Malignant Arrhythmias During Induction of Target Temperature Management After Cardiac Arrest

A Commentary on the Effect of Targeted Temperature Management in Patients Resuscitated from Cardiac Arrest

The members of the International Liaison Committee on Resuscitation (ILCOR) Advanced Life Support Task Force have written a comprehensive summary of trials of the effectiveness of induced hypothermia (IH) or targeted temperature management (TTM) in comatose patients after cardiac arrest (CA). However, in-depth analysis of these studies is incomplete, especially since there was no significant difference in primary outcome between hypothermia versus normothermia in the recently reported TTM2 trial. We critically appraise trials of IH/TTM versus normothermia to characterize reasons for the lack of treatment effect, based on a previously published framework for what to consider when the primary outcome fails. We found a strong biologic rationale and external clinical evidence that IH treatment is beneficial. Recent TTM trials mainly included unselected patients with a high rate of bystander cardiopulmonary resuscitation. The treatment was not applied as intended, which led to a large delay in achievement of target temperature. While receiving intensive care, sedative drugs were likely used that might have led to increased neurologic damage as were antiplatelet drugs that could be associated with increased acute stent thrombosis in hypothermic patients. It is reasonable to still use or evaluate IH treatment in patients who are comatose after CA as there are multiple plausible reasons why IH compared to normothermia did not significantly improve neurologic outcome in the TTM trials.

A New Scoring System for Predicting Ventricular Arrhythmia Risk in Patients with Acute Myocardial Infarction

Objective

In this study, a risk score for ventricular arrhythmias (VA) were evaluated for predicting the risk of ventricular arrhythmia (VA) of acute myocardial infarction (AMI) patients.

Methods

Patients with AMI were divided into two sets according to whether VA occurred during hospitalization. Another cohort was enrolled for external validation. The area under the curve (AUC) of receiver operating characteristic (ROC) was calculated to evaluate the accuracy of the model.

Results

A total of 1493 eligible patients with AMI were enrolled as the training set, of whom 70 (4.7%) developed VA during hospitalization. In-hospital mortality was significantly higher in the VA set than in the non-VA set (31.4% vs 2.7%, P=0.001). The independent predictors of VA in patients with AMI including Killip grade ≥3, STEMI patients, LVEF <50%, frequent premature ventricular beats, serum potassium <3.5 mmol/L, type 2 diabetes, and creatinine level. The AUC of the model for predicting VT/VF in the training set was 0.815 (95% CI: 0.763-0.866). A total of 1149 cases were enrolled from Xuzhou Center Hospital as the external validation set. The AUC of the model in the external validation set for predicting VT/VF was 0.755 (95% CI: 0.687-0.823). Calibration curves indicated a good consistency between the predicted and the observed probabilities of VA in both sets.

Conclusion

We have established a clinical prediction risk score for predicting the occurrence of VA in AMI patients. The prediction score is easy to use, performs well and can be used to guide clinical practice.

An Overview of Therapy Guidelines for Cardiac Arrest and the Potential Benefits of Hemoglobin-Based Oxygen Carriers

Currently, there is an unmet therapeutic need for the medical management of cardiac arrest, as is evident from the high mortality rate associated with this condition. These dire outcomes can be attributed to the severe nature and poor prognosis of this disorder. However, the current treatment modalities, while helping to augment survival, are limited and do not offer adequate improvements to outcomes. Treatment modalities are particularly lacking when considering the underlying pathophysiology of the metabolic phase of cardiac arrest. In this study, we explore the three phases of cardiac arrest and assess the factors related to positive clinical outcomes and survival for these events. Furthermore, we evaluate the present guidelines for resuscitation and recovery, the issues related to ischemia and tissue reperfusion, and the benefit of oxygen-delivery therapeutic methods including blood transfusion therapy and synthetic hemoglobins (HBOCs). The current therapy protocols are limited specifically by the lack of an efficient method of oxygen delivery to address the metabolic phase of cardiac arrest. In this article, we investigate the next generation of HBOCs and review their properties that make them attractive for their potential application in the treatment of cardiac arrest. These products may be a viable solution to address complications associated with ischemia, reperfusion injury, and organ damage.