Table 1. Three clinical trials on the prevention of CIN including a randomly assigned group between receiving intravenous hydration and not receiving prophylaxis.

Authors	Patients	Criteria for CIN	Incidence of CIN, H− group	Incidence of CIN, H+ group	Significant difference
Luo et al. (6)	216 consecutive STEMI patients who underwent PCI	An increase in SCr level >0.5 mg/dL or ≥25% within 3 days	CIN: 35.2% (38/108), dialysis: 2.78% (3/108), hospital mortality: 9.25% (10/108)	CIN: 20.4% (22/108), dialysis: 0% (0/108), hospital mortality: 2.78% (3/108)	P<0.05, P=0.081, P=0.045
Jurado-Román et al. (7)	408 consecutive STEMI patients who underwent PCI	An increase in SCr level >0.5 mg/dL or ≥25% within 3 days	CIN: 21% (43/204)	CIN: 11% (22/204)	P=0.016
Kooiman et al. (10)	138 CKD patients who underwent CTPA	An increase in SCr level >0.5 mg/dL or ≥25% within 4 days	CIN: 9.0% (6/67)	CIN: 7.0% (5/71)*	Not significant

*, 1-h 250 mL 1.4% sodium bicarbonate hydration before CTPA. CIN, contrast-induced nephropathy; CKD, chronic kidney disease; CTPA, computed tomography pulmonary angiography; STEMI, ST-segment elevation myocardial infarction; PCI, percutaneous coronary intervention; SCr, serum creatinine; H+ group = received standard 0.9% NaCl prophylactic intravenous hydration; H− group = received no prophylaxis.