Blood urea nitrogen is associated with long-term all-cause mortality in stable angina pectoris patients: 8-year follow-up results

Abstract

Background    Elevation of blood urea nitrogen (BUN) indicates renal dysfunction and is associated with increased mortality in cardiovascular diseases. We investigated the relationship between the BUN concentration measured at hospital admission and the long-term all-cause mortality in patients with stable angina pectoris (SAP).Methods    The mortality rate of 344 patients who underwent coronary angiography (CAG) in our clinic due to SAP was analyzed during a mean follow-up period of 8 yrs.Results    Age (p<0.001), male gender (p=0.020), waist circumference (p=0.007), body-mass index (p=0.002), fasting glucose (p=0.004), BUN (p<0.001), serum creatinine (Cr) (p<0.001), hemoglobin (p=0.015), triglyceride concentrations (p=0.033), and the Gensini score (p<0.001) were related to all-cause mortality as shown by univariate Cox regression analysis. Age (OR 1.056, 95 % CI 1.015–1.100, p=0.008), fasting glucose (OR 1.006, 95 % CI 1.001–1.011, p=0.018), BUN, (OR 1.077, 95 % CI 1.026–1.130, p=0.003), and the Gensini score (OR 2.269, 95 % CI 1.233–4.174, p=0.008) were significantly related with mortality as shown by multivariate Cox regression analysis. According to receiver operating characteristic analysis ofthe sensitivity and specificity of BUN and Cr for predicting mortality, the area under the curve values of BUN and Cr were 0.789 (p<0.001) and 0.652 (p=0.001), respectively. BUN had a stronger relationship with mortality than Cr. A concentration of BUN above 16.1 mg / dl had 90.1 % sensitivity and 60 % specificity for predicting mortality (OR=2.23).Conclusion    In patients who underwent CAG due to SAP, the BUN concentration was associated with all-cause mortality during a mean follow-up period of 8 yrs.