Which Factors Contribute to Acute Kidney Injury After Primary PCI?

Acute kidney injury (AKI) following primary percutaneous coronary intervention (pPCI) is associated with older age, glomerular filtration rate, heart failure, and hemodynamic instability, and not with contrast exposure, a recent study showed.

Exposure to contrast material post-pPCI is frequently interpreted as the cause of AKI. However, AKI may result from other factors.

In their study, the researchers evaluated 2025 patients with ST‐segment-elevation myocardial infarction who underwent pPCI, and a control group of 1025 patients receiving fibrinolysis or no reperfusion who were not exposed to contrast material during their first 72 hours of hospitalization.

The researchers defined AKI as creatinine of 0.5 mg/dL or higher, or a rise in creatinine by more than 25% within 72 hours.

AKI rates were similar in both the pPCI and control groups. The researchers matched 931 pairs of PCI patients and controls with balanced baseline covariates via propensity score matching. Among these matches, AKI rates were similar in pPCI patients and controls.

Results showed that independent predictors of AKI in patients with pPCI included age 70 years or older, insulin‐treated diabetes, diuretic therapy, anterior infarction, baseline estimated glomerular filtration rate, and variables related to reduced left ventricular ejection fraction and the presence of pump failure, like higher Killip class and intra‐aortic balloon pump use.

However, contrast material dose was not found to be an independent predictor of AKI following pPCI. The researchers noted that risk score based on the pPCI group had similar discriminatory capacity for AKI in the control group.

“The development of AKI in patients with ST‐segment-elevation myocardial infarction undergoing pPCI is mainly related to older age, baseline estimated glomerular filtration rate, heart failure, and hemodynamic instability,” the researchers concluded. “Risk for AKI is similar among ST‐segment–elevation myocardial infarction patients with and without contrast material exposure.”

—Christina Vogt

Reference:

Caspi O, Habib M, Cohen Y, et al. Acute kidney injury after primary angioplasty: is contrast-induced nephropathy the culprit? [Published online June 24, 2017]. J Am Heart Assoc. doi:10.1161/JAHA.117.005715.