Postprocedural Antiplatelet Treatment after Emergent Carotid Stenting in Tandem Lesions Stroke: Impact on Stent Patency beyond Day 1

BACKGROUND AND PURPOSE:Postprocedural dual-antiplatelet therapy is frequently withheld after emergent carotid stent placement during stroke thrombectomy. We aimed to assess whether antiplatelet regimen variations increase the risk of stent thrombosis beyond postprocedural day 1.MATERIALS AND METHODS:Retrospective review was undertaken of all consecutive thrombectomies for acute stroke with tandem lesions in the anterior circulation performed in a single comprehensive stroke center between January 9, 2011 and March 30, 2020. Patients were included if carotid stent patency was confirmed at day 1 postprocedure. The group of patients with continuous dual-antiplatelet therapy from day 1 was compared with the group of patients with absent/discontinued dual-antiplatelet therapy.RESULTS:Of a total of 109 tandem lesion thrombectomies, 96 patients had patent carotid stents at the end of the procedure. The early postprocedural stent thrombosis rate during the first 24 hours was 14/96 (14.5%). Of 82 patients with patent stents at day 1, in 28 (34.1%), dual-antiplatelet therapy was either not initiated at day 1 or was discontinued thereafter. After exclusion of cases without further controls of stent patency, there was no significant difference in the rate of subacute/late stent thrombosis between the 2 groups: 1/50 (2%) in patients with continuous dual-antiplatelet therapy versus 0/22 (0%) in patients with absent/discontinued dual-antiplatelet therapy (P = 1.000). In total, we observed 88 patient days without any antiplatelet treatment and 471 patient days with single antiplatelet treatment.CONCLUSIONS:Discontinuation of dual-antiplatelet therapy was not associated with an increased risk of stent thrombosis beyond postprocedural day 1. Further studies are warranted to better assess the additional benefit and optimal duration of dual-antiplatelet therapy after tandem lesion stroke thrombectomy.

In around 15% of endovascular procedures for anterior circulation stroke,¹ there is a tight stenosis or occlusion of the cervical carotid artery in addition to the intracranial artery occlusion. The optimal endovascular management of tandem lesions has yet to be defined; however, there is mounting evidence^2,3 that emergent stent placement in the carotid artery associated with at least 1 antiplatelet agent could lead to better recanalization rates and improved clinical outcomes. A more definitive answer should be provided by the Thrombectomy In TANdem lesions (TITAN) randomized multicenter trial,⁴ designed to assess the safety and efficacy of emergent internal carotid artery stent placement in tandem lesion thrombectomy. This study recently enrolled the first patient in early 2020.In patients undergoing emergent carotid stent placement, there is no consensus regarding the optimal periprocedural antiplatelet therapy. Many groups^5,6 chose to avoid dual-antiplatelet therapy (DAPT) during the first 24 hours in an attempt to reduce the risk of hemorrhagic transformation. Conversely, less aggressive antiplatelet regimens might increase the risk of carotid stent thrombosis.Stent thrombosis was recently identified as a predictor of unfavorable clinical outcome.^7,8 To date, available data regarding stent patency rates remain scarce. Most case series of endovascular management for tandem lesions^5,9-11 do not report postprocedural stent patency, while some publications^12-15 offer partial data for a subgroup of patients for whom carotid imaging controls were available. Reported rates of stent thrombosis ranged between 1.2% and 22.0%.^{6-8,12-14,16,17}To date, no study has attempted to differentiate between early (first 24 hours) and subacute/late postprocedural stent thrombosis. During the first 24 hours, protection against stent thrombosis is conferred by antiplatelet agents administered during the procedure (periprocedural antiplatelets). Beyond 24 hours, the recommended antiplatelet regimen is DAPT for 4–12 weeks,^9,17 but in reality, antiplatelets are often tailored in view of neurological and extra-neurological hemorrhagic events. It is currently unknown whether discontinuation of DAPT is associated with an increased risk of late stent thrombosis.Thus, we aimed to describe the variations in the postprocedural antiplatelet regimen in a large consecutive cohort of tandem lesion thrombectomies with emergent carotid artery stent placement and to assess whether discontinuation of DAPT was associated with an increased risk of carotid stent thrombosis.     

Anatomic Snuffbox (Distal Radial Artery) and Radial Artery Access for Treatment of Intracranial Aneurysms with FDA-Approved Flow Diverters

BACKGROUND AND PURPOSE:Transradial access for neurointerventional procedures has been proved a safer and more comfortable alternative to femoral artery access. We present our experience with transradial (distal radial/anatomic snuffbox and radial artery) access for treatment of intracranial aneurysms using all 3 FDA-approved flow diverters.MATERIALS AND METHODS:This was a high-volume, dual-center, retrospective analysis of each institution’s data base between June 2018 and June 2020 and a collection of all patients treated with flow diversion via transradial access. Patient demographic information and procedural and radiographic data were obtained.RESULTS:Seventy-four patients were identified (64 female patients) with a mean age of 57.5 years with a total of 86 aneurysms. Most aneurysms were located in the anterior circulation (93%) and within the intracranial ICA (67.4%). The mean aneurysm size was 5.5 mm. Flow diverters placed included the Pipeline Embolization Device (Flex) (PED, n = 65), the Surpass Streamline Flow Diverter (n = 8), and the Flow-Redirection Endoluminal Device (FRED, n = 1). Transradial access was successful in all cases, but femoral crossover was required in 3 cases (4.1%) due to tortuous anatomy and inadequate support of the catheters in 2 cases and an inability to navigate to the target vessel in a patient with an aberrant right subclavian artery. All 71 other interventions were successfully performed via the transradial approach (95.9%). No access site complications were encountered. Asymptomatic radial artery occlusion was encountered in 1 case (3.7%).CONCLUSIONS:Flow diverters can be successfully placed via the transradial approach with high technical success, low access site complications, and a low femoral crossover rate.

The transradial access (TRA), including distal radial artery (dRA) access in the anatomic snuffbox and radial artery (RA) access at the palmar surface of the wrist, is being increasingly used as primary vascular access for neurointerventional procedures. In prior years, large randomized trials in the field of interventional cardiology and more recent articles in neurointerventional surgery have shown higher patient preference for the TRA, cost reduction, as well as lower morbidity and mortality compared with the traditional transfemoral access (TFA).^1-11 Reduction in access site complications has been a particular advantage of wrist over femoral access and is an important consideration for vascular access choice in the treatment of intracranial aneurysms using flow diversion. Patients undergoing flow diversion are required to take dual-antiplatelet agents and receive heparin during the procedure, all of which increase the risk of bleeding from the access site.¹² Also, flow diverters (FDs) may require large-bore catheter assemblies for delivery and deployment, which may increase the risk of radial artery occlusion, access site bleeding, or vascular injury.^13,14To date, only a limited number of case reports and case series have described the safety and feasibility of TRA for the treatment of intracranial aneurysms using flow diverters.^15-22Recently, a large, retrospective multicenter study reported the safety of TRA for flow diversion, showing a lower access site (P = .039) and overall complication rate (P = .035).¹² This study, however, did not cover catheter systems, patient functional outcome, and aneurysm occlusion. Here, we report our experience with TRA (dRA [anatomic snuffbox] and RA) for the treatment of intracranial aneurysms using all 3 FDA-approved flow diverters, including technical feasibility, procedural safety, patient outcome, and aneurysm occlusion on follow-up. Additionally, we reviewed the current literature on use of flow diverters via TRA.     

Analysis of Stroke Detection during the COVID-19 Pandemic Using Natural Language Processing of Radiology Reports

BACKGROUND AND PURPOSE:The coronavirus disease 2019 (COVID-19) pandemic has led to decreases in neuroimaging volume. Our aim was to quantify the change in acute or subacute ischemic strokes detected on CT or MR imaging during the pandemic using natural language processing of radiology reports.MATERIALS AND METHODS:We retrospectively analyzed 32,555 radiology reports from brain CTs and MRIs from a comprehensive stroke center, performed from March 1 to April 30 each year from 2017 to 2020, involving 20,414 unique patients. To detect acute or subacute ischemic stroke in free-text reports, we trained a random forest natural language processing classifier using 1987 randomly sampled radiology reports with manual annotation. Natural language processing classifier generalizability was evaluated using 1974 imaging reports from an external dataset.RESULTS:The natural language processing classifier achieved a 5-fold cross-validation classification accuracy of 0.97 and an F1 score of 0.74, with a slight underestimation (−5%) of actual numbers of acute or subacute ischemic strokes in cross-validation. Importantly, cross-validation performance stratified by year was similar. Applying the classifier to the complete study cohort, we found an estimated 24% decrease in patients with acute or subacute ischemic strokes reported on CT or MR imaging from March to April 2020 compared with the average from those months in 2017–2019. Among patients with stroke-related order indications, the estimated proportion who underwent neuroimaging with acute or subacute ischemic stroke detection significantly increased from 16% during 2017–2019 to 21% in 2020 (P = .01). The natural language processing classifier performed worse on external data.CONCLUSIONS:Acute or subacute ischemic stroke cases detected by neuroimaging decreased during the COVID-19 pandemic, though a higher proportion of studies ordered for stroke were positive for acute or subacute ischemic strokes. Natural language processing approaches can help automatically track acute or subacute ischemic stroke numbers for epidemiologic studies, though local classifier training is important due to radiologist reporting style differences.

There is much concern regarding the impact of the coronavirus disease 2019 (COVID-19) pandemic on the quality of stroke care, including issues with hospital capacity, clinical resource re-allocation, and the safety of patients and clinicians.^1,2 Previous reports have shown that there have been substantial decreases in stroke neuroimaging volume during the pandemic.^3,4 In addition, acute ischemic infarcts have been found on neuroimaging studies in many hospitalized patients with COVID-19, though the causal relationship is unclear.^5,6 Studies like these and other epidemiologic analyses usually rely on the creation of manually curated databases, in which identification of cases can be time-consuming and difficult to update in real-time. One way to facilitate such research is to use natural language processing (NLP), which has shown utility for automated analysis of radiology report data.⁷ NLP algorithms have been developed previously for the classification of neuroradiology reports for the presence of ischemic stroke findings and acute ischemic stroke subtypes.^8,9 Thus, NLP has the potential to facilitate COVID-19 research.In this study, we developed an NLP machine learning model that classifies radiology reports for the presence or absence of acute or subacute ischemic stroke (ASIS), as opposed to chronic stroke. We used this model to quantify the change in ASIS detected on all CT or MR imaging studies performed at a large comprehensive stroke center during the COVID-19 pandemic in the United States. We also evaluated NLP model generalizability and different training strategies using a sample of radiology reports from a second stroke center.     

Mind the gap: Teachers’ conceptions of student-staff partnership and its potential to enhance educational quality

Abstract

Introduction: Student-staff partnerships as a concept to improve medical education have received a growing amount of attention. Such partnerships are collaborations in which students and teachers seek to improve education by each adding their unique contribution to decision-making and implementation processes. Although previous research has demonstrated that students are favourable to this concept, teachers remain hesitant. The present study investigated teachers’ conceptions of student-staff partnerships and of the prerequisites that are necessary to render such partnerships successful and enhance educational quality.

Method: We conducted semi-structured interviews with 14 course coordinators who lead course design teams and also teach in 4 bachelor health programmes, using Bovill and Bulley’s levels of student participation as sensitising concepts during data analysis.

Results: The results pointed to three different conceptions of student-staff partnerships existing among teachers: Teachers teach and students study; teachers teach and value students’ feedback; and teachers and students co-create. The prerequisites for effective co-creation teachers identified were: Teachers must be open to involve students and create dialogues; students must be motivated and have good communication skills; the organisation must be supportive; and teachers should have the final say.

Conclusion: We conclude that teachers’ conceptions are consistent with Bovill and Bulley’s levels of student participation. Under certain conditions, teachers are willing to co-create and reach the highest levels of student participation.     

Fifty shades of graft: How to improve the efficacy of faecal microbiota transplantation for decolonization of antibiotic-resistant bacteria

Background

Spontaneous decolonization of antibiotic-resistant bacteria (ARB) takes time: approximately 25% after 30 days for carbapenem-producing Enterobacteriaceae or extended-spectrum beta-lactamase-producing Enterobacteriaceae. Faecal microbiota transplantation (FMT) has been proposed as a new strategy to promote decolonization in order to reduce the risk of superinfection due to these ARB. This paper discusses the literature on the use of FMT for this indication, and the improvement levers available to promote its efficacy.

Managing invasive aspergillosis in haematological patients in the era of resistance polymerase chain reaction and increasing triazole resistance: A modelling study of different strategies

Objectives

Triazole resistance in Aspergillus spp. is emerging and complicates prophylaxis and treatment of invasive aspergillosis (IA) worldwide. New polymerase chain reaction (PCR) tests on broncho-alveolar lavage (BAL) fluid allow for detection of triazole resistance at a genetic level, which has opened up new possibilities for targeted therapy. In the absence of clinical trials, a modelling study delivers estimates of the added value of resistance detection with PCR, and which empiric therapy would be optimal when local resistance rates are known.

Does ablation of atrial fibrillation at the time of septal myectomy improve survival of patients with obstructive hypertrophic cardiomyopathy?

ObjectiveTo evaluate the outcomes after septal myectomy in patients with obstructive hypertrophic cardiomyopathy according to atrial fibrillation and surgical ablation of atrial fibrillation.MethodsWe reviewed patients with obstructive hypertrophic cardiomyopathy who underwent septal myectomy at the Mayo Clinic from 2001 to 2016. History of atrial fibrillation was obtained from patient histories and electrocardiograms. All-cause mortality was the primary end point.ResultsA total of 2023 patients underwent septal myectomy, of whom 394 (19.5%) had at least 1 episode of atrial fibrillation preoperatively. Among patients with atrial fibrillation, 76 (19.3%) had only 1 known episode, 278 (70.6%) had recurrent paroxysmal atrial fibrillation, and 40 (10.2%) had persistent atrial fibrillation. Surgical ablation was performed in 190 patients at the time of septal myectomy, including 148 with pulmonary vein isolation and 42 with the classic maze procedure. Among all patients, operative mortality was 0.4%, and there were no early deaths in patients undergoing surgical ablation. Over a median follow-up of 5.6 years, patients with preoperative atrial fibrillation had increased mortality (hazard ratio, 1.36; 95% confidence interval, 0.97-1.91; P = .070) after multivariable adjustment for comorbidities. When considering the impact of atrial fibrillation with or without surgical treatment, the adjusted hazard ratio for mortality in patients undergoing ablation compared with no ablation was 0.93 (95% confidence interval, 0.52-1.69; P = .824).ConclusionsAtrial fibrillation is present preoperatively in one-fifth of patients with obstructive hypertrophic cardiomyopathy undergoing myectomy and showed a trend toward higher all-cause mortality. Survival of patients undergoing septal myectomy with preoperative atrial fibrillation was similar between those who did and did not receive concomitant surgical ablation.     

Comparison of Patch Materials for Pulmonary Artery Reconstruction

Graphical abstract summarizing the overall results of our study comparing reintervention for a main or central branch pulmonary artery reconstruction site and various patch materials. Autologous pericardium was associate with the lowest reintervention and was free. Multivariable analysis demonstrated lack of superiority of homograft branch patch, which clearly has a much higher cost.

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Novel Risk Factors for Progression of Diabetic and Nondiabetic CKD: Findings From the Chronic Renal Insufficiency Cohort (CRIC) Study

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