The aim of the current study is to evaluate prospectively whether concomitant administration of renin-angiotensin-aldosterone system (RAAS) blockers (namely ACE-I and ARBs') influence the change in estimated glomerular filtration rate or GFR (eGFR) after administration of contrast media in patients undergoing non-emergent coronary angiography.

Contrast-induced nephropathy (CIN) is defined as an absolute or relative increase in serum creatinine compared to the baseline values, together with exposure to a contrast agent and exclusion of alternative explanations for renal impairment. Most frequently the renal impairment develops 48 hours post exposure. Although RAAS blocking agents are widely used among patients requiring contrast studies, data regarding the effect of these agents on the development of CIN are sparse and inconsistent. Patients undergoing percutaneous coronary intervention are frequently treated with RAAS blocking agents. Despite the not infrequent occurrence of CIN following percutaneous coronary intervention (PCI) no guidelines are available on the topic of the cessation of the RAAS inhibitors prior to the procedure.

Inclusion Criteria:

• age > 18 years,
• chronic therapy with ACE-I and/or ARBs' (confirmed by electronic records in their medical file) and
• planned coronary angiography

Exclusion Criteria:

• chronic utilization of NSAIDS and Cox-2 selective inhibitors,
• chronic treatment with mineralocorticosteroid receptor blocker, and
• administration of contrast within 14 days prior to the enrollment.