Intensity of hydration changes the role of renin-angiotensin-aldosterone system blockers in contrast-induced nephropathy risk after coronary catheterisation in patients with chronic kidney disease.

Objective: This study evaluated the potential effect of hydration intensity on the role of angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin receptor blockers (ARBs) on contrast-induced nephropathy in patients with renal insufficiency.

Methods: All eligible patients were included and stratified according to hydration intensity defined as saline hydration volume to body weight tertiles: <10.21 mL/kg, 10.21 to <17.86 mL/kg, and ⩾17.86 mL/kg.

Results: In total, 84 (6.7%) of 1254 patients developed contrast-induced nephropathy: 6.2% in the ACEI/ARB group versus 10.8% in the non-ACEI/ARB group ( P=0.029), with an adjusted odds ratio (OR) of 0.89 (95% confidence interval (CI) 0.46-1.73, P=0.735). The incidence of contrast-induced nephropathy was lower in the ACEI/ARB group than in the non-ACEI/ARB group in the second tertile ( P=0.031), while not significantly different in the first ( P=0.701) and third ( P=0.254) tertiles. ACEIs/ARBs were independently associated with a lower contrast-induced nephropathy risk (OR 0.26, 95% CI 0.09-0.74, P=0.012) and long-term all-cause death (hazard ratio 0.461, 95% CI 0.282-0.755, P=0.002) only in the second hydration volume to body weight tertile.

Conclusion: The effects of ACEIs/ARBs on contrast-induced nephropathy risk vary according to saline hydration intensity in chronic kidney disease patients, and may further reduce contrast-induced nephropathy risk in patients administered moderate saline hydration.