Effects of withdrawing vs continuing renin-angiotensin blockers on incidence of acute kidney injury in patients with renal insufficiency undergoing cardiac catheterization: Results from the Angiotensin Converting Enzyme Inhibitor/Angiotensin Receptor Blocker and Contrast Induced Nephropathy in Patients Receiving Cardiac Catheterization (CAPTAIN) trial.

BACKGROUND: It is unclear if holding angiotensin-converting enzyme inhibitors (ACEI) or angiotensin receptor blockers (ARB) prior to coronary angiography reduces contrast-induced acute kidney injury (AKI). We undertook a randomized trial to investigate the effect of holding ACEI/ARB therapy prior to coronary angiography on the incidence of AKI.

METHODS: We randomly assigned 208 patients with moderate renal insufficiency (creatinine ≥ 1.7mg/dL within 3 months and/or documented creatinine ≥ 1.5mg/dL within 1 week before cardiac catheterization) to hold ACEI/ARB ≥24 hours preprocedure or continue ACEI/ARB. The primary outcome was the incidence of AKI defined as an absolute rise in serum creatinine of ≥0.5mg/dL from baseline and/or a relative rise in serum creatinine of ≥25% compared with baseline measured at 48 to 96 hours postcardiac catheterization.

RESULTS: All patients were taking an ACEI (72.1%) or ARB (27.9%) prior to randomization. At 48 to 96 hours, the primary outcome occurred in 18.4% of patients who continued ACEI/ARB compared with 10.9% of the patients who held ACEI/ARB (hazard ratio 0.59, 95% CI 0.30-1.19, P = .16). In a prespecified secondary outcome, there was a lower rise in mean serum creatinine after the procedure in patients who held ACEI/ARB (0.3 ± 0.5 vs 0.1 ± 0.3mg/dL, P = .03). The clinical composite of death, myocardial infarction, ischemic stroke, congestive heart failure, rehospitalization for cardiovascular cause, or need for dialysis preprocedure occurred in 3.9% who continued ACEI/ARB compared with 0% who held the ACEI/ARB (hazard ratio 0.11, 95% CI 0.01-2.96, P = .06).

CONCLUSION: In this pilot study of patients with moderate renal insufficiency undergoing cardiac catheterization, with-holding ACEI/ARB resulted in a non-significant reduction in contrast-induced AKI and a significant reduction in post-procedural rise of creatinine. This low cost intervention could be considered when referring a patient for cardiac catheterization.