INTRODUCTION: Inflammatory indices derived from routine blood tests, such as the systemic inflammatory response index (SIRI), the derived neutrophil-to-lymphocyte ratio (dNLR), the neutrophil-to-HDL ratio (NHR), and the monocyte-to-HDL ratio (MHR), have gained interest as potential cardiovascular biomarkers. This study aimed to establish reference intervals for these indices in healthy adults and assess their clinical relevance in acute myocardial infarction (AMI), heart failure (HF), and heart failure following AMI.
METHODS: This retrospective study included adult patients from the Istanbul Faculty of Medicine Central Laboratory. Reference intervals were established using the Bhattacharya method, and odds ratios (ORs) were calculated to assess the association between elevated inflammatory indices and cardiovascular conditions.
RESULTS: The upper reference limits (URLs) for the inflammatory indices were as follows: dNLR≤2.57, MHR≤0.49, NHR≤3.62, and SIRI≤1.24. Elevated levels of SIRI, MHR, and NHR were significantly associated with increased odds of AMI (ORs of 3.43, 3.44, and 2.93, respectively). In HF patients, all four indices were significantly elevated, with MHR (OR=7.82) and SIRI (OR=5.52) showing the strongest associations. In the AMI+HF group, SIRI (OR=2.38) and dNLR (OR=2.63) were significantly elevated.
DISCUSSION AND CONCLUSION: This study demonstrates the clinical relevance of CBC-derived inflammatory indices, particularly SIRI and MHR, in distinguishing patients with coexisting myocardial infarction and heart failure. Our robust approach, including healthy controls and precise determination of reference intervals, highlights the potential utility of these markers for enhanced risk stratification and management in cardiovascular disease.