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Highly efficient neutron detectors are critical in many sectors, including national security1,2, medicine3, crystallography4 and astronomy5. The main neutron detection technologies currently used involve 3He-gas-filled proportional counters6 and light scintillators7 for thermalized neutrons. Semiconductors could provide the next generation of neutron detectors because their advantages could make them competitive with or superior to existing detectors. In particular, solids with a high concentration of high-neutron-capture nuclides (such as 6Li, 10B) could be used to develop smaller detectors with high intrinsic efficiencies. However, no promising materials have been reported so far for the construction of direct-conversion semiconductor detectors. Here we report on the semiconductor LiInP2Se6 and demonstrate its potential as a candidate material for the direct detection of thermal neutrons at room temperature. This compound has a good thermal-neutron-capture cross-section, a suitable bandgap (2.06 electronvolts) and a favourable electronic band structure for efficient electron charge transport. We used α particles from an 241Am source as a proxy for the neutron-capture reaction and determined that the compact two-dimensional (2D) LiInP2Se6 detectors resolved the full-energy peak with an energy resolution of 13.9 per cent. Direct neutron detection from a moderated Pu-Be source was achieved using 6Li-enriched (95 per cent) LiInP2Se6 detectors with full-peak resolution. We anticipate that these results will spark interest in this field and enable the replacement of 3He counters by semiconductor-based neutron detectors.
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An amendment to this paper has been published and can be accessed via a link at the top of the paper.
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INTRODUCTION: In low- and middle-income countries (LMIC), the diagnosis of epilepsy should be made by Non-Physician Health Workers (NPHW) who are widely available in these settings. Recently a smartphone app (Epilepsy Diagnosis Aid) has been developed and validated to be used by NPHW, in order to confirm the diagnosis of epilepsy. The aim of our study was to perform a validation of the app in two different contexts: a hospital-based setting of a high-income country (HIC) and a population-based setting of the rural communities of a LMIC. MATERIAL AND METHODS: For the hospital-based setting, the app was administered to a sample of patients with epilepsy (PWE) and to a sample of subjects affected by syncope attending the epilepsy center of the University of Catania. For the population-based setting, performed in the rural communities of the Gran Chaco region in Bolivia,the app was administered by NPHW to a sample of PWE previously identified. Sensitivity and specificity were calculated for the diagnosis of epilepsy. RESULTS: In the hospital-setting, the app was administered to 100 PWE and 20 syncopes. A probability scoreâ¯>â¯80 showed a sensitivity of 76% (95%CI 66.4-84) and a specificity of 100% (95%CI 83.2-100) for the diagnosis of epilepsy; higher values were found for active epilepsy with tonic-clonic seizures. In the rural-setting, the app was administered to 38 PWE, giving a sensitivity of 92.1% (95%CI 78.6-98.3). CONCLUSION: The app for epilepsy could represent a valuable instrument, which can be easily employed by trained NPHW to diagnose epilepsy in primary health-care settings of LMIC.
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Epilepsia , Población Rural , Bolivia , Epilepsia/diagnóstico , Epilepsia/epidemiología , Humanos , Convulsiones , Teléfono InteligenteRESUMEN
The two-dimensional Ruddlesden-Popper (RP) phases are an important class of halide perovskites with versatile optoelectronic properties. So far, only organic-inorganic hybrid RP phases involving long organic spacers were reported in this class. Here, we report an all-inorganic RP phase lead halide perovskite, Cs2PbI2Cl2 (1, I4/ mmm space group; a = 5.6385(8) Å, c = 18.879(4) Å), synthesized by a solid-state method. The compound exhibits a band gap of Eg â¼ 3.04 eV and photoconductivity. We find an anomalous band gap evolution in Cs2Pb1- xSn xI2Cl2 solid solutions. Our combined density functional theory and experimental study supports the thermodynamically stable nature of 1 as a unique ordered phase in the Cs2PbX4 (X = Cl, Br, I) system. The calculations suggest that 1 is a direct bandgap semiconductor with relatively small effective carrier mass along the in-plane direction, consistent with the experimentally observed in-plane UV-light photoresponse. We also demonstrate that 1 is promising for radiation detection capable of α-particle counting. Moreover, 1 shows markedly ambient and thermal stability.
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The phase-change (PC) materials in the majority of optical data storage media in use today exhibit a fast, reversible crystal â amorphous phase transition that allows them to be switched between on (1) and off (0) binary states. Solid-state inorganic materials with this property are relatively common, but those exhibiting an amorphous â amorphous transition called polyamorphism are exceptionally rare. K2Sb8Se13 (KSS) reported here is the first example of a material that has both amorphous â amorphous polyamorphic transition and amorphous â crystal transition at easily accessible temperatures (227 and 263 °C, respectively). The transitions are associated with the atomic coordinative preferences of the atoms, and all three states of K2Sb8Se13 are stable in air at 25 °C and 1 atm. All three states of K2Sb8Se13 exhibit distinct optical bandgaps, Eg = 1.25, 1.0, and 0.74 eV, for the amorphous-II, amorphous-I, and crystalline versions, respectively. The room-temperature electrical conductivity increases by more than 2 orders of magnitude from amorphous-I to -II and by another 2 orders of magnitude from amorphous-II to the crystalline state. This extraordinary behavior suggests that a new class of materials exist which could provide multistate level systems to enable higher-order computing logic circuits, reconfigurable logic devices, and optical switches.
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A new polymorph of the RE2Ru3Ge5 (RE = Pr, Sm, Dy) compounds has been grown as single crystals via an indium flux. These compounds crystallize in tetragonal space group P4/mnc with the Sc2Fe3Si5-type structure, having lattice parameters a = 11.020(2) Å and c = 5.853(1) Å for RE = Pr, a = 10.982(2) Å and c = 5.777(1) Å for RE = Sm, and a = 10.927(2) Å and c = 5.697(1) Å for RE = Dy. These materials exhibit a structural transition at low temperature, which is attributed to an apparent charge density wave (CDW). Both the high-temperature average crystal structure and the low-temperature incommensurately modulated crystal structure (for Sm2Ru3Ge5 as a representative) have been solved. The charge density wave order is manifested by periodic distortions of the one-dimensional zigzag Ge chains. From X-ray diffraction, charge transport (electrical resistivity, Hall effect, magnetoresistance), magnetic measurements, and heat capacity, the ordering temperatures (TCDW) observed in the Pr and Sm analogues are â¼200 and â¼175 K, respectively. The charge transport measurement results indicate an electronic state transition happening simultaneously with the CDW transition. X-ray absorption near-edge spectroscopy (XANES) and electronic band structure results are also reported.
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Germanio/química , Elementos de la Serie de los Lantanoides/química , Teoría Cuántica , Rutenio/química , Fenómenos ElectromagnéticosRESUMEN
The high Z chalcohalides Hg3Q2I2 (Q = S, Se, and Te) can be regarded as of antiperovskite structure with ordered vacancies and are demonstrated to be very promising candidates for X- and γ-ray semiconductor detectors. Depending on Q, the ordering of the Hg vacancies in these defect antiperovskites varies and yields a rich family of distinct crystal structures ranging from zero-dimensional to three-dimensional, with a dramatic effect on the properties of each compound. All three Hg3Q2I2 compounds show very suitable optical, electrical, and good mechanical properties required for radiation detection at room temperature. These compounds possess a high density (>7 g/cm3) and wide bandgaps (>1.9 eV), showing great stopping power for hard radiation and high intrinsic electrical resistivity, over 1011 Ω cm. Large single crystals are grown using the vapor transport method, and each material shows excellent photo sensitivity under energetic photons. Detectors made from thin Hg3Q2I2 crystals show reasonable response under a series of radiation sources, including 241Am and 57Co radiation. The dimensionality of Hg-Q motifs (in terms of ordering patterns of Hg vacancies) has a strong influence on the conduction band structure, which gives the quasi one-dimensional Hg3Se2I2 a more prominently dispersive conduction band structure and leads to a low electron effective mass (0.20 m0). For Hg3Se2I2 detectors, spectroscopic resolution is achieved for both 241Am α particles (5.49 MeV) and 241Am γ-rays (59.5 keV), with full widths at half-maximum (FWHM, in percentage) of 19% and 50%, respectively. The carrier mobility-lifetime µτ product for Hg3Q2I2 detectors is achieved as 10-5-10-6 cm2/V. The electron mobility for Hg3Se2I2 is estimated as 104 ± 12 cm2/(V·s). On the basis of these results, Hg3Se2I2 is the most promising for room-temperature radiation detection.
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A unique possibility for a simple strain tolerant inorganic solid is envisioned whereby a set of isolated, one-dimensional (1D) nano objects are embedded in an elastically soft three-dimensional (3D) atomic matrix thus forming an interdimensional hybrid structure (IDHS). We predict theoretically that the concerted rotation of 1D nano objects could allow such IDHSs to tolerate large strain values with impunity. Searching theoretically among the 1:1:1 ABX compounds of I-I-VI composition, we identified, via first-principles thermodynamic theory, RbCuTe, which is a previously unreported but now predicted-to-be-stable compound in the MgSrSi-type structure, in space group Pnma. The predicted structure of RbCuTe consists of ribbons of copper and telluride atoms placed antipolar to one another throughout the lattice with rubidium atoms acting as a matrix. A novel synthetic adaptation utilizing liquid rubidium and vacuum annealing of the mixed elemental reagents in fused silica tubes as well as in situ (performed at the Advanced Photon Source) and ex situ structure determination confirmed the stability and predicted structure of RbCuTe. First-principles calculations then showed that the application of up to â¼30% uniaxial strain on the ground-state structure result in a buildup of internal stress not exceeding 0.5 GPa. The increase in total energy is 15-fold smaller than what is obtained for the same RbCuTe material but in structures having a contiguous set of 3D chemical bonds spanning the entire crystal. Furthermore, electronic structure calculations revealed that the HOMO is a 1D energy band localized on the CuTe ribbons and that the 1D insulating band structure is also resilient to such large strains. This combined theory and experiment study reveals a new type of strain tolerant inorganic material.
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Mn3Ta2O8, a stable targeted material with an unusual and complex cation topology in the complicated Mn-Ta-O phase space, has been grown as a ≈3-cm-long single crystal via the optical floating-zone technique. Single-crystal absorbance studies determine the band gap as 1.89 eV, which agrees with the value obtained from density functional theory electronic-band-structure calculations. The valence band consists of the hybridized Mn d-O p states, whereas the bottom of the conduction band is formed by the Ta d states. Furthermore, out of the three crystallographically distinct Mn atoms that are four-, seven-, or eight-coordinate, only the former two contribute their states near the top of the valence band and hence govern the electronic transitions across the band gap.
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Aortic intramural hematoma (IMH) accounts for approximately 10%-25% of acute aortic syndromes (AAS), and multi-slice computed tomography and magnetic resonance imaging are the leading techniques for diagnosis and classification. In this context, endovascular strategies provide a valid alternative to traditional open surgery and transesophageal echocardiography (TEE) could play a role in therapeutic decision-making and in endovascular repair procedure guidance. A 57-year-old female patient with IMH extending from the left subclavian artery to the upper tract of the abdominal aorta, underwent endovascular aortic repair using an unibody single-branched stent grafting in the aortic arch and descending aorta with a side branch inserted in the left common carotid artery. To restore proper flow in the left axillary artery, a carotid-subclavian bypass graft was performed. The procedure was guided by angiography and TEE. Intraoperative TEE revealed aortic IMH with a significant fluid component in the middle tunic of the aorta with a wall thickness of over 13 mm. TEE was useful in monitoring of all steps of the procedure, showing the presence of the guidewires into the true lumen, the advancement of the prosthesis, and the phases of release and anchoring. This case highlights the importance of using multimodality imaging techniques to evaluate AAS and demonstrates the growing potential of TEE in guiding endovascular repairs.
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Background: Pericardial agenesis is a rare congenital heart disease characterized by a variable clinical presentation. Case summary: A 32-year-old man was sent by an occupational health physician to our health care centre because of pathological electrocardiogram (ECG). On transthoracic echocardiogram, we had some difficulty to obtain a good quality of four-chamber apical view that was shifted upper and laterally towards the left anterior axillary line. Nonetheless, an abnormal diastolic expansion of the apex of the left ventricle (LV) that had an otherwise normal systolic function was detected. A chest X-ray confirmed the leftward shift of the heart, with the elongation of the left border of cardiac silhouette and cardiac MRI, finally revealed the absence of left-sided pericardium associated with a leftward dislocation of the heart and a dysmorphism of the LV apex that appeared rounded and curved. The non-invasive work-up was completed with 48â h long Holter ECG that was unremarkable. The exercise test was also negative for both inducible myocardial ischaemia and arrhythmias. Patient was scheduled for loop-recorder implantation, and a 6-month clinical follow-up was advised. Discussion: Pericardial agenesis is a rare congenital heart disease associated with an increased risk of cardiac arrhythmias and type A aortic dissection, however its clinical course could be also completely unremarkable. The diagnosis is challenging, and cardiac MRI remains the gold standard imaging modality. In complete left-sided and asymptomatic forms, no treatment is needed. Prognosis is not well established due to both the rarity of disease and extreme variability of clinical presentation.
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An 84-year-old man with extensive calcified atherosclerosis of the infrarenal abdominal aorta was diagnosed with severe aortic valve stenosis, presenting with dyspnea. To facilitate transfemoral approach during the TAVI procedure, IVUS-guided intravascular lithotripsy was successfully performed using Kissing Shockwave Balloon Technique.
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Aorta Abdominal , Estenosis de la Válvula Aórtica , Masculino , Humanos , Anciano de 80 o más Años , Aorta Abdominal/diagnóstico por imagen , Resultado del Tratamiento , Estenosis de la Válvula Aórtica/cirugía , Estenosis de la Válvula Aórtica/diagnósticoRESUMEN
Cardiovascular diseases (CVDs) remain a major global health challenge, leading to significant morbidity and mortality while straining healthcare systems. Despite progress in medical treatments for CVDs, their increasing prevalence calls for a shift towards more effective prevention strategies. Traditional preventive approaches have centered around lifestyle changes, risk factors management, and medication. However, the integration of imaging methods offers a novel dimension in early disease detection, risk assessment, and ongoing monitoring of at-risk individuals. Imaging techniques such as supra-aortic trunks ultrasound, echocardiography, cardiac magnetic resonance, and coronary computed tomography angiography have broadened our understanding of the anatomical and functional aspects of cardiovascular health. These techniques enable personalized prevention strategies by providing detailed insights into the cardiac and vascular states, significantly enhancing our ability to combat the progression of CVDs. This review focuses on amalgamating current findings, technological innovations, and the impact of integrating advanced imaging modalities into cardiovascular risk prevention, aiming to offer a comprehensive perspective on their potential to transform preventive cardiology.
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Heart failure (HF) is a leading cause of morbidity worldwide, imposing a significant burden on deaths, hospitalizations, and health costs. Anticipating patients' deterioration is a cornerstone of HF treatment: preventing congestion and end organ damage while titrating HF therapies is the aim of the majority of clinical trials. Anyway, real-life medicine struggles with resource optimization, often reducing the chances of providing a patient-tailored follow-up. Telehealth holds the potential to drive substantial qualitative improvement in clinical practice through the development of patient-centered care, facilitating resource optimization, leading to decreased outpatient visits, hospitalizations, and lengths of hospital stays. Different technologies are rising to offer the best possible care to many subsets of patients, facing any stage of HF, and challenging extreme scenarios such as heart transplantation and ventricular assist devices. This article aims to thoroughly examine the potential advantages and obstacles presented by both existing and emerging telehealth technologies, including artificial intelligence.
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Transient left ventricular dysfunction (TLVD), a temporary condition marked by reversible impairment of ventricular function, remains an underdiagnosed yet significant contributor to morbidity and mortality in clinical practice. Unlike the well-explored atherosclerotic disease of the epicardial coronary arteries, the diverse etiologies of TLVD require greater attention for proper diagnosis and management. The spectrum of disorders associated with TLVD includes stress-induced cardiomyopathy, central nervous system injuries, histaminergic syndromes, various inflammatory diseases, pregnancy-related conditions, and genetically determined syndromes. Furthermore, myocardial infarction with non-obstructive coronary arteries (MINOCA) origins such as coronary artery spasm, coronary thromboembolism, and spontaneous coronary artery dissection (SCAD) may also manifest as TLVD, eventually showing recovery. This review highlights the range of ischemic and non-ischemic clinical situations that lead to TLVD, gathering conditions like Tako-Tsubo Syndrome (TTS), Kounis syndrome (KS), Myocarditis, Peripartum Cardiomyopathy (PPCM), and Tachycardia-induced cardiomyopathy (TIC). Differentiation amongst these causes is crucial, as they involve distinct clinical, instrumental, and genetic predictors that bode different outcomes and recovery potential for left ventricular function. The purpose of this review is to improve everyday clinical approaches to treating these diseases by providing an extensive survey of conditions linked with TLVD and the elements impacting prognosis and outcomes.
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BACKGROUND: Smoker's paradox usually refers to the observation of a favorable outcome of smoking patients in acute myocardial infarction. METHODS: From April 2006 to December 2018 a population of 2456 patients with ST segment elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (pPCI) were prospectively enrolled in the MATRIX registry. Ischemic time, clinical, demographics, angiographic data, and 1-year follow-up were collected. RESULTS: Among 2546 patients admitted with STEMI, 1007 (41 %) were current smokers. Smokers were 10 years younger and had lower crude in-hospital and 1-year mortality (1.5 % vs 6 %, p < 0.0001 and 5 % vs 11 %, p < 0.0001), shorter ischemic time (203 [147-299] vs 220 [154-334] minutes, p = 0.002) and shorter decision time (60 [30-135] vs 70 [36-170] minutes, p = 0.0063). Smoking habit [OR:0.37(95 % CI:0.18-0.75)-p < 0.01], younger age [OR 1.06 (95%CI:1.04-1.09)-p < 0.001] and shorter ischemic time [OR:1.01(95%CI:1.01-1.02)-p < 0.05] were associated to lower in-hospital mortality. Only smoking habit [HR:0.65(95 % CI: 0.44-0.9)-p = 0.03] and younger age [HR:1.08 (95%CI:1.06-1.09)-p < 0.001] were also independently associated to lower all-cause death at 1-year follow-up. After propensity matching, age, cardiogenic shock and TIMI flow <3 were associated with in-hospital mortality, while smoking habit was still associated with reduced mortality. Smoking was also associated with reduced mortality at 1-year follow-up (HR 0.54, 95 % CI [0.37-0.78]; p < 0.001). CONCLUSIONS: Smoking patients show better outcome after PCI for STEMI at 1-year follow-up. Although "Smoking paradox" could be explained by younger age of patients, other factors may have a role in the explanation of the phenomenon.
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Background: The mismatch between tricuspid valve (TV) leaflet length and annulus dilation, assessed with the septal-lateral leaflet-to-annulus index (SL-LAI), predicts residual tricuspid regurgitation (TR) following tricuspid transcatheter edge-to-edge-repair (T-TEER). When posterior leaflet grasping is required, the anterior-posterior leaflet-to-annulus index (AP-LAI) may offer additional information. Methods: This single-center retrospective cohort study included all patients referred for T-TEER with severe and symptomatic TR with high surgical risk from April 2021 to March 2024. Patients were categorized into 'optimal result' (
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BACKGROUND: Infective endocarditis (IE) is marked by a heightened risk of embolic events (EEs), uncontrolled infection, or heart failure (HF). METHODS: Patients with IE and surgical indication were enrolled from October 2015 to December 2018. The primary endpoint consisted of a composite of major adverse events (MAEs) including all-cause death, hospitalizations, and IE relapses. The secondary endpoint was all-cause death. RESULTS: A total of 102 patients (66 ± 14 years) were enrolled: 50% with IE on prosthesis, 33% with IE-associated heart failure (IE-aHF), and 38.2% with EEs. IE-aHF and EEs were independently associated with MAEs (HR 1.9, 95% CI 1.1-3.4, p = 0.03 and HR 2.1, 95% CI 1.2-3.6, p = 0.01, respectively) and Kaplan-Meier survival curves confirmed a strong difference in MAE-free survival of patients with EEs and IE-aHF (p < 0.01 for both). IE-aHF (HR 4.3, 95% CI 1.4-13, p < 0.01), CRP at admission (HR 5.6, 95% CI 1.4-22.2, p = 0.01), LVEF (HR 0.9, 95% CI 0.9-1, p < 0.05), abscess (HR 3.5, 95% CI 1.2-10.6, p < 0.05), and prosthetic detachment (HR 4.6, 95% CI 1.5-14.1, p < 0.01) were independently associated with the all-cause death endpoint. CONCLUSIONS: IE-aHF and EEs were independently associated with MAEs. IE-aHF was also independently associated with the secondary endpoint.
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Background: The pathophysiological impact of systemic vascular resistance (SVR) and pressure-strain loop-derived global myocardial work index (GWI) in hypertrophic cardiomyopathy (HCM) and transthyretin cardiac amyloidosis (ATTR) has been randomly investigated. Methods: Both SVR and GWI were assessed in outpatients consecutively referred at two Italian cardiology departments for heart failure with preserved left ventricular ejection fraction (LVEF), affected by either nonobstructive HCM or wild-type ATTR. Based on relevant cross-tabulations, the patients were gathered into 4 functional classes according to cut-off values of 1440 dyne/s/cm-5 for SVR, and 1576 mm Hg% for GWI, as suggested by previous studies. Results: A total of 60 patients, 30 in each group, aged 61 ± 16 years, with 78% males, were studied. HCM patients were younger than those with ATTR and in a better clinical condition (23% HCM vs. 77% ATTR were NYHA class II-III, p < 0.001). Overall, 51 patients (85%) showed a high SVR, 21/30 HCM (70%), and 30 ATTR (100%) (p < 0.005). Both SVR and GWI (expressions of ventricular-arterial coupling) were impaired in 43% of HCM patients (showing greater LV concentric hypertrophy) and 93% of ATTR patients (in advanced NYHA functional class) (p < 0.001). Conclusions: A substantial percentage of present study population showed impaired SVR and/or GWI, despite preserved LVEF. The proposed classification may shed further light on the pathophysiological and clinical characteristics of such hypertrophic phenotypes.
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BACKGROUND: Transthyretin cardiac amyloidosis (ATTR-CA) has a deep impact on the quality of life (QoL), yet no specific patient-reported outcome measures (PROMs) for ATTR-CA exist. METHODS: The ITALY study involved 5 Italian referral centres (Pisa, Pavia, Ferrara, Florence, Messina) enrolling consecutive outpatients with ATTR-CA. RESULTS: Two 30-item questionnaires were created for wild-type (wt) and variant (v) ATTR-CA. Scores ranged from 100 (best condition) to 0 (worst condition). Out of 140 patients enrolled (77% with ATTRwt-CA), 115 repeated the re-evaluation at 6 months. At baseline, only 30% of patients needed help to fill out the questionnaires. Among baseline variables, all KCCQ and SF-36 domains were univariate predictors of ITALY scores in ATTRwt-CA patients, with the KCCQ Symptom Summary score (beta coefficient 0.759), Social Limitations (0.781), and Overall summary score (0.786) being the strongest predictors. The SF-36 Emotional well-being score (0.608), the KCCQ Overall summary score (0.656), and the SF-36 Energy/fatigue score (0.669) were the strongest univariate predictors of ITALY scores in ATTRv-CA. Similar results were found at 6 months. CONCLUSIONS: The ITALY questionnaires are the first specific PROMs for ATTRwt- and ATTRv-CA. Questionnaire completion is feasible. ITALY scores display close relationships with non-ATTR-specific measures of QoL.