Construction industry and its role in Lebanese economy

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Civil Engineering, 1987.MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING.Bibliography: leaves 225-234.by Nicolas Elie Chammas.M.S

Uncommon Variant of Wellens’ Syndrome: A Case Report and Review of Literature

A 48-year-old male was admitted to the emergency department because of intermittent chest pain of 2 days duration. At the time of examination, he was pain-free. An electrocardiogram (ECG) showed biphasic T waves in leads V2 to V6. Troponin-I level was negative. During his transfer to the cardiac catheterization laboratory, he had a short episode of chest pain. His ECG was normal. Despite the unusual extension of biphasic T waves to the lateral precordial leads, the condition was recognized as Wellens’ syndrome, which typically associates biphasic or deep symmetric T wave inversion in leads V2 and V3 during pain-free periods with a critical stenosis in the proximal left anterior descending artery. The syndrome is uncommon to medical practice but should be recognized immediately in the emergency department because it represents a pre-infarction stage and carries a high risk of mortality.

Association of hypertension with coronary artery disease onset in the Lebanese population

The onset of coronary artery disease (CAD) is influenced by cardiovascular risk factors that often occur in clusters and may build on one another. The objective of this study is to examine the relationship between hypertension and CAD age of onset in the Lebanese population. This retrospective analysis was performed on data extracted from Lebanese patients (n = 3,753). Logistic regression examined the association of hypertension with the age at CAD diagnosis after controlling for other traditional risk factors. The effect of antihypertensive drugs and lifestyle changes on the onset of CAD was also investigated. Results showed that hypertension is associated with late onset CAD (OR=0.656, 95% CI=0.504-0.853, p=0.001). Use of antihypertensive drugs showed a similar association with delayed CAD onset. When comparing age of onset in CAD patients with traditional risk factors such as hypertension, diabetes, hyperlipidemia, obesity, smoking and family history of CAD, the age of onset was significantly higher for patients with hypertension compared to those with any of the other risk factors studied (p < 0.001). In conclusion, hypertension and its treatment are associated with late coronary atherosclerotic manifestations in Lebanese population. This observation is currently under investigation to clarify its genetic and/or environmental mechanisms

Genome-Wide Association Study in a Lebanese Cohort Confirms PHACTR1 as a Major Determinant of Coronary Artery Stenosis

The manifestation of coronary artery disease (CAD) follows a well-choreographed series of events that includes damage of arterial endothelial cells and deposition of lipids in the sub-endothelial layers. Genome-wide association studies (GWAS) of multiple populations with distinctive genetic and lifestyle backgrounds are a crucial step in understanding global CAD pathophysiology. In this study, we report a GWAS on the genetic basis of arterial stenosis as measured by cardiac catheterization in a Lebanese population. The locus of the phosphatase and actin regulator 1 gene (PHACTR1) showed association with coronary stenosis in a discovery experiment with genome wide data in 1,949 individuals (rs9349379, OR = 1.37, p = 1.57×10−5). The association was replicated in an additional 2,547 individuals (OR = 1.31, p = 8.85×10−6), leading to genome-wide significant association in a combined analysis (OR = 1.34, p = 8.02×10−10). Results from this GWAS support a central role of PHACTR1 in CAD susceptibility irrespective of lifestyle and ethnic divergences. This association provides a plausible component for understanding molecular mechanisms involved in the formation of stenosis in cardiac vessels and a potential drug target against CAD

Large Scale Association Analysis Identifies Three Susceptibility Loci for Coronary Artery Disease

Genome wide association studies (GWAS) and their replications that have associated DNA variants with myocardial infarction (MI) and/or coronary artery disease (CAD) are predominantly based on populations of European or Eastern Asian descent. Replication of the most significantly associated polymorphisms in multiple populations with distinctive genetic backgrounds and lifestyles is crucial to the understanding of the pathophysiology of a multifactorial disease like CAD. We have used our Lebanese cohort to perform a replication study of nine previously identified CAD/MI susceptibility loci (LTA, CDKN2A-CDKN2B, CELSR2-PSRC1-SORT1, CXCL12, MTHFD1L, WDR12, PCSK9, SH2B3, and SLC22A3), and 88 genes in related phenotypes. The study was conducted on 2,002 patients with detailed demographic, clinical characteristics, and cardiac catheterization results. One marker, rs6922269, in MTHFD1L was significantly protective against MI (OR = 0.68, p = 0.0035), while the variant rs4977574 in CDKN2A-CDKN2B was significantly associated with MI (OR = 1.33, p = 0.0086). Associations were detected after adjustment for family history of CAD, gender, hypertension, hyperlipidemia, diabetes, and smoking. The parallel study of 88 previously published genes in related phenotypes encompassed 20,225 markers, three quarters of which with imputed genotypes The study was based on our genome-wide genotype data set, with imputation across the whole genome to HapMap II release 22 using HapMap CEU population as a reference. Analysis was conducted on both the genotyped and imputed variants in the 88 regions covering selected genes. This approach replicated HNRNPA3P1-CXCL12 association with CAD and identified new significant associations of CDKAL1, ST6GAL1, and PTPRD with CAD. Our study provides evidence for the importance of the multifactorial aspect of CAD/MI and describes genes predisposing to their etiology

A Deep Learning based System for Writer Identification in Handwritten Arabic Historical Manuscripts

International audienc

Clinical significance of the hemodynamic gain index in patients undergoing exercise stress testing and coronary computed tomography angiography

Abstract Background Many hemodynamic parameters provide limited information regarding obstructive coronary artery disease (CAD) during exercise stress testing particularly when exercise is suboptimal. Hemodynamic gain index (HGI) is a recent sensitive indicator of ischemia and has been associated with increased mortality. This study evaluated the clinical impact of HGI in patients who underwent concomitant exercise stress testing and coronary computed tomography angiography (CCTA). Methods A total of 284 consecutive patients from the executive health program between 2010 and 2018 were identified. Resting and peak heart rate (HR) as well as systolic blood pressure (SBP) measurements were recorded. Framingham risk score (FRS), Duke treadmill score (DTS) and HGI $$(\frac{{{\text{HRpeak}} \times {\text{SBPpeak}} - {\text{HRrest}} \times {\text{SBPrest}}}}{{{\text{HRrest}} \times {\text{SBPrest}}}})$$ ( HRpeak × SBPpeak - HRrest × SBPrest HRrest × SBPrest ) were calculated. The latter was divided into quartiles. CCTA was used as a reference test to detect any CAD. Multivariate analysis and artificial neural network were used to determine the independent predictors of obstructive CAD. Results Mean age was 53 ± 12 years with 83% male. Mean HGI was 1.74 ± 0.67, with cut-off value of severely blunted HGI ≤ 1.25 (Quartile 4). Patients with severely blunted HGI were older, had higher FRS, and worse DTS. Patients with obstructive CAD had lower HGI when compared to those with normal CCTA/non-obstructive CAD (1.36 ± 0.53 vs. 1.77 ± 0.67, P = 0.005), and showed a higher prevalence of severely blunted HGI (44% vs. 22%, P = 0.019). After adjusting for traditional risk factors, HGI remained an independent predictor of obstructive CAD while severely blunted HGI was associated with threefold increased odds of having obstructive CAD (P = 0.05). Using artificial intelligence analysis, severely blunted HGI independently predicted obstructive CAD with an area under the curve of 0.83 and 0.96, and normalized importance of HGI of 100% and 63%, respectively for different models. Conclusions Among patients who underwent concomitant exercise stress testing and CCTA, severely blunted HGI independently predicted obstructive CAD after multivariate adjustment for traditional risk factors

Cardiac involvement in hypereosinophilic syndrome

A 9-year-old boy with hypereosinophilic syndrome (HES) was referred for cardiac magnetic resonance (CMR) imaging following an abnormal echocardiogram that showed a large mass layered on the inferolateral wall of the left ventricle, causing secondary severe mitral regurgitation. Cardiac involvement in HES usually affects the ventricular apex. In our case, CMR confirmed the presence of a large mural thrombus of 0.9 cm × 4.2 cm. This unusual cardiac involvement in HES was diagnosed in its intermediate thrombotic stage. CMR is very sensitive and specific in staging the disease. It explained the etiology of mitral regurgitation and guided therapy, especially when echocardiography was nonconclusive