Specialized, coordinated emergency networks dramatically reduce time-to-treatment for patients with STEMI, according to a pooled analysis published in the April issue of the Journal of the American College of Cardiology: Cardiovascular Interventions.
"This study shows that organized STEMI networks consistently provide the fastest treatment of acute heart attacks," said the study's lead author Ivan Rokos, MD, from the Olive View-University of California Los Angeles Medical Center's department of emergency medicine. "For decades, paramedics, emergency departments and cardiology teams have co-existed, but we have only recently recognized how important it is to coordinate all three into one seamless unit that that delivers rapid primary PCI and restores blood flow in a blocked coronary."
The researchers performed a pooled analysis of 10 pioneering STEMI networks involving 72 hospitals in Oregon, California, Minnesota, Michigan, North Carolina and Georgia. Each program independently implemented common approaches including universal access to 911; pre-hospital diagnosis of STEMI by paramedics using special ECGs; early activation of the cath lab team at the nearest designated STEMI hospital; and rapid transport via ambulance (with planned bypass of hospitals without specialized cath lab capability).
"Whether it was big cities like Los Angeles or smaller towns like Medford, Oregon, the creation of these networks was feasible," Rokos said. "Common to each region was a spirit of multi-disciplinary collaboration, often initiated by a small group of visionary healthcare providers, who saw new opportunities to improve STEMI heart attack care in their communities."
To determine the efficacy of the networks in providing timely treatment, the researchers tracked door-to-balloon (D2B) times. The national quality standard is a D2B time of 90 minutes or less; each 15 minute delay beyond these 90 minutes is associated with an increased risk of death.
Rokos and colleagues found that 86 percent of patients with a STEMI who called 911 and were treated within a coordinated regional network received skilled coronary intervention within 90 minutes, which surpassed the American College of Cardiology (ACC) D2B Alliance target (a greater than 75 percent rate of D2B in at least 90 minutes). "This is a marked improvement compared to registry data from 1999 to 2002 that showed 40 percent of patients were treated within 90 minutes," according to the authors.
"As this study shows, paramedics can diagnose STEMI heart attacks quickly and can trigger the activation of an entire system, which allows patients to enter a virtual express-lane to the cath lab team at the nearest STEMI-hospital," Rokos said.
In some of the networks, wireless transmission of the ECG allowed physician diagnosis of STEMI prior to the patient's arrival at the hospital.
Rokos noted that ambulance transport of STEMI patients is critically important in an era of hospital over-crowding, which has gridlocked many U.S. emergency departments.
"The most important lesson of this study is that reperfusion with primary PCI can be provided more rapidly if EMS is placed in its rightful position as the front line for integrated STEMI care," according to an accompanying editorial written by Christopher Granger, MD, a cardiologist at Duke University Medical Center in Durham, N.C. "Coordinated efforts between paramedics and hospitals equipped to perform PCI can dramatically improve the care of patients with heart attacks. Still, we must find ways to improve inter-hospital transfer for patients presenting at hospitals without cath labs."
Rokos said that further study is needed using more sophisticated data collection by existing national quality improvement registries, such as the ACTION Registry-GWTG. Also, the study findings suggest that inappropriate cath lab activations can occur based on paramedic analysis of pre-hospital ECGs, though the exact frequency could not be determined. The potential to maximize system efficiency with wireless transmission of the pre-hospital ECG to the receiving hospital is under study.