Safety & Efficacy of RenalGuard® Therapy in the Prevention of Cardiac Surgery Associated Acute Kidney Injury

Inclusion criteria

• Male or female and >18 years old.
• Patient able to give written consent.
• Scheduled for the following non-emergent cardiac surgery procedure requiring CPB, isolated or in combination:

• coronary artery bypass graft (CABG)
• aortic valve replacement or repair alone, with or without aortic root repair
• mitral, tricuspid, or pulmonic valve replacement or repair
• simultaneous replacement of several cardiac valves
• CABG with aortic, mitral, tricuspid, or pulmonic valve replacement or repair
• Surgery on the aorta: aortic root and/ or ascending aorta
• AF ablation surgery if combined with other cardiac procedures.
• ASD closure if combined with other cardiac procedures.
• Excision of myxoma if combined with other cardiac procedures
• Have at least one of the following risk factors for CSA-AKI:

• CKD-EPI eGFR 20-59 mL/min/1.73 m²
• Undergoing combined surgery (e.g. CABG + Valve)
• STS Score ≥4 or Logistic EuroScore of ≥5 or, Euroscore II of ≥4
• Left ventricular ejection fraction (LVEF) ≤ 35%
• Insulin-requiring diabetes
• Non-insulin-requiring diabetes with HbA1C ≥ 6.1% in the last 6 months
• Preoperative anemia (hemoglobin ≤11g/dl for men and women) within 4 weeks of surgery

Exclusion criteria

• Patient requiring emergency surgery
• Surgery to be performed without CPB
• Patient receiving furosemide at a dose>100 mg/day orally (or the equivalent dose of an alternative loop diuretic) in the last week
• Patient who cannot be urethrally catheterize for any reason
• Patients already dialysis dependent
• Patients with CKD-EPI eGFR <20 mL/min/1.73 m²
• Known or suspected AKI (KDIGO criteria) at the time of screening
• IV contrast within 48 hours of surgery
• Patients participating in another interventional drug or device study or have received an investigational drug or device treatment within the last 30 days
• Pregnant patient, self-reported
• Patients whose planned surgery to be performed under conditions of circulatory arrest or hypothermia with rectal temperature < 28°Celsius (82.4° Fahrenheit)
• Patient with suspected or confirmed bacteraemia, endocarditis, or pyelonephritis at hospital admission
• Patients with pneumonia, aspiration, or bilateral pulmonary infiltrates from an infectious aetiology reported on chest x-ray or CT scan in the last 7 days
• Patients in cardiogenic shock or hemodynamic instability which require inotropes or vasopressors or other mechanical devices (Impella, IABP) within 24 hours prior to surgery
• Patients on extracorporeal membrane oxygenation (ECMO) or durable ventricular assist device (VAD) at the time of screening, or planned use within 24h prior to surgery
• Patients currently treated with chemotherapy or radiation therapy that may have an impact on kidney function.
• Patient underwent prior solid organ transplantation
• Patients underwent major surgery within the last 3 months
• Any condition which, in the judgement of the investigator, might increase the risk to the patient