Optimal Expansion Research Articles

Single-Session Versus Staged Multivessel Optimal IVUS-Guided PCI in Patients With CCS or NSTE-ACS

BackgroundThere are no studies comparing single-session vs staged multivessel intravascular ultrasound (IVUS)-guided percutaneous coronary intervention (PCI) in patients with chronic coronary syndrome (CCS) or non–ST-segment-elevation acute coronary syndrome (NSTE-ACS). ObjectivesThe authors aimed to compare single-session vs staged multivessel IVUS-guided PCI in patients with CCS or NSTE-ACS. MethodsThe OPTIVUS-Complex PCI study multivessel cohort was a prospective multicenter single-arm trial enrolling 1,021 patients with CCS or NSTE-ACS undergoing multivessel PCI including left anterior descending coronary artery using IVUS aiming to meet the prespecified OPTIVUS criteria for optimal stent expansion. We compared single-session vs staged multivessel PCI. The primary endpoint was a composite of death, myocardial infarction, stroke, or any coronary revascularization. ResultsThere were 246 patients (24.1%) undergoing single-session multivessel PCI, and 775 patients (75.9%) undergoing staged multivessel PCI. There was a wide variation in the prevalence of single-session multivessel PCI across the participating centers. The staged multivessel PCI group more often had complex coronary anatomy such as 3-vessel disease, chronic total occlusion, and calcified lesions requiring an atherectomy device compared with the single-session multivessel PCI group. The rates of PCI success, procedural complications, and meeting OPTIVUS criteria were not different between groups. The cumulative 1-year incidence of the primary endpoint was not different between single-session and staged multivessel PCI groups (9.0% vs 10.8%, log-rank P = 0.42). After adjusting confounders, the effect of single-session multivessel PCI relative to staged multivessel PCI was not significant for the primary endpoint (HR: 0.95; 95% CI: 0.58-1.55; P = 0.84). ConclusionsSingle-session and staged multivessel IVUS-guided PCI had similar 1-year outcomes.

Study of the independent cooling performance of adiabatic compressed air energy storage system

The adiabatic compressed air energy storage (A-CAES) system can realize the triple supply of cooling, heat, and electricity output. With the aim of maximizing the cooling generation and electricity production with seasonal variations, this paper proposed three advanced A-CAES refrigeration systems characterized by chilled water supply, cold air supply, and hybrid supply systems, respectively. Corresponding system models were established with a storage capacity of 5000 m3 and an operating pressure range of 4.6–10 MPa. After validating the simulation model with literature data, a parametric study and following economy analysis were conducted in different seasons. The optimal expansion unit configurations of the three systems were confirmed based on their cooling and electricity production under different configurations. Results showed that the maximum cooling capacity of the three systems under optimal configurations are 20.33GJ, 40.05GJ, and 45.05GJ, which can supply 100, 197, and 213 households, respectively. The enhanced cooling capacity of the three systems indicated promising alternatives for refrigeration equipment in the residential area, reducing investment and peak power consumption simultaneously. In addition, the static payback periods of the three systems presented in this study are 21.45 years, 11.88 years, and 16.50 years, respectively. The expansion unit configuration of the hybrid cooling system was confirmed to be the most suitable configuration for cooling maximization. This study can provide a reference for the system design integrated with A-CAES technology for cooling supply and cost savings.

Renewable Energy Community’s Barriers and Impact on Centralised Energy Production

Major changes are taking place in the energy sector. In order to achieve climate neutrality, it is crucial to increase energy production from renewable energy sources. One way to accomplish this is to establish energy communities and cooperatives, which require optimal development and expansion solutions. Energy cooperatives are, by definition, community projects whose primary goal is to generate electricity and heat for their own use as well as for sale and distribution. The main reasons for establishing such communities are to reduce costs and the negative impact on the environment, as well as to democratise and decentralise production, reducing reliance on larger producers. This kind of collaborative effort also allows people who lack the necessary funds and knowledge to participate in the production of renewable energy. The goal of energy communities is to use energy produced primarily from renewable energy sources; the easiest way to do this is to use solar panels, but there are also other options. Although the European Union has launched several programmes to increase the number of energy communities, there are several barriers that prevent them from being established. In the conditions where energy communities are connected to largescale energy systems, it is also important to assess how energy communities affect centralised energy production and overall energy efficiency. This study provides a thorough analysis of the barriers to establishing energy communities as well as their impact on centralised energy production and overall energy production efficiency.

Optimal expansion planning of electric vehicle fast charging stations

With the penetration rate of electric vehicles (EVs) increasing exponentially, the high charging load may cause new issues in future power system, e.g., voltage drop. Besides, EV Charging stations (EVCSs) located in inadequate places exacerbate these issues, causing charging demand to concentrate on a few EVCSs. Therefore, the charging demand estimation for EVCSs and their strategic placement is essential for the system operators and charging station owner. The paper proposes a method for optimal EVCS placement to achieve charging demand dispersion considering not only installation cost but also drivers’ preferences and existing charging stations. To optimally place EVCSs, this work first estimates the charging demand of existing EVCSs based on kernel density estimation. The charging demand for new and existing EVCSs is modeled using the nearest neighbor search to consider drivers’ preference for the nearer station. Next, the EVCS placement problem is formulated to minimize the peak charging demand using integer nonlinear programming, a non-convex problem. To tackle this non-convex problem, a minimax genetic algorithm is proposed, which is genetic algorithm combined with game theory. The validity and effectiveness of the proposed method are demonstrated through simulations based on real data from Jeju Island. After applying the proposed method, new EVCS placement is determined by analyzing the tradeoff between the degree of charging demand dispersion and installation cost. As a result, the charging demand concentrated on a particular EVCS is suitably dispersed.

The Degree of Stent Apposition Measured by Stent Enhancement at the Level of the Side Branch as a Novel Predictor of Procedural Success in Left Main PCI.

Stent enhancement techniques allow adequate visualization of stent deformation or incomplete stent expansion at the ostium of the side branch. Measuring the stent enhancement side branch length (SESBL) could reflect procedural success in terms of optimal stent expansion and apposition with better long-term outcomes. A longer SESBL may reflect a better stent apposition at the polygon of confluence and at the side branch (SB) ostium. We evaluated 162 patients receiving the left main (LM) provisional one-stent technique and measured the SESBL, dividing them into two groups: SESBL≤ 2.0 mm and SESBL > 2.0 mm. The mean SESBL was 2.0 ± 1.2 mm. More than half of the bifurcations had both main and side branch lesions (Medina 1-1-1) (84 patients, 51.9%) and the length of the SB disease was 5.2 ±1.8 mm. Kissing balloon inflation (KBI) was performed in 49 patients (30.2%). During follow-up (12 months), there was a significantly higher rate of cardiac death in the SESBL ≤ 2.0 mm group (p = 0.02) but no significant difference in all major adverse cardiovascular events (MACEs) (p = 0.7). KBI did not influence the outcomes (p = 0.3). Suboptimal SESBL is positively correlated with worse outcomes and SB compromise. This novel sign could aid the LM operator to assess the level of stent expansion at the ostium of the SB in the absence of intracoronary imaging.

Planning of EV Charging Station With Distribution Network Expansion Considering Traffic Congestion and Uncertainties

Proper planning for electric vehicle (EV) charging stations along with the required expansion of the distribution network is essential for the continuous growth of EV and conventional loads. This paper proposes a realistic and sustainable solution for deciding the location and capacity of the EV fast-charging stations along with the optimal multistage expansion of the distribution network to cope with future load growth. An overlaid traffic network with a distribution network is taken for the realistic approach. EV user convenience factor and user happiness factor are proposed along with the distribution network energy loss for better planning of fast-charging stations. To get charged, the appropriate fast-charging station and its best route are decided through minimum energy consumption by the EVs, considering traffic congestion and distances. Up-gradation of lines, up-gradation of the substation, addition of new fast-charging station, allocation of DSTATCOM and allocation of renewable-based distributed generation are performed for distribution network expansion planning. The whole work is formulated in three layers with a sub-layer. Uncertainties of EV driving patterns, energy requirement, traffic congestion, load and renewable generation are undertaken by the 2m point estimation method. The solution is carried out along with validation using different metaheuristic methods and integer linear programming.

"Burying" covered coronary stents under drug-eluting stents: A novel approach to ensure long-term stent patency.

Covered coronary stent (CS) implantation is associated with a high risk for in-stent restenosis (ISR) and stent thrombosis (ST). We describe the outcomes after overstenting ("burying") CS using contemporary drug-eluting stents (DES). We analyzed short- and long-term outcomes of consecutive patients who had had a CS implanted, which was consecutively covered ("buried") with a third-generation DES. CSs were primarily post-dilated and then covered with a longer DES overlapping the proximal and distal edges of the CS. To ensure optimal stent expansion and appositions, all lesions were post-dilated using adequately sized non-compliant balloons. Between 2015 and 2020, 23 patients (mean age 67 ± 14 years, 74% males) were treated using this novel approach. Reasons for implanting CS included treatment of coronary aneurysms (n = 7; 30%), coronary perforations (n = 13; 57%), and aorto-ostial dissections (n = 3; 13%). All CSs were successfully deployed, and no peri-procedural complications occurred. The median time of follow-up was 24.5 (interquartile range [IQR] 11.7-37.9) months. All patients had a 1-month follow-up (FU) and 19/23 (83%) patients had 12-month FU (FU range 1-60 months). No probable or definite STs occurred, and no cardiovascular deaths were observed. Among patients undergoing angiographic FU (11/23 [48%]), 1/23 showed angiographically significant ISR 6 months post CS implantation. Burying a coronary CS under a DES appears to be a safe and promising strategy to overcome the limitations of the currently available CS devices, including a relatively high risk for target lesion failure due to ISR and ST.

Sodium Chloride Physiological Saline Solution Versus Water Preparations Injectable in the Use of Shockwave Intravascular Lithotripsy: A Single-Center Experience

Shockwave intravascular lithotripsy (IVL) coronary system is a very useful new technology for de novo severely calcified coronary artery plaques before percutaneous coronary intervention (PCI). The device uses a semi-compliant low-pressure balloon, integrated into a sterile catheter, to deliver by vaporizing fluid an expanding bubble that generates high-pressure ultrasonic energy by waves that create multiplane longitudinal micro-macro fractures in calcified plaques, which facilitate optimal stent placement and expansion, and luminal gain. The use of Shockwave IVL coronary system in our cardiac catheterization laboratory (Cath lab) at the "Clinique Saint-Hilaire" in Rouen, France, started in March 2019, with 42 procedures performed since this date: two patients in 2019, two patients in 2020, seven patients in 2021, 23 patients in 2022, and eight patients since the beginning of 2023. We had experienced problems at the beginning of our activity for the first 11 patients (two patients in 2019, two patients in 2020, and seven patients in 2021): after less than five pulses, the shock therapy stopped. We used initially for Shockwave IVL semi-compliant low-pressure integrated balloons a mixture of 50% contrast and 50% water preparations injectable (PPI). After changing water PPI by sodium chloride physiological saline solution, we never encountered this problem again for the following 31 patients (23 patients in 2022, and eight patients since the beginning of 2023). In fact, the proper functioning of Shockwave IVL system requires ions in balloon mixture in addition to the contrast. It is thanks to the ions contained in sodium chloride physiological saline solution that the spark necessary for shocks delivery after balloon inflation is produced. Water PPI or sodium chloride physiological saline solution is used in angioplasty balloons in a lot of Cath labs worldwide. It is therefore essential to disseminate in the worldwide Cath lab the obligation to put in Shockwave IVL semi-compliant low-pressure integrated balloons sodium chloride physiological saline solution, rather than water PPI for optimal performance, and the importance of Shockwave Medical reporting this to interventional cardiologists.

Development of Chinese Dynamic Optimal Power Expansion Planning Model Integrated with Hydrogen and Fuel Cell System

This study evaluates optimal carbon‐neutral power supply strategy in China up to 2060 with a multi‐region high spatial and temporal dynamic optimal power expansion planning model. Furthermore, this study explores installable potential of hydrogen and fuel cell system and analyzes the influences of its capital cost reduction at different levels. The results show that the national installed capacity would rise to be over 9000 GW in 2060, in which wind and solar PV will take up around 61%; the intermittency of renewable power generation is mainly managed with hydrogen production, power output curtailment and charge and discharge of energy storage; hydrogen and fuel cell system would improve the capacity factor and reduce the curtailment rate of renewable power generation. © 2023 The Authors. IEEJ Transactions on Electrical and Electronic Engineering published by Institute of Electrical Engineer of Japan and Wiley Periodicals LLC.

Optimal Intravascular Ultrasound-Guided Percutaneous Coronary Intervention in Patients With Multivessel Disease

BackgroundIntravascular ultrasound (IVUS) was only rarely used in landmark trials comparing percutaneous coronary intervention (PCI) with coronary artery bypass grafting (CABG) in patients with multivessel disease. ObjectivesThe authors aimed to evaluate clinical outcomes after optimal IVUS-guided PCI in patients undergoing multivessel PCI. MethodsThe OPTIVUS (OPTimal IntraVascular UltraSound)-Complex PCI study multivessel cohort was a prospective multicenter single-arm study enrolling 1,021 patients undergoing multivessel PCI, including left anterior descending coronary artery using IVUS, aiming to meet the prespecified criteria (OPTIVUS criteria: minimum stent area > distal reference lumen area [stent length ≥28mm], and minimum stent area >0.8 × average reference lumen area [stent length <28mm]) for optimal stent expansion. The primary endpoint was major adverse cardiac and cerebrovascular events (MACCE) (death/myocardial infarction/stroke/any coronary revascularization). The predefined performance goals were derived from the CREDO-Kyoto (Coronary REvascularization Demonstrating Outcome study in Kyoto) PCI/CABG registry cohort-2 fulfilling the inclusion criteria in this study. ResultsIn this study, 40.1% of the patients met OPTIVUS criteria in all stented lesions. The cumulative 1-year incidence of the primary endpoint was 10.3% (95% CI: 8.4%-12.2%), which was significantly lower than the predefined PCI performance goal of 27.5% (P < 0.001), and which was numerically lower than the predefined CABG performance goal of 13.8%. The cumulative 1-year incidence of the primary endpoint was not significantly different regardless of meeting or not meeting OPTIVUS criteria. ConclusionsContemporary PCI practice conducted in the OPTIVUS-Complex PCI study multivessel cohort was associated with a significantly lower MACCE rate than the predefined PCI performance goal, and with a numerically lower MACCE rate than the predefined CABG performance goal at 1 year.

AC transmission expansion planning based on self‐organized criticality to mitigate the risk of cascading blackouts

AbstractThe secular increase of load causes the evolving power system to operate near the critical margins. In such attitudes, the probability of cascading line outages, as the major reason for recent blackouts, is much more than expected. As a result, an innovative approach for optimal AC transmission expansion planning (TEP) to minimize the risk of cascading blackouts is presented in this paper. The proposed multi‐objective AC‐TEP problem minimizes the expected energy not supplied due to the total load shedding imposed on the system to mitigate the risk of cascading line outages along with the total investment and operational costs of the new transmission lines planned to be optimally added to the system. This probabilistic procedure is based on self‐organized criticality and considers the actual aspects of the power system such as reactive power and voltage concerns in the planning stage. The obtained Pareto front set provides the opportunity for the planners to choose the most preferred solution. The proposed method is implemented and verified in the IEEE 118‐bus test system and compared with two types of TEP approaches. The first one is a previously reported version of this work which was a simplified DC model of the problem and the second one is the conventional AC‐TEP model. The obtained results show the benefits of the proposed AC model on the mitigation of cascading line outages in a more realistic framework, considering the impact of reactive power and voltage stability concerns.

Short-term energy scenario of district energy system using optimised renewable energy mix with and without energy storage

The study proposes a multi-objective, multi-node optimisation model for the district energy system to achieve high renewable energy share by 2030. A combined analysis is conducted to reduce total system cost, carbon footprint; and satisfy inertia and flexibility requirements of integrated renewable energy system of the considered district. An hourly deterministic tool, Flextool, developed by IRENA, is used for analysis. Multiple scenarios are analysed to identify an optimal capacity expansion plan. The interaction between various energy generation units while meeting hourly energy demand is studied. The flexibility issues concerned with high VRE (Variable renewable energy) integration expected in the future energy grid are identified, and the effect of battery storage on curtailment is evaluated. The maximum VRE absorption capacity of the district is examined, and the shadow value is calculated for all considered scenarios. It is concluded that the district energy system could achieve 52% renewable energy share, zero loss of load and minimum curtailment in 2030 with adequate policy interventions. If the recommended investment pattern is followed, carbon intensity will reduce from 10.729 g/kWh to 6.70 g/kWh and 6.02 g/kWh without and with battery storage systems. The application of battery storage as a flexibility solution resulted in a significant reduction in curtailments. The study demonstrated that Flextool is a competent flexibility assessment tool which provides comprehensive support to optimise capacity expansion and system operations.

Determination of Physical and Mechanical Properties of Porous Blocks (Bricks) Produced with Brick Clay

Clay brick has recently become a very inevitable product for the construction industry due to the being a sustainable and relatively cheaper material especially with the parallel of developments on foam-forming agents. These bricks have two main problems. These are high unit volume weight and thermal conductivity. In this study, an expansion agent was added to the brick raw material to reduce the unit weight of the brick and to increase the thermal insulation. Samples were produced by adding a mixture of expanding at certain rates. The produced samples were fired at 850, 900, 950, 1000, 1050 and 1100 oC to obtain 100×100×100 mm bricks. The unit volume weight, water absorption, void ratio, compressive strength, compressive strength after freezing-thawing and thermal conductivity properties of the produced bricks were investigated. According to the data obtained in the research, the optimum expansion chemical ratio is 15%. The most suitable firing temperature was determined as 1100 oC. The samples produced with 15% expander at 1100 °C, unit volume weight 744 kg/m3, water absorption 31.83%, void ratio 36.88 %, compressive strength 6.93 MPa, compressive strength after freezing-thawing 5.10 MPa and thermal conductivity λ=0.16 W/mK.

Treatment of Calcified Lesions Using a Dedicated Super-High Pressure Balloon: Multicenter Optical Coherence Tomography Registry

BackgroundCalcified lesions often lead to difficulty achieving optimal stent expansion. OPN non-compliant (NC) is a twin layer balloon with high rated burst pressure that may modify calcium effectively. MethodsRetrospective, multicenter registry in patients undergoing optical coherence tomography (OCT) guided intervention with OPN NC. Superficial calcification with > 180o arc and > 0.5 mm thickness, and/or nodular calcification with > 90o arc were included. OCT was performed in all cases before and after OPN NC, and after intervention. Primary efficacy endpoints were frequency of expansion (EXP) ≥80 % of the mean reference lumen area and mean final EXP by OCT, and secondary endpoints were calcium fractures (CF), and EXP ≥90 %. Results50 cases were included; 25 (50 %) superficial, and 25 (50 %) nodular. Calcium score of 4 in 42 (84 %) cases and 3 in 8 (16 %). OPN NC was used alone, or after other devices if further modification was needed, NC in 27 (54 %), cutting in 29 (58 %), scoring in 1 (2 %), IVL in 2 (4 %); or if non-crossable lesion, rotablation in 5 (10 %) cases. EXP ≥80 % was achieved in 40 (80 %) cases with mean final EXP post intervention of 85.7 % ± 8.9. CF were documented in 49 (98 %) cases; multiple in 37 (74 %). There were 1 flow limiting dissection requiring stent deployment and 3 non-cardiovascular related deaths in 6 months follow-up. No records of perforation, no-reflow or other major adverse events. ConclusionAmong patients with heavy calcified lesions undergoing OCT guided intervention with OPN NC, acceptable expansion was achieved in most cases without procedure related complications.

CBCT Evaluation of Mid-palatine Suture Maturation for Optimum Expansion Mechanics

CBCT Evaluation of Mid-palatine Suture Maturation for Optimum Expansion Mechanics

Identifying optimal capacity expansion and differentiated capacity payments under risk aversion and market power: A financial Stackelberg game approach

We investigate how capacity payments in combination with scarcity pricing of energy can ensure resource adequacy in electricity markets, defined as the ability of supply and other resources to provide enough energy and capacity to meet demand under steady-state operating conditions. This work generalizes models for determining capacity payments by deriving second-best discriminatory payments by resource type that account not only for the “missing money” market failure that arises from energy price caps, but also for market power in the capacity market and differences in risk tolerance among resource types that can arise from failures in risk and capital markets. A bi-level equilibrium-constrained optimization model is proposed to define second-best capacity payments in a static long-run setting, considering the impacts of those payments on the mix and cost of generation investment and energy outputs. The lower-level suppliers play a Nash game to determine the generation mix under a capacity payment scheme, while the upper-level regulator considers consumer welfare and resource adequacy. We introduce an equivalent formulation via a variational inequality approach, and find conditions for the solution to exist. Discriminatory payments are found to be second-best when there are market power in the investment game, price caps in energy markets and imperfections in risk markets that lead to diverse risk attitudes.

Dynamic material flow analysis of Chinese ethylene production processes and optimal pathway exploration with potential environmental-economic impacts

China is expected to become the largest ethylene producer globally; environmental problems related with traditional ethylene production process of Chinese petrochemical industry will be further stern. This study aims to propose a feasible and optimal ethylene production expansion pathway to improve the trade-off between the environment and economy. A novel approach was adopted with material-energy-value flow analysis integration by combining dynamic scenario analysis. According to the results of scenario analysis, cleaner and lightweight production processes optimization achieved by adopting the alternative ethylene production process mix alleviated environmental pressure and achieved a weak decoupling of the low-carbon economy. A 26.1% increase in carbon productivity was achieved compared with the baseline scenario, whereas the coal to ethylene route should be phased-out, as more than 90% of the pollutants are generated by 10%–17% of the coal to ethylene facilities. However, CO2 emissions from ethylene will inevitably increase along with doubling ethylene production. An imbalance in pollutant generation also emerges if large-scale naphtha is exclusively promoted for ethylene plant implementation. The study provides methodological support for investigating feasible roadmaps for key product capacity expansion, and has practical meaning for high-quality industrial development domestically and globally.

ETCTN 10450: A phase I trial of peposertib and lutetium 177 DOTATATE in well-differentiated somatostatin receptor-positive gastroenteropancreatic neuroendocrine tumors (GEP-NETs).

TPS658 Background: Radiolabeled somatostatin analogues provide a means of delivering targeted radiation with a high therapeutic index to NETs that express somatostatin receptors (SSTRs). Radiolabeled somatostatin analogue Lutetium 177 DOTATATE (Lutathera) is a beta-emitting radionuclide, FDA approved for use in SSTR positive gastroenteropancreatic neuroendocrine tumors (GEPNETS) in the US based on the NETTER-1 Phase III trial. Despite favorable PFS and safety profile, the drug has limited cytoreductive capability with a 17% ORR. Peptide receptor radionuclide therapy (PRRT) also doesn’t seem to be very effective in treating peritoneal disease. We hypothesize that addition of an effective radiation sensitizer could help improve antitumor activity of Lutathera. Radiation is a potent inducer of DNA double-strand break (DSB); targeting signaling networks involved in DSB repair is a promising approach for enhancing cellular radiosensitivity. The primary repair mechanism of radiation-induced DSBs is nonhomologous end-joining (NHEJ) pathway, in which the DNA-PK (Deoxyribonucleic acid protein kinase) complex plays a pivotal role. Upregulation of DNA-PK promotes repair of DSBs leading to tumor radio-resistance preclinically and clinically. Thus, DNA-PK is an important molecular target for inhibiting DSB repair and enhancing the cytotoxicity of radiation. Peposertib is a selective inhibitor of DNA-PK that targets tumor cell DNA damage repair and survival by blocking NHEJ. We previously reported strong anti-tumor activity when Peposertib was used as radiation sensitizer in pre-clinical NET models. Methods: This study is an investigator initiated, NCI sponsored, multicenter phase 1 trial of peposertib and Lutetium Lu 177 DOTATATE in well-differentiated somatostatin receptor-positive gastroenteropancreatic neuroendocrine tumor (GEP-NETs) after the failure of at least one line of prior systemic cancer treatment. A total of 29 patients will be enrolled in the dose escalation with help of Bayesian optimal interval design (BOIN) and dose expansion cohorts. The study will be open through the NCI ETCTN (National Cancer Institute Experimental Therapeutics Clinical Trials Network) program. Patients will be treated with 177 lutetium dotatate in combination with peposertib. Peposertib will be administered orally from D1-21 with each dose of PRRT [200 mCi]. Primary endpoint is to evaluate recommended phase II dose (RP2D). Secondary endpoints are to evaluate safety, pharmacokinetics, and clinical activity (ORR and PFS). We are also evaluating Lu-177 DOTATATE dosimetry in collaboration with NIH IROC and plasma hPG80, a novel blood based diagnostic biomarker. In addition, the study will correlate clinical outcome with somatic tumor mutations and germline mutations. Clinical trial information: 04750954 .

Intravascular lithotripsy in calcified coronary lesions-A single tertiary care center experience from India

Abstract Funding Acknowledgements Type of funding sources: None. Aims Severe coronary calcification is a serious impediment to optimal stent expansion and can lead to stent failure and adverse outcomes. We hereby present Indian experience with intravascular lithotripsy(IVL) for the treatment of calcific lesions in acute and chronic coronary syndromes at our tertiary care center. Methods and results This is a single-center prospective study of all patients treated with intravascular lithotripsy (IVL) between June 2021 and June 2022. Patient demographics, procedural variables, and treatment outcomes and early MACE(30 days) were evaluated. During this period, there were 25 patients and 30 coronary lesions were treated with IVL-assisted percutaneous coronary intervention (PCI). The mean age of study population is 72.8±9.0 years. 96% of the study population were male. 88% of the study population were hypertensives and 68% were diabetics. Indications for PCI were acute coronary syndromes in 10 patients (40%), and chronic coronary syndrome in 13 patients (52 %). Optical Coherence Tomography (OCT) was used in 28% of the patients and Intravascular ultrasound(IVUS) was used in 12% of the patients. Rotablation was used in 12% of the patients. Upfront IVL usage was done in 32% of cases and rest of the cases (68%) IVL was done for suboptimal initial balloon pre dilatation or stent under expansion. Angiographic success (&amp;lt;20% residual stenosis) and final thrombolysis in myocardial infarction (TIMI) 3 flow occurred in 24 patients(96%).One patient (4%)had in hospital death post procedure. Conclusions IVL appears to be a safe and effective modality in modifying coronary calcium to achieve optimal stent expansion with low early MACE(Major adverse cardiovascular events).

Optimal grid expansion under future electricity demand for groundwater irrigation in Ethiopia

Ethiopia is a lower-income country with an agrarian based, fast-growing economy that is susceptible to climate change impacts. As the nation continues to develop, domestic electricity consumption and electricity export opportunities will increase alongside a growing electricity demand for groundwater irrigation to mitigate the effects of drought. There are upcoming mega-dams– the Grand Ethiopian Renaissance Dam, Genale Dawa III, and Koysha – that will triple the electricity generation capacity. However, the central electricity grid is not sufficient to efficiently utilize this new capacity. We model future grid expansion scenarios by building a regional-scale linear optimal power flow model based on a transshipment representation of power flow that guides cost-optimal generation operations and transmission expansion, while satisfying competing electricity demand for domestic electricity consumption, groundwater irrigation, and international electricity export.We first evaluate cost-optimal generation and transmission expansion for a baseline case, with an estimate of current Ethiopian electricity demand. We then consider five potential future demand scenarios. These demand scenarios include estimates of both present and future domestic electricity demand, multiple levels of productive electricity demand for groundwater irrigation, and demand for international exports. Compared to the baseline, seasonal capacity factors for generators in the five model scenarios increased when collocated with an increase in electricity demand except for the generators that already operated at maximum capacity. All scenarios with higher domestic regional demand than the baseline surpass the transmission expansion planned by the Ethiopian Electric Power Corporation, independent of changes in irrigation and export demand. Our analysis suggests that the current expansion plan is not sufficient to meet future demand. Our research contributes to the literature by creating an optimal power flow model that can be applied in data-poor environments to model endogenous electricity infrastructure decisions under different scenarios of internal and external demand.