Prehospital ECGs Reduce Door-to-Balloon Time for Heart Attack

August 2, 2010

The use of prehospital ECGs by trained paramedics can reduce door-to-balloon time and improve patients' chances of recovery from heart attack.

According to an article in the Minneapolis Star Tribune, a recent study shows that “patients get faster care, and are more likely to survive, if an ambulance crew takes them straight to a specialized hospital cath lab.” Results from the study, “Very Rapid Treatment of ST-Segment—Elevation Myocardial Infarction – Utilizing Prehospital Electrocardiograms to Bypass the Emergency Department,” by Kenneth Baran, MD, and colleagues, were published in the July issue of Circulation: Cardiovascular Quality and Outcomes.

The Tribune article noted that this system requires the hospital to employ paramedic crews that have been trained to diagnose heart attacks. When properly deployed, this approach can “cut the time needed to treat the most dangerous heart attacks from an average of 81 minutes to 36 minutes, and vastly improve the chances of recovery.”

In the study, patients who arrived at the cath lab during daytime hours received treatment for their blocked arteries within an average of 22 minutes. This led to noticeable improvements in mortality rates — the article reports that “patients who went straight to the catheter lab were less likely to die in the hospital (3.9 percent) than those who came through the emergency room (7.5 percent).”

With hospitals and medical centers nationwide striving to cut “door-to-balloon time” to meet the 90-minute gold standard, Baran said he began thinking about ways to further reduce the time to treatment and noticed that “heart attack patients coming from other hospitals would go straight to the catheter lab without stopping in the emergency room,” prompting him to start a program to train paramedics to use ECG machines in the field to determine whether a patient is eligible to go straight to the cath lab.

Baran said that the program encountered some initial skepticism from interventional cardiologists, who were “worried that they would face more false alarms, and have to act as both emergency room doctor and heart specialist.” But with the results from this study, attitudes may be changing. If further research confirms the benefits of training and equipping paramedics in the field to use and read ECGs for heart attack patients, Baran said that would be enormous potential long-term implications in terms of improved survival and reduced need for defibrillators and transplants.