A Contrast Medium Sparing Strategy Using Automated CO2 Injection During PVI for Prevention of Major Adverse Kidney Events (MAKE)

Inclusion Criteria:

1. Symptomatic peripheral arterial disease presenting with either acute symptoms (Rutherford clinical categories I-IIb) and/or chronic symptoms (Rutherford clinicalcategories 3-6)

2. Planned peripheral vascular intervention of infrainguinal arteries due tofemoropopliteal and/or infrapopliteal lesions

3. Increased risk of CA-AKI identified by a baseline risk score of ≥ 5 points based ona published dedicated PVI risk score and a pre-angiographic estimated glomerularfiltration rate (eGFR) < 60 ml/min/1.73 m²

4. Both angiographic strategies seem feasible at the investigator's discretion

5. Age 18 years or older

6. Written informed consent

Exclusion Criteria:

1. Very agitated patients

2. Patients with planned full anaesthesia during procedure

3. Patients with a life-expectancy less than one year

4. Patients confined to bed that are completely non-ambulatory

5. Known acute renal failure or known unstable renal function as evidenced by a recentincrease in serum creatinine (SCr) of > 0.5 mg/dl or > 25% within 7 days

6. Iodinated contrast medium exposure within 7 days prior to procedure with change inSCr ≥ 0.1 mg/dl on two SCr measures ≥ 24 h apart

7. Advanced chronic kidney disease (CKD) with an eGFR < 30 ml/min/1.73m² and/ordialysis

8. Current use of nephrotoxic agents (aminoglycoside antibiotics, sulfonamides,amphotericin B, or pentamidine), or an active chemotherapy agent

9. Acute or chronic pulmonary disease requiring oxygen therapy

10. Patients with known patent foramen ovale or atrial septal defect

11. Patients with planned nitrous oxide anaesthesia during intervention

12. Patients with manifest hyperthyroidism or manifest thyrotoxicosis

13. Known allergies or hypersensitivity to iodinated contrast media that cannot beadequately pre-treated prior to index procedure

14. Patients with decompensated heart failure

15. Patients with manifest tetany

16. Planned further procedure with a need for > 10 ml of iodinated contrast medium (CM) in any location (e.g., CT scan, coronary angiography) within a period of 90days

17. Any surgical procedure (except minor amputations) or intervention performed within 30 days prior to or planned within 90 days post index procedure

18. Fertile women (within two years of their last menstruation) without appropriatecontraceptive measures (implanon, injections, oral contraceptives, intrauterinedevices, partner with vasectomy) until day 30 after PVI.

19. Participation in other interventional trials. Exceptions are described in the trialprotocol.

20. Suspected lack of compliance

21. Pregnant or nursing women