Use of Remote Ischaemic Preconditioning in the Prevention of Contrast Induced Nephropathy

With an increasingly ageing population the incidence of peripheral arterial disease (PAD) is rising. With approximately one quarter of all PAD patients ultimately progressing to Critical Limb Ischaemia (CLI), increased demands are being placed on vascular imaging to accurately assess stenotic lesions. Early infrainguinal lesions (i.e. TASC A \& B) can be treated with angioplasty+/- stenting and accurate assessment relies on the imaging gold standard of angiography. Patients with PAD often have concomitant co morbidities such as diabetes and chronic renal impairment placing them at increased risk of developing contrast induced nephropathy (CIN) when exposed to iodinated contrast media. High risk individuals with decreased eGFR \<60ml/min have a risk of between 20-30% of developing CIN. They have increased morbidity and mortality risks with a greater need for dialysis and prolonged in patient hospital stays. Ideally, the investigators should be searching for ways to decrease the incidence of CIN. Animal studies and more recently pilot human trials have shown that subjecting a remote vascular bed to a brief ischaemic stress, followed by a period of reperfusion; in what has been termed remote ischemic preconditioning (RIPC), may confer a protective benefit against the development of CIN. This study aims to determine if RIPC can protect against CIN in patients undergoing elective peripheral angiography for infrainguinal disease.