Meta-Analysis: Tailored Hydration Strategies Decrease CI-AKI and MACE in Coronary Angiography

Background: Contrast-induced acute kidney injury (CI-AKI) poses a considerable burden on patients undergoing coronary angiography or percutaneous coronary intervention (PCI). Beyond the direct tubular toxicity of iodine contrast, several risk factors, including chronic kidney disease (CKD) and hemodynamic instability, further increase the likelihood of renal damage. Although guideline-based prevention strategies recommend peri-procedural intravenous hydration, the optimal volume and method remain unclear.

Objective: This meta-analysis aimed to determine whether patient-tailored intravenous fluid administration (using parameters other than body weight alone) can reduce the incidence of CI-AKI, as well as major adverse cardiovascular events (MACE), compared with conventional non-tailored hydration protocols in patients undergoing coronary angiography and/or PCI.

Methods: A systematic review of randomized controlled trials (RCTs) was performed, including 13 studies and 4,458 participants. Tailored hydration strategies encompassed left ventricular end-diastolic pressure (LVEDP)-guided infusion, diuresis-driven matched replacement (RenalGuard®), bioimpedance vector analysis, central venous pressure, or inferior vena cava ultrasound measurements. These were compared against standard non-tailored fluid protocols. The primary outcome was CI-AKI (variously defined but measured within 7 days), and secondary outcomes included MACE, all-cause mortality, and renal replacement therapy (RRT).

Results: Across 12 RCTs (n=3,669), tailored hydration significantly reduced CI-AKI rates (risk ratio 0.56, 95% CI [0.46–0.69], p<0.00001; I²=26%). Ten studies (n=3,377) revealed lower MACE incidence in the tailored hydration arm (RR=0.57, 95% CI [0.42–0.78], p=0.0005; I²=12%). A significant reduction in all-cause mortality (RR=0.57, 95% CI [0.35–0.94], p=0.03) and RRT requirement (RR=0.51, 95% CI [0.29–0.89], p=0.02) was also observed, with no significant increase in pulmonary edema. Subgroup analyses (e.g., CKD) supported the overall benefit of individualizing fluid regimens.

Conclusions: Tailored hydration strategies appear superior to standard approaches in lowering the risk of CI-AKI, MACE, mortality, and RRT after coronary angiography or PCI. Although LVEDP-guided protocols are simple to implement and effective, the RenalGuard® system may offer additional benefits in selected populations, albeit at higher cost and complexity.

Implications for Practice: Clinicians should consider personalized hydration based on physiological or hemodynamic parameters to optimize fluid volume, reduce renal injury, and potentially improve clinical outcomes. Nevertheless, practical challenges include access to specialized equipment and the need for close monitoring in some techniques.

Study Strengths and Limitations: This systematic review highlights consistent treatment effects across diverse RCTs and methods. However, potential biases due to lack of blinding, varying CI-AKI definitions, and limited head-to-head comparisons among tailored approaches constrain definitive conclusions. The small sample size of certain studies and underpowered subgroup analyses also limit the generalizability of findings.

Future Research: Further large-scale trials are warranted to compare various tailored protocols directly, focusing on cost-effectiveness, ease of implementation, and patient-centered endpoints. Ongoing investigations, such as the NEPTUNE trial, aim to clarify whether combining multiple parameters (like LVEDP and contrast volume/eGFR ratio) yields optimal renal protection.

Reference: Cossette F, Trifan A, Prévost-Marcotte G, et al. Tailored Hydration for the Prevention of Contrast-Induced Acute Kidney Injury After Coronary Angiogram or PCI: A Systematic Review and Meta-Analysis. American Heart Journal. Published online January 4, 2025. DOI: http://doi.org/10.1016/j.ahj.2025.01.002