Effect of a single high-concentration sodium bicarbonate bolus on contrast-induced nephropathy in STEMI patients undergoing Primary PCI: a prospective randomized study

Background Contrast-induced nephropathy (CIN) remains an important complication following primary percutaneous coronary intervention (PPCI) in patients with ST-segment elevation myocardial infarction (STEMI). In emergency settings, preventive strategies must be rapid and compatible with timely reperfusion. This study evaluated whether a single preprocedural bolus of high-concentration sodium bicarbonate was associated with a lower incidence of CIN.Methods In this prospective randomised study, 110 STEMI patients undergoing PPCI at two tertiary centres were enrolled. All patients received standard care, including isotonic saline hydration. Participants were assigned to saline hydration alone or saline plus a single intravenous bolus of 20 mEq of 8.4% sodium bicarbonate administered 5–10 min before contrast exposure. The primary endpoint was CIN within 48 ± 12 h, defined as an increase in serum creatinine ≥0.5 mg/dL or ≥25% from baseline.Results Baseline characteristics were generally comparable, although baseline blood urea nitrogen was higher and estimated glomerular filtration rate lower in the control group. CIN occurred more frequently in controls than in the sodium bicarbonate group (16.4% vs. 1.8%; p = 0.008). Renal function trajectories also favoured sodium bicarbonate. However, sodium bicarbonate did not remain an independent predictor of CIN after multivariable adjustment (OR 0.061, 95% CI 0.003–1.205; p = 0.066).Conclusions Sodium bicarbonate administration was associated with a lower unadjusted incidence of CIN. These findings should be considered hypothesis-generating and require confirmation in larger multicentre studies.