This study aims to investigate the effect of pentoxifylline administration on the status of endothelial function and oxidative stress biomarkers in patients with Acute Coronary Syndrome (ACS).

The study will be carried out at Ain Shams University Hospitals. Patients with ACS who meet the eligibility criteria and consent to participate in the study will be randomly allocated to either the intervention group or the control group.

All participants will receive the standard pharmacologic treatment for ACS according to the applied guidelines offered by the facility. In addition, patients in the intervention group will receive Pentoxifylline tablets 400mg orally three times daily.

Patient follow-up will be scheduled every 2 weeks for each patient to check the tolerability, the development of side effects, any medication change and medication adherence. Physical examination at each visit will be done by physician in attendance for all patients in both groups.

A blood sample will be taken at baseline and at the end of the study after 2 months. for measurement of basic laboratory parameters (Complete Blood Count, Liver Function Tests, Kidney Function Tests ,..etc), the level of Soluble Vascular Cell Adhesion Molecule-1 (sVCAM-1) as a marker for endothelial dysfunction, the level of Malondialdehyde (MDA) as a marker for oxidative stress.

Inclusion Criteria:

• Patients aged 18-80 years old.
• Recent ACS diagnosed-patients within the past 2 weeks.

Exclusion Criteria:

• Known allergy to pentoxifylline
• Heart failure New York Heart Association (NYHA) class III or IV
• Severe Left Ventricular Dysfunction (left ventricular ejection fraction <30%)
• High Serum creatinine level ≥ 2 mg/dl
• Liver disease (baseline alanine transaminase >2.5 times the upper limit of normal)
• Active bleeding or bleeding diathesis
• Major surgery or trauma within 1 month
• Recent cerebral and/or retinal hemorrhage within 3 months