Hybrid Micro Grid Systems - Drivers & Challenges

Increasing environmental concerns, consumer expectations in terms of reliability & better quality of power supply and improving economics of distributed energy resources (DER) based on renewable, is making Micro Grid a viable proposition. Hybrid Micro grid utilising diversity of various energy resources including Wind, Solar, Biomass, and Energy Storage Batteries is found to be a better solution than single source Micro grid system. However, integration of multiple resources poses many issues & challenges. Moreover, present distribution system offers many technical & operational glitches for successful integration of Micro Grid Technologies. Paper addresses such challenges, issues and solutions. The Micro Grid resources optimization is generally being done based on self-sufficiency criterion which utilizes the grid support only in the event of contingencies like fault, generation disruptions (DER) etc. Paper also discusses various resources optimization techniques to serve the net load requirements in all time of the Day (TOD). Keywords: Distributed Energy, Black Start, net load, Islanding, MGCC, PSO, Genetic Algorith

Right Ventricular Systolic Pressure - Non-Invasive Bedside Predictor of Mortality and Readmission in Heart Failure With Reduced and Preserved Ejection Fraction Hospitalization

OBJECTIVE: To study the prognostic role of right ventricular systolic pressure (RVSP) in patients with heart failure (HF). BACKGROUND: Although RVSP is a readily available echocardiographic parameter, it is often underused. Its prognostic role in patients with heart failure is not well established compared with pulmonary artery pressure measured by right heart catheterization. METHODS: This single-center retrospective cohort study included patients with acute heart failure hospitalization admitted to the hospital from January 2005 to December 2018. The primary predictor was right ventricular systolic pressure (RVSP) obtained from bedside transthoracic echocardiography at admission. We divided RVSP into two groups, RVSP \u3c40 mm Hg (reference group) and RVSP ≥40 mm Hg. Primary outcome was all-cause mortality. Secondary outcomes were all-cause readmission and cardiac readmission. We conducted propensity-score matching and applied cox-proportional hazard model to compute hazard ratio (HR) with 95% confidence interval (CI). RESULTS: Out of 972 HF patients, 534 patients had RVSP \u3c40 mm Hg and 438 patients had RVSP ≥40 mm Hg. Patients with RVSP ≥40 mm Hg compared with RVSP \u3c40 mm Hg were associated with higher rates of death [HR: 1.60, 95% CI: 1.22-2.09, P-value = 0.001], all-cause readmissions [HR: 1.37, 95% CI: 1.09-1.73, P-value = 0.008] and cardiac readmissions [HR: 1.41, 95% CI: 1.07-1.85, P-value = 0.014]. CONCLUSION: Higher RVSP (≥40 mm Hg) in HF patients was associated with higher rates of death, all-cause readmissions, and cardiac readmissions. RVSP can be considered as a prognostic marker for mortality and readmission

Absolute Lymphocyte Count as a Predictor of Mortality and Readmission in Heart Failure Hospitalization

BACKGROUND: There is renewed interest in pursuing frugal and readily available laboratory markers to predict mortality and readmission in heart failure. We aim to determine the relationship between absolute lymphocyte count (ALC) and clinical outcomes in patients with heart failure hospitalization. METHODS: This was a retrospective cohort study of patients with heart failure. Patients were divided into two groups based on ALC, less than or equal to 1500 cells/mm3 and \u3e 1500 cells/ mm3. The primary outcome was all-cause mortality. We did subgroup analysis based on ejection fraction and studied the association between ALC categories and clinical outcomes. Both ALC groups are matched by propensity score, outcomes were analyzed by Cox regression, and estimates are presented in hazard ratios (HR) and 95% confidence intervals (CI). RESULTS: We included 1029 patients in the pre-matched cohort and 766 patients in the propensity-score matched cohort. The median age was 64 years (IQR, 54-75), and 60.78% were male. In the matched cohort, ALC less than or equal to 1500 cells/mm3 had a higher risk of mortality compared with ALC \u3e 1500 cells/mm3 (HR 1.51, 95% CI: 1.17-1.95; P = 0.002). These results were reproducible in subgroups of heart failure. When ALC was divided into four groups based on their levels, the lowest group of ALC had the highest risk of mortality. CONCLUSIONS: In patients with heart failure and both subgroups, ALC less than or equal to 1500 cells/mm3 had a higher risk of mortality. Patients in lower groups of the ALC categories had a higher risk of mortality

Meta-Analysis of Transcatheter Aortic Valve Implantation in Patients With Stenotic Bicuspid Versus Tricuspid Aortic Valve

Most of the trials investigating the role of transcatheter aortic valve implantation (TAVI) across various strata of risk categories have excluded patients with bicuspid aortic stenosis (BAS) due to its anatomical complexities. The aim of this study was to perform a meta-analysis with meta-regression of studies comparing clinical, procedural, and after-procedural echocardiographic outcomes in BAS versus tricuspid aortic stenosis (TAS) patients who underwent TAVI. We searched the PubMed and Cochrane databases for relevant articles from the inception of the database to October 2019. Continuous and categorical variables were pooled using inverse variance and Mantel-Haenszel method, respectively, using the random-effect model. To rate the certainty of evidence for each outcome, we used the GRADE (Grading of Recommendations, Assessment, Development, and Evaluations) approach. Nineteen articles were included in the final analysis. There was no difference in the risk of 30-day mortality, 1-year mortality, 30-day cardiovascular mortality, major and/or life-threatening bleeding, major vascular complications, acute kidney injury, permanent pacemaker implantation, device success, annular rupture, after-procedural aortic valve area, and mean pressure gradient between the 2 groups. BAS patients who underwent TAVI had a higher risk of 30-day stroke, conversion to surgery, need for second valve implantation, and moderate to severe paravalvular leak. In conclusion, the present meta-analysis supports the feasibility of TAVI in surgically ineligible patients with BAS. However, the incidence of certain procedural complications such as stroke, conversion to surgery, second valve implantation, and paravalvular leak is higher among BAS patients compared with TAS patients, which must be discussed with the patient during the decision-making process