Assessment of Interhemispheric Cerebral Perfusion Deficit in Carotid Artery Stenosis

Asymptomatic carotid stenosis patients manifest compromised cognitive performance compared to controls. Cerebral perfusion deficit could be an important contributor to cognitive impairment. The relationship between carotid stenosis and cerebral perfusion deficit is not established. If established, this could lead to a more informed selection of ACS patients likely to benefit from carotid revascularization. Perfusion-weighted MR imaging (PWI) is a clinically viable non-invasive technique to quantify cerebral perfusion. However, its impact is limited due to lack of efficient clinical tools to analyze PWI data in different brain regions for characterizing interhemispheric perfusion asymmetry. Development of automated approaches to characterize clinically relevant perfusion deficits is therefore required. Moreover, there is no established evidence of association between perfusion deficit and stenosis severity. In this paper, we propose an approach to quantify interhemispheric perfusion differences in different brain regions using clinical data. Our proposed metrics, based on the PWI mean transit time, for characterizing difference between ipsilateral and contralateral hemispheres demonstrate a very strong relationship with Doppler ultrasound based peak systolic velocity measured at stenosis. Our approach also highlights dependence of perfusion asymmetry on effective collateralization through the cerebral vasculature. In future studies, we plan to extend this method to a larger cohort and refine the methods for validating novel biomarker for risk-stratification of carotid stenosis.

Asymptomatic carotid stenosis is associated with mobility and cognitive dysfunction and heightens falls in older adults

BACKGROUND

Atherosclerosis of the carotid bifurcation with plaque formation causes asymptomatic carotid artery stenosis (ACAS), which may also be associated with cerebral hypoperfusion. Cerebral hypoperfusion adversely affects multiple aspects of mobility and cognition. This study tests the hypothesis that community-dwelling older adults with a 50% or greater diameter-reducing ACAS will have mobility and cognitive impairments that heighten their risk for falls.

METHODS

Eighty community-dwelling adults completed a mobility assessment (Short Physical Performance Battery, Berg Balance Scale, Four Square Step Test, Dynamic Gait Index, Timed Up and Go, and gait speed), self-reported physical function (Activities-Specific Balance Confidence, SF-12 Physical Function Component), and cognitive tests (Mini-Mental State Examination). Falls were recorded for the past 6 months. Standardized carotid ultrasound examination classified participants into no stenosis (<50% diameter reduction) (n = 54), moderate stenosis (50%-69%) (n = 17), and high-grade stenosis (70%-99%) (n = 9) groups. Linear and logistic regression analyses determined the associations between these measures and the degree of stenosis (three groups).

RESULTS

Logistic regression analysis showed their degree of stenosis was associated with reductions in mobility (Short Physical Performance Battery [P = .008], Berg Balance Scale [P = .0008], Four Square Step Test [P = .005], DGI [P = .0001], TUG [P = .0004], gait speed [P = .02]), perceived physical function (ABC [P < .0001], SF-12 Physical Function Component [P < .0001]), and cognition (MMSE [P = .003]). Adults with moderate- and high-grade stenosis had a greater incidence of falls compared with those without stenosis (relative risk, 2.86; P = .01). Results remained unchanged after adjustment for age, sex and cardiovascular risk factors.

CONCLUSIONS

ACAS is associated with impaired mobility and cognition that are accompanied with increased fall risk. These impairments increased with worsening severity.

Quality Assurance for Carotid Stenting in the CREST-2 Registry

BACKGROUND

The CREST-2 Registry (C2R) was approved by National Institute of Neurological Disorders and Stroke-National Institutes of Health in September 2014 with Centers for Medicare & Medicaid Services, U.S. Food and Drug Administration, and industry collaboration to enroll patients undergoing CAS. The registry credentials interventionists and promotes optimal patient selection, procedural-technique, and outcomes.

OBJECTIVES

This study reports periprocedural outcomes in a cohort of carotid artery stenting (CAS) performed for asymptomatic and symptomatic carotid stenosis.

METHODS

Asymptomatic patients with ≥70% and symptomatic patients with ≥50% carotid stenosis, ≤80 years of age, and at standard or high risk for carotid endarterectomy are eligible for enrollment. Interventionists are credentialed by a multispecialty committee that reviews experience, lesion selection, technique, and outcomes. The primary endpoint was a composite of stroke and death (S/D) in the 30-day periprocedural period. Myocardial infarction and access-site complications were assessed as secondary outcomes.

RESULTS

As of December 2018, 187 interventionists from 98 sites in the United States performed 2,219 CAS procedures in 2,141 patients with primary atherosclerosis (78 were bilateral). The mean age of the cohort was 68 years, 65% were male, and 92% were white; 1,180 (55%) were for asymptomatic disease, and 961 (45%) were for symptomatic disease. All U.S. Food and Drug Administration-approved stents and embolic protection devices were represented. The 30-day rate of S/D was 1.4% for asymptomatic, 2.8% for symptomatic, and 2.0% for all patients.

CONCLUSIONS

C2R is the first national registry for CAS cosponsored by federal and industry partners. CAS was performed by experienced operators using appropriate patient selection and optimal technique. In that setting, a broad group of interventionists achieved very low periprocedural S/D rates for asymptomatic and symptomatic patients.

The CREST-2 experience with the evolving challenges of COVID-19: A clinical trial in a pandemic

The coronavirus disease 2019 pandemic has disrupted the lives of whole communities and nations. The multinational multicenter National Institute of Neurological Disorders and Stroke Carotid Revascularization and Medical Management for Asymptomatic Carotid Stenosis Trial stroke prevention trial rapidly experienced the effects of the pandemic and had to temporarily suspend new enrollments and shift patient follow-up activities from in-person clinic visits to telephone contacts. There is an ethical obligation to the patients to protect their health while taking every feasible step to ensure that the goals of the trial are successfully met. Here, we describe the effects of the pandemic on the trial and steps that are being taken to mitigate the effects of the pandemic so that trial objectives can be met.

High prevalence of chronic venous disease among health care workers in the United States

BACKGROUND

Health care workers spend extended times standing and walking short distances and are at risk for development of chronic venous insufficiency (CVI). We conducted a hospital-wide venous screening program designed to measure the prevalence of and risk factors for clinical manifestations of CVI and ultrasound evidence of venous reflux or obstruction in health care workers. We also determined their risk for deep venous thrombosis (DVT).

METHODS

Free venous screening and education were offered to all hospital employees; the program started in April 2016, and results are presented from the first year. Demographics, medical history, and use of compression stockings were recorded. A physical examination determined the clinical class of the Clinical, Etiology, Anatomy, and Pathophysiology (CEAP) classification for clinical disease, and an ultrasound test evaluated for reflux or obstruction in the common femoral vein, popliteal vein, and saphenofemoral junction. The Caprini score was recorded to evaluate risk of DVT. Descriptive statistics were reported, and logistic regression was used for multivariate analysis of risk factors.

RESULTS

We enrolled 636 participants (1272 legs); 93.0% were women. The median age was 42 years (interquartile range, 31-52 years), mean body mass index was 29.2 ± 6.6 kg/m2, and most participants were white (49.1%) or African American (39.5%); 18% reported having hypertension, 7.1% had diabetes, and 6.1% were current smokers. The majority reported occasional leg pain (72.7%) and evening leg swelling (42.3%). Only 2.7% used daily compression stockings. Clinical evidence of CVI was present in at least one leg in 69.1% (C1, 49.0%; C2, 17.7%; C3, 1.9%; C4, 0.2%; C5, 0.2%). Venous reflux was present in at least one leg in 82.1%; obstruction was rare (0.2%). Reflux in either the superficial (saphenofemoral junction) or the deep (femoral or popliteal) venous system was present in the majority (71.0%) of patients with CVI (clinical class ≥C1). Reflux and white race were risk factors for clinical disease; clinical disease, age, female sex, and white race were risk factors for reflux. On the basis of the Caprini score, 14.1% of participants were in the highest risk category for DVT when experiencing a high-risk situation (including 2.2% with history of DVT).

CONCLUSIONS

Prevalence of clinical CVI and venous reflux is high among health care workers despite a low frequency of cardiovascular comorbidities. Increased awareness about CVI and DVT and preventive strategies for venous disease must be instituted in this high-risk cohort.

Infrapopliteal Arterial Pseudoaneurysm Development Secondary to Blunt Trauma: Case Series and Literature Review

OBJECTIVES

Infrapopliteal arterial pseudoaneurysms (IAP) following blunt trauma with associated orthopedic injuries are uncommon, often present in a delayed fashion, and encompass a diagnostic and therapeutic dilemma. Herein, we present a series of IAPs that were diagnosed following blunt trauma and their management.

METHODS

Case series consisting of 3 patients and a review of the international literature.

RESULTS

Our case series included 3 patients presenting with IAPs following blunt trauma with associated orthopedic injuries. They were all identified in a delayed manner (>3 weeks) after the orthopedic injuries were treated. All patients presented with pain and a pulsatile mass while one concurrently had neurologic deficits. The pseudoaneurysms were diagnosed by duplex ultrasound and confirmed by angiography to be originating from the tibioperoneal trunk, anterior tibial, and posterior tibial arteries respectively. Two patients were treated with surgical excision. Of these, one required an arterial bypass procedure while the other underwent direct ligation only. The third patient was treated by endovascular coiling. A literature review from 1950 to the present found 51 reported cases of IAP resulting from blunt trauma. Ninety percent of trauma-related infrapopliteal injuries occurred in men with a mean delay in diagnosis of 5.6 months (median 1.8 months) after injury. Since 1950, management has shifted from primarily ligation to incorporating minimally invasive endovascular techniques when appropriate.

CONCLUSIONS

Infrapopliteal artery pseudoaneurysms are rare following blunt skeletal trauma. A delay in diagnosis often occurs and can result in major morbidity and extensive surgical intervention. We recommend a high index of suspicion and a thorough vascular examination in patients with lower extremity skeletal trauma to help identify and treat these injuries early and effectively.

Abstract TP123: Baseline Differences in Risk Factor Control Between CREST-2 and SAMMPRIS

Baseline Differences in Risk Factor Control and Medication Use Between 2 Trials Employing Intensive Medical Management (SAMMPRIS & CREST2)

Background: The CREST2 trial Intensive Medical Management (IMM) protocol was adapted from the SAMMPRIS trial. However, since the 2011 publication of initial results of SAMMPRIS, there has been a greater appreciation for the importance of risk factor control in patients at risk of stroke associated with atherosclerosis. Therefore, we sought to determine differences in baseline risk factor control and medication use between SAMMPRIS and CREST2.

Methods: Baseline risk factor and medication use data from 451 patients enrolled in SAMMPRIS (2008-2011) with severe symptomatic intracranial atherosclerosis and 1473 patients enrolled in CREST2 (2014-2019) with severe asymptomatic carotid stenosis were compared using the Chi-square test and t-test.

Results: The Table shows baseline risk factor values and medications. SAMMPRIS patients were younger but had significantly worse risk factor control than CREST2 patients for all measures. There was no significant difference in statin use at baseline, but the mean SAMMPRIS subjects’ LDL was 16.1 mg/dL higher than in CREST2. CREST2 patients had higher rates of use of angiotensin receptor blockers (ARB), calcium channel blockers (CCB), and thiazides, but lower rates of use of angiotensin converting enzyme (ACE) inhibitors.

Conclusions: Despite being older, CREST2 patients have significantly better baseline risk factor profiles than SAMMPRIS patients. This could be due to greater appreciation of the importance of risk factor control and healthy lifestyle habits for stroke prevention or more aggressive treatment targets in guideline recommendations. Although risk factor control appears to be improving since SAMMPRIS, many CREST2 patients are still not meeting recommended risk factor goals at baseline and may benefit from IMM protocols.

Abstract TP131: Carotid Stenosis and Polyvascular Disease

Background: Presence of atherosclerotic disease in more than one vascular bed (polyvascular disease) is associated with an increased risk of long-term vascular events. In the setting of asymptomatic carotid stenosis, the predictors of disease in other vascular beds is not well delineated.

Objective: To identify the frequency and predictors of disease in other vascular beds the CREST 2 randomized trial population with hemodynamically significant stenosis.

Methods: Recorded baseline characteristics among CREST 2 participants included: demographics, past medical history, lifestyle factors, and laboratory studies. Each variable was tested against three potential definitions of disease in other beds (cardiac, peripheral arterial disease (PAD) or disease in cardiac + PAD). Statistical analysis was done with Chi square and t tests as appropriate.

Results: Data from 1447 patients were available for analysis. In these subjects with carotid disease, 51% also had cardiac disease, 24% also had PAD, and 16% had disease in in both cardiac and PAD. There was no relationship between age or race and presence of disease in other beds. Those with cardiac disease were more likely to be male. Diabetes, hypertension, hypercholesterolemia, and former history of smoking were all more common in those with either cardiac and PAD (TABLE). Elevated triglyceride and low HDL levels were also associated with all three definitions of disease in other beds. Those with either PAD or cardiac + PAD were more likely to be current smokers.

Conclusions: Among CREST 2 participants, several medical conditions and lifestyle factors were associated with an increased frequency of disease in other vascular beds. Smoking, in particular, appears to be more common in those with PAD. Future analyses will address whether those with disease in other beds have higher rates of stroke or death.

Abstract TP141: Can the Human Eye Match a Computer Algorithm in Identifying Hypoperfusion in Asymptomatic Carotid Artery Stenosis?

Background: Perfusion weighted imaging on MRI (MRP) and computerized tomography perfusion (CTP) are increasingly required to manage large vessel disease. Computerized algorithms can quantify perfusion data, but the programs are expensive and not widely used outside acute stroke evaluation. We aimed to determine how well human observers can identify asymmetries in cerebral perfusion images compared with an automated computer algorithm.

Methods: Ten clinicians experienced in treating carotid artery disease (4 vascular neurologists, 3 neuroradiologists, 1 vascular surgeon, 1 neurosurgeon, 1 interventional radiologist) were given 28 post-processed, color-coded, axial-slice MRP scans from patients in the Carotid Revascularization Endovascular versus Stenting Trial - Hemodynamics (CREST-H) study. All patients had >70%, unilateral, asymptomatic carotid artery stenosis and had varying degrees of time-to-peak (TTP) delay on the side of stenosis, ranging from 0 to 2 secs, quantified by a semi-automated system that computes quantitative perfusion maps, using deconvolution of tissue and arterial signals (Olea, Cambridge, MA). A minimum volume of 10cc was required for a given TTP delay. Clinicians were asked to determine asymmetry (y/n) and side of occlusion for each case. Number of correct responses that matched the computer output were tallied.

Results: We averaged correct responses by the 10 clinicians for cases at each increment of TTP delay; (Figure). At TTP delays ≥1.5 seconds, accuracy was ≥80%. At 1.25 sec accuracy fell to 60%, and at ≤ 1 sec, accuracy was ≤50%. For TTP=0 (no asymmetry), accuracy was 71%.

Conclusions: Visual impression of hemodynamic asymmetry among experienced clinicians was reasonably accurate for TTP delays ≥1.5 seconds, but declined with more subtle asymmetries. Depending on the clinical impact of TTP delays (for CREST-H: correlation with cognitive decline), experienced clinicians may perform as well as an automated algorithm.

Transcarotid Artery Revascularization Results in Low Rates of Periprocedural Neurologic Events, Myocardial Infarction, and Death

PURPOSE OF REVIEW

Transcarotid artery revascularization (TCAR) is a novel hybrid procedure that reverses carotid flow and places a stent using surgical access of the carotid artery in the neck under local anesthesia. We discuss the indications for carotid revascularization, the clinical rationale for TCAR, and evidence for its potential role in the management of carotid stenosis.

RECENT FINDINGS

Results from pre-clinical studies, prospective single-arm studies, and comparative analyses of registry data indicate that TCAR results in low amounts of periprocedural microembolization, cerebral lesions detectable on magnetic resonance imaging, and neurologic events, myocardial infarctions (MIs), and death. Non-randomized comparisons suggest that TCAR may offer a novel solution to reducing periprocedural stroke, death, and MI in patients with carotid stenosis. A state of equipoise appears to have been reached with TCAR versus the traditional carotid revascularization procedures and a well-controlled randomized trial with careful oversight should be prioritized to obtain level 1 evidence.

Choosing a Mouse Model of Venous Thrombosis

Murine models are widely used valuable tools to study deep vein thrombosis. Leading experts in venous thrombosis research came together through the American Venous Forum to develop a consensus on maximizing the utility and application of available mouse models of venous thrombosis. In this work, we provide an algorithm for model selection, with discussion of the advantages, disadvantages, and applications of the main mouse models of venous thrombosis. Additionally, we provide a detailed surgical description of the models with guidelines to validate surgical technique.

Variability in the management of line-related upper extremity deep vein thrombosis

Objectives:

Central-venous devices are risk-factors for upper extremity deep vein thrombosis. We surveyed physicians to identify practice-patterns and adherence to American College of Chest Physicians guidelines.

Methods:

The 13-question survey obtained physician-demographics and treatment-choices. Respondents were grouped into surgical and medical specialists. Data were reported as ratios and percentages, and compared using Fisher’s exact test.

Results:

We received 143 responses from physicians; 65% treated one-to-two new cases/month. Most physicians (69.2%) used anticoagulation; 36.4% retained the catheter and 32.9% removed it. Medical-specialists retained catheters more often than surgeons (p = 0.027). For recurrences, 84% repeated anticoagulation; 50.3% retained the catheter. A majority anticoagulated upper-extremity deep-vein thrombosis in long-term catheters for three months only (55.1%). Direct oral anticoagulants were used frequently (43.6%). Only 10% believed that existing guidelines were appropriate and only 2.8% followed all guidelines.

Conclusion:

There is great variability in treatment-decisions for upper-extremity deep-vein thrombosis. The existing guidelines are considered inadequate and not followed by most physicians.

Factors influencing credentialing of interventionists in the CREST-2 trial

BACKGROUND

The Carotid Revascularization and Medical Management for Asymptomatic Carotid Stenosis Trial (CREST-2) is a pair of randomized trials assessing the relative efficacy of carotid revascularization in the setting of intensive medical management (IMM) in patients with asymptomatic high-grade atherosclerotic stenosis. One of the trials assesses IMM with or without carotid artery stenting (CAS). Given the low risk of stroke in nonrevascularized patients receiving IMM, it is essential that there be low periprocedural risk of stroke for CAS if it is to show incremental benefit. Thus, credentialing of interventionists to ensure excellence is vital. This analysis describes the protocol-driven approach to credentialing of CAS interventionists for CREST-2 and its outcomes.

METHODS

To be eligible to perform stenting in CREST-2, interventionists needed to be credentialed on the basis of a detailed Interventional Management Committee (IMC) review of data from their last 25 consecutive cases during the past 24 months along with self-reported lifetime experience case numbers. When necessary, additional prospective cases performed in a companion registry were requested after webinar training. Here we review the IMC experience from the first formal meeting on March 21, 2014 through October 14, 2017.

RESULTS

The IMC had 102 meetings, and 8311 cases submitted by 334 interventionists were evaluated. Most were either cardiologists or vascular surgeons, although no single specialty made up the majority of applicants. The median total experience was 130 cases (interquartile range [IQR], 75-266; range, 25-2500). Only 9% (30/334) of interventionists were approved at initial review; approval increased to 46% (153/334) after submission of new cases with added training and re-review. The median self-reported lifetime case experience for those approved was 211.5 (IQR, 100-350), and the median number of cases submitted for review was 30 (IQR, 27-35). The number of CAS procedures performed per month (case rate) was the only factor associated with approval during the initial cycle of review (P < .00001).

CONCLUSIONS

Identification of interventionists who were deemed sufficiently skilled for CREST-2 has required substantial oversight and a controlled system to judge current skill level that controls for specialty-based practice variability, procedural experience, and periprocedural outcomes. High-volume interventionists, particularly those with more recent experience, were more likely to be approved to participate in CREST-2. Primary approval was not affected by operator specialty.

Choosing a mouse model of venous thrombosis: a consensus assessment of utility and application

Murine models are widely used valuable tools to study deep vein thrombosis (VT). Leading experts in VT research came together through the American Venous Forum to develop a consensus on maximizing the utility and application of available mouse models of VT. In this work, we provide an algorithm for model selection, with discussion of the advantages, disadvantages, and applications of the main mouse models of VT. Additionally, we provide a detailed surgical description of the models with guidelines to validate surgical technique.

Quantitative assessment of carotid plaque morphology (geometry and tissue composition) using computed tomography angiography

OBJECTIVE

Quantification of carotid plaque morphology (geometry and tissue composition) may help stratify risk for future stroke and assess plaque progression or regression in response to medical risk factor modification. We assessed the feasibility and reliability of morphologic measurements of carotid plaques using computed tomography angiography (CTA) and determined the minimum detectable change in plaque features by this approach.

METHODS

CTA images of both carotid arteries in 50 patients were analyzed by two observers using a semiautomatic image analysis program, yielding 93 observations per user (seven arteries were excluded because of prior stenting). One observer repeated the analyses 4 weeks later. Measurements included total plaque volume; percentage stenosis (by diameter and area); and tissue composition for calcium, lipid-rich necrotic core (LRNC), and intraplaque hemorrhage (IPH). Reliability of measurements was assessed by intraclass and interclass correlation and Bland-Altman plots. Dice similarity coefficient (DSC) and modified Hausdorff distance (MHD) assessed reliability of geometric shape measurements. We additionally computed the minimum amount of change in these features detectable by our approach.

RESULTS

The cohort was 51% male (mean age, 70.1 years), and 56% had a prior stroke. The mean (± standard deviation) plaque volume was 837.3 ± 431.3 mm³, stenosis diameter was 44.5% ± 25.6%, and stenosis area was 58.1% ± 29.0%. These measurements showed high reliability. Intraclass correlation coefficients for plaque volume, percentage stenosis by diameter, and percentage stenosis by area were 0.96, 0.87, and 0.83, respectively; interclass correlation coefficients were 0.88, 0.84, and 0.78. Intraclass correlations for tissue composition were 0.99, 0.96, and 0.86 (calcium, LRNC, and IPH, respectively), and interclass correlations were 0.99, 0.92, and 0.92. Shape measurements showed high intraobserver (DSC, 0.95 ± 0.04; MHD, 0.16 ± 0.10 mm) and interobserver (DSC, 0.94 ± 0.05; MHD, 0.19 ± 0.12 mm) luminal agreement. This approach can detect a change of at least 3.9% in total plaque volume, 1.2 mm³ in calcium, 4.3 mm³ in LRNC, and 8.6 mm³ in IPH with the same observer repeating measurements and 9.9% in plaque volume, 1.9 mm³ in calcium, 7.9 mm³ in LRNC, and 6.8 mm³ in IPH for two different observers.

CONCLUSIONS

Carotid plaque geometry (total volume, diameter stenosis, and area stenosis) and tissue composition (calcium, LRNC, and IPH) are measured reliably from clinical CTA images using a semiautomatic image analysis program. The minimum change in plaque volume detectable is ∼4% if the same observer makes both measurements and ∼10% for different observers. Small changes in plaque composition can also be detected reliably. This approach can facilitate longitudinal studies for identifying high-risk plaque features and for quantifying plaque progression or regression after treatment.

Abstract TP527: Baseline Physical Activity Profiles in CREST-2 Trial Participants

Background: The importance of physical activity in preventing major vascular events has received increased attention in the past decade. Due to the inclusion of the INTERVENT lifestyle modification program, the CREST2 trial provides a unique opportunity to study physical activity profiles in patients with severe asymptomatic extracranial carotid stenosis.

Hypothesis: Based on data from a trial of intracranial stenosis patients, we aimed to evaluate the hypothesis that <40% of carotid stenosis subjects will have optimal physical activity levels. We also assessed key subgroups to determine patterns of physical activity.

Methods: We analyzed 1087 CREST2 participants with baseline data on physical activity. The Physician-based Assessment and Counseling for Exercise (PACE) score is recorded for each patient and dichotomized as “in target” (4-8 points) or “out of target” (<4 points). A PACE score of <4 indicates a subject who does not engage in regular exercise. Results are analyzed for the entire trial. Chi square testing and t-tests were performed for evaluation of subgroup differences.

Results: The mean age of the study population is 69.5±7.8 years (60% male). The median PACE score at baseline is 4.0 (mean 3.8±2.1; IQR 2 to 6). The Table shows baseline characteristics of patients by mean PACE score. Being male, not having diabetes mellitus, having a body mass index <30kg/m2, being a non-smoker, and not having a history of peripheral arterial disease were associated with significantly higher mean PACE scores (P<0.01).

Conclusions: We have defined several patient groups with asymptomatic carotid stenosis that have suboptimal physical activity. These results provide opportunities for targeted efforts to improve primary stroke prevention. These baseline data will also allow investigators to determine if trial involvement and the INTERVENT program leads to improvement in the level of physical activity.

Abstract TMP96: Carotid Plaque Characteristics Correlated to Baseline Vascular Risk Factors in a Large Randomized Trial: Results from CREST-2

Objectives: Assessment of carotid disease is most commonly performed with duplex ultrasonography (DUS). Measures of plaque area and tissue composition from DUS images may identify patients at risk for future neurologic events, and may assess the effects of vascular risk-factor modification (by measuring change in plaque area and/or tissue constituents). We quantified plaque area and tissue constituents from DUS images of CREST-2 participants at baseline and correlated them with their baseline vascular risk factors.

Methods: CREST-2 consists of two multicenter, randomized trials in patients with asymptomatic ≥70% carotid stenosis comparing intensive medical management (IMM) plus endarterectomy or stenting vs IMM alone. Baseline B-mode DUS images from 500 patients underwent manual plaque outlining and automatic pixel brightness assessment. Plaque area, grayscale median (GSM), Gray-Weale score for heterogeneity, and areas for intraplaque hemorrhage and lipid were the output parameters. We computed the parameter estimates (95% confidence intervals) for baseline patient characteristics (age, sex, race, diabetes, smoking, BMI, blood pressure and LDL levels) versus plaque characteristics.

Results: High-risk plaque features (larger plaque area, lower GSM , lower Gray-Weale scores, or larger areas of hemorrhage and lipid) were present in older patients, males, and those with elevated diastolic blood pressure and LDL levels (Table).

Conclusions: In a randomized trial of asymptomatic patients with high-grade carotid stenosis, DUS-based computation of plaque geometry and tissue composition is feasible. Elevated diastolic blood pressure and LDL levels at baseline are associated with high-risk plaque characteristics. These novel findings identify potentially modifiable targets for aggressive treatment to reduce stroke-risk in patients with carotid stenosis.

Is Hemispheric Hypoperfusion a Treatable Cause of Cognitive Impairment?

PURPOSE OF REVIEW

To review the current literature that supports the notion that cerebral hemodynamic compromise from internal carotid artery stenosis may be a cause of vascular cognitive impairment that is amenable to treatment by revascularization.

RECENT FINDINGS

Converging evidence suggests that successful carotid endarterectomy and carotid artery stenting are associated with reversal of cognitive decline in many patients with severe but asymptomatic carotid artery stenosis. Most of these findings have been derived from cohort studies and comparisons with either normal or surgical controls. Failure to find treatment benefit in a number of studies appears to have been the result of patient heterogeneity or confounding from concomitant conditions independently associated with cognitive decline, such as heart failure and other cardiovascular risk factors, or failure to establish pre-procedure hemodynamic failure. Patients with severe carotid artery stenosis causing cerebral hemodynamic impairment may have a reversible cause of cognitive decline. None of the prior studies, however, were done in the context of a randomized clinical trial with large numbers of participants. The ongoing CREST-2 trial comparing revascularization with medical therapy versus medical therapy alone, and its associated CREST-H study determining whether cognitive decline is reversible among those with hemodynamic compromise may address this question.

Prospective study of cryopreserved placental tissue wound matrix in the management of chronic venous leg ulcers

OBJECTIVE

Chronic venous leg ulcers (VLUs) affect up to 2% of the general population, resulting in a significant socioeconomic burden. Placental tissue that contains mesenchymal stem cells and active growth factors has been shown to be beneficial in healing of chronic wounds. We compared the efficacy of a human viable wound matrix (hVWM) of cryopreserved placental tissue for the treatment of refractory VLUs with standard therapy.

METHODS

This prospective single-center open-label single-arm study enrolled patients with Clinical, Etiology, Anatomy, and Pathophysiology clinical class C6 VLUs. The ulcers of all enrolled patients had failed to heal after a trial of standard therapy of at least 12 weeks, which included weekly multilayer compression therapy along with local wound care. The same patients subsequently received application of hVWM (Grafix; Osiris Therapeutics, Columbia, Md) every 1 to 2 weeks in addition to standard therapy. Healing with hVWM therapy was then compared with standard therapy, with each patient serving as his own control.

RESULTS

There were 30 VLUs in 21 consecutive eligible patients who were enrolled in the study. All patients were men with an average age of 67 years (standard deviation [SD], ±10.8 years), and the average area of venous ulcers before hVWM initiation was 12.2 cm² (SD, ±14.6 cm²; range, 3.3-12.3 cm²). Duplex ultrasound confirmed superficial or deep system venous reflux in all patients. Complete ulcer healing was achieved in 53% (16/30) of VLUs refractory to standard therapy after application of hVWM. There was a mean reduction in wound surface area by 79% (SD, ±27.3%; P < .001 compared with standard therapy) after a mean treatment time of 10.9 weeks. Eighty percent of VLUs were reduced in size by half compared with 25% with standard therapy (P < .001). The mean rate of reduction in ulcer area after hVWM applications was 1.69% per day vs 0.73% per day with standard therapy (P = .01).

CONCLUSIONS

Cryopreserved placental tissue (hVWM) improves healing processes to achieve complete wound closure in a significant proportion of chronic VLUs refractory to standard therapy. Adjunctive therapy with hVWM provides superior healing rates in refractory VLUs.