1- to find metabolic factors that correlate with the development of no reflow phenomenon that may help prevent its occurrence .

Acute myocardial infarction (AMI) with its accompanying adverse sequelae is one of the most common causes of morbidity and mortality in the world .

Although reperfusion techniques for ST- elevation myocardial infarction (STEMI ) are constantly improving, no-reflow can still lead to poor prognosis .

At present, the exact mechanism of no-reflow remains unclear, but clinical and laboratory findings suggest that it is related to the embolism of the capillary bed, ischemic injury, vascular endothelial dysfunction, production of oxygen free radical , and other factors .

The no-reflow phenomenon is one of complications of poor functional and clinical outcomes for patients with (AMI) .

The no-reflow phenomenon is present in 25% to 30% of patients with (AMI) underwent successful coronary recanalization, as shown by angiography . The myocardial no-reflow phenomenon is associated with a reducution of antegrade myocardial blood flow inspite of an open infarct-related artery in patients with (STEMI ) undergoing (PCI). Importantly, no-reflow is known to be related to unfavorable clinical outcome and prognosis . The cause of this complex phenomenon is the variable combination of four pathogenetic components: distal atherothrombotic embolization, ischemic injury, reperfusion injury and susceptibility of coronary microcirculation to injury . As a consequence, appropriate strategies are expected to prevent or treat these components are expected to avoid the no-reflow. Coronary reperfusion therapy is widely performed in patients with (AMI) . However, in spite of patency of the infarct-related artery , there is no guarantee of salvage of myocardium at risk of ischemia .The no-reflow phenomenon is found in >30% of patients after thrombolysis or catheter-based (PCI) for (AMI) . It is important, therefore, to be able to predict which lesions are high risk for no reflow before beginning PCI .

There are numerous recognized risk factors for the development of coronary artery disease (CAD), one of the best known is the association between blood lipids and CAD . Several prospective studies have established that the risk of cardiac morbidity and mortality is directly related to the concentration of plasma cholesterol. ' The most prevalent view is that the increased risk of myocardial infarction associated with elevated plasma cholesterol levels can be adequately explained on the basis of the increase in number and severity of coronary atherosclerotic vascular lesions . .

Inclusion Criteria:

• diabetic patients with STEMI treated with primary PCI

Exclusion Criteria:

non diabetic . with selected PCI

• (1) a history of an unprotected left main artery with severe liver and kidney diseases or coronary artery bypass grafting .

  (2) patients who had valvular disease or cardiomyopathy . (3) severe dissection, thromboembolism in other parts, or vasospasm; and known malignancy .

  (4) patients with contraindications for anticoagulant therapy, such as active visceral hemorrhage, hemorrhagic stroke, or ischemic stroke within half a year (including transient ischemic attack), or aortic dissection, or patients with hematological diseases complicated with coagulation disorders .