Increased Plasma Fibroblast Growth Factor 23 and In-hospital Acute Kidney Injury after Cardiac Surgery

Area of Science:

• Nephrology
• Cardiology
• Biomarker Research

Background:

• Acute kidney injury (AKI) affects 20-30% of cardiac surgery patients, often mild.
• Previous studies linked FGF23 to severe AKI, but not all-stage AKI.
• The association between FGF23 and all-stage AKI requires further investigation.

Purpose of the Study:

• To determine if fibroblast growth factor 23 (FGF23) biomarker measurements six hours after cardiopulmonary bypass (CPB) are associated with all-stage AKI.
• To investigate the predictive value of intact FGF23 (iFGF23) and C-terminal FGF23 (cFGF23) for AKI after cardiac surgery.

Main Methods:

• Prospective observational study of 173 patients undergoing coronary artery bypass graft (CABG) and/or valve surgery on CPB.
• AKI defined by Kidney Disease: Improving Global Outcomes (KDIGO) serum creatinine criteria through postoperative day 7.
• Plasma iFGF23 and cFGF23 levels measured six hours post-CPB.

Main Results:

• 18.5% of patients developed in-hospital AKI.
• A two-fold increase in cFGF23 was associated with 1.57-fold increased odds of AKI (OR, 1.57; P < 0.0001), remaining significant after adjustments.
• A two-fold increase in iFGF23 was associated with 1.59-fold increased odds of AKI (OR, 1.59; P = 0.018).

Conclusions:

• Early postoperative cFGF23 and iFGF23 levels are associated with all-stage AKI after cardiac surgery.
• These FGF23 biomarkers show potential for risk classification in cardiac surgery patients.
• Further research is needed to establish the clinical utility of FGF23 for AKI risk stratification.