Research indicates that mortality and morbidity can be reduced in patients with STEMI when they have faster times to reperfusion. Guidelines from the American College of Cardiology (ACC) and American Heart Association (AHA) recommend that PCI devices be activated within 90 minutes of first medical contact in this patient group. Although the adoption of various strategies has led to significant improvements in national reperfusion metrics, research suggests that the ACC/AHA guideline-recommended goals have yet to be systematically achieved. Other studies indicate that delays with triage and ED evaluation may contribute to the inability to achieve timely reperfusion.
Adopting a New Approach
As an interventional cardiologist in Canada, Akshay Bagai, MD, MHS, worked in a hospital cath lab where patients with pre-hospital electrocardiograms (ECGs) showing that they had STEMI were routinely brought directly to the lab by emergency medical services (EMS). “We found that we were saving time by bypassing the ED,” he explains. When Dr. Bagai learned that this practice was not endorsed in the United States, he and his colleagues sought to study the approach further.
In an analysis published in Circulation: Cardiovascular Interventions, Dr. Bagai and colleagues reviewed data from the Reperfusion of Acute Myocardial Infarction in Carolina Emergency Departments (RACE) project, a program among North Carolina hospitals that collaborated to develop a coordinated, regional system to care for STEMI patients. From 21 of these hospitals, they studied 1,687 patients with pre-hospital STEMI who had been transported via EMS for primary PCI and were either evaluated in the ED or taken directly to the cath lab.
The median time from first medical contact to reperfusion was 15 minutes shorter for patients who bypassed the ED when compared with the ED evaluation group, says Dr. Bagai (Table 1). “We found that about 75% of patients who bypassed the ED met the target of having STEMI patients undergo reperfusion within 90 minutes of first medical contact. This compared favorably to the 50% rate we observed for patients evaluated in the ED.”
Among most hospitals in the U.S., cath lab teams that perform PCI procedures do not stay within the hospital 24 hours a day. Many teams come into the hospital during off hours and only for emergency cases. “Since the cath lab teams tend to already be in the hospital during working hours, reperfusion times tend to be shorter during daytime hours when compared with nighttime hours,” Dr. Bagai says. “That’s because patients don’t need to wait for the cath lab team to come in.” However, findings from Dr. Bagai’s study also showed that patients who bypassed the ED during night (off) hours had shorter reperfusion times than those evaluated in the ED (Table 2).
The investigation also revealed that in-hospital mortality was lower in the ED bypass group. “However, we found that patients evaluated in the ED were slightly sicker,” he says. “After adjusting for this factor and others, no differences were observed in mortality.” That said, Dr. Bagai adds that the differences in time to reperfusion observed between the two groups would likely lead to a difference in their outcomes when studied in a larger number of patients. This has been seen in numerous other strategies that have led to reperfusion time reductions.
More Work Required
In order to adopt the ED bypass approach, Dr. Bagai says emergency physicians, cardiologists, interventional cardiologists, EMS, and state and regional healthcare governing bodies need to collaborate and make plans for their region on how best to care for STEMI patients. “It starts with the ability of EMS to perform pre-hospital ECG and call the hospital to inform them that they’re en route with a STEMI patient who needs the cath lab to be activated,” Dr. Bagai says. “During off hours, the cath lab team needs to come to the hospital at the same time. To do this, systems are needed to direct clinicians on what to do if the patient arrives before the cath lab team. An in-hospital cardiologist, internist, fellow, coronary care unit nurse, or other provider will need to look after the patient in the cath lab until the team arrives.”
Dr. Bagai also says systems should be in place for obtaining patient information from EMS while they are in transit to the hospital. “All constituents need to be prepared for admissions via the cath lab and recognize what must be done with patients who are determined in the cath lab to not have STEMI. All of these systems need to be in place, but that can only happen if leaders in each of these departments collaborate and develop a plan that works best for everyone. As more hospitals take this approach, we hope to learn from what other institutions are doing to further improve outcomes for STEMI patients.”
Readings & Resources (click to view)
Bagai A, Al-Khalidi H, Munoz D, et al. Bypassing the emergency department and time to reperfusion in patients with prehospital ST-segment elevation: findings from the reperfusion in acute myocardial infarction in Carolina emergency departments project. Circ Cardiovasc Interv. 2013 Jul 16. [Epub ahead of print]. Available at: http://dev.physiciansweekly.com/wp-content/uploads/2014/02/pci_stemi.pdf.
O’Gara P, Kushner F, Ascheim D, et al. 2013 ACCF/AHA guideline for the management of ST-elevation myocardial infarction: a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines. Circulation. 2013;127:e362-e425.
Jollis J, Granger C, Henry T, et al. Systems of care for ST-segment-elevation myocardial infarction: a report from the American Heart Association’s Mission: Lifeline. Circ Cardiovasc Qual Outcomes. 2012;5:423-428.
Krumholz H, Herrin J, Miller L, et al. Improvements in door-to-balloon time in the United States, 2005 to 2010. Circulation. 2011;124:1038-1045.
Cheskes S, Turner L, Foggett R, et al. Paramedic contact to balloon in less than 90 minutes: a successful strategy for st-segment elevation myocardial infarction bypass to primary percutaneous coronary intervention in a Canadian emergency medical system. Prehosp Emerg Care. 2011;15:490-498.