Effect of Type 2 Diabetes Mellitus on Expression of Vascular Endothelial Growth Factor-A (VEGF-A) in various grades of Stenosis of Coronary Artery Segments: An Autopsy-based Study

Background: VEGF has been reported as an important factor promoting collateral formation in Ischemic Cardiac diseases. However, the complete mechanism and factors affecting VEGF expression during Acute myocardial infarction are not fully understood. The present study aims to correlate the effect of Diabetes Mellitus on VEGF expression in endothelial cells in various grades of Coronary artery stenosis. Materials and Methods: Selective coronary angiography of both right and left coronary arteries was done to know the grade of occlusion in autopsy samples with a history of sudden cardiac death.5cm slice, of coronary artery segments were taken at the level of the highest grade of stenosis. Decedents hearts were selected as the control and cases based on patients history and 3D image build after selective coronary Angiography (without any coronary occlusion). In control group segments were taken from the proximal part of both the Right and left coronary arteries for Analysis. A routine histo-technique was done to grade the stenosis in case study group on sections taken at the level of maximum occlusion. Immunohistochemical staining was done in all sections to know the VEGF expression of endothelial cells and infiltrated Monocyte. VEGF expression was then correlated based on the grades of stenosis, presence of cardiovascular risk factors like diabetes mellites and hypertension. Results: The Coronary artery with less than 90% stenosis showed no substantial VEGF expression. A statistical significance was found when the VEGF expression was correlated with the various grade of stenosis and the presence of cardiovascular risk factors like diabetes Mellitus. Conclusion: Considerable variation was shown in the Monocyte migration and expression of the VEGF in the endothelial cells of the coronary artery in Diabetic patients in higher grade of stenosis. Impaired monocyte migration might explain the reduced arteriogenic potential in diabetic patients when corelated with the control group. KEYWORDS: Coronary artery disease, Selective Coronary Angiography, VEGF (Vascular endothelial growth factor), Arteriogenesis, Angiogenesis, Diabetes mellitus.