The persistent discrepancy between the door-to-balloon times of on-hours versus off-hours in STEMI patients undergoing PCI procedures can be solved through cost-effective means; however, some argue that an expensive and complex pre-activation program is needed to bring off-hour times in line with those of on-hours.

Early in 2006, the American College of Cardiology (ACC) recognized the urgent need to reduce door-to-balloon times for patients experiencing ST-segment elevation myocardial infarction (STEMI). In June of that year, the college began building the D2B Alliance, a nationwide network of hospitals, physician champions and strategic partners committed to addressing the door-to-balloon challenge.

However, recent clinical data has confirmed what many cath lab directors already knew—door-to-balloon times are much longer for patients on weekends and after regular hours, often defined as “off-hours.” As a result, many systems and methods have been recommended and implemented to improve this disparity. While several components contribute to this difference in performance, a consistent obstacle seems to be the speed in which the cath lab can be staffed.

“When a patient presents off-hours, the hospital is typically at a reduced staffing level across all departments, which affects how a patient is initially managed and how the cath lab gets activated,” says Brahmajee Nallamothu, MD, a professor in the department of internal medicine at the University of Michigan in Ann Arbor. “We are seeking certain hospital-based, cost-effective procedures that could shorten the time for treatment of STEMI patients. Although it is still under investigation, ED activation and using a single-call system, as well as a pre-hospital ECG system, could serve to better treat these patients in the off-hours.”

The D2B Alliance, led by Yale University epidemiologist Elizabeth H. Bradley, MD, recommended four strategies for reducing door-to-balloon times, regardless of presentation hour (NEJM 2006;355:2308-2320):

• Emergency department physician activates the cath lab;
• Single call to activate the cath lab;
• Cath lab operational within 20-30 minutes of activation; and
• Real-time data feedback for case review.

While these four strategies are quite effective for reducing on-hour door-to-balloon times, hospitals most likely can not eliminate the off-hour discrepancy by just implementing these four strategies, notes Henry Ting, MD, vice-chair of the division of cardiovascular disease at the Mayo Clinic College of Medicine in Rochester, Minn.

Bradley and colleagues also suggested two additional strategies, but less forcefully, because they could prove costly to a hospital:

• having an attending interventional cardiologist always present in the hospital,
• and installing a pre-hospital ECG to activate the cath lab while the patient is en route.

Even for the busiest of U.S. hospitals with 300 to 400 STEMI patients a year, it would be difficult to financially justify staffing an interventional cardiologist, plus the entire cath lab team in-house, 24/7, according to Ting. “Economically, it is a very expensive endeavor to incur for potentially 150 STEMI patients a year.”

Frank V. Aguirre, MD, of the department of internal medicine and interventional cardiology at Memorial Medical Center in Springfield, Ill., initiated in 2001 the four main strategies outlined by Bradley et al. The hospital quickly demonstrated a significant reduction in door-to-balloon times, but still had a “serious discrepancy” in its off-hour versus on-hour times. Approximately, 60 percent of STEMI patients in the U.S. present in off-hours.

To combat the problem, Memorial Medical Center, which performs an estimated 75 PCI procedures on STEMI patients yearly, adopted two other methods. First, it cross-trained the ED nurses to initiate the cath lab process before the cath lab nurses come into the hospital. Second, Aguirre adjusted working hours so some cath lab personnel began their shift about five hours later, essentially eliminating some of the unstaffed off-hours.

“By adopting these additional tactics, we further decreased the overall door-to-balloon times by 11 percent. By 2007, our overall median door-to-balloon time was 58 minutes and our off-hour door-to-balloon time was 57 minutes,” Aguirre says.


ECG with the EMS

While a pre-activation ECG is a sure-fire method of reducing door-to-balloon times, it is not necessarily the most economical. On average, a pre-activation ECG device costs the hospital about $30,000, and between $15,000 and $18,000 to update current equipment. Even more important and challenging is coordinating pre-activation ECG with local emergency medical services (EMS). The two methods adopted by Memorial Medical Center were less challenging and less expensive then initiating a pre-activation ECG, Aguirre says.

Ting further breaks down the door-to-balloon process into four time-sensitive areas:

• Door to ECG time
• ECG to cath lab activation time
• Cath lab activation to cath lab arrival time, and
• Cath lab arrival to balloon time.

For example, even if someone else activates the cath lab, the point of activation to the point of actually getting the patient’s artery open off-hours is on average 30 minutes, according to Ting, which is why he felt it necessary to examine the complications involved with each step separately.

The main stumbling block to reducing off-hour door-to-balloon times lies in the cath lab activation to cath lab arrival time. Typically, cath lab personnel will arrive within 20 to 30 minutes. Aguirre notes that during on-hours, 36 percent of the time is spent waiting for a cath lab to become available, while during off-hours, 57 percent of the time is spent in the ED, waiting for the cath lab to become activated.
 

Many experts agree, however, that pre-hospital ECG is the best method to reduce off-hour door-to-balloon times. “Theoretically, when the paramedics make a diagnosis with a pre-hospital ECG at first medical contact, the team can be right behind the patient arriving to the hospital,” says Ting.

George M. Kichura, MD, a member of the Mercy Health System in St. Louis, Mo., has run into logistical snags trying to initiate a statewide door-to-balloon program. Even with companion bills in the Missouri House and Senate to support a statewide door-to-balloon program, the sticking point is finding regional solutions that fit the many EMS companies. What if the patient is closest to a hospital across the state line? Who determines which hospitals to bypass? Who will pay for the 12-lead ECG machines needed in the EMS vehicles? If you can solve these and other problems and enact an on-hours door-to-balloon program, you can then begin to focus on off-hour improvement, Kichura said. He is committed to the project, but worries that others will find the process to initiate a door-to-balloon program too cumbersome and will instead resort to first-line thrombolytic treatment.

While there is a role for thrombolytics—not everyone can get optimal door-to-balloon times, for example—the key is to have a system in place, a standardized approach, according to Timothy Henry, MD, an interventional cardiologist at the Minneapolis Heart Institute. Henry’s door-to-balloon area has several zones, depending on the distance from the main hospital, and each zone’s protocol may differ somewhat to accommodate the travel time. The advantage of having a system in place, however, is that it can be adjusted for the slightest changes, such as those needed to improve off-hour door-to-balloon times, Henry said.

Once the logistics of organizing the local EMS are ironed out, another challenge is to educate the public to utilize the emergency service, rather than relying on relatives to drive them to the hospital. Paramedics are much more highly trained than in years past and are able to provide important pre-hospital treatment. Ting and his Mayo colleagues have implemented a pre-activation ECG method that allows the EMS to diagnose a STEMI patient at first medical contact. If the pre-activated ECG is integrated with a downstream system of care, the paramedics can also be trained to activate the cath lab in the off-hours.

Stressing the necessity of collaboration, Ting said that the major success of the initial door-to-balloon initiative lies in “breaking down the silos between the cardiologist and the ED physician. Joint accountability and partnership in a patient-centered process will produce the best model,” including extending that collaboration outside the hospital to the paramedic.

“The latest data supports the effectiveness of this method, including a scientific statement from the American Heart Association to be published in the next six months indicating the amount of training required by EMS in order to implement a pre-activation ECG,” Ting says.

The University of Michigan Medical Center, which implemented a pre-hospital ECG program with its single EMS provider, boasted an average 82-minute door-to-balloon time in 2007 for both on- and off-hours, according to Nallamothu. The cath lab was activated 101 times for acute MI.

“If a paramedic activates a pre-hospital ECG, the interventionalist is given a 20-minute head-start that the patient is coming,” Nallamothu said.

Of course, different geographic locations throughout the U.S. can present varied challenges. Some rural areas do not have paramedics, and EMS personnel in these areas will need more in-depth training to interpret an ECG, while Los Angeles county has 7,000 paramedics for approximately 10 different EMS services, which can cause a lot of variability.

Despite the geographic and financial implications, Ting still says that the pre-activation ECG method has a lot of potential because it simply organizes systems of care to deliver the best care.


The Bottom Line

While physicians from varying institutions have each implemented different methods to effectively reduce their off-hour door-to-balloon times, one question remains–can it be done inexpensively?

The ACC is pushing toward the adoption of widespread pre-hospital ECG-activation. In fact, the most recently updated guidelines take into consideration first medical contact with EMS, instead of the traditional door-to-balloon timing. As a result, the first responders will be encouraged to become involved to develop systems to coordinate their care and develop strategies to transport the patient to facilities that can care for the patient most efficiently.

This adoption would entail expensive up-front equipment costs to the hospitals. However, Aguirre says this system could be utilized by all first-responder care in the U.S., whether trauma, stroke or bioterrorism, so the benefits could be tremendous for patient care on a national level.

Despite the potential national benefits of these systems, Memorial Medical was able to reduce its off-hour door-to-balloon times without incurring additional costs. And despite the strong movement within the cardiovascular community, Aguirre says he is unsure whether the adoption of pre-activation ECGs would reduce their off-hour door-to-balloon times any further, even though it may affect the on-hour times. The only other step Aguirre’s hospital could take to further reduce its off-hour times is to have a cath lab team on-site 24-hours, which is tremendously costly, he says.

In the end, the shift toward adopting a pre-hospital ECG activation and a greater reliance upon first responders seems inevitable. While the initial costs may be burdensome, the STEMI patients continue to benefit, regardless of the time of day.