Mild therapeutic hypothermia after out-of-hospital cardiac arrest: What does really matter?

The prognostic impact of therapeutic hypothermia after a sudden cardiac arrest in the course of myocardial infarction

BACKGROUND

Mild therapeutic hypothermia (MTH) is one of the treatment methods recommended in post-sudden cardiac arrest (SCA) patients who remain unconscious after cardiopulmonary resuscitation. The present study aimed at assessing the prognostic impact of intravascular MTH on invasively treated patients with an acute myocardial infarction complicated by SCA.

METHODS

The presented data were collected via a single-center retrospective analysis of the hospitalization and follow-up of 54 patients with post-myocardial infarction complicated by SCA. The patients were treated in the years 2014-2020 and the average follow-up period was 1141 ± 163 days. The population was divided into two groups: 28 patients treated with MTH (a therapeutic hypothermia [TH] group) and 26 patients treated without MTH (a non-TH group).

RESULTS

The results indicate a trend toward improved in-hospital prognosis in the TH group, but the differences did not reach statistical significance: TH 25.0% vs. non-TH 34.5%, p = 0.554. An additional analysis of younger patients (under 60 years of age) revealed no significant differences between the TH and non-TH subgroups concerning in-hospital survival (in-hospital mortality rate: TH 6.7% vs. non-TH 30.0%, p = 0.267). Still, TH patients aged < 60 achieved a significantly better rate of follow-up survival (p = 0.041). The older (≥ 60) patient group showed no in-hospital mortality rate differences (TH 46.2% vs. non-TH 37.5%, p = 0.638). However, in-hospital bleeding frequency was significantly higher in patients aged ≥ 60 from the hypothermia group (TH 50.0% vs. non-TH 6.7%, p = 0.011).

CONCLUSIONS

Intravascular MTH may improve the follow-up prognosis in patients aged < 60 with SCA in the early phase of myocardial infarction.

Elevated serum transaminases in patients with acute coronary syndromes: Do we need a revision of exclusion criteria for clinical trials?

BACKGROUND

Elevations of hepatic transaminase (serum alanine transaminase [ALT] and serum aspartate aminotransferase [AST]) levels in patients with acute coronary syndrome (ACS), although transient, may result in exclusions from clinical efficacy trials due to suspected liver disease. The aim of this study was to evaluate the concentrations of serum transaminases in ACS and relate these to currently accepted AST/ALT exclusion criteria from clinical trials.

METHODS

One hundred consecutive patients with ACS were prospectively examined. Blood samples for AST, ALT, total bilirubin and troponin I concentration were obtained at the time of admission and after 6, 12 and 24 hours.

RESULTS

Eighty percent of patients had elevated AST, and 47% ALT; 43% of patients characterized AST concentration > 3 × upper limit of normal (ULN) in at least one measurement, while 8% of patients presented ALT concentration > 3 × ULN. AST presented higher concentrations when compared to ALT, resulting in a high De-Ritis ratio at every time point. No significant or high correlations were found between the concentrations of serum transaminases, De-Ritis ratio and troponin I. Two different cut-off values of troponin I were adopted to define the amount of infarcted myocardium that distinguished 28-31% of individuals with "large infarction". Among these patients, approximately 93% presented AST concentrations > 3 × ULN.

CONCLUSIONS

Hepatic transaminases are often elevated in ACS, with the majority of patients with more extensive myocardial injury presenting high concentrations of AST. In the setting of ACS, current transaminase thresholds for liver dysfunction used in clinical trials may lead to excessive and inadequate exclusions of patients with larger infarcts from such trials.