STEMI Networks: Not Why, But How

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Reperfusion is the preferred strategy for patients presenting with ST-segment elevation MI (STEMI) and outcomes improve with regionalized systems of care. Yet, such systems are not all equal and competition for patients within regionalized care can impede their initiation and effectiveness.

To begin at the beginning

STEMI patients in the U.S. number about 400,000 each year—representing about one-third of MI sufferers. The American College of Cardiology’s (ACC) Door-to-Balloon (D2B) Alliance proposed a target in 2006 that more than 75 percent of U.S. providers achieve D2B times of 90 minutes, whereas the baseline rate across the U.S. was less than 40 percent. While sending a prehospital ECG to the ED has proved to help reduce D2B times during emergent PCI for patients with STEMI, its utilization was less than 10 percent, according to National Registry of MI data from 2000 to 2002 (J Am Coll Cardiol 2006;47:1544-1552).

More recently, STEMI-receiving center networks have demonstrated that the use of prehospital ECGs results in dramatic improvement in the rate of timely reperfusion. Rokos et al found that 10 independent STEMI networks—across disparate regions in the U.S.— demonstrated a combined 86 percent rate of D2B of 90 minutes or less (J Am Coll Cardiol Intv 2009;2:339-346).

Empowering emergency medical services (EMS) is one of the first steps in forming an effective STEMI regional network. “EMS is the gateway for medical services,” says Christopher B. Granger, MD, director of the cardiac care unit at Duke University School of Medicine in Durham, N.C. “By engaging EMS when designing a system of care, the hospitals are forced to become engaged.”

For instance, to improve Tennessee’s quality of cardiac care, the Tennessee Cardiac Systems of Care Task Force has been “actively involved” with the American Heart Association’s (AHA) Mission: Lifeline to establish a STEMI system of care for the Greater Nashville region, explains David Chambers, MD, a cardiologist at Horizon Medical Center in Dickson, Tenn., who is chairman of the task force. Mission: Lifeline has been assisting the task force with establishing processes and funding. Tennessee recently ranked 48 out of 50 states in cardiovascular mortality.

To improve STEMI care across Tennessee, the task force is meeting with various EMS representatives to enhance prehospital 12-lead ECG capabilities in the ambulatory setting, says Chambers, who serves as medical director for Dickson County EMS. “The task force also is assessing protocols for paramedics to perform a 12-lead ECG, diagnose a STEMI and activate the cath lab at the designated STEMI center.”

“The creation of formal destination protocols by regional authorities allows EMS providers to bypass facilities without cath labs when they have identified a STEMI patient,” says Ivan C. Rokos, MD, from the UCLA Olive View department of emergency medicine in Los Angeles, who also is the AHA’s chair of the Western STEMI Task Force. The task force is seeking to regionalize STEMI care for all of California and nine Western states.

Granger adds, “When developing these networks, a manual of standardized protocols is needed for each point of STEMI care—starting with EMS through the ED through cath lab activation—which should seek to establish best practices at each point in the patient care continuum.”

Inter-hospital transfer

In Los Angeles County, there are 75 paramedic-receiving hospitals, serving 10 million people—30 of which are designated STEMI centers. Although the remaining 45 hospitals do not have cath lab capabilities for primary PCI interventions, some are now active STEMI referral facilities. After two years of planning and a price tag of $7 million, Los Angeles County commenced its prehospital cardiac triage process in December 2006.
“While the establishment of appropriate prehospital triage protocols was relatively seamless, inter-hospital transfers to STEMI centers have caused more challenges,” says Rokos. This is particularly important because 50 percent of STEMI patients in the U.S. do not utilize EMS.

Therefore, Los Angeles County established a “rapid and reliable transfer option using 9-1-1 providers. If a patient presents at a hospital without a cath lab, the ED staff can call 9-1-1 to have EMS providers transfer the STEMI patient to a STEMI receiving center,” he says.

While this may seem contrary to the bottom line of the referring hospital, Rokos suggests that providers are “unlikely to gain or lose much revenue from their STEMI program, as this is a small subset of their overall cardiac patient population.” In fact, he says, patients who present with unstable angina and non-STEMI provide a much larger proportion of a cardiology department’s revenue.

Also, if a patient with STEMI presents to an ED of a STEMI referral facility, the treating ED physician should be able to submit reimbursement for critical care even if the patient is not admitted to the hospital, Rokos adds.

Recent data have shown that adopting a system of care does not equate to a loss of revenue for hospitals, but a potential gain for payors. Khot et al assessed the financial impact of ED physician cath lab activation and the immediate transfer of the patient to an available cath lab by an in-house transfer team consisting of an emergency department nurse, a critical care unit nurse and a chest pain unit nurse. By comparing STEMI patients pre- and post-protocol implementation, they found that insurance payments (hospital revenue) decreased ($35,043 vs. $25,329), along with the total hospital costs ($28,082 vs. $18,195) (BMC Cardiovascular Disorders 2009;9:32-44).

“Khot et al found that if a hospital can produce fast D2B times, the frequency of expensive patient outliers with cardiogenic shock or prolonged ICU admissions is minimal,” Rokos says. Ultimately, the authors found that the hospital breaks even, but the payors save about $10,000.

Transfer is tricky, and essential

The Minneapolis Heart Institute’s (MHI) Level 1 Heart Attack program was launched in 2003 based on the need to connect rural areas of Minnesota and Wisconsin to improve levels of heart attack care. “Early European data showed that having a standardized protocol to establish a process to transfer acute MI patients for PCI, as opposed to fibrinolytic therapy, improved outcomes,” says Timothy D. Henry, MD, director of cardiovascular research at MHI. The program now includes 35 referral hospitals and 10 clinics that are up to 210 miles away and the MHI at Abbott Northwestern Hospital in Minneapolis. For the transferred STEMI patients, about 65 percent are transferred by helicopter, and the remaining 35 percent arrive via ground transport.

MHI first began air transfer of patients within their designated Zone 1, which is approximately 60 miles from the hospital. “We initially chose 60 miles because that was the anticipated distance to achieve D2B times of less than 90 minutes,” Henry says. “When we considered incorporating facilities that were farther away than 60 miles, we anticipated that the D2B times would be longer than 90 minutes, and therefore, we elected to employ a pharmacoinvasive strategy.”

Rokos concurs that when patients are too far away from a STEMI receiving center, they should receive a pharmacoinvasive strategy, which involves early PCI within three to 24 hours of successful fibrinolysis. “People are inclined to always transfer patients just a little farther, but we don’t want a young anterior MI patient to spend two hours in transfer as he or she is burning through myocardium. It’s one of the biggest challenges,” he says. “Each network’s protocols should use current ACC/AHA guideline benchmarks to draw a line in the sand about which patients should receive a pharmacoinvasive approach rather than transfer PCI.”

Despite the intricacies of in-hospital transfer, the MHI Level 1 program has had very successful results. From March 2003 to November 2006, 1,345 consecutive STEMI patients were treated, including 1,048 patients transferred from non-PCI hospitals. Henry et al reported that the median D2B times for patients in Zone 1 and Zone 2 from the PCI center was 95 minutes and 120 minutes, respectively (Circulation 2007;116:721-728). Despite the unselected patient population, in-hospital mortality was 4.2 percent, and median length of stay was three days.

The overall transfer times for the 421 patients in Zone 2 were longer than those for the 627 patients transferred within Zone 1; however, 79 percent of Zone 1 patients and 49 percent of patients in Zone 2 achieved D2B times of less than 120 minutes (approximately 40 percent of Zone 1 patients and 12 percent of Zone 2 patients achieved times under 90 minutes).

Henry notes that “proximity does not equal time. While there is a relative relationship, if a helicopter sits in a town that is 60 miles away, those patients can be a lot closer time wise than a patient 40 miles away that can travel by ground. These aspects need to be carefully assessed throughout the implementation process.”

Without the standardized protocol of a STEMI network, the capability of transferring patients via helicopter does not guarantee the targeted D2B times. Based on a study of 179 subjects from 16 referring and six receiving hospitals, McMullan et al found STEMI patients presenting to non-PCI facilities who are transferred to a PCI-capable hospital by helicopter EMS do not commonly receive fibrinolysis and rarely achieve PCI within 90 minutes (Ann Emerg Med 2010; online Oct 18).

“The biggest lag time was in arranging the transfer process, as there was almost a 30-minute delay between the ECG at the transfer hospital and the call to the STEMI center,” explains Jason T. McMullan, MD, associate director in the prehospital care division at the University of Cincinnati. Yet, there is not a formal STEMI network in the Cincinnati region, and data have shown that “these systems of care directly target the time period to arrange the transfer, so that process could be streamlined,” he adds.

Therefore, the Level 1 program at MHI has established a different standardized transfer protocol with each referring institution, as each has unique regional and staff considerations.

Collaboration bests competition?

U.S. hospitals treating patients within a certain region are naturally competitive with each other. “Competition is a double-edge sword,” says Granger, “because it can be leveraged as a motivator to get providers involved, but it also presents obstacles as hospitals don’t necessarily want to commit to a plan that may help their competition.”

As a result, McMullan suggests that not every region is able to participate in a STEMI network, particularly in the Cincinnati region that has several competing STEMI centers—“all of which have their tentacles in the referring communities. There are major political aspects, especially for transfer patterns, that would need to be overcome to appropriately regionalize and unify primary PCI care in this area.”

However, there is precedent for overcoming such challenges. In Charlotte, N.C., which has three PCI-capable hospitals within two blocks of each other, the RACE organizers (Reperfusion of Acute MI in Carolina Emergency departments) brought in an independent representative who spoke on behalf of the guidelines and the patients. “This objectivity brought the credibility about the possibility of improving patient care that eventually won over those highly competitive institutions,” Granger says.

In Minneapolis, there are 12 primary PCI-capable centers, all of which have varied STEMI-based strategies. “Every EMS agency in our area tackles STEMI transfer differently, as they establish their own rules for how their people are trained or certified,” Henry explains. In the Level 1 protocol, EMS is not directed to the “closest site,” as suggested by the AHA Mission: Lifeline, but instead they are directed to take patients to the “most appropriate site.”

Going statewide

In an effort to extend the RACE project across the state of North Carolina, the directors, along with regional ACC leaders, identified five regions with 10 PCI-capable centers and 65 hospitals, and hired five coordinators for each of those zones. Granger, who also is the co-director of the RACE project, credits his coordinators for analyzing, unifying and implementing the standardization of STEMI care in each region.
In 2005, prior to the implementation of the RACE project, national registries indicated that only about 60 percent of North Carolinians who presented to an ED received reperfusion therapies for MI, compared with the national average of at least 70 percent.

In a study of 1,164 STEMI patients who presented after RACE was implemented, the median reperfusion times significantly improved according to first door-to-device (presenting to PCI hospital 85 to 74 minutes; transferred to PCI hospital 165 to 128 minutes), door-to-needle in non-PCI hospitals (35 to 29 minutes) and door-in to door-out for patients transferred from non-PCI hospitals (120 to 71 minutes) (JAMA 2007;298[20]:2371-2380). Non-reperfusion rates were unchanged in non-PCI hospitals and decreased from 23 percent to 11 percent in the PCI hospitals.

Since then, all 21 primary PCI centers and 119 hospitals in the state have joined the RACE program. Granger speaks to the tremendous amount of time, dedication and advocacy for all participants in creating a statewide network. “Of course, gathering funding for this work also has been a challenge, especially during these difficult economic times when state and federal grants are being slashed,” he adds.

Granger acknowledges that establishing these networks are “quite expensive.” He suggests, however, that some “low-hanging fruit for funding could be the PCI centers themselves as many hospitals are still earning respectable margins on their cardiovascular care programs, and they may be willing to re-invest some of that to improve care for their acute MI patients.”

Challenges will arise in the formation and implementation of a STEMI system of care, and many of these considerations are regional-specific. “The challenges that arise in Minnesota are not the same challenges that arise in Los Angeles County,” states Henry, who adds that the empowerment of coordinators is integral in understanding and fixing the local problems. Also, data collection and tracking is integral to making any periodic adjustments by the appointed MI committee.

Data: Outcomes & transparency

“Data collection is very important. Unless actions and performance are measured, it’s very difficult to improve,” Granger says. All 21 PCI centers in North Carolina agreed to partake in the ACC’s ACTION registry—Get with the Guidelines. “This participation gave us the ability to track how care was changing and improving,” he adds.

Rokos is hopeful that the ACTION registry will “provide a national standardized quality improvement [QI] infrastructure that can be used by regional authorities, but we’re not there yet. An underlying QI infrastructure is necessary for STEMI network implementation.”

Once the data are gathered for each region in North Carolina, the RACE organizers hold meetings at the various participating facilities to determine how they are doing and how they are in comparison to the other facilities in the state. At those meetings, it is discussed what additionally could be done to improve care, Granger says.

Due to the success of the various STEMI programs, Henry speaks to the potential of applying the same standardized protocol models across additional time-sensitive cardiovascular emergencies, including aortic dissection, out-of-hospital cardiac arrest with cooling, abdominal aortic aneurysms and non-STEMI patients.