Benefit to discontinuing ACE I ARBs prior to contrast exposure in CIN
Is there any benefit to discontinuing angiotensin-converting enzyme inhibitors and angiotensin receptor blockers (ACE-I/ARBs) prior to contrast exposure?
There are two opposing theories concerning the effects of ACE-I/ ARBs on the kidneys in the setting of contrast administration. First, ACE-I/ARBs increase the risk of CIN because these drugs are associated with a decrease in the glomerular filtration rate.
The second theory is that ACE-I/ARBs are protective against CIN by counteracting the afferent arteriolar vasoconstriction and the subsequent medullary ischemia precipitated with contrast. Retrospective and prospective studies are mixed on the questions, with some studies showing a neutral effect and others demonstrating a deleterious effect of ACEi/ARB. We do not recommend holding these drugs unless there is concern for volume depletion, and we do not feel that there is sufficient evidence to recommend starting these agents before a contrast administration purely for prophylactic purposes. Volume depletion increases the risk for CIN; therefore, holding diuretics immediately before and after contrast administration is prudent.