Immune Markers Are Associated With Asymptomatic Intracranial Large Artery Stenosis and Future Vascular Events in NOMAS.

BACKGROUND: Inflammation contributes to atherosclerosis but is incompletely characterized in intracranial large artery stenosis (ICAS). We hypothesized that immune markers would be associated with ICAS and modify the risk ICAS confers on future vascular events. METHODS: This study included a subsample of stroke-free participants in the prospective NOMAS (Northern Manhattan Study), who had blood samples analyzed with a 60-plex immunoassay (collected from 1993 to 2001) and ICAS assessment with time-of-flight magnetic resonance angiography (obtained from 2003 to 2008). We dichotomized ICAS as either ≥50% stenosis or not (including no ICAS). We ascertained post-magnetic resonance imaging vascular events. We used least absolute shrinkage and selection operator procedures to select immune markers independently associated with ICAS. Then, we grouped selected immune markers into a derived composite Z score. Using proportional odds regression, we quantified the association of the composite immune marker Z score, ICAS, and risk of vascular events. RESULTS: Among 1211 participants (mean age, 71±9 years; 59% women; 65% Hispanic participants), 8% had ≥50% ICAS. Using least absolute shrinkage and selection operator regression, we identified CXCL9 (C-X-C motif chemokine ligand 9), HGF (hepatocyte growth factor), resistin, SCF (stem cell factor), and VEGF-A(vascular endothelial growth factor A) to have the strongest positive relationships with ≥50% ICAS in fully adjusted models. Selected markers were used to derive a composite immune marker Z score. Over an average follow-up of 12 years, we found that each unit increase in immune marker Z scores was associated with an 8% (95% CI, 1.05-1.11), 11% (95% CI, 1.06-1.16), and 5% (95% CI, 1.01-1.09) increased hazard of death, vascular death, and any vascular event, respectively, in adjusted models. We did not find a significant interaction between immune marker Z scores and ICAS in their relationship with any longitudinal outcome. CONCLUSIONS: Among a diverse stroke-free population, selected serum immune markers were associated with ICAS and future vascular events. Further study is needed to better understand their role in the pathogenesis of ICAS and as a potential therapeutic target in stroke prevention.

Accreditation Status and Geographic Location of Outpatient Echocardiographic Testing Facilities Among Medicare Beneficiaries: The VALUE-ECHO Study.

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.