Safe Hydration to Prevent Contrast-Induced Acute Kidney Injury and Worsening Heart Failure in Patients with Renal Insufficiency and Heart Failure Undergoing Coronary Angiography or Percutaneous Coronary Intervention

: An optimal hydration volume (HV) that prevents contrast-induced acute kidney injury (CI-AKI) in patients with renal insufficiency and heart failure (HF) at a high risk of worsening HF (WHF) has not been determined. We aimed to determine a safe HV that prevents CI-AKI and WHF following coronary angiography (CAG) or percutaneous coronary intervention (PCI) in patients with renal insufficiency and HF. We recruited 1,307 patients with renal insufficiency and HF and investigated the relationships between the peri-procedural HV/weight (HV/W) ratio, and the risks of CI-AKI and WHF following CAG or PCI. Higher HV/W quartiles were associated with higher CI-AKI rates (Q1: 6.2%, Q2: 9.1%, Q3: 12.5%, and Q4: 18.7%; P < 0.001) and a greater likelihood of WHF (Q1: 2.2%, Q2: 2.7%, Q3: 4.9%, and Q4: 11.7%; P < 0.001). The multivariate analyses indicated that excessively high HV/W ratios were associated with moderately increased risks of CI-AKI (Q4 versus Q1: adjusted odds ratio [OR] 2.16, 95% confidence interval [CI] 1.17-4.00) and WHF (Q4 versus Q1: adjusted OR 3.09, 95% CI 1.21-7.88). The multivariate Cox regression analysis indicated that a higher HV/W ratio was associated with significantly increased long-term mortality (Q2 versus Q1: adjusted hazard ratio [HR] 2.36; Q3 versus Q1: adjusted HR 2.85; Q4 versus Q1: adjusted HR 2.94; all P < 0.05). In conclusion, an excessively high HV/W might be associated with a moderately increased risk of CI-AKI, WHF, and long-term mortality in patients with renal insufficiency and HF.