“Anti arrhythmic drugs are used commonly in out-of-hospital cardiac arrest for shock-refractory ventricular fibrillation or pulseless ventricular tachycardia, but without proven survival benefit. In this randomized, double-blind trial, researchers compared parenteral amiodarone, lidocaine, and saline placebo, along with standard care, in adults who had non-traumatic out-of-hospital cardiac arrest, shock-refractory ventricular fibrillation or pulseless ventricular tachycardia after at least one shock, and vascular access. Paramedics enrolled patients at 10 North American sites. The primary outcome was survival to hospital discharge; the secondary outcome was favorable neurologic function at discharge. The per-protocol (primary analysis) population included all randomly assigned participants who met eligibility criteria and received any dose of a trial drug and whose initial cardiac-arrest rhythm of ventricular fibrillation or pulseless ventricular tachycardia was refractory to shock.
Researchers concluded the use of either of two anti arrhythmic medications, amiodarone or lidocaine, doesn’t significantly improve survival to discharge or neurologic outcomes over placebo in patients who have an out-of-hospital cardiac arrest” (Kudenchek et al, 2016).
The Amiodarone, Lidocaine, or Placebo Study (ALPS) assessed more than 3000 patients who had an out-of-hospital arrest caused by pulseless ventricular tachycardia or shock-refractory ventricular fibrillation (VF). It showed that those who received a modified formulation of amiodarone that reduces hypotensive effects (Nexterone, Baxter Healthcare) had a statistically non-significant 3.2% higher rate of survival than those who received saline placebo (primary outcome, P=0.08); and those receiving lidocaine had a 2.6% higher rate vs placebo (P=0.16). The difference between the amiodarone vs lidocaine groups was only 0.7%.
In addition, rates of favorable neurologic function at discharge were similar between the treatment groups: 19% of those receiving amiodarone, 18% of those receiving lidocaine, and 17% of those receiving placebo.
However, in prespecified subgroup analysis of the participants who had a bystander-witnessed cardiac arrest, survival to discharge was significantly higher in those receiving amiodarone vs placebo (P=0.04) and those receiving lidocaine vs placebo (P=0.03).
There were no between-treatment differences for those with unwitnessed arrests, resulting in “no harm, no foul for them,” said Dr Peter J. Kudenchuk (University of Washington, Seattle) to attendees here at the American College of Cardiology (ACC) 2016 Scientific Sessions. The results were simultaneously published April 4, 2016 in the New England Journal of Medicine
Article credit: Deborah Brauser – Medscape, April 7, 2016
Image credits: New England Journal of Medicine
Kudenchuk, P. J., Brown, S. P., Daya, M., Rea, T., Nichol, G., Morrison, L. J., … & Christenson, J. (2016). Amiodarone, Lidocaine, or Placebo in Out-of-Hospital Cardiac Arrest. New England Journal of Medicine.