OBJECTIVES This meta-analysis investigated the impact of renin-angiotensin-aldosterone system (RAAS) blockade on the occurrence of contrast-induced nephropathy (CIN).

METHODS Twelve studies comparing the use of RAAS blockade in a total of 4,493 patients undergoing a contrast-using procedure were included. The primary endpoint was the overall postprocedural incidence of CIN.

RESULTS In the overall pooled analysis, there was no significant difference between the two groups, RAAS blockade 'used' versus 'not-used', in the incidence of postprocedural CIN in the random-effects model (OR 1.27, 95% CI 1.77-2.11, p = 0.351, I(2) = 61.9%). In the stratified analysis, however, for chronic RAAS blockade users, the continuation of the drug was significantly associated with a higher incidence of CIN compared with discontinuation (OR 2.06, 95% CI 1.62-2.61, p < 0.001, I2 = 0.0%). A hazard of continuation was marked in a subgroup of older patients or in patients with chronic kidney disease. For drug-naïve patients, however, administration of RAAS blockade before contrast procedures did not reduce the development of CIN significantly (OR 0.52, 95% CI 0.23-1.16, p = 0.108, I2 = 34.2%).

CONCLUSION Discontinuation of RAAS blockade in chronic users is associated with a significantly lower incidence of CIN, whereas administration of RAAS blockade as a preventive measure for naïve patients did not show a significant effect on the incidence of CIN.