Association Between Plasma Osmolality and Contrast-Induced Nephropathy in Patients With Acute Coronary Syndrome Undergoing Percutaneous Coronary Intervention

Objective: Contrast-induced nephropathy (CIN) is a clinically relevant complication of percutaneous coronary intervention (PCI), particularly in acute coronary syndrome (ACS). Calculated plasma osmolality (PO), derived from routine laboratory measurements, may reflect fluid and solute disturbances associated with renal vulnerability. This study evaluated the relationship between admission PO and CIN in patients with ACS undergoing PCI.Methods: This retrospective, single-center study included 542 patients with ACS who underwent coronary angiography and PCI between January 2016 and December 2017. The cohort comprised 81 patients with unstable angina pectoris, 288 with non-ST-segment elevation myocardial infarction, and 173 with ST-segment elevation myocardial infarction. PO was calculated from admission sodium, glucose, and blood urea nitrogen levels. CIN was defined as an absolute increase of ≥0.5 mg/dL or a relative increase of ≥25% in serum creatinine within 72 hours after contrast exposure. Associated factors were examined using multivariable logistic regression.Results: CIN developed in 62 patients (11.4%). Admission PO was higher among patients who developed CIN than among those who did not (295.4 [290.9–302.3] vs. 287.7 [283.4–292.6] mOsm/kg H₂O, p