According to the American Heart Association (AHA), 250,000 people in the U.S. suffer from a ST segment elevation myocardial infarction (STEMI) every year. For these patients, a lack of timely access from first medical contact (FMC) to percutaneous coronary intervention (FMC2B) is associated with an increased risk of morbidity and mortality. Current guidelines from the ACC and AHA recommend that STEMI patients are treated in 90 minutes or less from FMC, but unfortunately only a minority of patients meet this goal.

In a study published April 7 in the American Heart Journal, a team led by Bryn E. Mumma, MD, MAS, sought to better understand the relationship between the use of prehospital electrocardiograms (ECG) and patient home distance from the percutaneous coronary intervention (PCI) center on reperfusion time in STEMI patients. The authors established that patients with a prehospital ECG had a 10 minute reduction in their FMC2B time, however, "patient home distance from a PCI center does not substantially change this association."

The team conducted a retrospective cohort study, using data from the NCDR's ACTION Registry-GWTG. Research included all STEMI patients from July 1, 2008 to September 30, 2012, who were transported by ambulance with patient home distance classified by tertiles, and defined as the driving distance between the home zip code and the patient's PCI center.

Over a third, or 67 percent, of STEMI patients received a prehospital ECG and of those patients the median distance from a patient's home to the PCI center was 11 miles. The study established that, "baseline characteristics of patients who did and did not receive a prehospital ECG were similar; however, patients who did not receive a prehospital ECG had more comorbidities and more critical presentations," and ultimately prehospital ECGs led to a 10 minute reduction in FMC2B time.

Although the decrease of FMC2B time found in this study is clinically significant, it is more modest than data reported in previous ECG and FMC2B studies. This may be due to an improved process of care thanks in part to initiatives such as the ACC's Door to Balloon Alliance  and AHA's Mission: Lifeline program. It was also discovered in previous studies, that maximum benefit to patients was achieved when prehospital ECGs were used in conjunction with prehospital cardiac catheterization lab activation.

The authors concluded, "Prehospital ECGs are commonly used among STEMI patients and reduce FMC2B time by approximately 10 minutes. Patient home distance from a PCI hospital was not associated with this time interval, but presentation during off hours was associated with longer times."

Keywords: Registries, Myocardial Infarction, Hydroxamic Acids, Comorbidity, Religious Missions, Electrocardiography, Percutaneous Coronary Intervention, ACTION Registry, National Cardiovascular Data Registries