Epinephrine Versus Norepinephrine for Cardiogenic Shock After Acute Myocardial Infarction

Abstract

Background: Vasopressor agents could have certain specific effects in patients with cardiogenic shock (CS) after myocardial infarction, which may influence outcome. Although norepinephrine and epinephrine are currently the most commonly used agents, no randomized trial has compared their effects, and intervention data are lacking.

Objectives: The goal of this paper was to compare in a prospective, double-blind, multicenter, randomized study, the efficacy and safety of epinephrine and norepinephrine in patients with CS after acute myocardial infarction.

Methods: The primary efficacy outcome was cardiac index evolution, and the primary safety outcome was the occurrence of refractory CS. Refractory CS was defined as CS with sustained hypotension, end-organ hypoperfusion and hyperlactatemia, and high inotrope and vasopressor doses.

Results: Fifty-seven patients were randomized into 2 study arms, epinephrine and norepinephrine. For the primary efficacy endpoint, cardiac index evolution was similar between the 2 groups (p = 0.43) from baseline (H0) to H72. For the main safety endpoint, the observed higher incidence of refractory shock in the epinephrine group (10 of 27 [37%] vs. norepinephrine 2 of 30 [7%]; p = 0.008) led to early termination of the study. Heart rate increased significantly with epinephrine from H2 to H24 while remaining unchanged with norepinephrine (p < 0.0001). Several metabolic changes were unfavorable to epinephrine compared with norepinephrine, including an increase in cardiac double product (p = 0.0002) and lactic acidosis from H2 to H24 (p < 0.0001).

Conclusions: In patients with CS secondary to acute myocardial infarction, the use of epinephrine compared with norepinephrine was associated with similar effects on arterial pressure and cardiac index and a higher incidence of refractory shock. (Study Comparing the Efficacy and Tolerability of Epinephrine and Norepinephrine in Cardiogenic Shock [OptimaCC]; NCT01367743).

Keywords: acute myocardial infarction; cardiogenic shock; epinephrine; norepinephrine; vasopressor.