The value of lactate/albumin ratio for predicting the clinical outcomes of critically ill patients with heart failure

Background: Previous studies have shown that the lactate/albumin (L/A) ratio plays a role in predicting the outcomes of septic shock or severe sepsis. However, the role of the L/A ratio in predicting the outcomes of critically ill patients with heart failure remains unclear. We therefore performed a retrospective study to clarify this issue. Methods: The study was based on the Multiparameter Intelligent Monitoring in Intensive Care III (MIMIC-III) database and included critically ill adult patients with heart failure. The primary endpoints were 28-day and 1-year all-cause mortality after admission at the intensive care unit. Results: We analyzed 4,562 patients in this study. We divided the participants into five groups according to the L/A ratio: quintile (Q)1 (L/A ratio 50.40, n=913), Q2 (0.40< L/A ratio 50.51, n=912), Q3 (0.51< L/A ratio 50.66, n=912), Q4 (0.66 L/A ratio 50.92, n=912), and Q5 (L/A ratio 0.92, n=913). After stratifying by L/A ratio, the risk of 28-day and 1-year mortality were significantly different between the groups (log-rank P<0.001). Compared with the first quintile, the second, third, fourth, and fifth quintiles of the L/A ratio were associated with higher 28-day [hazard ratio (HR) 1.57, 95% confidence interval (CI): 1.21-2.03 for Q3, HR 1.72, 95% CI: 1.34-2.21 for Q4, and HR 3.15, 95% CI: 2.47-4.01 for Q5) and 1-year mortality (HR 1.19, 95% CI: 1.00-1.41 for Q2, HR 1.36, 95% CI: 1.15-1.60 for Q3, HR 1.42, 95% CI: 1.20-1.67 for Q4, and HR 2.46, 95% CI: 2.09-2.89 for Q5). The restricted cubic spline showed that the L/A ratio positively correlated with both 28-day and 1-year all-cause mortality. Conclusions: The L/A ratio could serve as a predictor of short and long-term mortality in critically ill patients with heart failure.