Networks Cut STEMI Door-to-Balloon Times
By Elizabeth Mechcatie
Elsevier Global Medical News
Almost 90% of patients with a prehospital electrocardiographic diagnosis of ST-elevation myocardial infarction had a "door-to-balloon" time of 90 minutes or less, in a study of patients treated at 10 regional networks of hospitals across the United States.
The 86% rate, which was the average of the 10 networks, surpassed the target set by the American College of Cardiology Door-to-Balloon (D2B) Alliance in 2006, pointed out Dr. Ivan Rokos, an emergency physician at the University of California, Los Angeles-Olive View Medical Center, Sylmar, and his associates. That target is to achieve at least a 75% rate of a door-to-balloon time of 90 minutes or less.
Moreover, each individual center in the study achieved the D2B Alliance's target, ranging from 77% in Atlanta to 97% in Minneapolis/St. Paul, they reported (J. Am. Coll. Cardiol. Intv. 2009;2:339-46).
The results indicate that "when we collaborate, we can put together a seamless system," Dr. Rokos said in an interview. "So, instead of having EMS, the ED, and cardiology all sort of coexist, as they have done literally for decades, they are now coordinated into one seamless care unit that can deliver very fast care."
The study also showed that in areas with such networks, 9-1-1 "can provide entire communities with access to quality STEMI care," Dr. Rokos added.
The networks that contributed data to the study are regional ST-elevation myocardial infarction receiving center (SRC) networks, established in 2006 as a grassroots effort to coordinate care of patients with an ECG diagnosis of STEMI identified by EMS personnel before patients reach the hospital. The SRC hospitals and networks, managed independently, meet certain criteria, including equipping EMS personnel with 12-lead ECG machines to diagnose acute STEMI in any patient who has called 9-1-1 with symptoms suggestive of acute cardiac ischemia.
The hospitals and networks also follow a protocol that directs paramedics to transport patients with a presumed STEMI on the ECG to the nearest designated SRC, a hospital that provides primary percutaneous coronary intervention (PPCI).
The analyses used pooled data on patients from the 10 networks, which represent 72 hospitals, in settings that range from urban to semirural hospitals. The other networks in the study were based in Medford, Ore.; Royal Oak, Mich.; Charlotte, N.C.; and California's Los Angeles, Marin, Orange, San Diego, and Ventura counties.
In the study, 2,712 patients were diagnosed with a STEMI with an ECG before arriving at the hospital and were transported directly to the nearest SRC, where 76% of the patients underwent PPCI. The primary end point was the proportion of patients who had an intervention within 90 minutes or less.
Shorter door-to-balloon times were secondary end points: 50% of the patients had a door-to-balloon time of 60 minutes or less, 25% had a door-to-balloon time of 45 minutes or less, and 8% had a door-to-balloon time of 30 minutes or less.
Fewer than half the patients in the United States are treated within the 90-minute time frame, the researchers noted. The results indicate that "successful use and broad translation" of prehospital ECGs "could be achieved with the creation of regional SRC networks focused on prehospital cardiac triage," they said.
The authors pointed out that, in 2005, the rate of door-to-balloon times of 90 minutes or less at four major hospitals in Los Angeles County was less than 50% for STEMI patients transported to the hospital by EMS, even though EMS providers routinely performed prehospital ECGs. In their study, however, the rate was 90% among the patients in the Los Angeles County region.
The finding that a quarter of the patients had a door-to-balloon time of 45 minutes or less--which is twice the speed of the national benchmark--was dependent not on building new cath labs, Dr. Rokos noted, but on "coordinating existing cath labs, paramedics, and hospitals."
In an editorial accompanying the study, Dr. Christopher Granger of Duke Clinical Research Institute, Durham, N.C., said that the study's "most important lesson ... 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" (J. Am. Coll. Cardiol. Intv. 2009;2:347-9).