Clinical significance of the prognostic nutritional index in patients undergoing cardiovascular surgery

Objective The prognostic nutrition index is an immunonutritional indicator and postoperative predictor of oncological surgery. However, its prognostic value in cardiovascular disease is unknown. This study assessed the value of the prognostic nutrition index in cardiovascular surgery. Methods This retrospective study included 453 patients who underwent cardiovascular surgery. The patients were divided according to cutoff values of the prognostic nutrition index: < 48, low prognostic nutrition index group and >= 48, high prognostic nutrition index group. Clinicopathologic features, including the preoperative state, surgical procedure, and postoperative morbidity and mortality, were compared between the groups. The Mann-Whitney U or Chi-square test, univariate and multivariate analyses, and log-rank test were used in the statistical analyses. Results Old age, a low body mass index, and elevated creatinine levels correlated significantly with a low prognostic nutrition index. Logistic regression analysis demonstrated that a high prognostic nutrition index status was statistically related to a shorter length of intensive care unit stay, shorter intubation time, and lower incidences of mediastinitis and pneumonia. Multivariate analysis revealed that male sex (hazard ratio 3.93; 95% confidence interval 1.29-11.91, p = 0.016), age (hazard ratio 3.35; 95% confidence interval 1.11-10.15 p = 0.032), and the prognostic nutrition index (hazard ratio 0.40; 95% confidence interval 0.18-0.90, p = 0.026) were independently associated with postoperative survival. Conclusions A low prognostic nutrition index was significantly associated with postoperative complications and survival. The prognostic nutrition index may be useful and reliable as a preoperative assessment of nutritional status, and it should be considered in the indication and strategy of cardiovascular surgery.