A short door-to-balloon time (D2B) ST-elevation myocardial infarction (STEMI) intervention has two major components that must be well understood to achieve the desired benefits of primary percutaneous coronary intervention (PCI). These components include the STEMI “process” — the series of actions, including the essential pre-hospital component, that deliver a STEMI patient to the cardiovascular laboratory in an expedited fashion, and the “procedure” that results in rapid restoration of epicardial and myocardial perfusion to the infarcting heart.
The success of outstanding primary PCI programs in Europe, Canada and at numerous U.S. centers is primarily a result of mastering both the “process” and the “procedure” of a STEMI intervention.1-6
Four Members of a STEMI Team and Similarities to Running a Relay
Table 1 lists the four member(s) whose participation is critical to achieving a short D2B STEMI intervention. Like a relay team, it is teamwork that is critical to achieving success and like a well-oiled relay team that seamlessly passes the baton to the next runner, the STEMI process should seamlessly move along through the different stations and run through the course in less than 90 minutes.
From having performed 325 short D2B STEMI interventions (as recorded in the Single Individual Community Experience Registry for Primary PCI [SINCERE] database), I can attest that the most relentless pressure is on the final runner who has to make up for any time lost by the other runners —the final runner in a STEMI intervention is the interventional cardiologist, who must run the last lap to get the team across the finish line. 7
With this example, it should be easy to appreciate the critical importance of teamwork. It is this teamwork that enables institutions to consistently achieve very short D2B times, even during off-hours. Institutions that are setting up STEMI programs need to review all the components of their STEMI pathway. An efficient way may be to first split the STEMI intervention into the process and the procedure, and then look at the four individual members. It is also a good policy while reviewing fallouts from the expected D2B time of 3
Calling Code Alert – Backward Integration for Reducing D2B Times
Figure 1 provides a diagram to describe this concept. It relies on enabling the earliest responders to STEMI in making critical management decisions in order to increase efficiency of the STEMI triage and treatment process, and for reducing D2B times. Consistent compliance with these policies will also eliminate the chaos that can occur in the STEMI process. Through this mechanism, the emergency medical technician (EMT) and emergency department (ED) are empowered with greater decision-making power and the interventional cardiologist must begin to accept this as an integral part of teamwork, rather than a threat to his or her traditional autonomy. It is impractical for the interventional cardiologist to be involved in the decision-making on-site or burden him or herself with management of the STEMI patient pre-hospital and during the transfer phase. The interventional cardiologist remains still in the driver’s seat and as has been described above, it is the interventional cardiologist who must run the final lap. Therefore, a plea is made to the interventional cardiologist to step back and accept that errors will be made that he must accept for the greater good of providing consistent, high-quality STEMI care and for reducing D2B times. Yet, experience from numerous centers shows that these “false alarms” can be lowered through feedback and with mandated education of the entire STEMI team. In a manner akin to the interventional cardiologist making way for the ED, the ED in turn, enables EMT and other EMS personnel to make critical decisions.
The role of technology and funding in this entire process cannot be understated as we move towards providing superior care for the STEMI patient. Additional training for paramedics and incorporating EKG transmission capabilities in ambulances are some of these important steps.
Closing the Gap with Europe and Canada in the STEMI Process by Eliminating Redundant Steps
Figures 2 and 3 provide diagrams of these processes. The inside tracks (Pathway A, green arrows) demonstrate the STEMI process presently occurring in several European centers, whereas the outer track (Pathway B, with red arrows) shows the existent pathways in most U.S. centers. It may be beneficial to eliminate the steps crossed out in Figure 3 to achieve reductions in D2B times.
Finally, we submit that reducing D2B times is the low-hanging fruit of STEMI interventions. The larger challenges are consistent off-hour D2B times and lowered “false alarm” rates for institutions. Beyond these, the true Achilles heel for STEMI care is education of the patient and legislative barriers preventing the formation of a national STEMI policy akin to the U.S. national trauma system.
Dr. Mehta can be contacted at firstname.lastname@example.org
1. Andersen HR, Nielsen TT, Rasmussen K, et al. DANAMI-2. A comparison of coronary angioplasty with fibrinolytic therapy in acute myocardial infarction. N Engl J Med 2003 Aug 21; 349(8):733-742.
2. Le May MR, So DY, Dionne R, et al. A Citywide Protocol for Primary PCI in ST-segment Elevation Myocardial Infarction. N Engl J Med 2008; 358:231-240.
3. Mehta S, Briceno R, Alfonso C, Bhatt M. Lessons from the Single INdividual Community Experience REgistry for Primary PCI (SINCERE) Database. In: Mehta S, ed. Textbook of STEMI Interventions. Malvern, PA: HMP Communications, 2008: 95-113.
4. Henry TD, Sharkey SW, Burke MN, et al. A regional system to provide timely access to percutaneous coronary intervention for ST-elevation myocardial infarction. Circulation 2007 Aug 14; 116(7):721-728.
5. Rokos I, on behalf of the Southern California STEMI Consortium. Regional STEMI Networks in Southern California Reduce Door-to-Balloon Times: Pooled Data from 4 Counties. October 22, 2007, at Transcatheter Cardiovascular Therapeutics 2007.
6. Jollis JG, Mehta RH, Roettig ML, et al. Reperfusion of Acute Myocardial Infarction in North Carolina Emergency Departments (RACE): study design. Am Heart J 2006; 152:851:e1-11.
7. Ting HH, Rihal CS, Gersh BJ, et al. Regional systems of care to optimize timeliness of reperfusion therapy for ST-elevation myocardial infarction: the Mayo Clinic STEMI Protocol. Circulation 2007 Aug 14; 116(7):729-736.