◽  
Giovanni Ughi ◽  
Robert M King ◽  
Matthew Gounis
Keyword(s):  
Optical Coherence Tomography ◽  
Cerebrovascular Disease ◽  
High Frequency ◽  
Ex Vivo ◽  
Thrombus Formation ◽  
Image Resolution ◽  
Patient Specific ◽  
Optical Coherence

Introduction: Optical coherence tomography (OCT) has played an important role in the diagnosis and treatment guidance in coronary artery disease. However, existing OCT systems are not suitable for routine neurovascular applications due to the size and tortuosity of the arteries. Hypothesis: We seek to demonstrate a prototype high-frequency OCT (HF-OCT) capable of high-resolution imaging in simulated cerebrovascular anatomy. Methods: A low-profile HF-OCT system was constructed with an image resolution approaching 10μm. Using an in vitro, patient-specific model of the circle of Willis with circulating porcine blood, we characterized the delivery of the device and ability to image in a tortuous path. Also, human cadaver intracranial atherosclerosis plaques were imaged with HF-OCT and assessed by an expert imager. Finally, neurovascular devices were implanted in 8 pigs (Fig 1) and HF-OCT imaging was compared with gold-standard DSA and CT. Results: In the phantom, optimal blood clearance was achieved through an intermediate catheter (5 Fr Navien) with infusion of contrast at 5 ml/s in the internal carotid and basilar artery, and 3 ml/sec in the MCA. The in vivo study demonstrated that both malapposition of devices or thrombus formation along the device surface could be reliably diagnosed among 3 reviewers (Fleiss’s kappa of 0.87 and 0.9, respectively). This agreement was superior to DSA and CT. Imaging in tortuous swine brachial showed in all cases imaging free of artifacts, uniform illumination and ability to visualize vessel wall layers. Plaque types including ‘lipid pools’, fibrotic, and calcific tissue from cadaver specimens of ICAD could be adequately depicted by HF-OCT. Conclusion: In vitro, in vivo and ex vivo characterization of a novel HF-OCT device has shown it is capable of imaging in the tortuous intracranial vascular anatomy. This technology has to potential to aid in the diagnosis of cerebrovascular disease and guide optimal endovascular treatment.

Image-based patient-specific flow simulations are consistent with stroke in pediatric cerebrovascular disease

2021 ◽  
Author(s):  
Shaolie S. Hossain ◽  
Zbigniew Starosolski ◽  
Travis Sanders ◽  
Michael J. Johnson ◽  
Michael C. H. Wu ◽  
...  
Keyword(s):  
Cerebrovascular Disease ◽  
Patient Specific ◽  
Specific Flow ◽  
Flow Simulations

scholarly journals Long-Term Impact of Urgent Secondary Prevention After Transient Ischemic Attack and Minor Stroke: Ten-Year Follow-Up of the EXPRESS Study

Stroke ◽  
2021 ◽  
Author(s):  
Ramon Luengo-Fernandez ◽  
Linxin Li ◽  
Louise Silver ◽  
Sergei Gutnikov ◽  
Nicola C. Beddows ◽  
...  
Keyword(s):  
Transient Ischemic Attack ◽  
Stroke Risk ◽  
Recurrent Stroke ◽  
Hazard Ratio ◽  
Minor Stroke ◽  
Phase 2 ◽  
Short Term ◽  
Ischemic Attack

Background and Purpose: Urgent assessment aimed at reducing stroke risk after transient ischemic attack or minor stroke is cost-effective over the short-term. However, it is unclear if the short-term impact is lost on long-term follow-up, with recurrent events being delayed rather than prevented. By 10-year follow-up of the EXPRESS study (Early Use of Existing Preventive Strategies for Stroke), previously showing urgent assessment reduced 90-day stroke risk by 80%, we determined whether that early benefit was still evident long-term for stroke risk, disability, and costs. Methods: EXPRESS was a prospective population-based before (phase 1: April 2002–September 2004; n=310) versus after (phase 2: October 2004–March 2007; n=281) study of the effect of early assessment and treatment of transient ischemic attack/minor stroke on early recurrent stroke risk, with an external control. This report assesses the effect on 10-year recurrent stroke risk, functional outcomes, quality-of-life, and costs. Results: A reduction in stroke risk in phase 2 was still evident at 10 years (55/23.3% versus 82/31.6%; hazard ratio=0.68 [95% CI, 0.48–0.95]; P =0.024), as was the impact on risk of disabling or fatal stroke (17/7.7% versus 32/13.1%; hazard ratio=0.54 [0.30–0.97]; P =0.036). These effects were due to maintenance of the early reduction in stroke risk, with neither additional benefit nor rebound catch-up after 90 days (post-90 days hazard ratio=0.88 [0.65–1.44], P =0.88; and hazard ratio=0.83 [0.42–1.65], P =0.59, respectively). Disability-free life expectancy was 0.59 (0.03–1.15; P =0.043) years higher in patients in phase 2, as was quality-adjusted life expectancy (0.49 [0.03–0.95]; P =0.036). Overall, 10-year costs were nonsignificantly higher in patients attending the phase 2 clinic ($1022 [-3865–5907]; P =0.66). The additional cost per quality-adjusted life year gained in phase 2 versus phase 1 was $2103, well below current cost-effectiveness thresholds. Conclusions: Urgent assessment and treatment of patients with transient ischemic attack or minor stroke resulted in a long-term reduction in recurrent strokes and improved outcomes, with little atrophy of the early benefit over time, representing good value for money even with a 10-year time horizon. Our results suggest that other effective acute treatments in transient ischemic attack/minor stroke in the short-term will also have the potential to have long-term benefit.

scholarly journals Location of Reentry Tears Affects False Lumen Thrombosis in Aortic Dissection Following TEVAR

2020 ◽  
Vol 27 (3) ◽  
pp. 396-404
Author(s):  
Chlöe Harriet Armour ◽  
Claudia Menichini ◽  
Kristijonas Milinis ◽  
Richard G. J. Gibbs ◽  
Xiao Yun Xu
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Stent Graft ◽  
Thrombus Formation ◽  
False Lumen ◽  
Patient Specific ◽  
Landing Zone ◽  
Wall Shear ◽  
Dynamics Simulations

Purpose: To report a study that assesses the influence of the distance between the distal end of a thoracic stent-graft and the first reentry tear (SG-FRT) on the progression of false lumen (FL) thrombosis in patients who underwent thoracic endovascular aortic repair (TEVAR). Materials and Methods: Three patient-specific geometrical models were reconstructed from postoperative computed tomography scans. Two additional models were created by artificially changing the SG-FRT distance in patients 1 and 2. In all 5 models, computational fluid dynamics simulations coupled with thrombus formation modeling were performed at physiological flow conditions. Predicted FL thrombosis was compared to follow-up scans. Results: There was reduced false lumen flow and low time-averaged wall shear stress (TAWSS) in patients with large SG-FRT distances. Predicted thrombus formation and growth were consistent with follow-up scans for all patients. Reducing the SG-FRT distance by 30 mm in patient 1 increased the flow and time-averaged wall shear stress in the upper abdominal FL, reducing the thrombus volume by 9.6%. Increasing the SG-FRT distance in patient 2 resulted in faster thoracic thrombosis and increased total thrombus volume. Conclusion: The location of reentry tears can influence the progression of FL thrombosis following TEVAR. The more distal the reentry tear in the aorta the more likely it is that FL thrombosis will occur. Hence, the distal landing zone of the stent-graft should be chosen carefully to ensure a sufficient SG-FRT distance.

Delayed diagnosis of atrial fibrillation after first-ever stroke increases recurrent stroke risk: a 5-year nationwide follow-up study

2018 ◽  
Vol 48 (6) ◽  
pp. 661-667 ◽  
Author(s):  
Ping-Song Chou ◽  
Bo-Lin Ho ◽  
Yi-Hsin Chan ◽  
Min-Hsien Wu ◽  
Han-Hwa Hu ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Stroke Risk ◽  
Recurrent Stroke ◽  
Delayed Diagnosis ◽  
Follow Up Study

Recurrent Stroke Risk in Pilots with Atrial Fibrillation

2020 ◽  
Vol 91 (4) ◽  
pp. 352-357
Author(s):  
Jessica Tedford ◽  
Valerie Skaggs ◽  
Ann Norris ◽  
Farhad Sahiar ◽  
Charles Mathers
Keyword(s):  
Atrial Fibrillation ◽  
General Population ◽  
Recurrent Events ◽  
Stroke Risk ◽  
Event Rate ◽  
Recurrent Stroke ◽  
Previous History ◽  
Recurrent Event ◽  
Recurrence Rates ◽  
Medical Certification

INTRODUCTION: Atrial fibrillation (AF) is one of the most common cardiac arrhythmias in the general population and is considered disqualifying aeromedically. This study is a unique examination of significant outcomes in aviators with previous history of both AF and stroke.METHODS: Pilots examined by the FAA between 2002 and 2012 who had had AF at some point during his or her medical history were reviewed, and those with an initial stroke or transient ischemic attack (TIA) during that time period were included in this study. All records were individually reviewed to determine stroke and AF history, medical certification history, and recurrent events. Variables collected included medical and behavior history, stroke type, gender, BMI, medication use, and any cardiovascular or neurological outcomes of interest. Major recurrent events included stroke, TIA, cerebrovascular accident, death, or other major events. These factors were used to calculate CHA2DS2-VASc scores.RESULTS: Of the 141 pilots selected for the study, 17.7% experienced a recurrent event. At 6 mo, the recurrent event rate was 5.0%; at 1 yr, 5.8%; at 3 yr 6.9%; and at 5 yr the recurrent event rate was 17.3%. No statistical difference between CHA2DS2-VASc scores was found as it pertained to number of recurrent events.DISCUSSION: We found no significant factors predicting risk of recurrent event and lower recurrence rates in pilots than the general population. This suggests CHA2DS2-VASc scores are not appropriate risk stratification tools in an aviation population and more research is necessary to determine risk of recurrent events in aviators with atrial fibrillation.Tedford J, Skaggs V, Norris A, Sahiar F, Mathers C. Recurrent stroke risk in pilots with atrial fibrillation. Aerosp Med Hum Perform. 2020; 91(4):352–357.

P2549The cardiovascular predictors of clinical outcomes in patients after ischemic stroke of undetermined etiology

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
A Bielecka-Dabrowa ◽  
P Gasiorek ◽  
A Sakowicz ◽  
M Banach
Keyword(s):  
Ischemic Stroke ◽  
Independent Predictor ◽  
Reference Group ◽  
Peak Velocity ◽  
Recurrent Stroke ◽  
Mitral Annular Velocity ◽  
Kaplan Meier ◽  
Unfavourable Prognosis ◽  
Undetermined Etiology

Abstract Purpose The study aimed to identify echocardiographic, hemodynamic and biochemical predictors of unfavourable prognosis after ischemic strokes of undetermined etiology (ESUS) in patients (pts) at age <65. Methods Out of 520 ischemic stroke pts we selected 64 pts diagnosed with ESUS [mean age 54 (SD: 47–58) years, 42% males] and additional 36 without stroke but with similar risk profile, which were treated as a reference group [age 53 (SD: 47–58) years, 61% males]. All pts underwent echocardiography, non-invasive assessment of hemodynamic parameters using SphygmoCor tonometer (Atcor Med., Australia), HDL subfraction distribution using Lipoprint (Quantimetrix) as well as measurements of selected biomarkers. Follow-up was 12 months. Results At 12-month follow-up 9% of patients had died, and recurrent ischemic stroke also occurred in 9% of patients - only in the ESUS group (Figure). Patients who died had significantly lower levels of LDL and HDL cholesterol (included HDL-8 and -9 subfractions) and higher level of triglicerides (p=0.01, p=0.01, and p=0.02; respectively), lower level of adiponectin (p=0.01), lower value of mean early diastolic (E') mitral annular velocity (p=0.04) and lower diastolic blood pressure (p=0.04). The atrial fibrillation (AF) occurred in 10% of pts during the 12 months (log-rang, p=0.254) (Figure). The log-rank test showed that ESUS group had a significantly poorer outcome of AF in the first 2 months after hospitalization compared to reference group (11% vs 5%, p=0.041). Based on a Kaplan-Meier analysis, the outcome of re-hospitalizationin the 1st year was 28% (18/64) in the ESUS group and 17% (6/36); log-rank, p=0.058. In the multivariate analysis mean early diastolic (E') mitral annular velocity (odds ratio [OR] 0.75, 95% confidence interval [CI]: 0.6–0.94; p=0.01) was significantly associated with CV hospitalizations assessed at 12-month follow-up. The only independent predictor of AF occurrence in the 12-month follow-up was lower value of Tissue Doppler-derived right ventricular systolic excursion velocity S' (OR 0.65, 95% Cl 0.45–0.93; p=0.01). The only independent predictor of recurrent stroke was the ratio of peak velocity of early diastolic transmitral flow to peak velocity of early diastolic mitral annular motion as determined by pulsed wave Doppler (E/E') (OR 0.75, 95% CI: 0.6–0.94; p=0.01). E/E' ratio was also independently associated with composite endpoint consisting of death, hospitalization and recurrent stroke (OR 1.90, 95% CI 1.1–3.2, p=0.01). Kaplan-Meier Analysis - survival and AF Conclusions The indices of diastolic dysfunction are significantly associated with unfavourable prognosis after ESUS. There is a robust role for outpatient cardiac monitoring especially during first 2 months after ESUS to detect potential AF. Acknowledgement/Funding The study was financed by research grants no. 502-03/5-139-02/502-54-229-18 of the Medical University of Lodz

scholarly journals Numerical computation of blood flow for a patient-specific hemodialysis shunt model

2021 ◽  
Author(s):  
Surabhi Rathore ◽  
Tomoki Uda ◽  
Viet Q. H. Huynh ◽  
Hiroshi Suito ◽  
Toshitaka Watanabe ◽  
...  
Keyword(s):  
Stokes Equations ◽  
Three Dimensional ◽  
Arteriovenous Shunt ◽  
Navier Stokes ◽  
Patient Specific ◽  
Stabilized Finite Element ◽  
Computed Tomography Scanning ◽  
Outflow Boundary ◽  
Stage Renal Disease ◽  
End Stage

AbstractHemodialysis procedure is usually advisable for end-stage renal disease patients. This study is aimed at computational investigation of hemodynamical characteristics in three-dimensional arteriovenous shunt for hemodialysis, for which computed tomography scanning and phase-contrast magnetic resonance imaging are used. Several hemodynamical characteristics are presented and discussed depending on the patient-specific morphology and flow conditions including regurgitating flow from the distal artery caused by the construction of the arteriovenous shunt. A simple backflow prevention technique at an outflow boundary is presented, with stabilized finite element approaches for incompressible Navier–Stokes equations.

scholarly journals Risk Factors for Failure in Conservatively Treated Osteoporotic Vertebral Fractures: A Systematic Review

2021 ◽  
pp. 219256822098227
Author(s):  
Max J. Scheyerer ◽  
Ulrich J. A. Spiegl ◽  
Sebastian Grueninger ◽  
Frank Hartmann ◽  
Sebastian Katscher ◽  
...  
Keyword(s):  
Risk Factors ◽  
Systematic Review ◽  
Treatment Failure ◽  
Patient Specific ◽  
Mineral Density ◽  
Radiographic Findings ◽  
Specific Risk ◽  
Fracture Development ◽  
Predict Treatment Failure

Study Design: Systematic review. Objectives: Osteoporosis is one of the most common diseases of the elderly, whereby vertebral body fractures are in many cases the first manifestation. Even today, the consequences for patients are underestimated. Therefore, early identification of therapy failures is essential. In this context, the aim of the present systematic review was to evaluate the current literature with respect to clinical and radiographic findings that might predict treatment failure. Methods: We conducted a comprehensive, systematic review of the literature according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) checklist and algorithm. Results: After the literature search, 724 potentially eligible investigations were identified. In total, 24 studies with 3044 participants and a mean follow-up of 11 months (range 6-27.5 months) were included. Patient-specific risk factors were age >73 years, bone mineral density with a t-score <−2.95, BMI >23 and a modified frailty index >2.5. The following radiological and fracture-specific risk factors could be identified: involvement of the posterior wall, initial height loss, midportion type fracture, development of an intravertebral cleft, fracture at the thoracolumbar junction, fracture involvement of both endplates, different morphological types of fractures, and specific MRI findings. Further, a correlation between sagittal spinal imbalance and treatment failure could be demonstrated. Conclusion: In conclusion, this systematic review identified various factors that predict treatment failure in conservatively treated osteoporotic fractures. In these cases, additional treatment options and surgical treatment strategies should be considered in addition to follow-up examinations.

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