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Objectives: The peak systolic velocity (PSV) and end‐diastolic velocity (EDV) obtained by carotid duplex ultrasound (CDU) imaging of the internal carotid arteries (ICAs) are parameters used to determine the severity of ICA stenosis. Severe aortic stenosis (AS) results in a parvus‐et‐tardus pattern on spectral Doppler waveforms; however, the impact of severe AS on CDU velocities is unclear. The purpose of this study was to assess the impact of severe AS on CDU velocities by evaluating changes in CDU velocities before and after aortic valve replacement (AVR) Methods: A single‐center retrospective review of patients with severe AS who underwent surgical AVR and who had preoperative and postoperative CDU examinations performed within 12 months of each other was conducted. Patients with any carotid intervention between the preoperative and postoperative CDU were excluded. Results: We identified 92 patients who satisfied all inclusion criteria. The mean age was 72.2 years; 71.7% were men; the mean preoperative aortic valve area ± SD was 0.8 ± 0.2 cm2; and the mean time from preoperative to postoperative AVR CDU was 182.3 ± 98.4 days. The peak aortic valve gradient decreased from 62.5 to 22.0 mm Hg after AVR (P <.001); however, there were no significant changes in the PSV or EDV in either the right or left ICA. Conclusions: Although severe AS may cause characteristic changes in the spectral Doppler waveform on CDU imaging, there is no significant effect on the ICA PSV or EDV. Adjustments in velocity criteria to determine the degree of carotid artery stenosis in patients with substantial AS may not be necessary. [ABSTRACT FROM AUTHOR]

Objectives: Accreditation of echocardiographic testing facilities by the Intersocietal Accreditation Commission (IAC) is supported by the American College of Cardiology and American Society of Echocardiography. However, limited information exists on the accreditation status and geographic distribution of echocardiographic facilities in the United States. Our study aimed to identify (1) the proportion of outpatient echocardiography facilities used by Medicare beneficiaries that are IAC accredited, (2) their geographic distribution, and (3) variations in procedure type and volume by accreditation status. Methods: As part of the VALUE‐ECHO (Value of Accreditation, Location, and Utilization Evaluation–Echocardiography) study, we examined the proportion of IAC‐accredited echocardiographic facilities performing outpatient echocardiography in the 2013 Centers for Medicare and Medicaid Services outpatient limited data set (100% sample) and their geographic distribution using geocoding in ArcGIS (ESRI, Redlands, CA). Results: Among 4573 outpatient facilities billing Medicare for echocardiographic testing in 2013, 99.6% (n = 4554) were IAC accredited (99.7% in the 50 US states and 86.2% in Puerto Rico). The proportion IAC‐accredited echocardiographic facilities varied by region, with 98.7%, 99.9%, 99.9%, 99.5%, and 86.2% of facilities accredited in the Northeast, South, Midwest, West, and Puerto Rico, respectively (P < .01, Fisher exact test). Of all echocardiographic outpatient procedures conducted (n = 1,890,156), 99.8% (n = 1,885,382) were performed in IAC‐accredited echocardiographic facilities. Most procedures (90.9%) were transthoracic echocardiograms, of which 99.7% were conducted in IAC‐accredited echocardiographic facilities. Conclusions: Almost all outpatient echocardiographic facilities billed by Medicare are IAC accredited. This accreditation rate is substantially higher than previously reported for US outpatient vascular testing facilities (13% IAC accredited). The uniformity of imaging and interpretation protocols from a single accrediting body is important to facilitate optimal cardiovascular care. [ABSTRACT FROM AUTHOR]

Objectives: Accreditation of cerebrovascular ultrasound laboratories by the Intersocietal Accreditation Commission (IAC) and equivalent organizations is supported by the Joint Commission certification of stroke centers. Limited information exists on the accreditation status and geographic distribution of cerebrovascular testing facilities in the United States. Our study objectives were to identify the proportion of IAC‐accredited outpatient cerebrovascular testing facilities used by Medicare beneficiaries, describe their geographic distribution, and identify variations in cerebrovascular testing procedure types and volumes by accreditation status. Methods: As part of the VALUE (Vascular Accreditation, Location, and Utilization Evaluation) Study, we examined the proportion of IAC‐accredited facilities that conducted cerebrovascular testing in a 5% Centers for Medicare and Medicaid Services random Outpatient Limited Data Set in 2011 and investigated their geographic distribution using geocoding. Results: Among 7327 outpatient facilities billing Medicare for cerebrovascular testing, only 22% (1640) were IAC accredited. The proportion of IAC‐accredited cerebrovascular testing facilities varied by region (χ2[3] = 177.1; P <.0001), with 29%, 15%, 13%, and 10% located in the Northeast, South, Midwest, and West, respectively. However, of the total number of cerebrovascular outpatient procedures conducted in 2011 (38,555), 40% (15,410) were conducted in IAC‐accredited facilities. Most cerebrovascular testing procedures were carotid duplex, with 40% of them conducted in IAC‐accredited facilities. Conclusions: The proportion of facilities conducting outpatient cerebrovascular testing accredited by the IAC is low and varies by region. The growing number of certified stroke centers should be accompanied by more accredited outpatient vascular testing facilities, which could potentially improve the quality of stroke care. [ABSTRACT FROM AUTHOR]

Background Fibromuscular dysplasia ( FMD) is an uncommon vascular disease that presents with stenosis, aneurysm, dissection, beading, and tortuosity of medium-sized arteries. It primarily manifests in the renal and extracranial carotid and vertebral arteries, and is associated with major vascular events such as carotid artery dissection, renal artery dissection, ruptured aneurysm, transient ischemic attack, stroke, and myocardial infarction (due to coronary artery dissection). Discussion There is a wide spectrum of disease severity among FMD patients. Symptoms of FMD are related to the vascular beds involved and the severity of arterial stenoses. Headache is an extremely common and important symptom reported by patients with FMD, although the precise mechanism of headache in this population is not yet known. Conclusion This review summarizes the most recent literature regarding FMD, including epidemiology, clinical manifestations, imaging practices, and treatment. Special attention will be paid to the association of headaches and FMD. Correct diagnosis, optimal medical management, and appropriate referral for vascular intervention are vital elements of the treatment of patients with FMD. There is a great need for more clinical research regarding the epidemiology, pathophysiology, and optimal treatment of headache in the FMD patient population. [ABSTRACT FROM AUTHOR]

Elevated free fatty acids (FFAs) contribute to the development of insulin resistance, type 2 diabetes mellitus (T2DM), and may be atherogenic. We tested the relationship among lipid-induced insulin resistance, endothelial dysfunction, and monocyte capacity to form foam cells through scavenger receptor A (SRA) and CD36. Ten healthy subjects underwent 24-h infusion of Intralipid/heparin and saline (0.5 ml/min) on two separate occasions followed by brachial artery reactivity testing and a euglycemic hyperinsulinemic (80 mU/(kg·min)) clamp study to determine insulin sensitivity. Isolation of blood monocytes was performed 24 h after infusion. Surface expression and function of CD36 and SRA to take up oxidized low-density lipoprotein (oxLDL) was determined by flow cytometry and quantitative confocal imaging. Lipid infusion resulted in a twofold increase in serum FFA levels, reduced whole-body glucose disposal by ~20% (P < 0.05), and possibly impaired endothelial-dependent vasodilation (P = 0.1). Blood monocytes obtained during lipid infusion demonstrated a ~25% increase in cell surface expression of CD36 (P < 0.05) but no change in SRA expression. Enhanced CD36 expression was associated with a 50% increase in internalization of oxLDL (P < 0.05). The increase in CD36 surface expression during lipid infusion correlated inversely with glucose disposal (P < 0.05) and not with FFA levels or brachial artery dilation. These data support a role for FFAs in induction of insulin resistance and provide a link to atherogenic mechanisms mediated by expression of scavenger receptor CD36. [ABSTRACT FROM AUTHOR]