- Contrast-induced nephropathy (CIN) is one of the major causes of new-onset renal failure in hospitalized patients. Although renin-angiotensin-aldosterone system (RAAS) blocking agents are widely used among patients requiring contrast studies, data on the effect of these agents on the development of CIN are sparse and inconsistent. To evaluate in a randomized controlled trial whether uninterrupted administration of angiotensin II (AnglI) blockade medications influence estimated glomerular filtration rate (eGFR) in patients undergoing non-emergent coronary angiography. Patients receiving treatment with angiotensin-converting enzyme inhibitors/angiotensin receptor blockers (ACE-I/ARB) were recruited consecutively. The enrolled subjects were randomized into three groups at a 1:1:1 ratio: group A (ACE/ARB stopped 24 hours prior to the procedure and restarted immediately after the procedure), group B (ACE/ARB stopped 24 hours prior to the procedure and restarted 24 hours after the procedure), and group C (ACE/ARB continued throughout the study period). Plasma creatinine was measured and eGFR was calculated according to the Cockroft-Gault equation before and 48 hours after the coronary angiography. The primary endpoint was a change in eGFR at 48 hours. Groups A, B and C comprised 30, 31 and 33 patients respectively. The mean age of the study population was 65 +/- 12 years and 67% were males. Fifty percent of the subjects had diabetes mellitus. The primary endpoint analysis showed that at 48 hours after the procedure there was no difference in delta eGFR between groups A and C (4.25 +/- 12.19 vs. 4.65 +/- 11.76, P = 0.90) and groups B and C (3.72 +/- 17.42 vs. 4.65 +/- 11.76, P = 0.82). In post-hoc analysis the patients were clustered according to the following groups: medical alternation (group A and B) versus control (group C), and to baseline eGFR > or = 60 ml/min vs. eGFR (< 60 ml/min. In patients with baseline eGFR < 60 ml/min the delta eGFR (baseline eGFR-eGFR 48 hours post-angiography) was significantly different between the intervention vs. control group (median 5.61 vs. median -2.19, P= 0.03 respectively). While in patients with baseline eGFR > or = 60 ml/min there was no significant difference in delta eGFR between the intervention and control groups. ACE-I and ARB can safely be used before and after coronary angiography in patients with eGFR > or = 60 ml/min.