A correlation between acute kidney injury and myonecrosis after scheduled percutaneous coronary intervention

Slight elevations in cardiac troponin I and T are frequently observed after percutaneous coronary inter- vention （PCI）. Contrast-induced acute kidney injury （CI-AKI） is a complex syndrome induced by exposure to in- travascular contrast media （CM）. Currently, the relationships between the CM, pre-existing kidney insufficiency, CI-AKI and myonecrosis after elective PCI are unclear. To investigate the relationship between CI-AKI and post-procedural myonecrosis （PMN） after PCI, we analyzed 327 non-ST-segment elevation acute coronary syndrome subjects un- dertaking elective PCI. The levels of cardiac troponins （cTns）, cTnl and cTnT, at baseline and on at least one occasion 18-24 h after PCI were measured. We also recorded serum levels of creatinine （SCr） and the urine albumin：creatinine ratio （ACR） before coronary angiography, and 24-48 h and 48-72 h after contrast administration. A post-procedure increase in cTns was detected in 16.21% （53/327） of subjects with cTns levels 〉99th to 5x99th percentile upper ref- erence limit （URL）. Twenty-seven patients （8.26%） developed CI-AKI. CI-AKI occurred more often in subjects with PMN than in those without PMN （20.8% versus 5.8%, respectively, /〉=-0.001）. Multiple logistic regression analysis revealed that pre-existing microalbuminuria （MA） was an important independent predictor of PMN （OR： 3.31; 95% CI： 1.26-8.65, P=0.01）. However, there was no correlation between the incidence of CI-AKI and PMN （OR： 2.38; 95% CI： 0.88-6.46, P=-0.09）. We conclude that pre-existing MA was not only an important independent predictor of CI-AKI but also of PMN.