Preventing kidney injury using carbon dioxide (KID trial): trial protocol for a multicentre randomised controlled...

Area of Science:

• Nephrology
• Vascular Surgery
• Radiology

Background:

• Peripheral arterial disease (PAD) frequently co-occurs with chronic kidney disease (CKD).
• Endovascular revascularization is crucial for PAD patients but uses nephrotoxic iodinated contrast, risking acute kidney injury (AKI) in CKD patients.
• Automated carbon dioxide (CO₂) injection offers a potential alternative contrast agent to mitigate renal risks.

Purpose of the Study:

• To evaluate if CO₂ contrast reduces the risk of AKI and short-term renal function decline in patients with PAD and CKD undergoing endovascular intervention.
• To compare the incidence and severity of AKI, major adverse kidney events, and long-term renal function changes between CO₂ and iodinated contrast groups.
• To assess the feasibility, acceptability, and cost-effectiveness of using CO₂ as an alternative contrast medium.

Main Methods:

• A multicentre, prospective, randomised controlled trial involving 174 patients with PAD and CKD.
• Patients were randomised 1:1 to receive either iodinated contrast (standard of care) or CO₂ via automated injector.
• Primary outcome: log serum creatinine at 2, 30, and 90 days post-procedure. Secondary outcomes include AKI incidence, major adverse kidney events, and quality of life.

Main Results:

• The study is currently evaluating the primary outcome of log serum creatinine levels at 2, 30, and 90 days post-procedure.
• Key secondary outcomes, including AKI incidence and major adverse kidney events, are being assessed within 90 days.
• Feasibility, acceptability, and cost-effectiveness of CO₂ use are also under investigation through patient and practitioner questionnaires and healthcare resource use analysis.

Conclusions:

• The findings will determine the safety and efficacy of CO₂ as a nephroprotective alternative to iodinated contrast in high-risk patients.
• This research aims to inform clinical practice guidelines for endovascular procedures in patients with comorbid PAD and CKD.
• Successful implementation of CO₂ angiography could significantly reduce contrast-induced nephropathy in vulnerable patient populations.