The relationship between prognostic nutritional index and long-term mortality in patients undergoing emergency coronary artery bypass graft surgery for acute-ST elevation myocardial infarction

BACKGROUND: Malnutrition and the prognosis of coronary artery disease (CAD) are shown to be correlated. The significance of nutritional status has been evaluated in patients with ST elevation myocardial infarction (STEMI), stable CAD, and elective coronary artery bypass graft (CABG) surgery. However, the prognostic impact of poor nutritional status on STEMI patients who underwent emergent CABG is not known. In this study, we aimed to investigate the relationship between nutritional status assessed by the prognostic nutritional index (PNI) and long-term mortality in STEMI patients who underwent emergent CABG. To the best of our knowledge, our study is the first one to evaluate the PNI effect on this specific population. METHODS: 131 consecutive patients with STEMI who did not qualify for primary percutaneous coronary intervention and required emergent CABG between 2013 and 2018 were included in our study. The study population was divided into two groups: survivors and non-survivors. The PNI was calculated as 10 x serum albumin (g/dL) + 0.005 x total lymphocyte count (per mm3) for both groups, using the preoperative data. The optimal cut-off value was obtained by receiver operating characteristic (ROC) analysis. According to the cut-off value, we investigated the relationship between PNI and long-term mortality. RESULTS: The mean age of the study population was 57.0 +/- 10.6. During the median 92.7 (70.0-105.3)-month follow-up, 32 of the 131 patients (24.4%) died. Regression analysis showed a significant association between glucose levels (hazard ratio (HR), 1.007; 95% confidence interval (CI), 1.002-1.012; p=0.011) and PNI (HR, 0.850; 95% CI, 0.787-0.917; p<0.001) and long-term mortality. Accord-ing to the ROC analysis, the cut-off value for PNI to predict all-cause mortality was found to be 44.9, with a sensitivity of 81.3% and a specificity of 89.9%. In addition, age, ejection fraction, glomerular filtration rate, Killip classification, and left anterior descending-left internal mammary artery graft use are significantly associated with long-term all-cause mortality in STEMI patients undergoing emergency CABG. CONCLUSION: The PNI was significantly associated with long-term mortality in patients with STEMI who underwent emergent CABG. PNI can be used to improve the accuracy of the risk assessment of STEMI patients undergoing emergent CABG.