Background: Among patients with rhabdomyolysis, the leakage into plasma of intracellular myocyte contents, such as creatine phosphokinase (CPK) has been shown to be associated with increased risk of acute kidney injury (AKI). We evaluated the possible relation between plasma CPK levels and the occurrence of AKI among ST elevation myocardial infarction (STEMI) patients undergoing primary coronary intervention (PCI).

Material and methods: We retrospectively included 2865 patients with STEMI treated with primary PCI. Patients were stratified according to plasma CPK levels into mild

(<1000 U/L, n=1649), moderate (1000-5000 U/L, n=1184) and Severe (>5000 U/L, n=82) CPK levels. Occurrence of AKI was defined by the KDIGO criteria as an increase in serum creatinine of ≥0.3 mg/dl within 48 hours following PCI. The predictive value of CPK for the risk of AKI was assessed using multivariable logistic regression.

Results and discussion: The overall incidence of AKI was 9.6%. The occurrence of AKI demonstrated a gradual and significant increase among patients having mild, moderate and severe plasma CPK levels (7.8% vs. 11.2% vs. 25.6%, respectively; p<0.001). In a multivariate logistic regression model both severe (OR 4.38, 95% CI 2.48-7.23; P=0.001) and ≤ moderate (OR 2.08, 95% CI 1.59-2.76; P=0.001) plasma CPK levels were independently associated with AKI.

Conclusion: Among STEMI patients undergoing PCI, elevated plasma CPK levels were independently associated with AKI.