Cardiac arrest patients who receive coronary angiography are twice as likely to survive without significant brain damage compared with those who don't have the procedure, according to a study published online in the forthcoming the May/June issue of the Journal of Intensive Care Medicine.
The researchers showed that patient outcomes improved with coronary angiography, regardless of certain clinical and demographic factors that influenced who received the procedure.
"Given the low odds of survival--about 6 percent--for patients who suffer out-of-hospital cardiac arrests, it's important to understand which treatments might make a difference in these dismal outcomes," said the study's corresponding author Jon C. Rittenberger, MD, an assistant professor in the department of emergency medicine at the University of Pittsburgh Medical Center (UPMC).
The importance of prompt coronary angiography is well-established for cardiac arrest patients presenting with certain types of heart problems, Rittenberger noted. "But our study, which shows that angiography is independently associated with good neurologic outcomes, suggests that clinicians should consider the procedure for all post-cardiac arrest patients," he added.
The researchers retrospectively analyzed the charts of 241 adult cardiac arrest patients who were treated at UPMC Presbyterian Hospital between Jan. 1, 2005, and Dec. 31, 2007. Coronary artery disease was present in 52 percent of the patients, and the rate did not differ between those who received coronary angiography (40 percent of the group) and those who did not. The authors said that their findings are consistent with prior research showing that 60 to 80 percent of cardiac arrests are a result of cardiovascular disease.
Just over half of patients who received coronary angiography experienced a good clinical outcome--defined as being discharged to home or to an acute rehabilitation facility--compared with 24.8 percent of patients who do not have the procedure. Early angiography, performed within 24 hours of a patient's arrival, was not associated with improved survival when compared to having the procedure done later, but researchers noted that the small number of patients may have made it impossible to prove a difference.
"Coronary angiography appears to put patients on a more proactive path of care, which may lead to a better outcome," said Rittenberger. "As this study demonstrates, most of these cardiac arrest patients have heart disease, which is often something that we can fix. Many of the patients who get coronary angiography go on to get bypass surgery, a balloon pump, a defibrillator or other such aggressive treatments."
Rittenberger and his colleagues found no significant differences between those who received angiography and those who did not with respect to age, history of cardiac disease and use of therapeutic hypothermia, a procedure used to cool patients who remain comatose after resuscitation following cardiac arrest to prevent brain damage.
However, the researchers said that patient sex, location of the arrest, the initial heart rhythm disturbance and certain coronary and neurologic abnormalities were among the predictors of who would receive angiography. Men who suffered cardiac arrests outside of the hospital were more likely to have the procedure. The researchers also found that coronary angiography was more likely to be performed on patients with better neurological status. However, with the use of therapeutic hypothermia, patients may not reveal their true neurological state for several days after the return of spontaneous blood circulation, the authors noted.