Inverse Association Between Bystander Use of Audiovisual Feedback From an Automated External Defibrillator and Return of Spontaneous Circulation

Background Treatment with an automated external defibrillator (AED) improves outcome in out‐of‐hospital cardiac arrest (OHCA). Audiovisual feedback from an AED may assist bystanders achieve higher quality cardiopulmonary resuscitation. However, the association between audiovisual feedback and clinical outcomes is not well assessed in real‐life OHCA. The aim of this study was to assess the association between audiovisual feedback from an AED used in bystander resuscitation with rates of return of spontaneous circulation (ROSC) and 30‐day survival in a real‐life cohort of patients with OHCA. Methods and Results We included 325 patients treated with bystander AED use before arrival of emergency medical services during 2016 to 2019 from the Capital Region of Denmark. Patients were divided into a “feedback” and a “nonfeedback” group, depending on presence of audiovisual feedback from the AED. Audiovisual feedback was defined as voice prompts with continuous feedback to ongoing resuscitation. Rates of ROSC upon hospital admission and 30‐day survival were assessed, and univariate and multivariable models were applied to decide the association to audiovisual feedback. Multivariable models were adjusted for sex, age, primary heart rhythm, and location of OHCA. A total of 155 (48%) patients had a bystander AED applied with audiovisual feedback and 170 (52%) without audiovisual feedback. A lower rate of ROSC was found in the feedback group compared with the nonfeedback group (33% [n=51] versus 45% [n=76]; P=0.03). No association was observed between AV feedback and 30‐day survival (feedback=27% [n=42] and nonfeedback=31% [n=53]; P=0.49). In the unadjusted logistic regression model, audiovisual feedback was associated with a decreased chance of ROSC (odds ratio, 0.61; 95% CI, 0.38–0.95; P=0.03), which remained significant after adjusted analysis (odds ratio, 0.53; 95% CI, 0.29–0.97; P=0.04), whereas we found no significant association between audiovisual feedback and 30‐day survival in the unadjusted and adjusted analyses. Conclusions Audiovisual feedback from an AED used by bystanders was associated with a lower chance of ROSC at hospital admission, but we found no significant difference in 30‐day survival. Focus on early and correct bystander cardiopulmonary resuscitation and AED use remain key for OHCA survival

Targeted plasma metabolomics in resuscitated comatose out-of-hospital cardiac arrest patients

Background: Out-of-hospital cardiac arrest (OHCA) is a leading cause of death. Even if successfully resuscitated, mortality remains high due to ischemic and reperfusion injury (I/R). The oxygen deprivation leads to a metabolic derangement amplified upon reperfusion resulting in an uncontrolled generation of reactive oxygen species in the mitochondria triggering cell death mechanisms. The understanding of I/R injury in humans following OHCA remains sparse, with no existing treatment to attenuate the reperfusion injury. Aim: To describe metabolic derangement in patients following resuscitated OHCA. Methods: Plasma from consecutive resuscitated unconscious OHCA patients drawn at hospital admission were analyzed using ultra-performance-liquid-mass-spectrometry. Sixty-one metabolites were prespecified for quantification and studied. Results: In total, 163 patients were included, of which 143 (88%) were men, and the median age was 62 years (53–68). All measured metabolites from the tricarboxylic acid (TCA) cycle were significantly higher in non-survivors vs. survivors (180-days survival). Hierarchical clustering identified four clusters (A-D) of patients with distinct metabolic profiles. Cluster A and B had higher levels of TCA metabolites, amino acids and acylcarnitine species compared to C and D. The mortality was significantly higher in cluster A and B (A:62% and B:59% vs. C:21 % and D:24%, p < 0.001). Cluster A and B had longer time to return of spontaneous circulation (A:33 min (21–43), B:27 min (24–35), C:18 min (13–28), and D:18 min (12–25), p < 0.001). Conclusion: Circulating levels of metabolites from the TCA cycle best described the variance between survivors and non-survivors. Four different metabolic phenotypes with significantly different mortality were identified

Lactate is a Prognostic Factor in Patients Admitted With Suspected ST-Elevation Myocardial Infarction

AIMS: The diagnosis of cardiogenic shock depends on clinical signs of poor perfusion and low blood pressure. Lactate concentration will increase with poor tissue perfusion, and it has prognostic value in cardiogenic shock patients. We sought to assess the prognostic value of lactate concentration in subjects admitted with suspected ST-elevation myocardial infarction (STEMI). METHODS AND RESULTS: In 2,094 (93%) out of 2,247 consecutive suspected STEMI-subjects, lactate concentration was measured on admission. The prognostic value of lactate concentration on 30-day mortality was assessed in addition to clinical signs of peripheral hypoperfusion, systolic blood pressure (sBP), and left ventricular ejection fraction (LVEF) in multivariable models.Lactate concentration added prognostic information beyond signs of peripheral hypoperfusion, sBP, and LVEF, and was independently associated with 30-day mortality (hazard ratio [95% confidence interval] 1.11 [1.07-1.14], P < 0.0001). Lactate also provided predictive information on 30-day mortality to the combination of signs of peripheral hypoperfusion, sBP, and LVEF (area under the receiver-operating characteristics curve = 0.88 vs. 0.83, P < 0.0001). CONCLUSIONS: In conclusion, admission lactate concentration in suspected STEMI-subjects contains prognostic information on 30-day mortality when added to variables used in cardiogenic shock-definition. We recommend lactate measurement in STEMI-subjects, especially when signs of compromised hemodynamics are present