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

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.