Lactate to albumin ratio and bicarbonate conc. may predict mortality risk in patients with acute MI

The study showed that the lactate-to-albumin ratio correlated positively with the risk of 30-day all-cause mortality for AMI patients. An increase in mortality rate was seen with an increase in the L/A ratio. Further, bicarbonate concentrations < 22 mmol/L were associated inversely with 30-day mortality risk in patients with AMI. Lower concentrations of bicarbonate were tied to a higher 30-day mortality risk. The hemoglobin level, when less than 10 g/dl, was inversely associated with the mortality risk.

Previous studies have suggested that the L/A ratio is predictive of the prognosis of ICU patients with heart failure. Also, some studies have suggested that a low serum bicarbonate concentration is related inversely to the mortality risk of cardiogenic shock patients. However, there needs to be more clarity on the utility of the L/A ratio and bicarbonate for predicting the mortality risk of AMI patients. Therefore, Jia-Liang Zhu and colleagues from China conducted a retrospective study to explore this problem.

The study included patients with acute myocardial infarction; the data was obtained from an intensive care database. 30-day all-cause mortality after admission was recorded (primary endpoint). For endpoint events, a comparison was drawn between the predictive value of lactate, albumin, and L/A ratio. Also, the effects of different levels of L/A ratio and different bicarbonate concentrations were compared on 7-day and 30-day all-cause mortality.

The study revealed the following findings:

· The Area Under Curve (AUC) of lactate, L/A ratio, and albumin were 0.718, 0.736, and 0.620, respectively. (1) L/A ratio: The patients were categorized into three groups as per their L/A ratio: tertile T1 with L/A ratio ≤ 0.47, tertile T2 with L/A ratio ≤ 0.97, and tertile T3 with L/A ratio > 0.97. The T2 and T3 groups had more significant 30-day all-cause mortality risks compared to the T1 group.

· The restricted cubic spline (RCS) model suggested a nonlinear relationship between the L/A ratio and 30-day mortality.

· Bicarbonate concentration: The patients were also categorized into three groups as per their bicarbonate concentration: G1 with a concentration of 22–27 mmol/L, G2 with < 22 mmol/L, and G3 with > 27 mmol/L concentration. The G2 and G3 groups had more significant 30-day all-cause mortality risks compared to the G1 group.

· The RCS model revealed a nonlinear relationship between bicarbonate concentration and 30-day mortality.

· The RCS model revealed a nonlinear relationship between hemoglobin level and 30-day all-cause mortality.

"L/A ratio, bicarbonate concentration, and hemoglobin level are predictive for predicting 30-day mortality in acute myocardial infarction patients," the authors concluded.

Reference:

Zhu, JL., Liu, H., Wang, LL. et al. Association of lactate to albumin ratio and bicarbonate with short-term mortality risk in patients with acute myocardial infarction. BMC Cardiovasc Disord 22, 490 (2022). https://doi.org/10.1186/s12872-022-02902-4