Primary percutaneous coronary intervention (PCI) is the most effective treatment available for acute ST-elevation myocardial infarction (STEMI). Patients have better odds of survival if they receive reperfusion within two hours of first medical contact, after which the opportunity for salvaging the heart muscle steadily diminishes.
To meet that time window, patients must be either transported directly to a PCI-capable hospital or transferred from a referring hospital as soon as possible after symptoms develop.
Current guidelines developed by the American Heart Association/American College of Cardiology (AHA/ACC) recommend that communities develop systems of care to promote cooperation and coordination among hospitals and emergency medical services (EMS).
While some communities have developed effective systems in response, up to 50% of patients still are not transferred within the recommended timeframe, according to a study in the August 2016 Circulation. That's despite a sharp increase in the number of hospitals capable of performing PCI and the fact that 90% of Americans live within a 60-minute drive of a PCI-capable center.
“It's become obvious over the past decade that, in spite of PCI being so effective and so available, the biggest challenge by far is simply getting it applied in a timely way,” said Christopher Granger, MD, professor of medicine at Duke University in Raleigh, N.C., and chair of the AHA's Mission: Lifeline STEMI Systems Accelerator program, aimed at improving STEMI care across the country. “We are completely dependent on regional systems of care in order to do that.”
Such systems are especially important given that PCI is not available at the majority of U.S. hospitals, noted Dr. Granger. Obstacles to speedy transfer include bottlenecks in the ED, access to emergency vehicles, and fragmentation and competition in the U.S. health care system.
“If you're part of a network of hospitals and the closest center is in a competing network, you might have a financial incentive to send patients farther away than necessary. Those issues need to be worked out regionally to avoid competitive situations that delay patient care,” said Dr. Granger.
Barriers to efficiency
The AHA/ACC guidelines recommend a contact-to-device time of 90 minutes or less for patients transported directly to a PCI center and 120 minutes or less for patients transferred from a non-PCI hospital. When clinicians anticipate missing the two-hour window, non-PCI hospitals should administer fibrinolytic therapy within 30 minutes of a patient's arrival, followed by transfer for PCI within 24 hours, the guidelines say.
While the recommendations may seem straightforward, they have been difficult to implement in many communities where competing systems of care often interfere with cooperation. ED diversion policies and potential financial disincentives associated with transferring high-acuity patients are among the main barriers to timely reperfusion, according to the study in Circulation.
Bottlenecks in the ED are a common reason for slow reperfusion times. In one recent study in Vancouver, Canada, for example, implementation of a regional system led to higher overall rates of timely PCI but no accompanying reductions in mortality.
The apparent discrepancy was likely caused in part by slow transfers between hospitals, the authors noted. Almost half of patients in the study who were transferred from non-PCI to PCI centers were unable to achieve a door-to-device time of less than two hours, according to the results published last year in the Canadian Journal of Cardiology.
“We're finding that the delays are eaten up by patients getting hung up in the ED,” said the study's lead investigator Graham Wong, MD, director of cardiac care at Vancouver General Hospital and regional leader of acute cardiac care for the Vancouver Coastal Health Authority. “Just walking into a non-PCI hospital tends to result in losing about an hour compared with going directly to a PCI center.”
Another problem is lack of consistency in the way EMS providers are organized across the country, noted Dr. Granger. Some states, such as Maryland, have coordinated statewide networks encompassing all EMS while others, such as North Carolina, have hundreds of individually run agencies that are not integrated with health care networks.
“There is a huge range of quality, funding, training, and certification requirements across EMS services,” said Elizabeth Pathak, PhD, an epidemiologist who studied regional systems while at the University of South Florida. Despite its critical role in the health care system, EMS usually falls under the jurisdiction of local transportation or fire department services, she added.
That's a major problem because EMS is the “glue that holds regional systems together,” said Dr. Granger. Paramedics can speed transfers by performing electrocardiograms (EKGs) to diagnose or rule out STEMI en route to the PCI hospital. If the images indicate a clear-cut case of STEMI, paramedics can then alert physicians at the receiving hospital to activate the catheterization lab.
Despite regional competition among hospitals, non-PCI hospitals do not lose significant revenue by transferring STEMI patients, according to a study led by Dr. Pathak. The analysis of 112 non-PCI hospitals in Florida concluded that potential lost inpatient revenue from STEMI represented less than 1% of total charges at most hospitals.
Even in a worst-case scenario involving loss of all revenue from acute coronary syndrome patients, the average projected loss remained under 2%, the authors noted, adding that patients with other conditions represent the bulk of these hospitals' cardiology-related revenue. The findings were published in 2015 in Open Heart.
“The purpose of our study was to debunk the idea that small hospitals would be put out of business if they transfer out these patients,” said Dr. Pathak. “But for the vast majority of these hospitals, only a tiny fraction of patients who present with chest pain are having STEMI and the financial impact of transferring them is very low.”
Keys to success
To assist hospitals with creating regional systems, the AHA introduced its Mission: Lifeline program in 2007. The initiative offers a road map for developing common protocols and implementing care processes across regions. A recent analysis reported that the program significantly improved system performance in 16 U.S. metropolitan regions.
Hospitals that adopted key processes—such as activating the catheterization lab prior to the patient's arrival at a PCI hospital and initiating transfers with a single phone call—had the most impressive results, according to the findings published in January in Circulation: Cardiovascular Interventions.
For example, the average contact-to-device time in groups that implemented prehospital catheterization lab activation was 88 minutes versus 98 minutes for non-implementers. Similarly, single-call transfer protocols led to faster care (112 minutes vs. 167 minutes).
“We've been successful at going to different regions, identifying leaders at the major hospitals, and developing a team approach,” said Dr. Granger, senior author of the study. “Each EMS service and hospital has a protocol in place so they already know what to do before a STEMI patient comes in.”
The ability to make a single call to initiate transfers without worrying about bed availability saves a huge amount of time, noted Harold Dauerman, MD, a cardiologist at the University of Vermont Medical Center in Burlington.
“STEMI should be similar to the way hospitals deal with trauma cases,” he said. “Every hospital should know within minutes of a patient's arrival whether they're giving thrombolytics or transferring them for primary PCI. There needs to be a plan to move these patients as rapidly as possible in and out of the ED.”
In an analysis of the Mission: Lifeline program, led by Dr. Dauerman, lack of standardized processes was a major reason for delays in transferring STEMI patients. The study, which included more than 14,000 STEMI patients presenting to non-PCI hospitals, found that one-third of patients missed the two-hour window despite estimated transfer times of less than an hour. The findings were published in April 2015 in Circulation: Cardiovascular Interventions.
For smaller community hospitals, improving access to transportation and streamlining decision making are critical to achieving shorter contact-to-device times, said Dr. Dauerman. Physicians must be empowered to take action based on established protocols rather than going through multiple layers of decision makers, and they must have reliable access to ambulances.
The latter is often problematic when hospitals use their own ambulance services, which can take up to an hour to arrive, noted Dr. Granger. As a result, it's now fairly common for hospital EDs to call 911 for STEMI transfers, after which an ambulance typically arrives on the scene within eight to 10 minutes, he said.
Technology can also help make transfers more efficient. For example, one study in South Korea tested the use of a smartphone application to enable rapid communication among physicians. The app allowed the ED physician at the referring hospital to activate the catheterization lab while simultaneously sending brief information on the patient and a picture of the EKG.
The receiving physician could then page the catheterization team. Use of the smartphone application was associated with a 27-minute decrease in the median contact-to-device time, according to findings published in the September 2016 Journal of the American College of Cardiology.
“The timeliness of reperfusion therapy for transferred STEMI patients begins at the referral center,” the authors note. “Smartphone social network use allows for bypassing the search process for a PCI-capable hospital and enables a patient's rapid triage.”
Where it's working
Studies in Canada—where there is a publicly funded national health care system—demonstrate the potential for regional systems to succeed when the elements of competition and fragmentation are removed. In a small system of one PCI and two non-PCI hospitals in Ontario, for example, STEMI patients are routinely transferred between hospitals within the recommended time window.
“We used to look at our reperfusion times daily, but holdups due to delays in the ED or extra testing have become fairly uncommon,” said Akshay Bagai, MD, an interventional cardiologist at St. Michael's Hospital and assistant professor of medicine at the University of Toronto in Ontario, Canada. “Although it took a few years to get to this point, our processes have become much more streamlined.”
A major element in the program's success is having EMS integrated into the publicly funded system, he said. In addition, STEMI patients in stable condition are automatically sent back to the referring hospital after PCI, which frees up beds at the PCI hospital and allows non-PCI hospitals to handle convalescent care and maintain ties with patients during follow-up.
Vancouver General Hospital has a similar repatriation program for its network of two PCI hospitals and 11 peripheral facilities, said Dr. Wong. Once stable, STEMI patients are sent back to their community hospitals, which frees up beds for more STEMI patients at the PCI center.
Vancouver General also benefits from participating in the British Columbia Patient Transfer Network, a hub for accessing air and ground transport that is used for a variety of urgent conditions including STEMI, he said. Under the program, STEMI care processes are set into motion with one emergency call, coordinated by an operator who communicates with receiving hospitals and tracks patients' progress en route.
No matter where a hospital is located, the success of a regional STEMI system depends on educating clinicians, EMS, and the public, experts said. EMS personnel must be trained to recognize STEMI and familiar with which hospitals in their region are PCI-capable.
Even in single-payer systems, there can be competition among hospitals and concerns about using limited resources on false alarms, said Dr. Bagai. The key is continuous discussion and feedback so everyone stays focused on the bottom line—improving patient outcomes.
“These systems have to be a partnership among all stakeholders,” he said. “Everyone has to come into the room and say, ‘What is best for the patient and how do we deliver the most efficient and timely reperfusion?’”