Abstract 286: Prognostic Value of Blood Urea Nitrogen / Creatinine Ratio in Patients Post Myocardial Infarction: Experience From the Survival and Ventricular Enlargement Trial

Abstract

Introduction: Renal function assessed by serum creatinine-based estimated glomerular filtration rate (eGFR), is an established prognostic marker in the general population and following an acute myocardial infarction. Elevation of the blood urea nitrogen / creatinine ratio (BUN/CR) indicates appropriate renal response to systemic hypoperfusion and suggests acute cardio-renal alteration. We aimed to determine the prognostic value of the BUN/CR for adverse cardiovascular (CV) events and mortality in patients with acute myocardial infarction and left ventricular dysfunction. Methods: We used data from the Survival and Ventricular Enlargement (SAVE) trial that randomized 2231 patients 3 to 16 days following an acute myocardial infarction with left ventricular ejection fraction of ≤ 40% to captopril or placebo. Patients with a creatinine level >2.5 mg/dl were not included in the trial. Patients were categorized according to quartiles of BUN/CR, or as high BUN/CR (if ≥ 20) versus low. Cox proportional hazard regression models were used to evaluate the association of BUN/CR with mortality and adverse CV events. Results: There were 461 patients with high BUN/CR (≥ 20). They were older, more likely to be women, have a lower body mass index, higher eGFR, a prior myocardial infarction and a lower left ventricular ejection fraction at baseline. In univariable analysis, an elevated BUN/CR was associated with an increased risk of heart failure but not with other clinical endpoints (death, CV death, or a composite of death, MI or heart failure). In multivariable models that included age, gender, eGFR, diabetes, Killip class, hypertension, assignment to captopril arm, and left ventricular ejection fraction, a high BUN/CR was not predictive of any endpoint (p>0.5). Conclusion: Although an elevated BUN/CR may represent systemic hypoperfusion, it does not appear to be an independent prognostic marker for adverse CV events and mortality in patients with acute myocardial infarction and left ventricular dysfunction.