Association between serum lactate levels and mortality in patients with cardiogenic shock receiving mechanical circulatory support: a multicenter retrospective cohort study

Abstract

Background: To evaluate the prognostic value of peak serum lactate and lactate clearance at several time points in cardiogenic shock treated with temporary mechanical circulatory support (MCS) using veno-arterial extracorporeal membrane oxygenation (VA-ECMO) or Impella CP^®.

Methods: Serum lactate and clearance were measured before MCS and at 1 h, 6 h, 12 h, and 24 h post-MCS in 43 patients at four tertiary-care centers in Southern Brazil. Prognostic value was assessed by univariable and multivariable analysis and receiver operating characteristic (ROC) curves for 30-day mortality.

Results: VA-ECMO was the most common MCS modality (58%). Serum lactate levels at all time points and lactate clearance after 6 h were associated with mortality on unadjusted and adjusted analyses. Lactate levels were higher in non-survivors at 6 h, 12 h, and 24 h after MCS. Serum lactate > 1.55 mmol/L at 24 h was the best single prognostic marker of 30-day mortality [area under the ROC curve = 0.81 (0.67-0.94); positive predictive value = 86%). Failure to improve serum lactate after 24 h was associated with 100% mortality.

Conclusions: Serum lactate was an important prognostic biomarker in cardiogenic shock treated with temporary MCS. Serum lactate and lactate clearance at 24 h were the strongest independent predictors of short-term survival.

Keywords: Cardiogenic shock; Extracorporeal membrane oxygenation; Impella; Lactic acid; Mechanical circulatory support.

Fig. 1

Differences in lactate levels at the time points of interest between survivors and non-survivors. Legend: The box plot inner horizontal lines indicate median; boxes, interquartile range (25th and 75th percentiles); vertical whiskers, 1.5 interquartile range beyond the 25th and 75th percentiles; and dots, more extreme values

Fig. 2

Kaplan–Meier curves of survival in groups stratified by lactate cutoff levels determined with Youden’s J statistic for area under the ROC curve. a Lactate at 6 h ≤ 3.27 mmol/L; b Lactate at 12 h ≤ 3.15 mmol/L; c Lactate at 24 h ≤ 1.55 mmol/L; d Lactate clearance at 24 h ≥ 46.5%