Development and Validation of Nomogram Based on the Systemic-Immune Inflammation Response Index for Predicting Contrast-Induced Nephropathy in ST-Elevation Myocardial Infarction Patients

Contrast-induced nephropathy (CIN) is a prominent complication of ST-elevation myocardial infarction (STEMI) after primary percutaneous coronary intervention (pPCI). The systemic immune inflammation response index (SIIRI) is a novel inflammatory marker developed by multiplying the monocyte count by the systemic immune inflammation index (SII) and is associated with coronary artery disease severity. We investigated the predictive ability of SIIRI for detecting CIN in STEMI patients (n = 2289) following pPCI and developed a nomogram based on SIIRI for risk stratifying. CIN was diagnosed based on an elevation in baseline creatinine levels >.5 mg/dL or 25% within 72 h after pPCI; 219 CIN (+) and 2070 CIN (−) patients were included. CIN (+) patients had higher SIIRI than CIN (−) patients and SIIRI was an independent predictor of CIN. A nomogram based on SIIRI had good calibration and discrimination abilities for predicting CIN development. SIIRI was superior to SII in discriminating CIN (+) patients. Adding SIIRI to the baseline model, which consists of age, hypertension, hemoglobin, estimated glomerular filtration rate, albumin, ejection fraction, lesion length, and pain-to-balloon time, had a higher discriminative ability and benefit in detecting CIN (+) patients than baseline model as assessed by decision curve analysis.