Improvement of star identification algorithms using a database generation method based on spatial correlation of stars.

A star tracker, in lost-in-space (LIS) and tracking operation modes, applies an accurate algorithm in the star identification phase. The pattern-matching-based star identification algorithms apply patterns to search a prebuilt database. By applying this newly proposed database, it is possible to apply many LIS algorithms in the LIS and tracking modes. Modifying accurate LIS mode algorithms through this proposed method and applying them in the tracking mode would improve reliability, accuracy, and speed. The simulation results indicate that this proposed approach would reduce the search time for all applied algorithms by a tens factor based on the algorithm's specifications.

ELECTIVE PERCUTANEOUS CORONARY INTERVENTIONS--A COMPARISION OF EFFICACY OF CLOPIDOGREL AND PRASUGREL.

BACKGROUND: Percutaneous coronary interventions are almost always preceded by the loading dose of platelets inhibiter drugs such as clopidogrel or prasugrel and followed by maintenance therapy to decrease the mortality and morbidity due to stent thrombosis. This study was conducted to compare the efficacy of clopidogrel and prasugrel for inhibiting platelet aggregation among patients undergoing elective percutaneous coronary intervention. METHODS: This randomized controlled trial study was done in Department of Cardiology, Postgraduate Medical Institute Govt. Lady Reading Hospital Peshawar. A total of 148 patients were randomly allocated to either group-A containing 74 patients using clopidogrel or group-B containing 74 patients using prasugrel RESULTS: Group-A had 55 (74.3%) male and 19 (25.7%) females while group-B had 56(75.7%) males and 18 (24.3%) females (p=0.85). Mean age was 54.9 +/- 11.2 years in group-A and was 57.7 +/- 8.7 years in group-B (p=0.09). Mean body weight was 71.8?6.4 Kg in group-A and 70.8 +/- 6.3 Kg in group-B (p=0.35). Mean Baseline platelet aggregation before drug administration was 10.43 +/- 1.9 ohm in group-A while 10.12 +/- 2.2 ohm in group-B (p=0.36). Mean Follow up platelet aggregation 6 hours after drug administration was 5.88 +/- 2.9 in group-A while it was 3.47 +/- 1.8 ohm in group-B (p=0.001). Mean Difference between basal and follow up platelet aggregation +/-SD was 52.9649 +/- 24.77 in group-A while it was 82.25 +/- 14.34 in group-B (p=0.001). 63(85.15%) of group-A had inhibition of platelets aggregation >10% as compare to 72(97.3%) of group-B had inhibition of platelets aggregation >10% (p=0.009). CONCLUSION: Prasugrel is more efficacious than clopidogrel in term of inhibition of platelets aggregation.

Impact of drug-eluting stent-associated coronary artery spasm on 3-year clinical outcomes: A propensity score matching analysis.

BACKGROUND: It has been reported that significant endothelial dysfunction or clinically evident vasospasm can be associated with drug-eluting stents (DESs). However, the impact of DES associated coronary artery spasm (CAS) on long-term clinical outcomes has not been fully elucidated as compared with those of patients with vasospastic angina. METHODS: A total of 2797 consecutive patients without significant coronary artery lesion (<70%), who underwent the Acetylcholine (Ach) provocation test, were enrolled between Nov 2004 and Oct 2010. DES-associated spasm was defined as significant CAS in proximal or distal to previously implanted DES site at follow-up angiography with Ach test. Patients were divided into two groups (DES-CAS; n = 108, CAS; n = 1878). For adjustment, propensity score matching (PSM) was done (C-statistics = 0.766, DES-CAS; n = 102, CAS; n = 102). SPSS 20 (Inc., Chicago, Illinois) was used to analyze this data. RESULTS: Baseline characteristics were worse in the DES-CAS group. After PSM, both baseline characteristics and the Ach test results were balanced except higher incidence of diffuse CAS and ECG change in the DES-CAS group. During Ach test, the incidence of diffuse spasm (93.1% vs. 81.3%, p = 0.012) and ST-T change (10.7% vs. 1.9%, p = 0.010) were higher in the DES-CAS group. At 3-year, before and after adjustment, the DES-CAS group showed a higher incidence of coronary revascularization (9.8% vs. 0.0%, p = 0.001), recurrent chest pain requiring follow up coronary angiography (CAG, 24.5% vs. 7.8%, p = 0.001) and major adverse cardiac events (MACEs, 9.8% vs. 0.9%, p < 0.005). CONCLUSION: In this study, DES associated CAS was associated with higher incidence of diffuse spasm, ST-T change and adverse 3-year clinical outcomes. Special caution should be exercised in this particular subset of patients.

Relationship Between High Glycated Hemoglobin and Severity of Coronary Artery Disease in Type II Diabetic Patients Hospitalized With Acute Coronary Syndrome.

Introduction Diabetes mellitus (DM) is a chronic metabolic disease. It is the principal cause behind the high morbidity and mortality attributed to cardiovascular disease. This article's objective was to determine a connection between high glycated haemoglobin levels (HbA1c) and coronary artery disease (CAD). Materials and Methods Cross-sectional research took place at the lady reading hospital, Peshawar, Pakistan, from 1st July 2020 to 31st December 2020. In this study, one hundred fifty-one type II diabetic patients took part. We labelled all of them as acute coronary syndrome (ACS) on arrival. Non-probability consecutive random sampling technique was used for sampling. We categorized patients based on their HbA1c levels into two groups. These groups included good glycemic control (HBA1c≤7. 5%) and patients with poor glycemic control (HBA1c ≥7.5%). We classified the angiographic results of these patients as normal coronary arteries (NCAs), single vessel disease (SVD), double vessel disease (DVD), and triple vessel disease (TVD). Continuous variables such as age, weight, height, and body mass index (BMI) between HBA1c levels were analyzed using the Mann-Whitney U test. The fisher's exact test was performed to compare the categorical variables between the two classes. Results Of the total 151 patients, 89 (58.9%) were males, and the rest were female. The mean age was 55.4 ± 11.2 years. The most common risk factors were diabetes and hypertension, whereas ST-segment elevation myocardial infarction (STEMI) was the most common presentation. 107 (70.86%) patients had poor glycemic control (HbA1c>7.5%). Coronary angiographies showed TVD in 77 (50.99%) patients. Among these patients with TVD, 6 (14%) patients had good glycemic control, while 71 (66%) patients had poor glycemic control, which is significant (P≤0. 001). None of the patients with poor glycemic control had NCAs. Conclusion This article found a link between high levels of HbA1c and the degree of coronary artery disease (CAD) among diabetic patients. Our study's results demonstrated that high HbA1c was related to severe CAD. It would need additional studies with a large sample size to evaluate the more profound impact of HBA1c on coronary arteries.

Determinants of the Downward Trend in Coronary Artery Bypass Graft Surgery Among Patients With Multivessel Disease and Class-I Indication for Surgery.

Introduction Coronary artery bypass graft (CABG) is the most effective coronary revascularization procedure, and it has been endorsed by many trials and studies over the years. However, due to CABG's immediate adverse effects, patients tend to prefer percutaneous coronary intervention (PCI) for coronary revascularization over it. This article focuses on the recent downtrend in CABG procedures for revascularization among patients for whom it is indicated. This study's main objective was to identify the factors responsible for the downtrend in patients undergoing CABG despite a clear indication for it in those with multivessel diseases. Methods This study was conducted at the Lady Reading Hospital, Peshawar, Pakistan, from August 1, 2020, to January 1, 2021. A total of 340 patients with a class-I indication (presence of conditions regarding which there is evidence and/or general agreement that a given procedure or treatment is beneficial, useful, and effective) for CABG were enrolled in the study. Data related to all the variables were collected from patients and hospital records through an adequately designed proforma. For analysis, we applied the chi-square test to elaborate on the data for information and point biserial correlation to rule out the effect of age and weight on CABG's downward trend. Results The mean age of the patients was 58.77 ± 9.54 years; 65.88% were male, and 34.12% were female. Only 17.65% of the patients underwent CABG; 71.47% opted for medical treatment, and 9.41% underwent PCI. Out of the 280 patients who did not undergo CABG, 26.76% had financial issues; 23.82% were high-risk patients and hence refused surgeries by the surgeons; 20.59% of patients were not willing to undergo surgery; 7.94% were on the waiting list, and 3.24% had deranged renal function tests (RFTs). Conclusions A limited number of patients underwent revascularization therapy even though they had clear indications for CABG. The high-risk status of patients, patients' unwillingness, and the cost of the procedure were the primary reasons behind the downtrend in CABG procedures among patients with a clear indication for the same.

Cardiac Troponin I Levels in Hospitalized COVID-19 Patients as a Predictor of Severity and Outcome: A Retrospective Cohort Study.

Introduction The COVID-19 (coronavirus disease) has affected millions of people, wreaking havoc worldwide. World Health Organization (WHO) labelled this disease as a serious threat to public health since its rapid spread from Wuhan, China. The respiratory manifestations of COVID-19 are common, but myocardium involvement causing myocardial injury and rise in cardiac markers is much less discussed. Materials and methods We conducted this retrospective cohort study from 1st April 2020 to 1st October 2020. Data was collected from the Hospital Management and Information System (HMIS) based on inclusion criteria. We used the Cox proportional hazard regression model for survival analysis, estimated the probability curves of survival using the Kaplan-Meier method, and contrasted it with the log-rank test. Results Among the 466 patients, 280 (69%) were male; the rest were female. The majority were both hypertensive and diabetic, and one-third had a myocardial injury on arrival. The most frequent symptoms in more than half of the patients (51.90%) included a combination of fever, dry cough, and shortness of breath. Out of 466 patients, 266 patients were discharged, and 200 did not survive. In our study, 168 (36.05%) patients had a cardiac injury; among them, 38 (22.61%) were in the discharge group, and the remaining 130 (77.39%) patients were in the nonsurvivor group. Our study results showed that the mortality rate was higher in patients with high cardiac troponin I (cTnI) levels (hazard ratio [HR] 3.61) on admission. Conclusion Our result concluded that measuring cTnI levels on presentation could help predict the severity and outcome in COVID-19 patients. It will allow physicians to triage patients and decrease mortality.

Does BMI affect cholesterol, sugar, and blood pressure in general population?

BACKGROUND: Higher BMI in child hood is also associated with an increase risk for coronary heart disease in adulthood. Impaired glucose tolerance is highly prevalent in children and adolescents with severe obesity. Positive correlations between BMI and glucose, lipids and BP have previously been reported. The objective of this study was to find the correlation of BMI with cholesterol and sugar level in general population. METHODS: This study was a part of 'Peshawar Heart Study', performed at Cardiology Department, Lady Reading Hospital, Peshawar in 2008-2009. Individuals with different ages, gender, professions, socioeconomic class were randomly selected from general population. Random blood sugar and cholesterol was measured with strip method. Height and weight of each individual was recorded and BMI calculated. All individuals were asked about any current medical illness and whether they were performing any exercise or not. Using SPSS-13, descriptive statistics were used for frequencies. Bivariate correlations were used for measuring correlation between BMI, sugar and cholesterol. Partial correlations were used to factor out the effect of other variables. RESULTS: A total of 2,270 individuals, 1,798 (79.2%) male and 472 (20.8%) female were examined. Mean age was 38.47 +/- 12.66. Mean BMI was 26.38 +/- 4.97. Mean RBS was 113.7 +/- 47.145. Mean cholesterol was 168.47 +/- 28.23. Exercise was performed by 929 (40.90%) individuals. Diabetes was present in 113 (5.0%) and history of high cholesterol in 25 (1.1%) persons. When bivariate correlation analysis were done systolic BP, diastolic BP, RBS and cholesterol had positive correlation with BMI [correlation coefficient of 0.317 (p < 0.000), 0.319 (p < 0.000), 0.125 (p < 0.000) and 0.205 (p < 0.000) respectively]. These variables also showed a positive correlation among themselves. After factoring out the effects of age, exercise, gender and current medical status on the above correlations, the correlation of RBS and cholesterol with BMI decreased to 0.025 (p = 0.232) and 0.135 (p < 0.000) respectively and between sugar and cholesterol decreased to 0.018 (p = 0.401). CONCLUSION: In general population BMI is positively correlated with RBS and cholesterol. With the effect of age, sex, exercise and current medical status, this correlation is reduced.

Association Study of Coronary Artery Disease-Associated Genome-Wide Significant SNPs with Coronary Stenosis in Pakistani Population.

Genome-wide association studies (GWAS) of coronary artery disease (CAD) have revealed multiple genetic risk loci. We assessed the association of 47 genome-wide significant single-nucleotide polymorphisms (SNPs) at 43 CAD loci with coronary stenosis in a Pakistani sample comprising 663 clinically ascertained and angiographically confirmed cases. Genotypes were determined using the iPLEX Gold technology. All statistical analyses were performed using R software. Linkage disequilibrium (LD) between significant SNPs was determined using SNAP web portal, and functional annotation of SNPs was performed using the RegulomeDB and Genotype-Tissue Expression (GTEx) databases. Genotyping comparison was made between cases with severe stenosis (≥70%) and mild/minimal stenosis (<30%). Five SNPs demonstrated significant associations: three with additive genetic models PLG/rs4252120 (p = 0.0078), KIAA1462/rs2505083 (p = 0.005), and SLC22A3/rs2048327 (p = 0.045) and two with recessive models SORT1/rs602633 (p = 0.005) and UBE2Z/rs46522 (p = 0.03). PLG/rs4252120 was in LD with two functional PLG variants (rs4252126 and rs4252135), each with a RegulomeDB score of 1f. Likewise, KIAA1462/rs2505083 was in LD with a functional SNP, KIAA1462/rs3739998, having a RegulomeDB score of 2b. In the GTEx database, KIAA1462/rs2505083, SLC22A3/rs2048327, SORT1/rs602633, and UBE2Z/rs46522 SNPs were found to be expression quantitative trait loci (eQTLs) in CAD-associated tissues. In conclusion, five genome-wide significant SNPs previously reported in European GWAS were replicated in the Pakistani sample. Further association studies on larger non-European populations are needed to understand the worldwide genetic architecture of CAD.

Impact of Angiotensin Converting Enzyme Inhibitor versus Angiotensin Receptor Blocker on Incidence of New-Onset Diabetes Mellitus in Asians.

PURPOSE: Angiotensin converting enzyme inhibitor (ACEI) and angiotensin receptor blocker (ARB) are associated with a decreased incidence of new-onset diabetes mellitus (NODM). The aim of this study was to compare the protective effect of ACEI versus ARBs on NODM in an Asian population. MATERIALS AND METHODS: We investigated a total of 2817 patients who did not have diabetes mellitus from January 2004 to September 2009. To adjust for potential confounders, a propensity score matched (PSM) analysis was performed using a logistic regression model. The primary end-point was the cumulative incidence of NODM, which was defined as having a fasting blood glucose ≥126 mg/dL or HbA1c ≥6.5%. Multivariable cox-regression analysis was performed to determine the impact of ACEI versus ARB on the incidence of NODM. RESULTS: Mean follow-up duration was 1839±1019 days in all groups before baseline adjustment and 1864±1034 days in the PSM group. After PSM (C-statistics=0.731), a total 1024 patients (ACEI group, n=512 and ARB group, n=512) were enrolled for analysis and baseline characteristics were well balanced. After PSM, the cumulative incidence of NODM at 3 years was lower in the ACEI group than the ARB group (2.1% vs. 5.0%, p=0.012). In multivariate analysis, ACEI vs. ARB was an independent predictor of the lower incidence for NODM (odd ratio 0.37, confidence interval 0.17-0.79, p=0.010). CONCLUSION: In the present study, compared with ARB, chronic ACEI administration appeared to be associated with a lower incidence of NODM in a series of Asian cardiovascular patients.

APOE gene polymorphism and risk of coronary stenosis in Pakistani population.

Genetic variation in lipid regulatory genes, particularly APOE, significantly influences the risk of coronary artery disease (CAD). This study aimed to assess the association between APOE polymorphism and angiographically assessed coronary stenosis in Pakistani population. A total of 695 subjects (22.3% female, mean age = 54 ± 11 years) presenting with chest pain were enrolled after obtaining written informed consent. CAD stenosis/extent was assessed by angiography. Patients were classified as having severe stenosis (≥ 70%), moderate stenosis (30-69%), and mild stenosis (<30%). CAD patients with ≥ 70% stenosis (n = 491) were further categorized based on possessing one, two, or three vessel diseases to assess the disease extent. Genomic DNA from leukocytes was isolated with DNA purification kit (Qiagen) and APOE polymorphisms (E2/E3/E4) were determined using TaqMan assays. Six hundred and seventy-two of 695 subjects were successfully genotyped. The frequency of APOE∗4 carriers (3/4 and 4/4 genotypes) was significantly higher in severe stenosis group (≥ 70%) as compared to mild group (<30%) (22.8% versus 13.01%; P = 0.01). In multiple regression, the odds ratio for APOE∗4 carriers to develop ≥ 70% stenosis was 2.16 (95% CI: 1.29-3.79; P < 0.005). In conclusion, the presence of APOE∗4 allele is a significant risk factor to develop severe coronary stenosis (>70%) among Pakistanis.

Comparison of diabetic and non-diabetic patients undergoing endovascular revascularization for peripheral arterial disease.

OBJECTIVE: Peripheral arterial disease (PAD) is associated with poor outcomes. We assessed the clinical outcomes of diabetic versus non-diabetic patients with PAD who underwent peripheral transluminal angioplasty (PTA). METHODS: The outcomes of 239 consecutive patients with symptomatic PAD who underwent PTA were analyzed. Restenosis and clinical outcomes were assessed at a follow-up of 2 years. RESULTS: Diabetic patients had a higher percentage of wound as the initial diagnosis for PTA (72.7% vs. 14.2%; P<.001), chronic kidney disease (26.7% vs. 6.3%; P<.01), need for dialysis (19.3% vs. 3.1%; P<.01), and coronary artery disease (67.6% vs. 50.7%; P=.02). Infrapopliteal PTA was more commonly performed in the diabetic group (70.4% vs. 25.3%; P<.001). Diabetic patients had lower rates of angiographic follow-up at 8 months (38.6% vs. 60.3%; P<.01). Diabetic patients had higher binary restenosis (54.4% vs. 31.5%; P=.02) and had a trend toward a higher incidence of total occlusion (34.0% vs. 19.5%; P=.08). At 2-year follow-up, the amputation rate was higher in the diabetic group (24.4% vs. 1.5%; P<.001) despite PTA. CONCLUSION: Diabetic patients more frequently presented with critical limb ischemia compared with non-diabetic patients and had higher rates of restenosis and amputation at 2 years following standard PTA. Improved therapies are needed for this high-risk group of patients.

Impact of low dose atorvastatin on development of new-onset diabetes mellitus in Asian population: Three-year clinical outcomes.

BACKGROUND: High dose atorvastatin is known to be associated with new onset diabetes mellitus (NODM) in patients with high risk for developing diabetes mellitus (DM). However, low dose atorvastatin is more commonly used as compared with high dose atorvastatin. The aim of this study is to investigate the impact of low dose atorvastatin (LDA, 10mg or 20mg) on the development of NODM up to three years in Asian patients. METHODS: From January 2004 to September 2009, we investigated a total of 3566 patients who did not have DM. To adjust for potential confounders, a propensity score matching (PSM) analysis was performed using the logistic regression model. After PSM (C-statistics: 0.851), a total of 818 patients (LDA group, n=409 patients and control group, n=409 patients) were enrolled for analysis. RESULTS: Before PSM, the cumulative incidence of NODM (5.8% vs. 2.1%, p<0.001), myocardial infarction (0.5% vs. 0.1%, p-value=0.007), and major adverse cardio-cerebral event (MACCE, 1.8% vs. 0.7%, p-value=0.012) at three-years were higher in the LAD group. However, after PSM, there was a trend toward higher incidence of NODM (5.9% vs. 3.2%, p=0.064) in the LDA group, but the incidence of MACCE (1.2% vs. 1.5%, p-value=1.000) was similar between the two groups. In multivariable analysis, the LDA administration was tended to be an independent predictor of NODM (OR: 1.99, 95% CI: 1.00-3.98, p-value 0.050). CONCLUSIONS: In this study, the use of LDA tended to be a risk factor for NODM in Asian patients and reduced clinical events similar to the control group. However, large-scale randomized controlled trials will be needed to get the final conclusion.

Five-year clinical outcomes in patients with significant coronary artery spasm: A propensity score-matched analysis.

BACKGROUND: Coronary artery spasm (CAS) is known to be a risk factor of acute coronary syndrome and angina pectoris. However, there is no currently available data with larger study population regarding long-term clinical outcomes of CAS in real world clinical practice. OBJECTIVES: We evaluated the prevalence of CAS and the impact of CAS on 5-year clinical outcomes in a series of Asian CAS patients documented by intracoronary acetylcholine (Ach) provocation test. METHODS: A total of 1413 consecutive patients without significant coronary artery disease (CAD) who underwent Ach provocation test between Nov. 2004 and Oct. 2008 were enrolled. Significant CAS was defined as >70% of narrowing by incremental intracoronary injection of 20, 50 and 100 µg. Patients were divided into two groups based on the presence of significant CAS (the non-CAS group: n=640, the CAS group; n=773). To adjust potential confounders, a propensity score matched (PSM) analysis was performed using the logistic regression model. RESULTS: A total of 54.7% (773/1413) patients were diagnosed as CAS documented by Ach provocation test. After PSM analysis, 2 propensity-matched groups (451 pairs, n=902, C-statistic=0.677) were generated. Despite of similar incidence of individual hard endpoints including mortality, myocardial infarction and revascularization, the CAS group showed the higher trend of recurrent angina requiring follow up angiography than the non-CAS group up to 5 years (HR; 1.56, 95% C.I.; 0.99-2.46, p=0.054). CONCLUSIONS: The prevalence of CAS was 54.7%. Although the cumulative incidence of recurrent angina requiring follow up coronary angiography seems to be increased up to 5 years in CAS patients, CAS patients was not associated with major individual and composite clinical outcomes such as mortality, MI, PCI, CVA with optimal medical therapy as compared with patients without CAS.