Prehospital ECGs Shorten Door-to-Balloon Times


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, a study has shown.

The 86% rate—the average of the 10 regional networks of U.S. hospitals studied, surpassed the target— at least a 75% rate— set by the American College of Cardiology Door-to-Balloon (D2B) Alliance in 2006, reported Dr. Ivan Rokos, an emergency physician at the University of California, Los Angeles, and his associates.

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).

Regional STEMI Receiving Center (SRC) networks—established in 2006 as a grassroots effort to coordinate care with an ECG diagnosis of STEMI identified by EMS personnel before patients reach the hospital—contributed data to the study. SRC hospitals and networks, managed independently, meet criteria that include equipping EMS personnel with 12-lead ECG machines to diagnose acute STEMI in any patient who has called 911 with symptoms suggestive of acute cardiac ischemia. They 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 study analyses were performed using pooled data on patients from the 10 networks, which represent 72 hospitals that range from urban to semirural. Five of the networks were based in California, in Marin, Ventura, Los Angeles, Orange, and San Diego counties. The other networks were in Medford, Ore.; Royal Oak, Mich.; Charlotte N.C.; Atlanta; and Minneapolis-St. Paul, Minn.

These results indicate that “when we collaborate, we can put together a seamless system 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,” Dr. Rokos said in an interview. He emphasized the multidisciplinary nature of the collaboration that also includes quality improvement staff and administrators.

The study also shows that in areas with such networks, 911 “can provide entire communities with access to quality STEMI care,” he added.

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 D2B time of 60 minutes or less, 25% had a time of 45 minutes or less, and 8% had a time of 30 minutes or less.

A unique finding of the study was that the rate of EMS contact to balloon time of 90 minutes or less was 68% among the five regions that measured this.

The study 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,” the investigators 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 pre-hospital ECGs. In the current study, however, the rate was 90% among the patients in the L.A. County region.

Acquiring an ECG before arriving at the hospital “represents an evidence-based yet underused strategy to reduce door-to-balloon times,” they added.

In the interview, Dr. Rokos said the finding that “a quarter of our patients had a door-to-balloon time of 45 minutes or less, which is twice the speed of our national benchmark, is truly remarkable,” especially considering that this was not dependent on building new cath labs, but “coordinating existing cath labs, paramedics, and hospitals.”

In an accompanying editorial, 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).

Expanding what the 10 networks have done “on a national scale—refined and coupled with better EMS support, data collection and feedback—will improve care and save lives,” he added.

Ten regional networks equipped EMS personnel with 12-lead ECG machines to speed diagnosis of STEMI. Courtesy Philips Healthcare

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