P1751Lactate as valuable tool to predict the survivors from refractory cardiogenic shock complicated with acute myocardial infarction

Abstract

Background: Acute myocardial infarction (AMI) patients complicated with refractory cardiogenic shock (CS) are at substantial risk for in-hospital death. As consequence of refractory CS patients present signs of end organ injury with elevated lactate. Previous studies show evidences concerning the predictive role of lactate levels in CS patients on mortality. Especially for patients underwent mechanical circulatory support (MCS), changes of lactate levels may allow the evaluation of effectiveness of MCS and possibly allows the estimation of outcomes. However, the efficacy of those evidences remains still unclear in the group of AMI patients with refractory CS. In this study, we assessed the trend of serial blood lactate levels in AMI patients with refractory CS patients and its predictive role on in-hospital mortality. Method: This retrospective analysis was performed with consecutive AMI patients with refractory CS between April 2015 and January 2018. All patients were diagnosed with AMI based on universal definition. Refractory CS was defined as systolic blood pressure (sBP) less than 75 mmHg-despite receiving an intravenous inotropic agent-that was associated with altered mental status and res- piratory failure. MCS were initiated as early as possible at the point to detect refractory CS. Emergent coronary angiography and percutaneous coronary intervention were performed in the conventional manner. The following variables were evaluated: vital signs, pre-hospital bystander CPR, arterial blood gas analysis, laboratory data upon hospital arrival and SYNTAX score. Blood lactate values were measured by arterial blood gas analysis on CCU in 2h interval after admission until stable conditions were achieved. Result: Among the 45 patients (37 male and 8 female, 68.8±14.9 years old), there were 17 in-hospital deaths while 28 patients survived to hospital discharge. Concerning of MCS (VA-ECMO, IABP), 94% (16/17) of patients use MCS in nonsurvivor group, whereas 75% (21/28) of patients use MCS in survivor group. In addition, 71% (12/17) of patients have cardiac arrest in non-survivor group, 50% (14/28) of patients have cardiac-arrest in survivor group. Lactate levels were elevated on admission of all (8.89 mmol/L), however there was no difference depending on in hospital mortality (survivors vs. non-survivors: 8.39 mmol/L vs. 10.78 mmol/L; P=0.224). Patients in survivor group had significant lower lactate level compared with non-survivor group after 4h (Figure 1). This significant difference persisted until 72h after admission. The lactate level at 12h decreased in 84.6% of patients (27/28) in survivor group, whereas in 47.1% of patients (8/17) in nonsurvivor group (p=0.0087). Conclusion: The serial measurements of lactate can be valuable tool during the early course of refractory CS with AMI and was strongly predictive of mortality. Therefore, MCS should be initiated in a timely fashion toward early significant decrement of lactate levels. (Figure Presented) .