Abstract
Introduction: Although blood urea nitrogen (BUN) and serum creatinine concentration (SCr) has been widely measured in daily clinical practice, blood urea nitrogen to serum creatinine (BUN-to-SCr) ratio (BCR) to assess prognosis in the patients admitted with acute myocardial infarction (AMI) remains yet understudied. This study aimed to determine the association between the BCR and in-hospital outcome in the patients with AMI admitted to a tertiary hospital, in Bangladesh.
Methods: All admitted patients with AMI in the Department of Cardiology, Chittagong Medical College Hospital from May 2023 to August 2024 were included in this prospective observational study. Outcome parameters included in-hospital mortality (IHM), left ventricular failure (LVF), cardiogenic shock (CS), ventricular arrhythmia (VA), conduction abnormality and length of hospital stay.
Results: A total of 297 patients with AMI were included in this study. Age ranged between 29 and 90 years with a mean±SD age of 56.5±10.3 years, 70.7% were male and 79.5% were diagnosed as ST-segment elevation myocardial infarction (STEMI). The receiver operating characteristic (ROC) curve analysis established that the area under the curve (AUC) for BCR was 0.782 [95% confidence interval (CI):0.713-0.852, p<0.001] and the threshold level for BCR was 19.50 with the sensitivity and specificity of 79.4% and 70%, respectively, for in-hospital mortality. High BCR at admission was associated with LVF (67.0 % vs. 21.5%, p<0.001), CS (69.8% vs. 25.7%, p<0.001), VA (19.8% vs. 3.7%, p<0.001) and in-hospital mortality (25.5% vs. 3.7%, p<0.001).After adjusting for additional confounding factors, the BCR remained a significant predictor of in-hospital mortality (>19.5vs.<19.5: Hazard ratio, 2.718;95% CI,1.137-6.495;p=0.024).
Conclusion: A high level of BCR at admission could be a useful predictor of IHM and other major complications in AMI patients. So, routine evaluation of BCR at admission can help to identify high risk cases of AMI with poor outcome.
Keywords: Acute myocardial infarction, BUN, serum creatinine, BUN/SCr ratio, in- hospital mortality.