DC Multibus based on a Single-Star Bridge Cells Modular Multilevel Cascade Converter for DC smart grids

In the last years a growing interest towards DC Smart Grids has been registered due to high penetration of distributed generation systems with embedded storage. Trying to foresee the possible future scenarios of the power systems, it can be noticed that DC Smart Grids can be even preferable to AC Smart Grids in terms of flexibility and redundancy since they are compatible with the achievement of a DC Multibus working at different voltage levels. In this paper the Single-Star Bridge Cells Modular Multilevel Cascade Converter is used to create a DC Multibus. The performances of the system are analyzed considering different load configurations and coexistence of different voltage levels of the buses forming the DC Multibus. Results confirms the validity of the proposed solution and the robustness of the control system in case of load variations

Impact of acute and persistent stent malapposition after percutaneous coronary intervention on adverse cardiovascular outcomes

INTRODUCTION: The association of coronary stent malapposition (SM) and adverse clinical outcomes after percutaneous coronary intervention (PCI) remains unclear. We aimed to perform a systematic review and meta-analysis of randomized and observational studies to assess the association between acute and persistent SM detected using intravascular ultrasound (IVUS) or optical coherence tomography (OCT) and adverse cardiovascular outcomes.EVIDENCE ACQUISITION: Available studies were identified through a systematic search of PubMed, reference lists of relevant articles, and Medline. Main efficacy outcomes of interest were: device-oriented composite endpoint (DoCE, including cardiac death, myocardial infarction [MI], target lesion revascularization [TLR], and stent thrombosis [ST]), major safety events (MSE, including cardiac death, MI and ST), TLR, and ST. A sensitivity analysis regarding the impact of major malapposition was also performed. EVIDENCE SYNTHESIS: A total of 9 studies enrolling 6497 patients were included in the meta-analysis. After a mean follow-up of 24 +/- 14 months, overall acute and/or persistent malapposition was not significantly associated with the occurrence of all the outcomes of interest, including DoCE (risk ratio [RR] 1.00, 95% confidence interval [CI, 0.79-1.26], P=0.99), MSE (RR 1.42, 95%CI [0.81-2.50], P=0.22), TLR (RR 0.84, 95%CI [0.59-1.19], P=0.33), and ST (RR 1.16, 95%CI [0.48-2.85], P=0.74). In the sensitivity analysis, we found a significant increase of MSE in patients with major malapposition (RR 2.97, 95%CI [1.51-5.87], P=0.001).CONCLUSIONS: Acute and persistent SM were not overall associated with adverse cardiovascular clinical outcomes at follow-up. However, major malapposition was associated with an increased risk of major safety events, including cardiac death, MI and ST. These findings should be taken into account during stent implantation and PCI optimization

Pre-stenting residual thrombotic volume assessed by dual quantitative coronary angiography predicts microvascular obstruction in patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention

BACKGROUND: Microvascular obstruction (MVO) is a frequent occurrence after primary percutaneous coronary intervention (pPCI), and is associated with adverse left ventricular remodeling and worse clinical outcome. Distal embolization of thrombotic material is one of the most important underlying mechanisms. The aim of this study was to investigate the relation between the thrombotic volume evaluated by dual quantitative coronary angiography (QCA) prior to stenting and the occurrence of MVO as assessed by cardiac magnetic resonance (CMR).METHODS: Forty-eight patients with ST-segment elevation myocardial infarction (STEMI) undergoing pPCI and receiving CMR within 7 days from admission were included. Pre-stenting residual thrombus volume at the site of the culprit lesion was measured by applying automated edge detection and video-assisted densitometry techniques (i.e., dualQCA), and patients were categorized into tertiles of thrombus volume. The presence of delayed-enhancement MVO, as well as its extent (MVO mass), were assessed by CMR.RESULTS: Pre-stenting dual-QCA thrombus volume was significantly greater in patients with MVO than in those without (5.85 mm(3) [2.05-16.71] vs. 1.88 mm(3) [1.03-6.92], P=0.009). Patients in the highest tertile showed greater MVO mass compared to those in the mid and lowest tertiles (113.3 gr [0.0-203.8] vs. 58.5 g [0.00-144.4] vs. 0.0 g [0.0-60.225], respectively; P=0.031). The best cut-off value of dual-QCA thrombus volume for prediction of MVO was 2.07 mm(3) (AUC: 0.720). The addition of dual-QCA thrombus volume to the traditional angiographic indices of no-reflow enhanced the prediction of MVO by CMR (R=0.752).CONCLUSIONS: Pre-stenting dual-QCA thrombus volume is associated with the presence and extent of MVO detected by CMR in patients with STEMI. This methodology may aid the identification of patients at higher risk of MVO and guide adoption of preventive strategies

Impact of acute and persistent stent malapposition after percutaneous coronary intervention on adverse cardiovascular outcomes

Introduction: The association of coronary stent malapposition (SM) and adverse clinical outcomes after percutaneous coronary intervention (PCI) remains unclear. We aimed to perform a systematic review and meta-analysis of randomized and observational studies to assess the association between acute and persistent SM detected using intravascular ultrasound (IVUS) or optical coherence tomography (OCT) and adverse cardiovascular outcomes. Evidence acquisition: Available studies were identified through a systematic search of PubMed, reference lists of relevant articles, and Medline. Main efficacy outcomes of interest were: device-oriented composite endpoint (DoCE, including cardiac death, myocardial infarction [MI], target lesion revascularization [TLR], and stent thrombosis [ST]), major safety events (MSE, including cardiac death, MI and ST), TLR, and ST. A sensitivity analysis regarding the impact of major malapposition was also performed. Evidence synthesis: A total of 9 studies enrolling 6497 patients were included in the meta-analysis. After a mean follow up of 24±14 months, overall acute and/or persistent malapposition was not significantly associated with the occurrence of all the outcomes of interest, including DoCE (risk ratio [RR] 1.00, 95% confidence interval [CI, 0.79-1.26], P=0.99), MSE (RR 1.42, 95%CI [0.81-2.50], P=0.22), TLR (RR 0.84, 95%CI [0.59-1.19], P=0.33), and ST (RR 1.16, 95%CI [0.48-2.85], P=0.74). In the sensitivity analysis, we found a significant increase of MSE in patients with major malapposition (RR 2.97, 95%CI [1.51-5.87], P=0.001). Conclusions: Acute and persistent SM were not overall associated with adverse cardiovascular clinical outcomes at follow-up. However, major malapposition was associated with an increased risk of major safety events, including cardiac death, MI and ST. These findings should be taken into account during stent implantation and PCI optimization

Pre-stenting residual thrombotic volume assessed by dual quantitative coronary angiography predicts microvascular obstruction in patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention

Background: Microvascular obstruction (MVO) is a frequent occurrence after primary percutaneous coronary intervention (pPCI), and is associated with adverse left ventricular remodeling and worse clinical outcome. Distal embolization of thrombotic material is one of the most important underlying mechanisms. The aim of this study was to investigate the relation between the thrombotic volume evaluated by dual quantitative coronary angiography (QCA) prior to stenting and the occurrence of MVO as assessed by cardiac magnetic resonance (CMR). Methods: Forty-eight patients with ST-segment elevation myocardial infarction (STEMI) undergoing pPCI and receiving CMR within 7 days from admission were included. Pre-stenting residual thrombus volume at the site of the culprit lesion was measured by applying automated edge detection and video-assisted densitometry techniques (i.e., dual-QCA), and patients were categorized into tertiles of thrombus volume. The presence of delayed-enhancement MVO, as well as its extent (MVO mass), were assessed by CMR. Results: Pre-stenting dual-QCA thrombus volume was significantly greater in patients with MVO than in those without (5.85 mm3 [2.05-16.71] vs. 1.88 mm3 [1.03-6.92], P=0.009). Patients in the highest tertile showed greater MVO mass compared to those in the mid and lowest tertiles (113.3 gr [0.0-203.8] vs. 58.5 g [0.00-144.4] vs. 0.0 g [0.0-60.225], respectively; P=0.031). The best cut-off value of dual-QCA thrombus volume for prediction of MVO was 2.07 mm3 (AUC: 0.720). The addition of dual-QCA thrombus volume to the traditional angiographic indices of no-reflow enhanced the prediction of MVO by CMR (R=0.752). Conclusions: Pre-stenting dual-QCA thrombus volume is associated with the presence and extent of MVO detected by CMR in patients with STEMI. This methodology may aid the identification of patients at higher risk of MVO and guide adoption of preventive strategies

Characteristics and outcomes of an international cohort of 600 000 hospitalized patients with COVID-19

Background: We describe demographic features, treatments and clinical outcomes in the International Severe Acute Respiratory and emerging Infection Consortium (ISARIC) COVID-19 cohort, one of the world's largest international, standardized data sets concerning hospitalized patients. Methods: The data set analysed includes COVID-19 patients hospitalized between January 2020 and January 2022 in 52 countries. We investigated how symptoms on admission, co-morbidities, risk factors and treatments varied by age, sex and other characteristics. We used Cox regression models to investigate associations between demographics, symptoms, co-morbidities and other factors with risk of death, admission to an intensive care unit (ICU) and invasive mechanical ventilation (IMV). Results: Data were available for 689 572 patients with laboratory-confirmed (91.1%) or clinically diagnosed (8.9%) SARS-CoV-2 infection from 52 countries. Age [adjusted hazard ratio per 10 years 1.49 (95% CI 1.48, 1.49)] and male sex [1.23 (1.21, 1.24)] were associated with a higher risk of death. Rates of admission to an ICU and use of IMV increased with age up to age 60 years then dropped. Symptoms, co-morbidities and treatments varied by age and had varied associations with clinical outcomes. The case-fatality ratio varied by country partly due to differences in the clinical characteristics of recruited patients and was on average 21.5%. Conclusions: Age was the strongest determinant of risk of death, with a ∼30-fold difference between the oldest and youngest groups; each of the co-morbidities included was associated with up to an almost 2-fold increase in risk. Smoking and obesity were also associated with a higher risk of death. The size of our international database and the standardized data collection method make this study a comprehensive international description of COVID-19 clinical features. Our findings may inform strategies that involve prioritization of patients hospitalized with COVID-19 who have a higher risk of death

ISARIC-COVID-19 dataset: A Prospective, Standardized, Global Dataset of Patients Hospitalized with COVID-19

The International Severe Acute Respiratory and Emerging Infection Consortium (ISARIC) COVID-19 dataset is one of the largest international databases of prospectively collected clinical data on people hospitalized with COVID-19. This dataset was compiled during the COVID-19 pandemic by a network of hospitals that collect data using the ISARIC-World Health Organization Clinical Characterization Protocol and data tools. The database includes data from more than 705,000 patients, collected in more than 60 countries and 1,500 centres worldwide. Patient data are available from acute hospital admissions with COVID-19 and outpatient follow-ups. The data include signs and symptoms, pre-existing comorbidities, vital signs, chronic and acute treatments, complications, dates of hospitalization and discharge, mortality, viral strains, vaccination status, and other data. Here, we present the dataset characteristics, explain its architecture and how to gain access, and provide tools to facilitate its use