Comparative Analysis of Neutrophil-to-lymphocyte Ratio, Systemic Immune-Inflammation Index, and Prognostic Nutritional Index in Acute Myocardial Infarction Patients Treated with Percutaneous Coronary Intervention

OBJECTIVE
Acute myocardial infarction constitutes one of the leading reasons for cardiac mortality. Therefore, early identification of high-risk patients provides better prognostic accuracy. This study aimed to investigate the prognostic significance of novel inflammatory biomarkers such as neutrophil-to-lymphocyte ratio, systemic immune-inflammation index, and prognostic nutritional index in acute myocardial infarction patients treated with percutaneous coronary intervention and to compare their predictive abilities with each other.


METHODS
A total of 828 acute myocardial infarction patients treated with percutaneous coronary intervention were retrospectively analyzed. The inflammatory indices, such as neutrophil-to-lymphocyte ratio, systemic immune-inflammation index, and prognostic nutritional index, were calculated by admission blood tests. The study population was divided into 2 groups according to the occurrence of major adverse cardiac events, which were defined as all-cause mortality, non-fatal myocardial infarction, and cerebrovascular events.


RESULTS
Multivariate Cox regression analysis determined prognostic nutritional index as an inde-pendent predictor of major adverse cardiac event and all-cause mortality (hazard ratio: 1.05,
95% CI: 1.02-1.07, P <.001 for major adverse cardiac event and hazard ratio: 1.05, 95% CI: 1.02-1.09, P =.002 for all-cause mortality). Receiver operating characteristic curves revealed that the predictive value of prognostic nutritional index with both regard to major adverse cardiac event and all-cause mortality was better than the systemic immune-inflammation index and neutrophil-to-lymphocyte ratio (by DeLong method, area under curvePNI vs. area
under curveSII z test = 2.66, P =.008; area under curvePNI vs. area under curveNLR z test = 2.8, P =.006; area under curvePNI vs. area under curveSII z test = 2.58, P =.009; area under curvePNI vs. area under curveNLR z test = 3.28, P =.001; respectively).


CONCLUSIONS
Prognostic nutritional index was demonstrated as an independent predictor of major adverse cardiac events and all-cause mortality and a more powerful prognostic index than other novel inflammatory biomarkers in acute myocardial infarction patients treated with percutaneous coronary intervention.