Study Identifies Delays in STEMI Patients Receiving Emergency PCI

September 19, 2011―The American Heart Association (AHA) announced the publication of a study that showed that despite improvements in treating heart attack patients needing emergency angioplasty procedures, delays still occur, particularly in transferring patients to hospitals that can perform the procedure. Michael D. Miedema, MD, et al published their findings online ahead of print in Circulation.

According to the AHA, fast response is critical for ST-segment elevation myocardial infarction (STEMI) patients, but only approximately 25% of hospitals in the United States are equipped to perform percutaneous coronary intervention (PCI). The facilities that cannot perform PCI typically refer and transfer patients to hospitals that can.

“While we are making tremendous progress in PCI hospitals, delays are still occurring during the transfer process,” commented Timothy D. Henry, MD, the study's Senior Investigator and Director of Research at the Minneapolis Heart Institute Foundation, which funded the study. “This is the first study that examines and identifies the specific reasons for delay of transfer patients.”

The study's investigators examined data from 2,034 STEMI patients who were transferred from 31 local non-PCI hospitals in Minnesota and Wisconsin to the Minneapolis Heart Institute from March 2003 to December 2009. Referring hospitals were up to 210 miles away from the institute. Despite long-distance transfers, 65.7% of patients were treated within 120 minutes from the time of presentation at the initial referring hospitals. Of the 34.2% of patients who experienced a delay in total treatment time, the study found that delays most frequently occurred at the referral hospital (64%), followed by the PCI center (15.7%), and during transport (12.6%).

Specifically, the 64% of delays that occurred at the referral hospital were caused by awaiting transportation (26%), emergency department delays (14%), diagnostic dilemma (9%), initial negative test for heart attack (9%), and cardiac arrest (6%). Delays related to cardiac arrest were the most likely to result in death, with an in-hospital mortality rate of 31%. In contrast, some delays, such as an initially negative heart attack test, had no increased risk of death.

Dr. Henry stated that it is important to recognize that higher-risk patients are faring the worst, so the less-successful outcomes may be related to their advanced disease states. He noted, “All delays are not created equally. By identifying where the delays are, we can improve the systems for transferring patients to get them the care they need.”

“Our ultimate goal is to improve timely access to angioplasty in patients with STEMI,” added Dr. Henry. “We have been very successful doing this in hospitals that are equipped to provide the procedure. This study emphasizes that now our focus should be on regional systems, which seek to incorporate those hospitals that require patient transfer in the process.”

The AHA noted that in 2007, it launched Mission: Lifeline to improve systems of care for STEMI patients by reducing barriers from the time 911 is called until hospital discharge. One of these barriers is a lack of timely access to a hospital that is capable of performing angioplasty 24 hours a day, 7 days a week. The AHA also offers Mission: Lifeline accreditation by the Society for Chest Pain Centers for hospitals that meet specific criteria for either a STEMI-receiving hospital or a STEMI-referral hospital.

“A study recently published in Circulation―Improvements in Door-to-Balloon Time in the United States, 2005 to 2010―found that more than twice as many people are getting treatment within 90 minutes of arriving at an angioplasty hospital than were 5 years ago, so we are making great progress,” commented Chris Granger, MD, Chairman of the Mission: Lifeline steering committee. “But Dr. Henry's study shows us that many patients still have delays and that certain types of delays are associated with worse outcomes. So there is an important opportunity to further improve care, especially for patients being transferred from hospitals not equipped to do angioplasty.”