The Effect of High Lactate Level on Mortality in Acute Heart Failure Patients With Reduced Ejection Fraction Without Cardiogenic Shock

Background We aimed to determine the effect of blood lactate levels on cardiovascular (CV) death and hospitalization for heart failure (HF) in acute HF patients with reduced left ventricular ejection fraction (EF). Methods Eighty-five acute HF patients with reduced ejection fraction were divided into two groups according to admission blood lactate levels. 48 of them had low blood lactate levels (< 2 mmol/l) and 37 of them had high blood lactate levels (>= 2 mmol/l). Patients with acute coronary syndrome, cardiogenic shock, sepsis and low blood pressure at admission were excluded from the study. Primary endpoint is the composite of cardiovascular (CV) death and hospitalization for heart failure (HHF) in 6-month follow-up. Secondary endpoint is the change in NT-proBNP levels from admission to 72 h. Results Baseline characteristics of patients were similar in two groups. On baseline echocardiographic evaluation; patients with high lactate revealed a higher mitral E/A ratio (2.34 [0.43-3.31], p = 0.008) and a lower TAPSE ratio (14 [10-27], p = 0.008) than patients with low lactate levels. Over a median follow-up period of 6 months, the primary end point occurred in 28 (75.7%) of 37 patients assigned to high lactate group and in 20 (41.7%) of 48 patients assigned to low lactate group (p = 0.006). High lactate levels significantly increased the risk of CV death and HHF at 6 months by nearly 5.35-fold in acute HF patients with reduced EF. The change in NT-proBNP levels at 72nd hour after admission were similar between two groups. Conclusion Higher lactate levels at admission related with higher HHF at 6 months and may be related with higher risk of CV death in acute HF patients with reduced EF.