Computed Tomography Versus Invasive Coronary Angiography in Patients With Diabetes and Suspected Coronary Artery Disease

Objective: To compare cardiac computed tomography (CT) with invasive coronary angiography (ICA) as the initial strategy in patients with diabetes and stable chest pain. Research design and methods: This prespecified analysis of the multicenter DISCHARGE trial in 16 European countries was performed in patients with stable chest pain and intermediate pretest probability of coronary artery disease. The primary end point was a major adverse cardiac event (MACE) (cardiovascular death, nonfatal myocardial infarction, or stroke), and the secondary end point was expanded MACE (including transient ischemic attacks and major procedure-related complications). Results: Follow-up at a median of 3.5 years was available in 3,541 patients of whom 557 (CT group n = 263 vs. ICA group n = 294) had diabetes and 2,984 (CT group n = 1,536 vs. ICA group n = 1,448) did not. No statistically significant diabetes interaction was found for MACE (P = 0.45), expanded MACE (P = 0.35), or major procedure-related complications (P = 0.49). In both patients with and without diabetes, the rate of MACE did not differ between CT and ICA groups. In patients with diabetes, the expanded MACE end point occurred less frequently in the CT group than in the ICA group (3.8% [10 of 263] vs. 8.2% [24 of 294], hazard ratio [HR] 0.45 [95% CI 0.22-0.95]), as did the major procedure-related complication rate (0.4% [1 of 263] vs. 2.7% [8 of 294], HR 0.30 [95% CI 0.13 - 0.63]). Conclusions: In patients with diabetes referred for ICA for the investigation of stable chest pain, a CT-first strategy compared with an ICA-first strategy showed no difference in MACE and may potentially be associated with a lower rate of expanded MACE and major procedure-related complications

Performance of a modular ton-scale pixel-readout liquid argon time projection chamber

The Module-0 Demonstrator is a single-phase 600 kg liquid argon time projection chamber operated as a prototype for the DUNE liquid argon near detector. Based on the ArgonCube design concept, Module-0 features a novel 80k-channel pixelated charge readout and advanced high-coverage photon detection system. In this paper, we present an analysis of an eight-day data set consisting of 25 million cosmic ray events collected in the spring of 2021. We use this sample to demonstrate the imaging performance of the charge and light readout systems as well as the signal correlations between the two. We also report argon purity and detector uniformity measurements and provide comparisons to detector simulations

Doping liquid argon with xenon in ProtoDUNE Single-Phase: effects on scintillation light

Doping of liquid argon TPCs (LArTPCs) with a small concentration of xenon is a technique for light-shifting and facilitates the detection of the liquid argon scintillation light. In this paper, we present the results of the first doping test ever performed in a kiloton-scale LArTPC. From February to May 2020, we carried out this special run in the single-phase DUNE Far Detector prototype (ProtoDUNE-SP) at CERN, featuring 720 t of total liquid argon mass with 410 t of fiducial mass. A 5.4 ppm nitrogen contamination was present during the xenon doping campaign. The goal of the run was to measure the light and charge response of the detector to the addition of xenon, up to a concentration of 18.8 ppm. The main purpose was to test the possibility for reduction of nonuniformities in light collection, caused by deployment of photon detectors only within the anode planes. Light collection was analysed as a function of the xenon concentration, by using the pre-existing photon detection system (PDS) of ProtoDUNE-SP and an additional smaller set-up installed specifically for this run. In this paper we first summarize our current understanding of the argon-xenon energy transfer process and the impact of the presence of nitrogen in argon with and without xenon dopant. We then describe the key elements of ProtoDUNE-SP and the injection method deployed. Two dedicated photon detectors were able to collect the light produced by xenon and the total light. The ratio of these components was measured to be about 0.65 as 18.8 ppm of xenon were injected. We performed studies of the collection efficiency as a function of the distance between tracks and light detectors, demonstrating enhanced uniformity of response for the anode-mounted PDS. We also show that xenon doping can substantially recover light losses due to contamination of the liquid argon by nitrogen