Spectral variability studies in Active Galactic Nuclei: Exploring continuum and emission line regions in the age of LSST and JWST

The investigation of emission line regions within active galaxies (AGNs) has a rich and extensive history, now extending to the use of AGNs and quasars as "standardizable" cosmological indicators, shedding light on the evolution of our universe. As we enter the era of advanced observatories, such as the successful launch of JWST and the forthcoming Vera C. Rubin Observatory's Legacy Survey of Space and Time (LSST), the landscape of AGN exploration across cosmic epochs is poised for exciting advancements. In this work, we delve into recent developments in AGN variability research, anticipating the substantial influx of data facilitated by LSST. The article highlights recent strides made by the AGN Polish Consortium in their contributions to LSST. The piece emphasizes the role of quasars in cosmology, dissecting the intricacies of their calibration as standard candles. The primary focus centers on the relationship between the broad-line region size and luminosity, showcasing recent breakthroughs that enhance our comprehension of this correlation. These breakthroughs encompass a range of perspectives, including spectroscopic analyses, photoionization modeling, and collaborative investigations with other cosmological tools. The study further touches on select studies, underlining how the synergy of theoretical insights and advancements in observational capabilities has yielded deeper insights into these captivating cosmic entities.Comment: 34 pages, 5 figures, accepted for publication as a review in MDPI/Univers

Expectations for time-delay measurements in active galactic nuclei with the Vera Rubin Observatory

The Vera Rubin Observatory will provide an unprecedented set of time-dependent observations of the sky. The planned Legacy Survey of Space and Time (LSST) operating for 10 years will provide dense lightcurves for thousands of active galactic nuclei (AGN) in Deep Drilling Fields (DDFs) and less dense lightcurves for millions of AGN. We model the prospects for measuring time delays for emission lines with respect to the continuum, using these data. We model the artificial lightcurves using Timmer-Koenig algorithm, we use the exemplary cadence to sample them, we supplement lightcurves with the expected contamination by the strong emission lines (Hbeta, Mg II and CIV as well as with Fe II pseudo-continuum and the starlight). We choose the suitable photometric bands appropriate for the redshift and compare the assumed line time delay with the recovered time delay for 100 statistical realizations of the light curves. We show that time delays for emission lines can be well measured from the Main Survey for the bright tail of the quasar distribution (about 15% of all sources) with the accuracy within 1 sigma error, for DDFs results for fainter quasars are also reliable when all 10 years of data are used. There are also some prospects to measure the time delays for the faintest quasars at the smallest redshifts from the first two years of data, and eventually even from the first season. The entire quasar population will allow obtaining results of apparently high accuracy but in our simulations, we see a systematic offset between the assumed and recovered time delay depending on the redshift and source luminosity which will not disappear even in the case of large statistics. Such a problem might affect the slope of the radius-luminosity relation and cosmological applications of quasars if simulations correcting for such effects are not performed.Comment: Submitted to Astronomy & Astrophysics, comments wellcom

Comparison of seven prognostic tools to identify low-risk pulmonary embolism in patients aged <50 years

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First three months of anticoagulation for venous thromboembolism in non-cancer patients: LMWH VS. VKAs. Findings from the RIETE registry

Background: The use of low-molecular-weight heparin (LMWH) for long-term therapy of venous thromboembolism (VTE) in patients without cancer has not been consistently evaluated. Methods: We used the data in the RIETE registry to compare the 3-month outcomes (VTE recurrences, major bleeding or death) in non-cancer patients with VTE, according to long-term therapy with LMWH or vitamin K antagonists (VKAs). Results: As of March 2018, 14,582 non-cancer patients with VTE had received initial therapy with LMWH and then switched to VKAs, while 9151 were prescribed LMWH for initial and long-term therapy. Overall, 11,494 had initially presented with pulmonary embolism (PE) and 12,239 with isolated deep vein thrombosis (DVT). Among 11,494 patients initially presenting with PE, 84 had VTE recurrences, 204 major bleeding and 406 died. Among 12,239 patients with isolated DVT, 133 developed VTE recurrences, 137 bled and 289 died. On propensity score analysis, PE patients on long-term LMWH therapy were at increased risk for PE recurrences (OR: 3.30; 95%CI: 1.67–6.48), major bleeding (OR: 1.68; 95%CI: 1.21–2.32) or death (OR: 3.16; 95%CI: 2.43–4.09) compared with those receiving VKAs. In patients with DVT, those on long-term LMWH also were at increased risk for PE recurrences (OR: 2.31; 95%CI: 1.13–4.73), major bleeding (OR 2.28; 95%CI: 1.51–3.44) or death (OR: 2.32; 95%CI: 1.54–3.51). Conclusions: In the RIETE non-cancer patients with VTE, long-term therapy with VKAs was associated with a lower risk for recurrences, major bleeding or death

Liver status and outcomes in patients without previous known liver disease receiving anticoagulant therapy for venous thromboembolism

The association between elevated liver enzymes or FIB-4 (fibrosis index 4) and outcome in patients with venous thromboembolism (VTE) has not been evaluated. Data from patients in RIETE (Registro Informatizado Enfermedad TromboEmbólica) were used to assess the association between elevated liver enzymes or FIB-4 levels and the rates of major bleeding or death in apparent liver disease-free patients with acute VTE under anticoagulation therapy. A total of 6206 patients with acute VTE and without liver disease were included. Of them, 92 patients had major bleeding and 168 died under anticoagulation therapy. On multivariable analysis, patients with elevated liver enzymes were at increased mortality risk (HR: 1.58; 95% CI: 1.10–2.28), while those with FIB-4 levels > 2.67 points were at increased risk for major bleeding (HR: 1.69; 95% CI: 1.04–2.74). Evaluation of liver enzymes and FIB-4 index at baseline in liver disease-free patients with VTE may provide additional information on the risk for major bleeding or death during anticoagulation

Timing and characteristics of venous thromboembolism after noncancer surgery

Background: Venous thromboembolism (VTE) is a major cause of morbidity and mortality postoperatively. The use of pharmacologic prophylaxis is effective in reducing the incidence of VTE. However, the prophylaxis is often discontinued at hospital discharge, especially for those with benign disease. The implications of this practice are not known. We assessed the data from a large, ongoing registry regarding the time course of VTE and outcomes after noncancer surgery. Methods: We analyzed the RIETE (Computerized Registry on Venous Thromboembolism) registry, which includes data from consecutive patients with symptomatic confirmed VTE. In the present study, we focused on general surgical patients who had developed symptomatic postoperative VTE in the first 8 weeks after noncancer surgery. The main objective was to assess the interval between surgery and the occurrence of VTE. Additional variables included the clinical presentation associated with the event, the use of thrombosis prophylaxis, and unfavorable outcomes. Results: The data from 3296 patients were analyzed. The median time from surgery to the detection of VTE was 16 days (interquartile range, 8-30 days). Of the VTE events, 77% were detected after the first postoperative week and 27% after 4 weeks. Overall, 43.9% of the patients with VTE had received pharmacologic prophylaxis after surgery for a median of 8 days (interquartile range, 5-14 days), and three quarters of the VTE events were detected after pharmacologic prophylaxis had been discontinued. Overall, 54% of the patients with VTE had presented with pulmonary embolism. For 15% of the patients, the clinical outcome was unfavorable, including 4% who had died within 90 days. Conclusions: The risk of VTE after noncancer general surgery remains high for ≤2 months. More than one half of the patients had presented with symptomatic PE as the VTE event, and 15% had had unfavorable outcomes. Only 44% of these patients had received pharmacologic prophylaxis for around 1 week

Derivation and validation of a clinical prediction rule for thrombolysis-associated major bleeding in patients with acute pulmonary embolism: The BACS score

Background: Improved prediction of the risk of major bleeding in patients with acute pulmonary embolism (PE) receiving systemic thrombolysis is crucial to guide the choice of therapy. Methods: The study included consecutive patients with acute PE who received systemic thrombolysis in the RIETE registry. We used multivariable logistic regression analysis to create a risk score to predict 30-day major bleeding episodes. We externally validated the risk score in patients from the COMMAND VTE registry. In addition, we compared the newly created risk score against the Kuijer and RIETE scores. Results: Multivariable logistic regression identified four predictors for major bleeding: recent major bleeding (3 points), age &gt;75 years (1 point), active cancer (1 point) and syncope (1 point) (BACS). Among 1172 patients receiving thrombolytic therapy in RIETE, 446 (38%) were classified as having low risk (none of the variables present, 0 points) of major bleeding according to the BACS score, and the overall 30-day major bleeding rate of this group was 2.9% (95% CI 1.6–4.9%), compared with 44% (95% CI 14–79%) in the high-risk group (&gt;3 points). In the validation cohort, 51% (149 out of 290) of patients were classified as having low risk, and the overall 30-day major bleeding rate of this group was 1.3%. In RIETE, the 30-day major bleeding event rates in the Kuijer and RIETE low-risk strata were 5.3% and 4.4%, respectively. Conclusions: The BACS score is an easily applicable aid for prediction of the risk of major bleeding in the population of PE patients who receive systemic thrombolysis

Real-Time Dissemination of Aggregate Data on Presentation and Outcomes of Patients With Venous Thromboembolism: The RIETE Infographics Project

In the current era of patient empowerment and precision medicine, access to timely information is critical to decision-making. Unfortunately, we currently lack patient-specific, real-time data about clinical presentation, risk of thrombotic or hemorrhagic events, key risk factors, and adverse outcomes in patients with venous thromboembolism (VTE). Accordingly, the Registro Informatizado Enfermedad TromboEmb\uf3lica (RIETE) investigators developed a tool to provide an open-source, real-time graphic representation of VTE-related data derived from over 90 000 patients with confirmed VTE. This information is intended to facilitate discussion in the informed decision-making process. The current article describes the aims, rationale, methods, and ongoing and future efforts of the real-time VTE infographics developed by the RIETE registry collaborators

Heart Rate and Mortality in Patients With Acute Symptomatic Pulmonary Embolism

Background: The association between heart rate (HR) and pulmonary embolism (PE) outcomes has not been well studied. Furthermore, optimal cutoffs to identify low-risk and intermediate- to high-risk patients are not well known. Research Question: Does an association exist between baseline HR and PE outcome across the continuum of HR values? Study Design and Methods: The current study included 44,331 consecutive nonhypotensive patients with symptomatic PE from the Registro Informatizado de la Enfermedad TromboEmbólica registry between 2001 and 2021. Outcomes included 30-day all-cause and PE-specific mortality. We used hierarchical logistic regression to assess the association between admission HR and outcomes. Results: A positive relationship was found between admission HR and 30-day all-cause and PE-related mortality. Considering an HR of 80 to 99 beats/min as a reference, patients in the higher HR strata showed higher rates of all-cause death (adjusted OR, 1.5 for HR of 100-109 beats/min; adjusted OR, 1.7 for HR of 110-119 beats/min; adjusted OR, 1.9 for HR of 120-139 beats/min; and adjusted OR, 2.4 for HR of ≥ 140 beats/min). Patients in the lower strata of HR showed significantly lower rates of 30-day all-cause mortality compared with the same reference group (adjusted OR, 0.6 for HR of 60-79 beats/min; and adjusted OR, 0.5 for HR of < 60 beats/min). The findings for 30-day PE-related mortality were similar. For identification of low-risk patients, a cutoff value of 80 beats/min (vs 110 beats/min) increased the sensitivity of the simplified Pulmonary Embolism Severity Index (sPESI) from 93.4% to 98.8%. For identification of intermediate- to high-risk patients, a cutoff value of 140 beats/min (vs 110 beats/min) increased the specificity of the Bova score from 93.2% to 98.0%. Interpretation: In nonhypotensive patients with acute symptomatic PE, a high HR portends an increased risk of all-cause and PE-related mortality. Modifying the HR cutoff in the sPESI and the Bova score improves prognostication of patients with PE

Edoxaban for the Long-Term Therapy of Venous Thromboembolism: Should the Criteria for Dose Reduction be Revised?

Edoxaban is used for venous thromboembolism (VTE) treatment. Real-life data are lacking about its use in long-term therapy. We aimed to assess the efficacy and the safety of edoxaban for long-term VTE treatment in a real-life setting. Patients with VTE included in the Registro Informatizado Enfermedad TromboEmb\uf3lica (RIETE) registry, receiving edoxaban 60 or 30&nbsp;mg daily were prospectively followed up to validate the benefit of using different dosages. The main outcome was the composite of VTE recurrences or major bleeding in patients with or without criteria for dose reduction. Multivariable analysis to identify predictors for the composite outcome was performed. From October 2015 to November 2019, 562 patients received edoxaban for long-term therapy. Most (94%) of the 416 patients not meeting criteria for dose reduction received 60&nbsp;mg daily, and 92 patients meeting criteria (63%) received 30&nbsp;mg daily. During treatment, two patients developed recurrent VTE, six had major bleeding and nine died (2 from fatal bleeding). Among patients not meeting criteria for dose reduction, those receiving 30&nbsp;mg daily had a higher rate of the composite event (hazard ratio (HR) 8.37; 95% confidence interval (CI) 1.12\u201342.4) and a significant higher mortality rate (HR 31.1; 95% CI 4.63\u2013262) than those receiving 60&nbsp;mg. Among patients meeting criteria for dose reduction, those receiving 60&nbsp;mg daily had no events, and a nonsignificantly higher mortality rate (HR 5.04; 95% CI 0.54\u2013133) than those receiving 30&nbsp;mg daily. In conclusion, edoxaban seems to be effective and safe for long-term VTE treatment in real life. Criteria for dose reduction should be reformulated