A STEMI heart attack blocks the blood flow to the heart, and it can be fatal.
People who experience a potentially fatal heart attack are more likely to survive if emergency medical services (EMS) and hospitals work together in a coordinated system, says a study published in the journal Circulation.
An ST-segment elevation myocardial infarction (STEMI) involves a complete blockage of the heart's blood supply.
STEMI has been described as the most deadly type of heart attack, but opening the blocked artery soon after the event can save lives by restoring normal blood flow and minimizing heart damage.
Guidelines in the United States prescribe maximum times for opening the blockage and restoring blood flow.
For patients who are taken straight to a hospital that carries out percutaneous coronary interventions (PCI), the unblocking should be completed within 90 minutes of the patient's first contact with emergency medical services personnel.
If patients have to be transferred from a hospital that does not perform PCI to one that does, the recommended time limit is 120 minutes.
However, up to 50 percent of the more than 250,000 patients in the U.S. who have a STEMI each year are not treated within the recommended time.
AHA project to speed up care for STEMI patients
The American Heart Association (AHA) set up a demonstration project known as "Mission: Lifeline STEMI Systems Accelerator" between July 2012 and December 2013.
Within the project, regional care systems were created that aimed to boost the number of people treated within the guideline recommendations.
This was the largest effort to organize regional STEMI care ever attempted in the U.S. It involved 484 hospitals and 1,253 EMS agencies in 16 regions across the U.S., and treatment was delivered to 23,809 people with STEMI.
Of these, 11,765 patients were transported by EMS, 6,502 took themselves directly to PCI-capable hospitals, and 5,542 patients transferred from another facility.
Results indicated that, for patients whose treatment came within the scope of the project, targets were met for:
- 59-61 percent of patients who went directly to PCI-capable hospitals
- 50-55 percent of those transported by EMS to PCI-capable hospitals
- 44-48 percent of those transferred from other facilities.
This reflects a "modest but significant increase" in the proportion of cases in which the guideline goals were met.
The five regions that showed the biggest improvement increased the proportion of patients treated within guideline goals from 45-57 percent. In one region, 75 percent of patients were being treated within the time limit by the end of the project.
Results varied between regions, and overall increases were modest.
This was partly because, in the relatively short time that the project was running, some regions did not act as quickly as others to incorporate protocols and systematic changes.
The reason why up to half of STEMI patients are not usually treated within the guideline time is due to a lack of coordination between EMS and the hospitals, says Dr. James G. Jollis, a study author and clinical professor of medicine at the University of North Carolina in Chapel Hill.
In addition, the 15,000 EMS agencies and 5,200 acute care hospitals in the U.S. have different treatment plans.
Coordinating care can reduce time to treatment
Dr. Jollis says that paramedics who use a 12-lead electrocardiogram (EKG) should be able to recognize if an artery is blocked and diagnose STEMI before taking patients to the hospital. They can then direct patients to specialized hospitals and forewarn the hospital of the need for heart catheterization team.
Dr. Christopher B. Granger, study co-author and professor of medicine at Duke University in Durham, NC, says that the project proves that emergency cardiovascular systems can be coordinated, and that this can transform care in some of the largest U.S. cities, such as New York, Houston, and Atlanta.
This coordinated care, he says, can shorten emergency department times and reduce the chance of fatality.
Dr. Jollis notes that, by the end of the study period, locations that had fully implemented the project were seeing fewer fatalities in the hospital, compared with national data.
"The long-term goal is to have this protocol in place for every STEMI patient who suffers a heart attack in the community. Ultimately, death from heart attack should become a rare event."
Dr. James Jollis