Appropriate inclusion of interactions was needed to avoid bias in multiple imputation

OBJECTIVE: Missing data are a pervasive problem, often leading to bias in complete records analysis (CRA). Multiple imputation (MI) via chained equations is one solution, but its use in the presence of interactions is not straightforward. STUDY DESIGN AND SETTING: We simulated data with outcome Y dependent on binary explanatory variables X and Z and their interaction XZ. Six scenarios were simulated (Y continuous and binary, each with no interaction, a weak and a strong interaction), under five missing data mechanisms. We use directed acyclic graphs to identify when CRA and MI would each be unbiased. We evaluate the performance of CRA, MI without interactions, MI including all interactions, and stratified imputation. We also illustrated these methods using a simple example from the National Child Development Study (NCDS). RESULTS: MI excluding interactions is invalid and resulted in biased estimates and low coverage. When XZ was zero, MI excluding interactions gave unbiased estimates but overcoverage. MI including interactions and stratified MI gave equivalent, valid inference in all cases. In the NCDS example, MI excluding interactions incorrectly concluded there was no evidence for an important interaction. CONCLUSIONS: Epidemiologists carrying out MI should ensure that their imputation model(s) are compatible with their analysis model

Justice Stevens: The First Three Terms

This Special Project undertakes an examination of Justice Stevens\u27 Supreme Court opinions in an effort to identify his philosophical orientations, to evaluate the consistency of his views, and to determine the extent to which he has developed workable analytical methods. To achieve these goals, Justice Stevens\u27 opinions are examined in three contexts: first, the area of federal-state relations,including commerce clause and supremacy clause questions; second, the individual rights area, emphasizing criminal constitutional and first amendment issues, and problems of fifth and fourteenth amendment analysis; and third, questions concerning the proper role of the Supreme Court in the constitutional scheme. Even though any vote cast by a Supreme Court Justice may illustrate a significant aspect of his ideology, this Special Project limits attention to opinions authored by Justice Stevens on the assumption that they most accurately represent his views.\u2

In vivo alpha-V beta-3 integrin expression in human aortic atherosclerosis.

OBJECTIVES: Intraplaque angiogenesis and inflammation are key promoters of atherosclerosis and are mediated by the alpha-V beta-3 (αvβ3) integrin pathway. We investigated the applicability of the αvβ3-integrin receptor-selective positron emission tomography (PET) radiotracer 18F-fluciclatide in assessing human aortic atherosclerosis. METHODS: Vascular 18F-fluciclatide binding was evaluated using ex vivo analysis of carotid endarterectomy samples with autoradiography and immunohistochemistry, and in vivo kinetic modelling following radiotracer administration. Forty-six subjects with a spectrum of atherosclerotic disease categorised as stable (n=27) or unstable (n=19; recent myocardial infarction) underwent PET and CT imaging of the thorax after administration of 229 (IQR 217-237) MBq 18F-fluciclatide. Thoracic aortic 18F-fluciclatide uptake was quantified on fused PET-CT images and corrected for blood-pool activity using the maximum tissue-to-background ratio (TBRmax). Aortic atherosclerotic burden was quantified by CT wall thickness, plaque volume and calcium scoring. RESULTS: 18F-Fluciclatide uptake co-localised with regions of increased αvβ3 integrin expression, and markers of inflammation and angiogenesis. 18F-Fluciclatide vascular uptake was confirmed in vivo using kinetic modelling, and on static imaging correlated with measures of aortic atherosclerotic burden: wall thickness (r=0.57, p=0.001), total plaque volume (r=0.56, p=0.001) and aortic CT calcium score (r=0.37, p=0.01). Patients with recent myocardial infarction had greater aortic 18F-fluciclatide uptake than those with stable disease (TBRmax 1.29 vs 1.21, p=0.02). CONCLUSIONS: In vivo expression of αvβ3 integrin in human aortic atheroma is associated with plaque burden and is increased in patients with recent myocardial infarction. Quantification of αvβ3 integrin expression with 18F-fluciclatide PET has potential to assess plaque vulnerability and disease activity in atherosclerosis

Subadventitial stenting around occluded stents: A bailout technique to recanalize in-stent chronic total occlusions

To evaluate the outcomes of subadventitial stenting (SS) around occluded stents for recanalizing in-stent chronic total occlusions (IS-CTOs).There is little evidence on the outcomes of SS for IS-CTO.We examined the outcomes of SS for IS-CTO PCI at 14 centers between July 2011 and June 2017, and compared them to historical controls recanalized using within-stent stenting (WSS). Target-vessel failure (TVF) on follow-up was the endpoint of this study, and was defined as a composite of cardiac death, target-vessel myocardial infarction, and target-vessel revascularization.During study period, 422 IS-CTO PCIs were performed, of which 32 (7.6%) were recanalized with SS, usually when conventional approaches failed. The most frequent CTO vessel was the right coronary artery (72%). Mean J-CTO score was 3.1 ± 0.9. SS was antegrade in 53%, and retrograde in 47%. Part of the occluded stent was crushed in 37%, while the whole stent was crushed in 63%. Intravascular imaging was used in 59%. One patient (3.1%) suffered tamponade. Angiographic follow-up was performed in 10/32 patients: stents were patent in six cases, one had mild neointimal hyperplasia, and three had severe restenosis at the SS site. Clinical follow-up was available for 29/32 patients for a mean of 388 ± 303 days. The 24-month incidence of TVF was 13.8%, which was similar to historical controls treated with WSS (19.5%, P = 0.49).SS is rarely performed, usually as last resort, to recanalize complex IS-CTOs. It is associated with favorable acute and mid-term outcomes, but given the small sample size of our study additional research is warranted

Optical coherence tomography versus intravascular ultrasound to evaluate stent implantation in patients with calcific coronary artery disease

AIMS: Stent underexpansion and malapposition are associated with adverse outcomes following percutaneous coronary intervention, but detection and treatment can be challenging in the presence of extensive coronary artery calcification. Frequency domain optical coherence tomography (FD-OCT) is a novel intravascular imaging technique with greater spatial resolution than intravascular ultrasound (IVUS) but its role in the presence of extensive coronary calcification remains unclear. We sought to determine the utility of FD-OCT compared to IVUS imaging to guide percutaneous coronary intervention in patients with severe calcific coronary artery disease. METHODS: 18 matched IVUS and FD-OCT examinations were evaluated following coronary stent implantation in 12 patients (10 male; mean age 70±7 years) undergoing rotational atherectomy for symptomatic calcific coronary artery disease. RESULTS: In-stent luminal areas were smaller (minimum in-stent area 6.77±2.18 vs 7.19±2.62 mm(2), p<0.05), while reference lumen dimensions were similar with FD-OCT compared with IVUS. Stent malapposition was detected in all patients by FD-OCT and in 10 patients by IVUS. The extent of stent malapposition detected was greater (20% vs 6%, p<0.001) with FD-OCT compared to IVUS. Postdilation increased the in-stent luminal area (minimum in-stent area: 8.15±1.90 vs 7.30±1.62 mm(2), p<0.05) and reduced the extent of stent malapposition (19% vs 34%, p<0.005) when assessed by FD-OCT, but not IVUS. CONCLUSIONS: Acute stent malapposition occurs frequently in patients with calcific coronary disease undergoing rotational atherectomy and stent implantation. In the presence of extensive coronary artery calcification, FD-OCT affords enhanced stent visualisation and detection of malapposition, facilitating improved postdilation stent apposition and minimal luminal areas. TRIAL REGISTRATION NUMBER: NCT02065102

In-Stent CTO Percutaneous Coronary Intervention: Individual Patient Data Pooled Analysis of 4 Multicenter Registries

OBJECTIVES: The authors sought to examine the outcomes of percutaneous coronary intervention (PCI) for in-stent restenosis (ISR) chronic total occlusions (CTOs). BACKGROUND: The outcomes of PCI for ISR CTOs have received limited study. METHODS: The authors examined the clinical and angiographic characteristics and procedural outcomes of 11,961 CTO PCIs performed in 11,728 patients at 107 centers in Europe, North America, Latin America, and Asia between 2012 and 2020, pooling patient-level data from 4 multicenter registries. In-hospital major adverse cardiovascular events (MACE) included death, myocardial infarction, stroke, and tamponade. Long-term MACE were defined as the composite of all-cause death, myocardial infarction, and target vessel revascularization. RESULTS: ISR represented 15% of the CTOs (n = 1,755). Patients with ISR CTOs had higher prevalence of diabetes (44% vs. 38%; p \u3c 0.0001) and prior coronary artery bypass graft surgery (27% vs. 24%; p = 0.03). Mean J-CTO (Multicenter CTO Registry in Japan) score was 2.32 ± 1.27 in the ISR group and 2.22 ± 1.27 in the de novo group (p = 0.01). Technical (85% vs. 85%; p = 0.75) and procedural (84% vs. 84%; p = 0.82) success was similar for ISR and de novo CTOs, as was the incidence of in-hospital MACE (1.7% vs. 2.2%; p = 0.25). Antegrade wiring was the most common successful strategy, in 70% of ISR and 60% of de novo CTOs, followed by retrograde crossing (16% vs. 23%) and antegrade dissection and re-entry (15% vs. 16%; p \u3c 0.0001). At 12 months, patients with ISR CTOs had a higher incidence of MACE (hazard ratio: 1.31; 95% confidence intervals: 1.01 to 1.70; p = 0.04). CONCLUSIONS: ISR CTOs represent 15% of all CTO PCIs and can be recanalized with similar success and in-hospital MACE as de novo CTOs

Medulloblastoma therapy generates risk of a poorly-prognostic H3 wild-type subgroup of diffuse intrinsic pontine glioma: a report from the International DIPG Registry

Abstract With improved survivorship in medulloblastoma, there has been an increasing incidence of late complications. To date, no studies have specifically addressed the risk of radiation-associated diffuse intrinsic pontine glioma (DIPG) in medulloblastoma survivors. Query of the International DIPG Registry identified six cases of DIPG with a history of medulloblastoma treated with radiotherapy. All patients underwent central radiologic review that confirmed a diagnosis of DIPG. Six additional cases were identified in reports from recent cooperative group medulloblastoma trials (total n = 12; ages 7 to 21 years). From these cases, molecular subgrouping of primary medulloblastomas with available tissue (n = 5) revealed only non-WNT, non-SHH subgroups (group 3 or 4). The estimated cumulative incidence of DIPG after post-treatment medulloblastoma ranged from 0.3–3.9%. Posterior fossa radiation exposure (including brainstem) was greater than 53.0 Gy in all cases with available details. Tumor/germline exome sequencing of three radiation-associated DIPGs revealed an H3 wild-type status and mutational signature distinct from primary DIPG with evidence of radiation-induced DNA damage. Mutations identified in the radiation-associated DIPGs had significant molecular overlap with recurrent drivers of adult glioblastoma (e.g. NRAS, EGFR, and PTEN), as opposed to epigenetic dysregulation in H3-driven primary DIPGs. Patients with radiation-associated DIPG had a significantly worse median overall survival (median 8 months; range 4–17 months) compared to patients with primary DIPG. Here, it is demonstrated that DIPG occurs as a not infrequent complication of radiation therapy in survivors of pediatric medulloblastoma and that radiation-associated DIPGs may present as a poorly-prognostic distinct molecular subgroup of H3 wild-type DIPG. Given the abysmal survival of these cases, these findings provide a compelling argument for efforts to reduce exposure of the brainstem in the treatment of medulloblastoma. Additionally, patients with radiation-associated DIPG may benefit from future therapies targeted to the molecular features of adult glioblastoma rather than primary DIPG.https://deepblue.lib.umich.edu/bitstream/2027.42/145180/1/40478_2018_Article_570.pd

Management of Patients with Advanced Prostate Cancer: Report from the Advanced Prostate Cancer Consensus Conference 2021.

BACKGROUND: Innovations in treatments, imaging, and molecular characterisation in advanced prostate cancer have improved outcomes, but various areas of management still lack high-level evidence to inform clinical practice. The 2021 Advanced Prostate Cancer Consensus Conference (APCCC) addressed some of these questions to supplement guidelines that are based on level 1 evidence. OBJECTIVE: To present the voting results from APCCC 2021. DESIGN, SETTING, AND PARTICIPANTS: The experts identified three major areas of controversy related to management of advanced prostate cancer: newly diagnosed metastatic hormone-sensitive prostate cancer (mHSPC), the use of prostate-specific membrane antigen ligands in diagnostics and therapy, and molecular characterisation of tissue and blood. A panel of 86 international prostate cancer experts developed the programme and the consensus questions. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The panel voted publicly but anonymously on 107 pre-defined questions, which were developed by both voting and non-voting panel members prior to the conference following a modified Delphi process. RESULTS AND LIMITATIONS: The voting reflected the opinions of panellists and did not incorporate a standard literature review or formal meta-analysis. The answer options for the consensus questions received varying degrees of support from panellists, as reflected in this article and the detailed voting results reported in the Supplementary material. CONCLUSIONS: These voting results from a panel of experts in advanced prostate cancer can help clinicians and patients to navigate controversial areas of management for which high-level evidence is scant. However, diagnostic and treatment decisions should always be individualised according to patient characteristics, such as the extent and location of disease, prior treatment(s), comorbidities, patient preferences, and treatment recommendations, and should also incorporate current and emerging clinical evidence and logistic and economic constraints. Enrolment in clinical trials should be strongly encouraged. Importantly, APCCC 2021 once again identified salient questions that merit evaluation in specifically designed trials. PATIENT SUMMARY: The Advanced Prostate Cancer Consensus Conference is a forum for discussing current diagnosis and treatment options for patients with advanced prostate cancer. An expert panel votes on predefined questions focused on the most clinically relevant areas for treatment of advanced prostate cancer for which there are gaps in knowledge. The voting results provide a practical guide to help clinicians in discussing treatment options with patients as part of shared decision-making

Influence of soil type and natural Zn chelates on flax response, tensile properties and soil Zn availability

A greenhouse experiment was conducted on weakly acidic and calcareous soils to evaluate the relative efficiencies of three natural Zn chelates [Zn-aminelignosulphonate (Zn-AML), Zn-polyhydroxyphenylcarboxylate (Zn-PHP) and Zn-S,S-ethylenediaminedisuccinate (Zn-S,S-EDDS)] applied to a crop textile flax (Linum ussitatisimum L.) at application rates of 0, 5 and 10 mg Zn kg−1. In the flax plant, the following parameters were determined: dry matter yield, soluble and total Zn concentrations in leaf and stem, chlorophyll, crude fibre, and tensile properties. For the different soil samples, the following parameters were determined: available Zn (DTPA-AB and Mehlich-3 extractable Zn), easily leachable Zn (BaCl2-extractable Zn), the distribution of Zn fractions, pH and redox potential. On the basis of the use of added Zn by flax, or Zn utilization, it would seem recommendable to apply Zn-S,S-EDDS at the low Zn rate in both soils. In contrast, adding the high Zn rate of this chelate to the weakly acidic soil produced an excessive Zn concentration in the plant, which caused a significant decrease in both dry matter yield and chlorophyll content. Furthermore, assessing available Zn with the DTPA-AB method proved the best way of estimating the level of excess Zn in flax plants. The soluble Zn concentration, which was established with 2-(N-morpholino)ethanesulfonic acid reagent (MES), of plant fresh and dry matter could be used as an alternative way of diagnosing the nutritional status of Zn in flax plants. In this experiment, the highest soil pHs were associated with the lowest redox potentials, which coincided with the smallest amounts of available Zn and water soluble Zn in soil, and the lowest levels of Zn uptake by flax plants