The following is a summary of “Association between normalized lactate load and in-hospital mortality in patients with acute myocardial infarction,” published in the March 2024 issue of Cardiology by Wu et al.
While lactate has been recognized as a prognostic indicator for acute myocardial infarction (AMI) patients, the relationship between normalized lactate load reflecting hypoxic burden over time and in-hospital mortality has remained ambiguous.
They obtained data for this study from the Medical Information Mart for Intensive Care IV (MIMIC-IV, version 2.1) database. The normalized lactate load, indicating the average intensity of hyperlactatemia, was computed as the area under the curve (AUC) of lactate divided by time. Among the 5,882 AMI patients included, they were categorized into survivor (n = 5015) and non-survivor groups (n = 867). The primary endpoint assessed was in-hospital mortality. Receiver operating characteristic (ROC) curves were constructed to evaluate the predictive performance of normalized lactate load for in-hospital mortality, and the areas under the curves of different parameters were compared using the DeLong test. Multivariate binary logistic regression analysis was conducted to investigate the relationship between normalized lactate load and in-hospital mortality, adjusting for variables such as age, gender, ethnicity, heart rate, systolic blood pressure, congestive heart failure, shock, dyslipidemia, cardiac arrest, cerebrovascular disease, neutrophil count, lymphocyte count, creatinine levels, blood urea nitrogen, clopidogrel use, beta-blockers, angiotensin-converting enzyme inhibitor (ACEI)/angiotensin receptor blocker (ARB) use, statins, dialysis, extracorporeal membrane oxygenation (ECMO), the Sequential Organ Failure Assessment (SOFA) score, and the Simplified Acute Physiology Score II (SAPS II). Restricted cubic spline (RCS) analysis assessed potential nonlinear associations between normalized lactate load and in-hospital mortality.
The results showed that the overall in-hospital mortality rate stood at 14.7%. Following adjustment for confounding variables, a normalized lactate load of 2.6 or higher was independently linked with a heightened risk of in-hospital mortality (OR, 95% CI: 1.56, 1.27–1.93). The RCS analysis revealed a positive linear correlation between normalized lactate load and in-hospital mortality (non-linear P=0.725). ROC curves indicated that normalized lactate load exhibited superior predictive ability for in-hospital mortality compared to first lactate, maximum lactate, and mean lactate, although it trailed behind SOFA and SAPS II scores. Among participants with at least nine lactate measures, normalized lactate load demonstrated predictive performance on par with SOFA and SAPS II scores.
Investigators concluded that measuring lactate changes over time (normalized lactate load) in AMI patients predicts death risk better than single readings, and the more measurements are taken, the more accurate the prediction.
Source: internationaljournalofcardiology.com/article/S0167-5273(23)01793-X/abstract#%20