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World J Cardiol. Aug 26, 2015; 7(8): 483-489
Published online Aug 26, 2015. doi: 10.4330/wjc.v7.i8.483
Clinical significance of lactate in acute cardiac patients
Chiara Lazzeri, Serafina Valente, Marco Chiostri, Gian Franco Gensini
Chiara Lazzeri, Serafina Valente, Marco Chiostri, Gian Franco Gensini, Intensive Cardiac Care Unit, Heart and Vessel Department, Azienda Ospedaliero-Universitaria Careggi, 50134 Florence, Italy
Gian Franco Gensini, Department of Experimental and Clinical Medicine, University of Florence, AOU Careggi, Fondazione Don Carlo Gnocchi IRCCS, 50100 Florence, Italy
Author contributions: Lazzeri C and Gensini GF designed the study and wrote the manuscript; Valente S and Chiostri M critically revised the manuscript.
Conflict-of-interest statement: None.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Chiara Lazzeri, MD, Intensive Cardiac Care Unit, Heart and Vessel Department, Azienda Ospedaliero-Universitaria Careggi, Viale Morgagni 85, 50134 Florence, Italy. lazzeric@libero.it
Telephone: +39-55-7947518 Fax: +39-55-7947518
Received: November 19, 2014
Peer-review started: November 20, 2014
First decision: December 12, 2014
Revised: April 6, 2015
Accepted: May 16, 2015
Article in press: May 18, 2015
Published online: August 26, 2015
Abstract

Lactate, as a metabolite of easy and quick assessment, has been studied over time in critically ill patients in order to evaluate its prognostic ability. The present review is focused on the prognostic role of lactate levels in acute cardiac patients (that is with acute coronary syndrome, cardiogenic shock, cardiac arrest, non including post cardiac surgery patients). In patients with ST-elevation myocardial infarction treated with mechanical revascularization, hyperlactatemia identified a subset of patients at higher risk for early death and in-hospital complications, being strictly related mainly to hemodynamic derangement. The prognostic impact of hyperlactatemia on mortality has been documented in patients with cardiogenic shock and in those with cardiac arrest even if there is no cut-off value of lactate to be associated with worse outcome or to guide resuscitation or hemodynamic management. Therapeutic hypothermia seems to affect per se lactate values which have been shown to progressively decrease during hypothermia. The mechanism(s) accounting for lactate levels during hypothemia seem to be multiple ranging from the metabolic effects of reduced temperatures to the hemodynamic effects of hypothermia (i.e., reduced need of vasopressor agents). Serial lactate measurements over time, or lactate clearance, have been reported to be clinically more reliable than lactate absolute value also in acute cardiac patients. Despite differences in study design, timing of lactate measurements and type of acute cardiac conditions (i.e., cardiogenic shock, cardiac arrest, refractory cardiac arrest), available evidence strongly suggests that higher lactate levels can be observed on admission in non-survivors and that higher lactate clearance is associated with better outcome.

Keywords: Lactate, Acute coronary syndrome, Cardiogenic shock, Cardiac arrest, Therapeutic hypothermia, Extracorporeal membrane oxygenation, Prognosis

Core tip: The present review is focused on the prognostic role of lactate levels in acute cardiac patients (acute coronary syndrome, cardiogenic shock, cardiac arrest). The prognostic impact of hyperlactatemia on mortality has been documented in cardiogenic shock and cardiac arrest even if there is no cut-off value of lactate to be associated with worse outcome or to guide resuscitation or hemodynamic management. Lactate clearance was reported to be clinically more reliable than lactate absolute value in these patients. Despite differences in study design, timing of lactate measurements and type of acute cardiac conditions (i.e., cardiogenic shock, cardiac arrest, refractory cardiac arrest), available evidence strongly suggests that higher lactate levels can be observed on admission in non-survivors and that a more favorable outcome is observed in patients with higher lactate clearance.