Data Collection and Definition of Variables
Baseline variables were collected including age, gender, weight, smoking history, blood pressure, heart rate, several cardiovascular risk factors such as hypertension, diabetes mellitus, dyslipidemia, history of CABG or PCI, cerebral infarction and old myocardial infarction (OMI). In addition, left ventricular ejection fraction (LVEF), serum creatinine (SCr), chronic renal insufficiency, cardiac shock (CS), lipid metabolism index (triglycerides (TG), total cholesterol (T-CHO), low density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C)), blood routine examination (hemoglobin (Hgb), red blood cells (RBC), white blood cells (WBC), blood platelet (PLT), hematocrit (HCT)), uric acid (UA) were immediately measured when patients admitted to hospital, and the results were recorded.
In this study, the definitions of CIN were shown as follows: the absolute value of SCr increased by 44.2 mol /L, or by more than 25%, within 24 ~ 72 h after using the contrast agent (0.5 mg /dL). Hypertension was defined as SBP ≥140 mmHg and/or DBP ≥90 mmHg. Diabetes mellitus was defined as fasting blood glucose ≥7.0 mmol /L. eGFR was estimated as follows: eGFR =186×SCr-1.154×age-0.203(Female:×0.742)。