Judith Kooiman (Leiden University Medical Center, The Netherlands) and others report in Circulation: Cardiovascular Interventions that nearly one third of in-hospital deaths after percutaneous coronary intervention (PCI) can be attributed to acute kidney injury. They also state that preventing nine cases of acute kidney injury could potentially prevent one death.
The authors write that post-PCI acute kidney injury is associated with increased mortality but add that it “remains unclear” whether this association is independent of other risk factors—noting that acute kidney injury and mortality share common risk factors (such as diabetes). Therefore, Kooiman et al, using data from the Blue Cross Blue Shield of Michigan cardiovascular consortium registry, reviewed the link between acute kidney disease and post-PCI mortality after adjustment for confounding by common risk factors.
From a cohort of 92, 317 PCI procedures (90,383 patients) performed between 2010 and 2013, the authors identified 2,156 cases of acute kidney injury (2,141 unique patients). Overall, these patients were more likely to have adverse in-hospital outcomes (eg. mortality) than patients without acute kidney injury.
In a matched analysis, Kooiman et al compared 1,371 acute kidney injury patients to 5,484 patients without the complication but who had similar characteristics at baseline. They found that acute kidney injury was “strongly associated” with in-hospital mortality after adjustment for baseline covariates (p<.0001 for the association). “Nearly one third [31.4%] of the in-hospital mortality risk post PCI is attributable to acute kidney injury. Additionally, our data suggest that avoiding nine cases of acute kidney injury post PCI could potentially save one life,” the authors comment. They add that while mortality risk was highest in those with cardiogenic shock, cardiac arrest or ST-segment elevation myocardial infarction (STEMI), it was also “clinically relevant” in patients with a more stable presentation.
Senior author of the study, Hitinder Gurm (associate Professor, University of Michigan) highlighted that “almost all research” on preventing acute kidney injury after PCI has focused on contrast media-induced injury, but notes that their study—despite suggesting that a high contrast dose significantly increased the risk of acute kidney injury—indicates that “contrast dosing is only a minor contributor to the overall burden of acute kidney injury in this population”. He states: “The independent impact of a high-contrast dose at time of PCI on in-hospital mortality risk was weak after adjustment for other baseline clinical covariates.” Therefore, Gurm suggests that future efforts to reduce the incidence and impact of acute kidney injury “need to move beyond contrast media choice and dosing and be targeted at other mechanistic pathways of acute kidney injury, such as inflammation, renal preconditioning and the potential for statin preloading.”
Gurm told Cardiovascular News: “The challenge is that there is no clinically effective method yet of preventing acute kidney injury during PCI (we are testing some in rabbit models) beyond contrast and we have probably reached a point of diminishing returns with that goal.”