This clinical trial evaluates whether continuing or withholding ACE inhibitors (specifically Ramipril) before coronary angiography affects the risk of contrast-induced nephropathy (CIN). CIN is a known complication of iodinated contrast exposure, particularly in patients with chronic conditions such as hypertension or diabetes. The trial involves 44 adult patients randomized into two groups: one continuing Ramipril and the other withholding it 48 hours before and restarting 72 hours after the procedure. Renal biomarkers including serum creatinine, NGAL, and superoxide dismutase will be assessed to evaluate renal function.