High Stroke Rate in Patients With Medically Managed Asymptomatic Carotid Stenosis at an Academic Center in the Southeastern United States.

BACKGROUND: Although the publication of randomized clinical trials defining the benefit of carotid endarterectomy (CEA) for asymptomatic carotid stenosis, medical management of carotid stenosis has changed significantly. With antiplatelet agents and statins, some question whether these trials are still relevant, suggesting that asymptomatic patients with >70% internal carotid artery (ICA) stenosis may do better with medial management alone, lessening the need for CEA and carotid stenting. The Vascular Quality Initiative (VQI) registry has shown that there are wide practice variations regarding the degree of stenosis that prompts surgical intervention but there are few reports of outcomes in patients who do not undergo intervention. We sought to determine the clinical outcomes of the >70% carotid stenosis patients who are treated with medical management alone at our institution. METHODS: We identified all patients with ICA stenosis >70% based on hemodynamic consensus criteria (peak systolic velocity >230 cm/s) in our peripheral vascular laboratory from January 2013 through December 2016. With a retrospective chart review, demographics, comorbid conditions, medications, radiographic studies, clinical follow-up, interventions, and outcomes at 2 years were included. Descriptive statistics were used to define these variables. RESULTS: One hundred and seventy three patients were identified with medically managed asymptomatic >70% ICA stenosis based on hemodynamic criteria on duplex ultrasound. The mean age was 67.5 years, 49% were male, 64% were White, 14% were Black, 13% race was undisclosed, 89% were prescribed antiplatelet therapy, 85% were prescribed a statin, and 60% had hypertension controlled to <140/90. Twenty patients (11.5%) experienced a cerebrovascular event during the 2-year study period. There were eight patients with transient ischemic attack, 10 with ipsilateral strokes, and 2 with strokes in unrelated territories. CONCLUSIONS: Despite good adherence to current recommendations for medical therapy, patients at our institution are developing symptomatic carotid disease at a rate similar to that reported in historical clinical trials. These data supports the concept that advances in medical management have not resulted in reduced stroke rates in asymptomatic patients with high-grade carotid stenosis at a large academic institution located in the southeastern United States. CEA and stenting provide a significant risk reduction and should be considered more often in this patient population.

Experimental evidence that effects of megaherbivores on mesoherbivore space use are influenced by species' traits.

The extinction of 80% of megaherbivore (>1,000 kg) species towards the end of the Pleistocene altered vegetation structure, fire dynamics and nutrient cycling world-wide. Ecologists have proposed (re)introducing megaherbivores or their ecological analogues to restore lost ecosystem functions and reinforce extant but declining megaherbivore populations. However, the effects of megaherbivores on smaller herbivores are poorly understood. We used long-term exclusion experiments and multispecies hierarchical models fitted to dung counts to test (a) the effect of megaherbivores (elephant and giraffe) on the occurrence (dung presence) and use intensity (dung pile density) of mesoherbivores (2-1,000 kg), and (b) the extent to which the responses of each mesoherbivore species was predictable based on their traits (diet and shoulder height) and phylogenetic relatedness. Megaherbivores increased the predicted occurrence and use intensity of zebras but reduced the occurrence and use intensity of several other mesoherbivore species. The negative effect of megaherbivores on mesoherbivore occurrence was stronger for shorter species, regardless of diet or relatedness. Megaherbivores substantially reduced the expected total use intensity (i.e. cumulative dung density of all species) of mesoherbivores, but only minimally reduced the expected species richness (i.e. cumulative predicted occurrence probabilities of all species) of mesoherbivores (by <1 species). Simulated extirpation of megaherbivores altered use intensity by mesoherbivores, which should be considered during (re)introductions of megaherbivores or their ecological proxies. Species' traits (in this case shoulder height) may be more reliable predictors of mesoherbivores' responses to megaherbivores than phylogenetic relatedness, and may be useful for predicting responses of data-limited species.

Ecological consequences of large herbivore exclusion in an African savanna: 12 years of data from the UHURU experiment.

Diverse communities of large mammalian herbivores (LMH), once widespread, are now rare. LMH exert strong direct and indirect effects on community structure and ecosystem functions, and measuring these effects is important for testing ecological theory and for understanding past, current, and future environmental change. This in turn requires long-term experimental manipulations, owing to the slow and often nonlinear responses of populations and assemblages to LMH removal. Moreover, the effects of particular species or body-size classes within diverse LMH guilds are difficult to pinpoint, and the magnitude and even direction of these effects often depends on environmental context. Since 2008, we have maintained the Ungulate Herbivory Under Rainfall Uncertainty (UHURU) experiment, a series of size-selective LMH exclosures replicated across a rainfall/productivity gradient in a semiarid Kenyan savanna. The goals of the UHURU experiment are to measure the effects of removing successively smaller size classes of LMH (mimicking the process of size-biased extirpation) and to establish how these effects are shaped by spatial and temporal variation in rainfall. The UHURU experiment comprises three LMH-exclusion treatments and an unfenced control, applied to nine randomized blocks of contiguous 1-ha plots (n = 36). The fenced treatments are MEGA (exclusion of megaherbivores, elephant and giraffe), MESO (exclusion of herbivores ≥40 kg), and TOTAL (exclusion of herbivores ≥5 kg). Each block is replicated three times at three sites across the 20-km rainfall gradient, which has fluctuated over the course of the experiment. The first 5 years of data were published previously (Ecological Archives E095-064) and have been used in numerous studies. Since that publication, we have (1) continued to collect data following the original protocols, (2) improved the taxonomic resolution and accuracy of plant and small-mammal identifications, and (3) begun collecting several new data sets. Here, we present updated and extended raw data from the first 12 years of the UHURU experiment (2008-2019). Data include daily rainfall data throughout the experiment; annual surveys of understory plant communities; annual censuses of woody-plant communities; annual measurements of individually tagged woody plants; monthly monitoring of flowering and fruiting phenology; every-other-month small-mammal mark-recapture data; and quarterly large-mammal dung surveys. There are no copyright restrictions; notification of when and how data are used is appreciated and users of UHURU data should cite this data paper when using the data.

Positioning operations in the dental safety net to enhance value-based care delivery in an integrated health-care setting.

OBJECTIVES: Impact of implementing data-driven performance metric-tracking across a 10-dental center infrastructure established by Family Heath Center of Marshfield (FHC-M) was examined for relative impact on achieving value-based care delivery in serving a patient population characterized by 88% Medicaid representation. METHODS: To track progress toward national benchmarks for preventive care delivery, dental quality analytics dashboard tracking was implemented in real time with sharing of performance metrics across centers. Compliance rate with Uniform Data Systems reporting requirements for sealant placement on permanent first molars in children aged 6-9 years of age at moderate-to-high risk of caries was targeted at FHC-M dental centers for comparison with those of other community health centers statewide and nationally. Hygienist-to-dentist ratio to support robust sealant placement capacity was further examined. RESULTS: Uniform Data Systems data for rate of sealant placement between 2016-2018 revealed that FHC-M consistently exceeded rates reported statewide and nationally. For this quality indicator, performance across all dental practices in 27 states reported by Centers for Medicare and Medicaid Services in 2018 achieved 23% in 2017 compared to 73% and 52% placement rates reported by FHC-M and community health centers, respectively. A 1:1 hygienist-to-dentist was documented across FHC-M dental centers compared to 0.5:1 reported nationally. CONCLUSIONS: Implementation of quality metric dashboard and a 1:1 dentist-to-hygienist ratio supported realization of value-based dental care delivery relative to caries prevention in a moderate-to-high risk pediatric Medicaid population through achievement of robust sealant placement. Importance of adequate hygienist staffing, "same day" sealant placement and performance feedback supported by technology are highlighted.