Relationship between brain natriuretic peptide, microalbuminuria, and contrast-induced nephropathy in patients with acute coronary syndrome

Patients may develop kidney failure because of the contrast agent given during coronary angiography. Renal dysfunction and heart failure were previously shown to be associated with the development of contrast nephropathy. In our study, we aimed to investigate whether there is a relationship between subclinical renal (indicated by microalbuminuria) and/or cardiac (indicated by the height of the BNP) dysfunction between the development of contrast-induced nephropathy on patients undergoing angiography due to acute coronary syndrome. This is an observational prospective cohort study. A total of 170 patients hospitalized with a diagnosis of acute coronary syndrome in the coronary care unit were included in this study. Blood samples were collected from 145 patients without microalbuminuria and 25 patients with microalbuminuria to determine their BNP levels before coronary angiography. The patients' urea and creatinine levels were examined before and 72 h after coronary angiography. Statistical analysis was performed using Kolmogorov-Smirnov test, Mann-Whitney U test, independent samples t-test and the chi-square test. The study subjects included 82 females and 88 males (average age, 64.4±14.5 years). The BNP levels and height distribution of the 145 patients without microalbuminuria were compared between those with and without contrast agent-induced nephropathy, but no significant difference was found (205.6±280.6, 198.0±310.0, p=0.817). Similarly, no relationship between the microalbumin level and contrast agent-induced nephropathy was found in 25 patients. A relationship between BNP, microalbuminuria, and contrast agent-induced nephropathy was not found in patients hospitalized in a coronary care unit with a diagnosis of acute coronary syndrome who were scheduled for coronary angiography. Additional multicenter studies with larger patient groups should be conducted to obtain more data.