CVD is a major public health problem throughout the world. It is the number one cause of morbidity and mortality world-wide. Cardiovascular Disease (CVD) is one of the major health problems that are prevalent in Bangladesh and will be followed by a lot of deaths [1]. The economic impact of different types of CVD is enormous. Traditionally, Bangladesh is a developing country burdened with communicable diseases. However, like many other low-income countries in the world, she has been experiencing epidemiological transition; the prevailing disease pattern is changing from communicable diseases to non-communicable diseases (NCD). Atherosclerosis, particularly in coronary heart causes heart failure and there is need to special treatment [2-3]. Coronary Artery Bypass Grafting (CABG) surgery is one of the effective and standard methods for treatment of coronary heart disease [4-5]. Although surgery is a reliable method to improve myocardial perfusion, but nevertheless there are multiple complications after the procedure [5-6]. A common complication after CABG is postoperative bleeding, which is considered as an important problem [7], and the most common complication in these patients leads to reoperation, so that the results of a study showed that postoperative bleeding with incidence of 58.7% is the main cause of reoperation which in 90% of cases has occurred within the first 24 hours after surgery [8]. On the other hand, massive bleeding after CABG is a major cause of postoperative mortality [9]. surgery is normal, but arteries bleeding is raised as life-threatening condition which is usually caused by rupture or leakage from sutures. On the other hand, venous bleeding is more common than arteries bleeding and can be created due to inadequate surgical hemostasis or coagulation disorders [10]. Cardiopulmonary bypass has many hemostatic effects.  Blood in contact with pipes and tanks pump is considered as a severe provocation to initiate inflammatory responses, and leads to activation of the hemostatic system [11]. However, inadequate surgical hemostasis is the most common cause of bleeding after Cardiopulmonary Bypass (CPB), but certainly coagulation disorders occur and can be unacceptable when it associated with micro vascular bleeding. Facing blood with oxygenators and CPB circuit causes platelet activation, degranulation and platelet aggregation. In addition, the relative thrombocytopenia usually occurs after CPB due to thin the blood and aggregation, platelet adhesion and degradation. 

The most common cause of extensive bleeding in cardiac surgery patients is fibrinolysis, and plate-let inhibition activity of CPB, especially in elderly patients [12]. In addition to the economic burden, administration of blood products in cardiac surgery have important clinical outcomes, that increased hospital mortality, renal dysfunction, per-operative infections, sepsis, and permanent impairment of quality of life and pulmonary dysfunction and prolonged mechanical ventilation are among these side effects [13-16]. The use of some drugs before surgery also adds to the increased risk of bleeding. For example, clopidogrel is an antiplatelet drug that has an important place among cardiovascular drugs. The main application of the drug is in combination with aspirin in the prevention of obstruction in patients, who have been undergoing CABG [17]. The aim of this study is to study only patients who have never used drugs above, so that it can assess postoperative bleeding in CABG with the absence of high-risk medications related to postoperative bleeding.