WEDNESDAY, Jan. 7, 2004 (HealthDayNews) -- When given to people whose hearts have stopped beating, a naturally occurring hormone called vasopressin may be an effective way to improve the odds for people who normally have little chance of survival.
The European study found vasopressin raised the odds of surviving cardiac arrest in those cases by as much as 50 percent when compared to standard treatment with another hormone, epinephrine. The findings appear in the Jan. 8 issue of the New England Journal of Medicine.
"Vasopressin is most helpful when shock or cardiac arrest is prolonged," says study author Dr. Volker Wenzel, an associate professor of anesthesiology and critical care medicine at the Leopold-Franzens University in Innsbruck, Austria. "It is nice to see that especially patients with the worst chance so far may now have better chances to survive."
While television and movies portray cardiac arrest as easily treatable with a shock or two from a defibrillator, reality is in stark contrast. Some 600,000 people die from sudden death every year in North America and Europe, according to the study. The American Heart Association (AHA) estimates that 95 percent of people who have cardiac arrest die before they even get to the hospital. Those lucky enough to be treated with a defibrillator in the first five to seven minutes fare considerably better, but still more than half will die, according to the AHA.
"Sudden death statistics are just abysmal," confirms Dr. David Haines, director of the heart rhythm center at William Beaumont Hospital in Royal Oak, Mich., who says he was encouraged by the findings. "This is really the first therapy that has been shown effective above and beyond CPR [cardiopulmonary resuscitation]. This offers a real window of hope for some people."
For the study, nearly 1,200 people in cardiac arrest were randomly selected to be treated either with vasopressin, an antidiuretic hormone, or with epinephrine, which has been the standard treatment for roughly a century. Of those, 589 were given vasopressin and 597 received epinephrine.
The patients were from 33 hospitals in Austria, Germany and Switzerland. Each person was given two injections of vasopressin or epinephrine. If these treatments failed, an additional injection of epinephrine was given.
Cardiac arrest can take several forms. One is ventricular fibrillation, where the heart speeds up dramatically. Another is pulseless electrical activity, which means there is no pulse, but there is still electrical activity occurring in the heart. Asystole means there is no heart activity at all. Haines says patients with asystole are particularly hard to treat.
In the study, the vasopressin group fared only slightly better than the epinephrine group if they had ventricular fibrillation or pulseless electrical activity.
In people with asystole, however, those treated with vasopressin did significantly better. Twenty nine percent survived to hospital admission, while only 20 percent of the epinephrine group did.
More than 700 people ended up getting the additional injection of epinephrine, and the combination of vasopressin and epinephrine appeared to be more effective than either drug used alone.
Almost 26 percent of those who received vasopressin and epinephrine lived to hospital admission, while only 16.4 percent of the epinephrine-only group did.
In an accompanying editorial in the journal, Dr. Kevin McIntyre from Brigham and Women's Hospital in Boston calls this study "an important breakthrough in the science of resuscitation," and says new guidelines for treating cardiac arrest should be developed based on this research.
"The results of this study suggest [vasopressin] will be used more widely," says Haines, who notes he will likely change the way he treats cardiac arrest cases as a result of this study.
To learn more about cardiac arrest, visit the Duke University Health System.