CO2 Angiography During PVI Associated With Fewer Cardiac and Renal Complications

Patients that receive peripheral vascular interventions (PVIs) with CO₂ angiography have significantly lower rates of postcontrast acute kidney injury (PC-AKI) and cardiac complications compared with patients that do not, according to a study published in the Journal of Vascular Surgery.

For this retrospective study, investigators used deidentified data from the Vascular Quality Initiative PVI dataset from 2010 to 2021. Patients aged 18 years and older with advanced chronic kidney disease (CKD) were who receiving PVI for peripheral artery disease (PAD) were included in the study. Advanced CKD was defined as having an estimated glomerular filtration rate (eGFR) of less than 45 ml/min/1.73 m². Patients were excluded if they had any of the following characteristics:

• History of renal transplantation
• On dialysis
• History of bypass surgery
• Missing data for CO₂ angiography, PC-AKI, or preoperative creatinine

The primary outcomes measured by the investigators were PC-AKI, defined by RENALCOMP as a creatinine increase greater than or equal to 0.5 mg/dL from baseline, or if the patient had a new dialysis requirement and cardiac complications, defined as any dysrhythmia, myocardial infarction, congestive heart failure, or other clinically significant cardiac complication observed during the PVI or following the procedure but before discharge from the hospital. Secondary outcomes included failure of the PVI to cross the lesion, amputation, thromboembolism, bleeding complications, and 30-day mortality.

The investigators found 157,317 PVIs performed between 2014 and 2021. Of these, 4.7% utilized CO₂ angiography during the procedure. Before matching the cohorts for specific characteristics, there were no significant differences in outcomes. However, after matching the cohorts, investigators discovered that the use of CO₂ angiography was associated with a significant reduction in PC-AKI from 4.8% to 3.9% (P =.03) and a significant reduction in cardiac complications from 2.9% to 2.1% (P =.03). There were no significant differences in the rates of procedural failure, thromboembolic complications, or amputation rates between the 2 matched cohorts.

The investigators noted a few limitations of the study. The main limitation is that it is retrospective and the investigators were unable to control for selection bias in the original set of data. According to the researchers, other limitations stem from the fact that certain complications of PVI were not tracked and could have impacted the decision to use or not to use CO₂ angiography in certain patients, and the type of contrast used in every patient is also unknown. Last, they note that their study demonstrates association but cannot prove causation.

They conclude, “The major finding of this paper is that the use of CO₂ angiography is associated with a decreased risk of PC-AKI and post-operative cardiac complications when patients with advanced CKD (eGFR<45) undergo PVI for PAD.” They note that “CO₂ angiography is currently under-utilized (22% of advanced CKD patients) and should be considered to reduce the risk of PC-AKI and cardiac complications in this vulnerable population.” According to the investigators, the significant reductions in both PC-AKI and cardiac complications equate to greatly reduced morbidity and mortality, considering the large number of patients struggling with advanced CKD at any point in time.