New Treatment for Cardiac Arrest Patients More Effective in Some Cases, Study Finds

People with asystole cardiac arrest are three times more likely to survive if they are given a hormone called vasopressin than if they receive epinephrine, a synthetic adrenaline that has been the standard emergency treatment for cardiac arrest for about 100 years, according to a study in Thursday's New England Journal of Medicine, the New York Times reports. In asystole cardiac arrest there is no pulse or electrical activity in the heart, according to the Times; the condition accounts for 20% to 40% of cardiac deaths in the United States. The study, which included 44 medical teams and was directed by Dr. Volker Wenzel, a professor at the University of Innsbruck in Austria, followed 1,186 patients in Austria, Germany and Switzerland who were treated by emergency teams outside of the hospital after their hearts suddenly stopped (Grady, New York Times, 1/8). The cardiac arrest patients were split into two groups. Patients in one group received the standard injection of epinephrine, while patients in the second group received vasopressin (AP/Long Island Newsday, 1/8). Of 262 asystole patients who were treated with epinephrine, 4 patients, or 1.5%, were eventually discharged from the hospital, compared with 12, or 4.7%, of 258 asystole patients treated with vasopressin, the study found. The study also found that patients with asystole who were given vasopressin were 40% more likely to reach the hospital alive than those given epinephrine. Among patients who experienced ventricular fibrillation, the most common and treatable form of cardiac arrest, the study did not find a difference between the survival rate of patients given vasopressin and those given epinephrine, the Wall Street Journal reports (Armstrong, Wall Street Journal, 1/8). Researchers said that vasopressin might be more effective in some cases than epinephrine because vasopressin does not decrease the amount of oxygen in the heart and brain as epinephrine does, the Times reports (New York Times, 1/8). Vinay Nadkarni, the recent past chair of the American Heart Association's Emergency Cardiovascular Care Committee, said that the committee will consider in March if the vasopressin study should be used to make immediate changes to resuscitation guidelines (Wall Street Journal, 1/8). However, Nadkarni noted that unlike Europe, U.S. emergency medical teams do not include physicians, calling into question whether the same results could be achieved in the United States (New York Times, 1/8). An abstract of the study is available online.

In an accompanying editorial, Dr. Kevin McIntyre, a professor at Harvard Medical School and Brigham and Women's Hospital in Boston, said that vasopressin does not seem to have the risks associated with epinephrine, the Washington Post reports (Washington Post, 1/8). McIntyre said that the study results were "an important breakthrough," and added, "These advances should be translated into a new standard of care immediately" (AP/Long Island Newsday, 1/8).