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.