Early Epinephrine Treatment During Cardiac Arrest Leads to Better Recovery

The following article is a part of conference coverage from the American Heart Association Scientific Sessions 2021, being held virtually from November 13 to 15, 2021. The team at Cardiology Advisor will be reporting on the latest news and research conducted by leading experts in cardiology. Check back for more from the AHA Scientific Sessions 2021.

In shockable initial rhythm out-of-hospital cardiac arrest (OHCA), early compared with late epinephrine administration following the first attempt at defibrillation was associated with better odds of recovery, according to study results presented at the American Heart Association (AHA) Scientific Sessions 2021, held from November 13 to 15, 2021.

For the study, researchers performed a retrospective analysis of adult North American patients with shockable initial rhythm OHCA between 2011 and 2015. Using multivariable logistic regression, researchers assessed the associations between epinephrine timing and prehospital return of spontaneous circulation (ROSC), survival to hospital discharge, and discharge from hospital with a favorable neurological outcome (modified Rankin Scale score ≤3). The researchers also assessed the robustness of associations using propensity score matching and subgroup analyses.

Patients had a median age of 64 years (IQR, 54-74); 80% were men; 35% received epinephrine within 4 minutes after first defibrillation; 80% had prehospital ROSC; 19% survival to hospital discharge; and 16% had a favorable neurological outcome at hospital discharge. After adjusting for confounders, each minute of later epinephrine administration showed lower odds of prehospital ROSC (odds ratio [OR] 0.95; 95% CI, 0.94-0.96; P <.001), survival to hospital discharge (OR 0.91; 95% CI, 0.89-0.92; P <.001), and favorable neurological outcomes at hospital discharge (OR 0.92; 95% CI, 0.90-0.93; P <.001).

Compared with epinephrine administered within 4 minutes after first defibrillation, later epinephrine administration was associated with lower odds of prehospital ROSC (OR 0.58; 95% CI, 0.51-0.68; P <.001), survival to hospital discharge (OR 0.50; 95% CI, 0.43-0.58; P <.001), and favorable neurological outcome at hospital discharge (OR 0.51; 95% CI, 0.43-0.59; P <.001). In a well-balanced propensity score, matched cohort and subgroup analyses by EMS response time, witness status, and total epinephrine dose, associations remained significant, according to the researchers.

“Our study’s findings should guide emergency medical services professionals towards earlier administration of epinephrine during out-of-hospital cardiac arrest management,” Dr Shengyuan Luo, lead study author, said in an AHA news release. “It is crucial that whenever a cardiac arrest event is suspected, the emergency medical system be notified and activated immediately, so that people with cardiac arrest receive timely, life-saving medical care.”

Researchers indicated that the findings are in agreement with the latest AHA CPR and Emergency Cardiovascular Care Guidelines, released in October 2020, which encourage epinephrine administration as early as possible to maximize good resuscitation outcomes. The AHA recommendation was based on previous observational data.

Disclosure: Several study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.

Reference

Luo S, Gu L, Zhang W, et al. Early compared to late administration of epinephrine in adults with shockable initial rhythm out-of-hospital cardiac arrest. Presented at: AHA Scientific Sessions 2021; November 13-15, 2021. Presentation 8875.

Earlier epinephrine treatment during cardiac arrest linked to better recovery. News release. American Heart Association. November 8, 2021. Accessed November 10, 2021. https://newsroom.heart.org/news/earlier-epinephrine-treatment-during-cardiac-arrest-linked-to-better-recovery