Objective To explore the risk factors of contrast induced nephropathy (CIN) in elderly patients with coronary heart disease undergoing the percutaneous coronary intervention (PCI).

Methods The clinical data of 378 elderly patients who underwent PCI in Zhongshan Hospital, Fudan University from January 2015 to December 2017 were selected, including basic data, complications, laboratory indicators and therapy to analyze the risk factors of contrast induced nephropathy by univariate and multivariate methods. Kaplan-Meier was used to analyze the effect of CIN on re-hospitalization rate.

Results CIN occurred in 58 of 378 elderly patients with coronary heart disease. Multivariate analysis showed that the preoperative creatinine (P=0.010, OR=0.721, 95%CI 0.622-0.834), the postoperative creatinine (P=0.023, OR=1.207, 95%CI 1.094-1.332), the glomerular filtration rate (P=0.024, OR=0.755, 95%CI 0.630-0.905), and the application of diuretics (P=0.032, OR=1.206, 95%CI 0.904-1.364) were the important risk factors of contrast induced nephropathy in elderly patients with coronary heart disease undergoing PCI. Kaplan-Meier showed that the occurrence of CIN would significantly increase the re-hospitalization rate of elderly patients with coronary heart disease after PCI (P=0.000 9, HR=2.359, 95%CI 1.192-4.668).

Conclusion The preoperative and postoperative creatinine, the glomerular filtration rate and diuretics are important risk factors of CIN in elderly patients with coronary heart disease undergoing coronary angiography.