International retrospective study of the pipeline embolization device: a multicenter aneurysm treatment study

BACKGROUND AND PURPOSE

Flow diverters are increasingly used in the endovascular treatment of intracranial aneurysms. Our aim was to determine neurologic complication rates following Pipeline Embolization Device placement for intracranial aneurysm treatment in a real-world setting.

MATERIALS AND METHODS

We retrospectively evaluated all patients with intracranial aneurysms treated with the Pipeline Embolization Device between July 2008 and February 2013 in 17 centers worldwide. We defined 4 subgroups: internal carotid artery aneurysms of ≥10 mm, ICA aneurysms of <10 mm, other anterior circulation aneurysms, and posterior circulation aneurysms. Neurologic complications included spontaneous rupture, intracranial hemorrhage, ischemic stroke, permanent cranial neuropathy, and mortality. Comparisons were made with t tests or ANOVAs for continuous variables and the Pearson χ(2) or Fisher exact test for categoric variables.

RESULTS

In total, 793 patients with 906 aneurysms were included. The neurologic morbidity and mortality rate was 8.4% (67/793), highest in the posterior circulation group (16.4%, 9/55) and lowest in the ICA <10-mm group (4.8%, 14/294) (P = .01). The spontaneous rupture rate was 0.6% (5/793). The intracranial hemorrhage rate was 2.4% (19/793). Ischemic stroke rates were 4.7% (37/793), highest in patients with posterior circulation aneurysms (7.3%, 4/55) and lowest in the ICA <10-mm group (2.7%, 8/294) (P = .16). Neurologic mortality was 3.8% (30/793), highest in the posterior circulation group (10.9%, 6/55) and lowest in the anterior circulation ICA <10-mm group (1.4%, 4/294) (P < .01).

CONCLUSIONS

Aneurysm treatment with the Pipeline Embolization Device is associated with the lowest complication rates when used to treat small ICA aneurysms. Procedure-related morbidity and mortality are higher in the treatment of posterior circulation and giant aneurysms.

Chronic Chagas' disease cardiomyopathy patients display an increased IFN-gamma response to Trypanosoma cruzi infection

One-third of all Trypanosoma cruzi -infected patients eventually develop chronic Chagas' disease cardiomyopathy (CCC), a particularly lethal inflammatory dilated cardiomyopathy, where parasites are scarce and heart-infiltrating mononuclear cells seem to be the effectors of tissue damage. Since T. cruzi is a major inducer of interleukin-12 production, the role of inflammatory cytokines in the pathogenesis of CCC was investigated. We assayed cytokine production by peripheral blood mononuclear cells (PBMC) from CCC and asymptomatic T. cruzi -infected (ASY) individuals, as well as by T cell lines from endomyocardial biopsies from CCC patients. PBMC from CCC and ASY patients produced higher IFN-gamma levels than normal (N) individuals in response to B13 protein and phytohaemagglutinin PHA; IFN-gamma high responders (> or =1 ng/ml) were 2-3 fold more frequent among CCC patients than ASY individuals. Conversely, IL-4 production in response to the same stimuli was suppressed among T. cruzi -infected patients. The frequency of PHA-induced IFN gammaproducing cells on PBMC was significantly higher among CCC than ASY and N individuals. IFN-gamma and TNF-alpha were produced by ten out of ten PHAstimulated T cell lines from CCC patients; IL-2 and IL-10 were produced by four out of ten and one out of ten lines, respectively; IL-4, IL-1alpha, IL-1beta, IL-6 and IL-12 were undetectable. Our results suggest that CCC and ASY patients may respond differentially to the IFN-gamma-inducing stimulus provided by T. cruzi infection. Given the T(1)-type cytokine profile of heart-infiltrating T cell lines from CCC patients, the ability to mount a vigorous IFN-gamma response may play a role on the differential susceptibility to CCC development.

Cytokine production profile of heart-infiltrating T cells in Chagas' disease cardiomyopathy

The hallmark of chronic Chagas' disease cardiomyopathy (CCC) is the finding of a T cell-rich inflammatory mononuclear cell infiltrate in the presence of extremely few parasites in the heart lesions. The scarcity of parasites in affected heart tissue casts doubt on the direct participation of Trypanosoma cruzi in CCC heart tissue lesions, and suggests the possible involvement of autoimmunity. The cells in the infiltrate are presumably the ultimate effectors of tissue damage, and there is evidence that such cells recognize cardiac myosin in molecular mimicry with T. cruzi proteins rather than primary reactivity to T. cruzi antigens (Cunha-Neto et al. (1996) Journal of Clinical Investigation, 98: 1709-1712). Recently, we have studied heart-infiltrating T cells at the functional level. In this short review we summarize the studies about the role of cytokines in human and experimental T. cruzi infection, along with our data on heart-infiltrating T cells in human Chagas' cardiomyopathy. The bulk of evidence points to a significant production of IFN-gamma and TNF-alpha which may be linked to T. cruzi-induced IL-12 production.

Antiplatelet Management for Stent-Assisted Coiling and Flow Diversion of Ruptured Intracranial Aneurysms: A DELPHI Consensus Statement

BACKGROUND AND PURPOSE

There is a paucity of data regarding antiplatelet management strategies in the setting of stent-assisted coiling/flow diversion for ruptured intracranial aneurysms. This study aimed to identify current challenges in antiplatelet management during stent-assisted coiling/flow diversion for ruptured intracranial aneurysms and to outline possible antiplatelet management strategies.

MATERIALS AND METHODS

The modified DELPHI approach with an on-line questionnaire was sent in several iterations to an international, multidisciplinary panel of 15 neurointerventionalists. The first round consisted of open-ended questions, followed by closed-ended questions in the subsequent rounds. Responses were analyzed in an anonymous fashion and summarized in the final manuscript draft. The statement received endorsement from the World Federation of Interventional and Therapeutic Neuroradiology, the Japanese Society for Neuroendovascular Therapy, and the Chinese Neurosurgical Society.

RESULTS

Data were collected from December 9, 2019, to March 13, 2020. Panel members achieved consensus that platelet function testing may not be necessary and that antiplatelet management for stent-assisted coiling and flow diversion of ruptured intracranial aneurysms can follow the same principles. Preprocedural placement of a ventricular drain was thought to be beneficial in cases with a high risk of hydrocephalus. A periprocedural dual, intravenous, antiplatelet regimen with aspirin and a glycoprotein IIb/IIIa inhibitor was preferred as a standard approach. The panel agreed that intravenous medication can be converted to oral aspirin and an oral P2Y12 inhibitor within 24 hours after the procedure.

CONCLUSIONS

More and better data on antiplatelet management of patients with ruptured intracranial aneurysms undergoing stent-assisted coiling or flow diversion are urgently needed. Panel members in this DELPHI consensus study preferred a periprocedural dual-antiplatelet regimen with aspirin and a glycoprotein IIb/IIIa inhibitor.

Impact of forced-aging process on madeira wine flavor

The aim of this study was to determine the optimal temperature and baking time to obtain a Madeira wine considered typical by an expert panel. For this purpose simultaneous descriptive analyses of typical Madeira wines were performed, and seven descriptors were selected: "dried fruit", "nutty", "musty", "baked", "oak", "mushroom", and "brown sugar". Up to 10 odor-active zones were the most frequently cited by the members of the GC-olfactometry panel as corresponding to the panel's descriptors. The odor importance of each of the zones reported by the GC-O analysis was ranked by AEDA. Three odor zones were identified as common to both Malvasia and Sercial wines and had retention indices (RI) of 1993 ("brown sugar" and "toasted"), 2151 ("brown sugar"), and 2174 ("nutty", "dried fruits"); sotolon was identified as responsible for this last aroma. Several molecules were selected to be quantified on baked wines on the basis of AEDA results and expected Maillard volatiles, such as sotolon, furfural, 5-methylfurfural, 5-ethoximethylfurfural, methional, and phenylacetaldehyde. It was observed that typicity scores were positively correlated with the concentrations of sotolon and sugar and baking time and negatively with the fermentation length.

A review of selection-based tests of abiotic surrogates for species representation

Because conservation planners typically lack data on where species occur, environmental surrogates--including geophysical settings and climate types--have been used to prioritize sites within a planning area. We reviewed 622 evaluations of the effectiveness of abiotic surrogates in representing species in 19 study areas. Sites selected using abiotic surrogates represented more species than an equal number of randomly selected sites in 43% of tests (55% for plants) and on average improved on random selection of sites by about 8% (21% for plants). Environmental diversity (ED) (42% median improvement on random selection) and biotically informed clusters showed promising results and merit additional testing. We suggest 4 ways to improve performance of abiotic surrogates. First, analysts should consider a broad spectrum of candidate variables to define surrogates, including rarely used variables related to geographic separation, distance from coast, hydrology, and within-site abiotic diversity. Second, abiotic surrogates should be defined at fine thematic resolution. Third, sites (the landscape units prioritized within a planning area) should be small enough to ensure that surrogates reflect species' environments and to produce prioritizations that match the spatial resolution of conservation decisions. Fourth, if species inventories are available for some planning units, planners should define surrogates based on the abiotic variables that most influence species turnover in the planning area. Although species inventories increase the cost of using abiotic surrogates, a modest number of inventories could provide the data needed to select variables and evaluate surrogates. Additional tests of nonclimate abiotic surrogates are needed to evaluate the utility of conserving nature's stage as a strategy for conservation planning in the face of climate change.

Rarity-weighted richness: a simple and reliable alternative to integer programming and heuristic algorithms for minimum set and maximum coverage problems in conservation planning

Here we report that prioritizing sites in order of rarity-weighted richness (RWR) is a simple, reliable way to identify sites that represent all species in the fewest number of sites (minimum set problem) or to identify sites that represent the largest number of species within a given number of sites (maximum coverage problem). We compared the number of species represented in sites prioritized by RWR to numbers of species represented in sites prioritized by the Zonation software package for 11 datasets in which the size of individual planning units (sites) ranged from <1 ha to 2,500 km². On average, RWR solutions were more efficient than Zonation solutions. Integer programming remains the only guaranteed way find an optimal solution, and heuristic algorithms remain superior for conservation prioritizations that consider compactness and multiple near-optimal solutions in addition to species representation. But because RWR can be implemented easily and quickly in R or a spreadsheet, it is an attractive alternative to integer programming or heuristic algorithms in some conservation prioritization contexts.

Reconstruction of the right anterior circulation with the Pipeline embolization device to achieve treatment of a progressively symptomatic, large carotid aneurysm

INTRODUCTION

We present the use of the Pipeline embolization device (PED) to achieve reconstruction of the right anterior circulation in a patient with a dolichoectatic internal carotid artery (ICA) and middle cerebral artery (MCA) and an associated symptomatic, large, carotid-ophthalmic segment aneurysm.

CLINICAL PRESENTATION

A 36-year-old man presented with progressive right eye vision loss followed by sudden severe headache. Subsequent neuroimaging revealed a large right carotid-ophthalmic segment aneurysm and diffuse ectasia of the supraclinoid ICA and proximal MCA. A coil embolization of the aneurysm was performed without stent support. Over the next year, the patient experienced increasing headache and progressive bitemporal vision loss. Serial MRI showed progressive coil compaction and recanalization of the aneurysm.

TREATMENT

The right anterior circulation was reconstructed with a total of six PEDs that extended from the distal M1 segment of the MCA proximally into the distal cavernous segment of the ICA. Follow-up angiography at 1 and 4 months demonstrated progressive complete occlusion of the aneurysm and a reorganization of blood flow to the anterior cerebral and anterior choroidal arteries. MRI and radiographic imaging provided evidence of progressive contraction of the intra-aneurysmal thrombus. The patient's headaches resolved and serial visual field examinations have demonstrated gradual improvement after treatment.

CONCLUSION

Extensive cerebrovascular reconstructions that are not possible using commercially available endovascular devices can be achieved with Pipeline. The safety, efficacy and long term implications of such reconstructions are currently being defined.

Considerations for Antiplatelet Management of Carotid Stenting in the Setting of Mechanical Thrombectomy: A Delphi Consensus Statement

BACKGROUND AND PURPOSE

There are only few data and lack of consensus regarding antiplatelet management for carotid stent placement in the setting of endovascular stroke treatment. We aimed to develop a consensus-based algorithm for antiplatelet management in acute ischemic stroke patients undergoing endovascular treatment and simultaneous emergent carotid stent placement.

MATERIALS AND METHODS

We performed a literature search and a modified Delphi approach used Web-based questionnaires that were sent in several iterations to an international multidisciplinary panel of 19 neurointerventionalists from 7 countries. The first round included open-ended questions and formed the basis for subsequent rounds, in which closed-ended questions were used. Participants continuously received feedback on the results from previous rounds. Consensus was defined as agreement of ≥70% for binary questions and agreement of ≥50% for questions with >2 answer options. The results of the Delphi process were then summarized in a draft manuscript that was circulated among the panel members for feedback.

RESULTS

A total of 5 Delphi rounds were performed. Panel members preferred a single intravenous aspirin bolus or, in jurisdictions in which intravenous aspirin is not available, a glycoprotein IIb/IIIa receptor inhibitor as intraprocedural antiplatelet regimen and a combination therapy of oral aspirin and a P2Y12 inhibitor in the postprocedural period. There was no consensus on the role of platelet function testing in the postprocedural period.

CONCLUSIONS

More and better data on antiplatelet management for carotid stent placement in the setting of endovascular treatment are urgently needed. Panel members preferred intravenous aspirin or, alternatively, a glycoprotein IIb/IIIa receptor inhibitor as an intraprocedural antiplatelet agent, followed by a dual oral regimen of aspirin and a P2Y12 inhibitor in the postprocedural period.

Multicenter Postmarket Analysis of the Neuroform Atlas Stent for Stent-Assisted Coil Embolization of Intracranial Aneurysms

BACKGROUND AND PURPOSE

The Neuroform Atlas is a new microstent to assist coil embolization of intracranial aneurysms that recently gained FDA approval. We present a postmarket multicenter analysis of the Neuroform Atlas stent.

MATERIALS AND METHODS

On the basis of retrospective chart review from 11 academic centers, we analyzed patients treated with the Neuroform Atlas after FDA exemption from January 2018 to June 2019. Clinical and radiologic parameters included patient demographics, aneurysm characteristics, stent parameters, complications, and outcomes at discharge and last follow-up.

RESULTS

Overall, 128 aneurysms in 128 patients (median age, 62 years) were treated with 138 stents. Risk factors included smoking (59.4%), multiple aneurysms (27.3%), and family history of aneurysms (16.4%). Most patients were treated electively (93.7%), and 8 (6.3%) underwent treatment within 2 weeks of subarachnoid hemorrhage. Previous aneurysm treatment failure was present in 21% of cases. Wide-neck aneurysms (80.5%), small aneurysm size (<7 mm, 76.6%), and bifurcation aneurysm location (basilar apex, 28.9%; anterior communicating artery, 27.3%; and middle cerebral artery bifurcation, 12.5%) were common. A single stent was used in 92.2% of cases, and a single catheter for both stent placement and coiling was used in 59.4% of cases. Technical complications during stent deployment occurred in 4.7% of cases; symptomatic thromboembolic stroke, in 2.3%; and symptomatic hemorrhage, in 0.8%. Favorable Raymond grades (Raymond-Roy occlusion classification) I and II were achieved in 82.9% at discharge and 89.5% at last follow-up. mRS ≤2 was determined in 96.9% of patients at last follow-up. The immediate Raymond-Roy occlusion classification grade correlated with aneurysm location (P < .0001) and rupture status during treatment (P = .03).

CONCLUSIONS

This multicenter analysis provides a real-world safety and efficacy profile for the treatment of intracranial aneurysms with the Neuroform Atlas stent.

Potential changes in the distribution of Carnegiea gigantea under future scenarios

Over the last decades several studies have identified that the directional changes in climate induced by anthropogenic emissions of greenhouse gases are affecting the ecology of desert ecosystems. In the Southwest United States, the impacts of climate change to plant abundance and distribution have already been reported, including in the Sonoran Desert ecosystem, home of the iconic Saguaro (Carnegiea gigantea). Hence, there is an urgent need to assess the potential impacts of climate change on the saguaro. The goals of this study are to provide a map of actual habitat suitability (1), describe the relationships between abiotic predictors and the saguaro distribution at regional extents (2), and describe the potential effect of climate change on the spatial distribution of the saguaro (3). Species Distribution Modeling (SDM) was used to investigate the relationships between abiotic variables and the Saguaro distribution. SDMs were calibrated using presence records, 2,000 randomly-generated pseudo absences, and ten abiotic variables. Of these, annual precipitation and max temperature of the warmest month was found to have the greatest relative influence on saguaro distribution. SDMs indicated that 6.9% and 8.1% of the current suitable habitat is predicted to be lost by 2050 and 2070, respectively. Therefore, predicted changes in climate may result in a substantial contraction of the suitable habitat for saguaro over the next century. By identifying the drivers of saguaro distribution and assessing potential changes in habitat suitability due to climate change, this study will help practitioners to design more comprehensive strategies to conserve the saguaro in the face of climate change.

Using abiotic variables to predict importance of sites for species representation

In systematic conservation planning, species distribution data for all sites in a planning area are used to prioritize each site in terms of the site's importance toward meeting the goal of species representation. But comprehensive species data are not available in most planning areas and would be expensive to acquire. As a shortcut, ecologists use surrogates, such as occurrences of birds or another well-surveyed taxon, or land types defined from remotely sensed data, in the hope that sites that represent the surrogates also represent biodiversity. Unfortunately, surrogates have not performed reliably. We propose a new type of surrogate, predicted importance, that can be developed from species data for a q% subset of sites. With species data from this subset of sites, importance can be modeled as a function of abiotic variables available at no charge for all terrestrial areas on Earth. Predicted importance can then be used as a surrogate to prioritize all sites. We tested this surrogate with 8 sets of species data. For each data set, we used a q% subset of sites to model importance as a function of abiotic variables, used the resulting function to predict importance for all sites, and evaluated the number of species in the sites with highest predicted importance. Sites with the highest predicted importance represented species efficiently for all data sets when q = 25% and for 7 of 8 data sets when q = 20%. Predicted importance requires less survey effort than direct selection for species representation and meets representation goals well compared with other surrogates currently in use. This less expensive surrogate may be useful in those areas of the world that need it most, namely tropical regions with the highest biodiversity, greatest biodiversity loss, most severe lack of inventory data, and poorly developed protected area networks.

Heads-up intraoperative endoscopic imaging: a prospective evaluation of techniques and limitations

OBJECTIVE

Endoscopes have been used adjunctively for spinal and cranial microsurgical procedures and directly for ventricular exploration, fenestration, and catheterization. Technological advances now allow for multi-imaging technologies, including a so-called "heads-up display," allowing the surgeon to view the operative field and the endoscopic image simultaneously.

INSTRUMENTATION

A high-resolution, active matrix liquid crystal display is built into the frame of the eyewear, with a display density of 182,000 pixels (280 x 650 pixels) and a resolution of 200 lines. The display occupies approximately 20% of the visual field. The headgear weighs 4 oz, with dimensions of 9 x 18 x 17 cm. The modular interface weighs 7 oz. Two different visualization systems can be used. The first uses a single integrated interface (IM 300), whereas the second (remote 900) is a 900-MHz frequency modulation wireless system that provides for a line-of-sight link between the NTSC source and the modular interface (range = 100 ft).

RESULTS

Heads-up adjunctive endoscopy was used in 60 patients during 18 months. The procedures included 16 craniotomies, 1 intradural lumbar biopsy, and 42 ventriculoperitoneal shunt placements. Follow-up was obtained at a minimum of 1 year. Patient age ranged from 1 month to 58 years. The only complication was a transient loss of auditory evoked potentials after contact of the eighth nerve by the endoscope.

CONCLUSION

We describe a portable, light-weight heads-up display imaging system, which we have used in 60 operative procedures. Benefits of the heads-up system include portability and a high-resolution digital monocular image, which reduces eye strain and vertigo. The ideal headgear will likely be an extremely high-resolution liquid crystal display-based or cathode ray tube-based semi-immersive system, with all of the benefits currently described for two-dimensional heads-up systems (i.e., light weight, portability, image quality, and the avoidance of complications associated with immersive systems).

Frequency of intra-abdominal injury in cases of blunt trauma to the cervical spinal cord

Historically, early management of the blunt trauma victim with hemodynamic instability and cervical spinal cord injury has been hampered by the physician's inability to perform an accurate physical examination. Invasive and time-consuming diagnostic tests are often run to check for the presence of occult intra-abdominal injuries. For this reason, we decided to study these patients by reviewing a clinical registry to assess the frequency of intra-abdominal injuries in cases of cervical spinal cord trauma. We hypothesized that intra-abdominal injury would occur infrequently in cases of blunt trauma to the cervical spinal cord. In fact, data from the Maryland Institute for Emergency Medical Services Systems revealed that blunt trauma victims with cervical cord injury rarely (2.6%) sustained intra-abdominal wounds. Further analysis of this population revealed that specific mechanisms of trauma and the presence of hemodynamic instability and other major injuries were factors strongly associated with occult intra-abdominal injury. In light of these findings, we have outlined a protocol for management of these patients that is geared toward more rapid stabilization of the injured spinal column.

Improving the use of environmental diversity as a surrogate for species representation

The continuous p‐median approach to environmental diversity (ED) is a reliable way to identify sites that efficiently represent species. A recently developed maximum dispersion (maxdisp) approach to ED is computationally simpler, does not require the user to reduce environmental space to two dimensions, and performed better than continuous p‐median for datasets of South African animals. We tested whether maxdisp performs as well as continuous p‐median for 12 datasets that included plants and other continents, and whether particular types of environmental variables produced consistently better models of ED. We selected 12 species inventories and atlases to span a broad range of taxa (plants, birds, mammals, reptiles, and amphibians), spatial extents, and resolutions. For each dataset, we used continuous p‐median ED and maxdisp ED in combination with five sets of environmental variables (five combinations of temperature, precipitation, insolation, NDVI, and topographic variables) to select environmentally diverse sites. We used the species accumulation index (SAI) to evaluate the efficiency of ED in representing species for each approach and set of environmental variables. Maxdisp ED represented species better than continuous p‐median ED in five of 12 biodiversity datasets, and about the same for the other seven biodiversity datasets. Efficiency of ED also varied with type of variables used to define environmental space, but no particular combination of variables consistently performed best. We conclude that maxdisp ED performs at least as well as continuous p‐median ED, and has the advantage of faster and simpler computation. Surprisingly, using all 38 environmental variables was not consistently better than using subsets of variables, nor did any subset emerge as consistently best or worst; further work is needed to identify the best variables to define environmental space. Results can help ecologists and conservationists select sites for species representation and assist in conservation planning.

Projected climate change threatens significant range contraction of Cochemiea halei (Cactaceae), an island endemic, serpentine-adapted plant species at risk of extinction

AIM

Threats faced by narrowly distributed endemic plant species in the face of the Earth's sixth mass extinction and climate change exposure are especially severe for taxa on islands. We investigated the current and projected distribution and range changes of Cochemiea halei, an endemic island cactus. This taxon is of conservation concern, currently listed as vulnerable on the International Union for the Conservation of Nature Red List and as a species of special concern under Mexican federal law. The goals of this study are to (a) identify the correlations between climate variables and current suitable habitat for C. halei; (b) determine whether the species is a serpentine endemic or has a facultative relationship with ultramafic soils; and (c) predict range changes of the species based on climate change scenarios.

LOCATION

The island archipelago in Bahía Magdalena on the Pacific coast, Baja California Sur, Mexico.

METHODS

We used temperature and precipitation variables at 30-arc second resolution and soil type, employing multiple species distribution modeling methods, to identify important climate and soil conditions driving current habitat suitability. The best model of current suitability is used to predict possible effects of four climate change scenarios based on best-case to worst-case representative concentration pathways, with projected climate data from two general circulation models, over two time periods.

MAIN CONCLUSIONS

The occurrence of the species is found to be strongly correlated with ultramafic soils. The most important climate predictor for habitat suitability is annual temperature range. The species is predicted to undergo range contractions from 21% to 53%, depending on the severity and duration of exposure to climate change. The broader implications for a wide range of narrowly adapted, threatened, and endemic plant species indicate an urgent need for threat assessment based on habitat suitability and climate change modeling.

A test of Conserving Nature's Stage: protecting a diversity of geophysical traits can also support a diversity of species at a landscape scale

Conserving Nature's Stage (CNS) is a concept from conservation planning that promotes the protection of areas encompassing a broad range of enduring geophysical traits to provide long-term habitat for diverse species. The efficacy of using enduring geophysical characteristics as surrogates for biodiversity, independent of non-geophysical features and when considering finer resolution area selections, has yet to be investigated. Here, we evaluated CNS using 33 fine-scale inventories of vascular plant, non-vascular plant, invertebrate or vertebrate species from 13 areas across three continents. For each inventory, we estimated a continuous multidimensional surrogate defined from topographic and soil estimates of the surveyed plots. We assessed surrogate effectiveness by comparing the species representation of surrogate selected plots to the representation from plots picked randomly and using species information. We then used correlation coefficients to assess the link between the performance and qualities of the inventories, surroundings and surrogates. The CNS surrogate showed positive performance for 24 of the 33 inventories, and among these tests, represented 28 more species than random and 83% of the total number of species on average. We also found a small number of weak correlations between performance and environmental variability, as well as qualities of the surrogate. Our study demonstrates that prioritizing areas for a variety of geophysical characteristics will, in most cases, promote the representation of species. Our findings also point to areas for future research that might enhance CNS surrogacy. This article is part of the Theo Murphy meeting issue 'Geodiversity for science and society'.

Incorporating coronary calcification into pretest assessment of the likelihood of coronary artery disease: validation and recalibration of a new diagnostic tool

Funding Acknowledgements

Type of funding sources: None.

Background

A new clinical tool was recently proposed to improve the estimation of pre-test probability of obstructive coronary artery disease (CAD) by incorporating coronary artery calcium score (CACS) with clinical risk factors. This new model (Clinical + CACS) showed improved prediction when compared to the method recommended by the 2019 ESC guidelines on chronic coronary syndromes, but was never tested or adjusted for use in our population. The aim of this study was to assess the performance of this new method in a Portuguese cohort of symptomatic patients referred for coronary computed tomography angiography (CCTA), and to recalibrate it if necessary.

Methods

We conducted a two-center cross-sectional study assessing symptomatic patients who underwent CCTA for suspected CAD. Key exclusion criteria were age &lt; 30 years, known CAD, suspected acute coronary syndrome, or symptoms other than chest pain or dyspnea. Obstructive CAD was defined as any luminal stenosis ≥50% on CCTA. The Clinical + CACS prediction model was assessed for discrimination and calibration. A logistical recalibration of the model was conducted in a random sample of 50% of the patients and subsequently validated in the other half.

Results

A total of 1910 patients (mean age 60 ± 11 years, 60% women) were included in the analysis. Symptom characteristics were: 39% non-anginal chest pain, 30% atypical angina, 19% dyspnea and 12% typical angina. The observed prevalence of obstructive CAD was 12.9% (n = 247). Patients with obstructive CAD were more often male, were significantly older, had higher prevalence of typical angina and cardiovascular risk factors, and higher CACS values. The new Clinical + CACS tool showed greater discriminative power than the ESC 2019 prediction model, with a C-statistic of 0.83 (CI 95% 0.81-0.86) versus 0.67 (CI 95% 0.64-0.71), respectively (p-value for comparison &lt; 0.001). Before recalibration, the Clinical + CACS model underestimated the likelihood of CAD in our population across all quartiles of pretest probability (mean relative underestimation of 49%), which was subsequently corrected by the recalibration procedure - Figure.

Conclusions

In a Portuguese cohort of symptomatic patients undergoing CCTA for suspected CAD, the new Clinical + CACS model showed better discrimination power than the 2019 ESC method. The underestimation of the Clinical + CACS model was corrected by recalibrating it for our population. This new tool might prove useful for guiding decisions on the need for further testing.

Coronary artery calcium score to predict coronary CT angiography interpretability: an old problem revisited

Funding Acknowledgements

Type of funding sources: None.

Introduction

Clinical guidelines recommend against the use of coronary computed tomography angiography (CCTA) in patients with heavy calcification due to interpretability concerns, but no specific approach or threshold is provided. Recently, alternative methods have been proposed as more reliable predictors of CCTA interpretability than the classic coronary artery calcium score (CACS).  The purpose this study was to compare the performance of different measures of coronary calcification as predictors of CCTA interpretability.

Methods

We conducted a retrospective analysis of consecutive patients undergoing CACS and CCTA between 2018 and 2020. The key exclusion criteria were known coronary artery disease, CACS of zero, and presence of non-assessable coronary lesions for reasons other than calcification (movement/gating artifacts or vessel diameter &lt; 2mm). CCTA studies were considered non-interpretable if the main reader considered one or more coronary lesions non-assessable due to calcification. Three different measures of coronary calcification were compared using ROC curve analysis: 1) total CACS; 2) CACS-to-lesion ratio (total CACS divided by the number of calcified plaques); and 3) calcium score of the most calcified plaque. Decision-tree analysis was performed to identify the algorithm that best predicts CCTA interpretability.

Results

A total of 432 patients (191 women, mean age 64 ± 11 years) were included. Overall, 31 patients (7.2%) had a non-interpretable CCTA due to calcification. Patients with non-interpretable CCTA had higher CACS (median 589 vs. 50 AU, p &lt; 0.001), higher CACS-to-lesion ratio (median 43 vs. 14 AU/lesion, p &lt; 0.001), and higher score of the most calcified plaque (median 445 vs. 43 AU, p &lt; 0.001). Among the 3 methods, CACS showed the highest discriminative power to predict a non-interpretable CCTA (C-statistic 0.93, 95%CI 0.89-0.95, p &lt; 0.001) - Figure.

Decision-tree analysis identified a single-variable algorithm (CACS value ≤ 515 AU) as the best discriminator of CCTA interpretability: 396 of the 409 patients (97%) with CACS ≤ 515 AU had an interpretable CCTA, whereas only 5 of the 23 patients (22%) with CACS &gt; 515 AU had an interpretable test, yielding a total of 96% correct predictions.

Conclusions

The recently proposed and more complex measures of coronary calcification seem unable to outperform total CACS as a predictor of CCTA interpretability. A simple CACS cutoff-value around 500 AU remains the best discriminator for this purpose.

Patterns of revascularization in stable ischemic heart disease in the pre-ISCHEMIA era

Introduction

New evidence on the role of myocardial revascularization in stable ischemic heart disease (SIHD), recently presented, showed that revascularization guided by the presence of moderate-to severe ischemia relieves angina more effectively than optimal medical therapy (OMT), without a significant benefit in hard clinical endpoints.

Aim

To assess the representativeness of the ISCHEMIA trial in a real-world population and compare management strategies between patients who fulfill the eligibility criteria of the trial (Group 1, G1) and those who do not (Group 2, G2).

Methods and population

Single centre retrospective analysis including all consecutive patients referred to coronary angiography (CA) for SIHD from January 2018 to December 2019. Patients were stratified in two groups (G1 and G2) according to the ISCHEMIA trial inclusion and exclusion criteria. G1 was compared with G2 and with a subset of G2 with obstructive coronary artery disease (CAD), defined as ≥70% luminal stenosis in at least one coronary artery or &gt;50% for the left main.

Results

A total of 1020 patients underwent CA, of whom only 124 (12.2%) would have been eligible for the ISCHEMIA trial (G1). Overall, there were no significant differences in baseline characteristics between the two groups. G1 patients had more extensive and severe disease, presenting more frequently with proximal left anterior descending (LAD) involvement (26.6% vs 10.4%; p&lt;0.001), two vessel disease without proximal LAD stenosis (23.4% vs 10.3%; p&lt;0.001) and three vessel disease (18.5% vs 5.9%; p&lt;0.001). These patients had higher rates of revascularization, both CABG (25.8% vs 10.8%, p&lt;0.001) and PCI (56.5% vs 39.5%, p&lt;0.001). However, when comparing G1 with the subset of G2 patients with obstructive CAD, G1 patients had higher rates of CABG (26.8% vs 17.8%, p=0.034) but there were no differences on the rates of PCI (58.0% vs 56.9%, p=0.916).

Conclusions

Patients included in the ISCHEMIA trial are underrepresented in a real-world population of SIHD patients referred to coronary angiography. PCI rates were similar among patients with at least one significant coronary artery stenosis, regardless of previous evidence or severity of ischemia. Our findings underline the need for further refinement in criteria for revascularization in SIHD.

Funding Acknowledgement

Type of funding source: None

Peri-procedural, 30-day and 1 year-outcomes in chronic dialysis patients undergoing transcatheter aortic valve implantation

Background

Patients on chronic dialysis (CD) due to end-stage renal disease (ESRD) with symptomatic severe aortic stenosis eligible for transcatheter aortic valve implantation (TAVI) were excluded from randomized clinical trials. Our study aimed to investigate the outcomes of patients with chronic dialysis who underwent TAVI.

Methods

Single center analysis on prospectively collected data of all consecutive patients who underwent TAVI between January 2011 and December 2020 according to baseline renal function: chronic dialysis group (CD) and control group (CTRL). Procedural, 30-day and 1-year outcomes were assessed. Outcomes were defined in accordance with the VARC-3 criteria.

Results

A total of 875 patients underwent TAVI during the study period, of whom 22 (2.5%) were on chronic dialysis. Patients on CD were younger (median age 80 years, [IQR 73–84] vs 84 years, [IQR 80–87]; p&lt;0.001), more likely to be men [365/863 (42.8%) vs 18/22 (81.8%); p&lt;0.001] and more likely to have peripheral vascular disease [41/853 (4.8%) vs 7/22 (31.8%); p=0.031] and lower body mass index (median 24.1 kg/m2, [IQR 21.5–26.5] vs 26.3 kg/m2, [IQR 23.7–29.3]). Short-term major or life-threatening bleeding were significantly higher in CD patients (odds ratio [95% confidential interval]: 3.67 [1.50–8.96], p 0.005). In contrast, no differences were found regarding rates of vascular complications requiring intervention (OR [95% CI]: 1.35 [0.31–5.90], p=0.662), permanent pacemaker implantation (OR [95% CI]: 0.87 [0.25–2.98], p=1.000) or stroke (OR [95% CI]: 1.51 [0.20–11.64], p=0.504). Importantly, dialysis patients had significantly higher rates of in-hospital, 30-day and 1-year mortality rates (13.6 vs 2.1%, p&lt;0.001; 18.9% vs 2.9, p&lt;0.001 and 26.4% vs 10.7%, p&lt;0.001, respectively). On multivariate analysis, after adjusting for age, gender, relevant co-morbidities, and procedure-related complications, CD remained independently associated with mortality at 1-year. Survival curves during follow up are presented in Figure 1.

Conclusions

Chronic dialysis patients submitted to TAVI had significantly higher rates of short-term life threatening and/or major bleeding, short-term and long-term mortality. Careful selection of patients who would benefit from TAVI among patients with ERDS requiring dialysis is necessary to prevent high rates of postprocedural complications and improve outcomes of this high-risk population.

Funding Acknowledgement

Type of funding sources: None.

Validation of a novel framework defining the acceptable standard of care for heart failure with reduced ejection fraction

Background

In heart failure with reduced ejection fraction (HFrEF), uptitration of neurohormonal antagonists to trial-proven doses shown to reduce mortality is challenging and seldomly achieved in clinical practice. A major reason for underdosing of these agents is the lack of a clear description of what constitutes an acceptable standard of care in HFrEF. To address this limitation, a novel framework for describing the physician adherence to evidence-based treatment was recently proposed. The aim of our study was to evaluate and validate the proposed framework in a real-world population of patients with HFrEF.

Methods

A cohort of patients with HFrEF, defined as left ventricular ejection fraction (LVEF) &lt;40%, under treatment with neurohormonal antagonists for at least 3 months were retrospectively identified at a tertiary hospital's Heart Failure Clinic. Demographic, clinical, echocardiographic and treatment data were assessed. Patients were divided in three strata for each neurohormonal antagonist, according to the proposed framework: Status I – patients receiving target doses or the highest tolerated dose; Status II – use of subtarget doses for reasons unrelated to clinically important intolerance; and Status III – not receiving the drug at any dose. The prognostic value of each strata was assessed for all-cause mortality.

Results

A total of 408 patients (mean age 68±12 years, 78% male, 63% ischemic etiology) were included. The median LVEF was 31% (IQR 25–36) and most patients were in NYHA class II or III [210 (51.5%) and 163 (40%), respectively]. Medical therapy is described in Table 1. During a median follow-up of 3.3 years (IQR 1.4–5.6), 210 patients died. On univariable analysis, achieving Status I of beta-blocker (BB) therapy (HR: 0.50; 95% CI: 0.32–0.81; P=0.004) or ACEi/ARB (HR: 0.56; 95% CI: 0.36–0.86; P=0.012) was associated with reduced all-cause mortality. The mortality of patients in Status II of BB or ACEi/ARB was similar to the mortality of those not receiving the drug (HR for BB: 0.90; 95% CI: 0.53–1.52; P=0.69 and HR for ACEi/ARB: 0.71; 95% CI: 0.42–1.18; P=0.182) – figure 1. Achieving Status I of BB remained independently associated with reduced mortality after adjustment for several clinical and echocardiographic confounders (n=13) (adjusted HR: 0.59; 95% CI: 0.35–0.98; P=0.041).

Conclusions

In this real-world population of patients with HFrEF, the vast majority of patients were in Status I of BB and ACEi/ARB therapy. Achieving Status I of BB therapy seems to be associated with reduced mortality, even after adjustment for several markers of disease severity, highlighting the need for uptitration of medical therapy to maximal tolerated doses according to trial-proven regimens.

Funding Acknowledgement

Type of funding sources: None.