Effect of sodium bicarbonate on preventing contrast-induced nephropathy in patients with myocardial infarction undergoing primary percutaneous coronary interventions

Objective To investigate whether hydration with sodium bicarbonate reduces the incidence of contrast-induced nephropathy （CIN） in patients with ST-segment elevation myocardial infarction （STEMI） undergoing primary percutaneous coronary interventions （PCI）. Methods From October 1， 2013 to October 1， 2014， 87 STEMI patients undergoing primary PCI in Daxing Hospital of Capital Medical University were consecutively enrolled in this study. All patients were randomly divided into sodium bicarbonate hydration （SB） group and control （NSB） group. The serum creatinine （SCr）， estimated glomerular filtration rate （eGFR），serum potassium， N-terminal pro brain natriureic peptide （NT-pro BNP） levels and the pH value， the concentration of standard bicarbonate in arterial blood sample were measured on admission and at 24 h， 48 h and 72 h after primary PCI. The incidences of CIN， hypokalemia and metabolic alkalosis were analyzed in each group. Results Forty-three patients were included in SB group while the other forty-four patients were included in NSB group. The average intake volume of 1.4% sodium bicarbonate solution in SB group was （583.2±87.7） ml. There was no significant difference in contrast volume administered during the process of primary PCI between two groups （SB: 237±95 ml vs. NSB: 249±102 ml， P＞ 0.05）. Within 72 h after primary PCI， the incidence of CIN in SB group was significantly lower than that in NSB group （2/43； 4.7%vs 10/44； 22.7%， P＜ 0.05）. While there were no significant differences in the levels of NT-pro BNP （SB: 1 275.3±116.9 pg/mlvs NSB: 1 238.9±135.4 pg/ml， P＞ 0.05）， the incidences of hypokalemia （SB: 6/43； 14.0%vs NSB: 4/44； 9.1%， P＞ 0.05） and metabolic alkalosis （SB: 5/43； 11.6%vs NSB: 3/44； 6.8%， P＞ 0.05）. Conclusion This study shows that using standard hydration regimen of sodium bicarbonate can effectively reduce the incidence of CIN in STEMI patients undergoing primary PCI without increasing incidences of hypokalemia and metabolic alkalosis，and additional intake of sodium bicarbonate solution does not worsen the heart function further in STEMI patients.