The purpose of this study is to determine whether periprocedural administration of folic acid is effective in the prevention of contrast induced nephropathy in patients undergoing coronary CTA/angiography/angioplasty.

Hyperhomocysteinemia is considered to be independently associated with a greater risk of contrast induced nephropathy (CIN) in previous studies. However, the relationship between homocysteine-lowering therapy and CIN remains uncertain. Folic acid is considered to be the most common agent for homocysteine-lowering therapy. Therefore, this study aims to determine whether periprocedural administration of folic acid is effective in the prevention of CIN. 400 patients undergoing coronary CTA/angiography/angioplasty are going to be initially enrolled. Of these patients,200 were randomly assigned to receive a standard dose of folic acid (5mg tid, given at least two days before the procedural and continued for two days after), 200 to receive placebo. Blood samples for estimations of serum creatinine were collected at 0, 24 and 48h of contrast agent administration. CIN is defined as an elevation of creatinine by ≥ 25% or ≥ 0.5 mg/dl from baseline within 48h. The occurrence of CIN and the major in-hospital clinical events were recorded and compared between the intervention and control groups.

Inclusion Criteria:

• Inpatients undergoing coronary CTA/angiography/angioplasty

Exclusion Criteria:

• exposure to nephrotoxic drugs prior to or during the study period
• end-stage renal failure requiring dialysis
• allergy to iodine-containing contrast medium
• pregnancy
• refusal to give informed consent