Publications by authors named "Christopher D Owens"

Introduction: The COVID-19 global pandemic has affected all ethnic and minority groups although not equally. The goals of the present study are twofold: describe the diverse COVID-19-related care needs Hispanic patients presenting to a primary care facility and the symptom clusters and socioeconomic factors that may impact their wellbeing.

Methods: This is a retrospective cohort of Hispanic patients in an outpatient clinic serving an urban lower socioeconomic demographic, between May 9 and July 31, 2020.

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In-stent restenosis is a pervasive challenge to the durability of stenting for the treatment of lower extremity ischemia. There is considerable controversy about the criteria for diagnosis, indications for treatment, and preferred algorithm for addressing in-stent restenosis. This evidence summary seeks to review existing information on strategies for the treatment of this difficult problem.

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Although the clinical range of interventions for coronary arteries is about 2 to 5 mm, the range of diameters of peripheral vasculature is significantly larger (about 10 mm for human iliac artery). When the vessel diameter is increased, the spacing between excitation electrodes on a conductance sizing device must also increase to accommodate the greater range of vessel diameters. The increase in the excitation electrodes distance, however, causes higher parallel conductance or current losses outside of artery lumen.

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Background: Current research in behavioral cardiology reveals a significant association between posttraumatic stress disorder (PTSD) and increased risk for cardiovascular disease and mortality; however, the underlying mechanisms remain poorly understood. We hypothesized that patients with PTSD would exhibit endothelial dysfunction, a potential mechanism involved in the development and progression of cardiovascular disease.

Methods And Results: A total of 214 outpatients treated at the San Francisco Veterans Affairs Medical Center underwent tests of endothelial function and evaluation for PTSD.

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The integrity of endothelial function in major arteries (EFMA) is a powerful independent predictor of heart attack and stroke. Existing ultrasound-based non-invasive assessment methods are technically challenging and suitable only for laboratory settings. EFMA, like blood pressure (BP), is both acutely and chronically affected by factors such as lifestyle and medication.

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Background: Patients with peripheral artery disease (PAD) experience significant morbidity and mortality. The OMEGA-PAD I Trial, a randomized, double-blinded, placebo-controlled trial, addressed the hypothesis that short-duration, high-dose n-3 polyunsaturated fatty acids (n-3 PUFA) oral supplementation improves endothelial function and inflammation in PAD.

Methods And Results: Eighty patients with stable claudication received 4.

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Inadequate nutrient intake may contribute to the development and progression of peripheral arterial disease (PAD). This study's aim was to assess intake of essential fatty acids and nutrients among veterans with PAD. All 88 subjects had ankle-brachial indices of <0.

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We have used a multimodality imaging approach to assess the inflammatory component of a growing iliac artery aneurysm in a 53-year-old man who presented with related ureteral obstruction. Research suggests that episodic and heterogeneous inflammatory processes are important for the progression of aneurysms. The combined PET and MRI evaluation of inflammation that we present here is a novel approach to vascular imaging that is well suited for emerging hybrid PET/MRI systems.

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Objective: We have previously shown that peripheral artery disease (PAD) is associated with marked impairment of endothelial function (EF). Given that poor EF is associated with functional status of PAD patients as well as with increased morbidity and mortality in patients undergoing vascular procedures, determination of factors associated with poor EF in a PAD cohort is important. We hypothesized that decreased kidney function is associated with impaired EF in patients with PAD.

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The vascular endothelium is a monolayer of cells that cover the interior of blood vessels and provide both structural and functional roles. The endothelium acts as a barrier, preventing leukocyte adhesion and aggregation, as well as controlling permeability to plasma components. Functionally, the endothelium affects vessel tone.

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Background: Renal toxicity from conventional, iodinated, intravenous contrast agents is a common complication in patients with peripheral artery disease (PAD). Similarly, the potential for serious side effects prevents the use of gadolinium-based agents in many patients with depressed renal function. Ferumoxytol-enhanced magnetic resonance angiography (Fe-MRA) is a novel technique that uses an intravenous, ultrasmall, superparamagnetic, iron oxide preparation, currently approved by the Food and Drug Administration for the treatment of iron deficiency anemia in adults with chronic kidney disease.

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Objective: Despite available medical therapies, patients with peripheral arterial disease (PAD) remain at high risk for cardiovascular events. The n-3 polyunsaturated fatty acids (PUFA), derived from marine sources, have been shown to improve cardiovascular mortality. The Omega-3 Index (O3I), a proportion of the n-3 PUFA eicosapentaenoic acid and docosahexaenoic acid in the red blood cell membrane, correlates with cardiovascular risk.

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Background: Sedentarism, also termed physical inactivity, is an independent risk factor for cardiovascular diseases. Mechanisms thought to be involved include insulin resistance, dyslipidemia, hypertension, and increased inflammation. It is unknown whether changes in vascular and endothelial function also contribute to this excess risk.

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Background: Plasma 25 hydroxycholecalciferol (vitamin D) deficiency has been associated with adverse cardiovascular outcomes in epidemiologic studies. Chronic kidney disease is associated with loss of 1α-hydroxylase and consequently vitamin D deficiency. We hypothesized that vitamin D deficiency was associated with increased mortality and increased vascular access failure in patients undergoing permanent vascular access for end-stage renal disease.

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Objective: Patients with peripheral artery disease (PAD) have varying degrees of walking disability that do not completely correlate with ankle-brachial index (ABI) or angiographic anatomy. We hypothesized that endothelial function (EF) is an independent predictor of symptom severity in PAD patients.

Methods: This was a cross-sectional study of 100 PAD patients presenting to a vascular surgery clinic.

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Objective: Restenosis following endovascular treatment of the femoropopliteal segment is associated with the inflammatory response produced in the artery wall at the time of the procedure. Although local drug delivery to the superficial femoral and popliteal arteries promises improved patency, data are currently limited. We hypothesized that improved percutaneous delivery of an anti-inflammatory compound into the adventitia of the femoropopliteal at the time of endovascular treatment would be safe, feasible, and decrease the inflammatory response.

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Background: Endovascular interventions on peripheral arteries are limited by high rates of restenosis. Our hypothesis was that adventitial injection of rapamycin nanoparticles would be safe and reduce luminal stenosis in a porcine femoral artery balloon angioplasty model.

Methods And Results: Eighteen juvenile male crossbred swine were included.

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After the creation of an autogenous lower extremity bypass graft, the vein must undergo a series of dynamic structural changes to stabilize the arterial hemodynamic forces. These changes, which are commonly referred to as remodeling, include an inflammatory response, the development of a neointima, matrix turnover, and cellular proliferation and apoptosis. The sum total of these processes results in dramatic alterations in the physical and biomechanical attributes of the arterialized vein.

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Despite current consensus guidelines recommending intensive cardiovascular risk factor management for peripheral artery disease (PAD), patients suffering from PAD continue to experience significant morbidity and mortality. This excess morbid burden is at least partially related to impaired vascular function and systemic inflammation. Interventions bridging this gap are critical.

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The endovascular management of symptomatic atherosclerotic superficial femoral artery disease is challenging and requires consideration of unique anatomic, hemodynamic, and biomechanical factors. For innovative local drug delivery technologies to have a cost-effective and clinically meaningful benefit, they must provide patency rates in more complex lesions equivalent or superior to those currently approved devices are able to provide. Several proof-of-concept trials have either been published or been recently presented and many more are in the pipeline suggesting biologic effectiveness of these hybrid devices in reducing restenosis.

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Among patients with coronary artery disease (CAD), those with peripheral artery disease (PAD) have a greater vulnerability to cardiovascular (CV) events than those with CAD alone. In a prospective cohort study of patients with CAD, we evaluated potential mechanisms that might explain the adverse CV outcomes associated with PAD. We performed a prospective cohort study of 1018 patients with stable CAD who were recruited from 2000 to 2002.

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Objective: The n-3 polyunsaturated fatty acids are dietary components derived from fish oil with beneficial cardiovascular effects that may relate in part to anti-inflammatory properties. Peripheral artery disease (PAD) is characterized by a marked proinflammatory state. We hypothesized that the n-3 polyunsaturated fatty acids content of red blood cells (omega-3 index) would be correlated with biomarkers of inflammation and vascular function in a PAD cohort.

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Objective: Factors responsible for the variability in outcomes after lower extremity vein bypass grafting (LEVBG) are poorly understood. Recent evidence has suggested that a single nucleotide polymorphism (SNP) in the promoter region of the p27(Kip1) gene, a cell-cycle regulator, is associated with coronary in-stent restenosis. We hypothesized an association with vein graft patency.

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Hemodynamic parameters play an important role in regulating vascular remodeling in arterio-venous fistula (AVF) maturation. Investigating the changes in hemodynamic parameters during AVF maturation is expected to improve our understanding of fistula failure, but very little data on actual temporal changes in human AVFs is available. The present study aimed to assess the feasibility of using a noncontrast-enhanced MRI protocol combined with CFD modeling to relate hemodynamic changes to vascular remodeling following native AVF placement.

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