Author + information
- Received January 11, 2013
- Revision received May 3, 2013
- Accepted May 28, 2013
- Published online October 1, 2013.
- B. Hadley Wilson, MD∗∗ (, )
- Angela D. Humphrey, MS†,
- John C. Cedarholm, MD∗,
- William E. Downey, MD∗,
- Robert H. Haber, MD∗,
- Glen J. Kowalchuk, MD∗,
- Michael J. Rinaldi, MD∗,
- Denise A. Miller, BSN†,
- Jennifer L. Sarafin, MSN∗ and
- J. Lee Garvey, MD‡
- ∗Sanger Heart & Vascular Institute, Carolinas Medical Center, Charlotte, North Carolina
- †Dickson Advanced Analytics Group, Carolinas HealthCare System, Charlotte, North Carolina
- ‡Department of Emergency Medicine, Carolinas Medical Center, Charlotte, North Carolina
- ↵∗Reprint requests and correspondence:
Dr. B. Hadley Wilson, The Sanger Heart & Vascular Institute, Carolinas Medical Center, 1001 Blythe Boulevard, Suite 300, Charlotte, North Carolina 28203.
Objectives A network approach to transfer ST-segment elevation myocardial infarction (STEMI) patients can achieve durable first door-to-balloon times (1st D2B) for percutaneous coronary intervention (PCI) within 90 min.
Background Nationally, a minority of STEMI patients from referral centers obtain 1st D2B in <2 h and even fewer in <90 min.
Methods Included were transfer STEMI patients from 9 network hospitals treated in 2007 compared with 2008 to 2011 after installing the following initiatives: 1) established hospital referral system; 2) goal-oriented performance protocols; 3) expedited transport by ground or air; 4) first hospital activation of the PCI hospital catheterization laboratory; and 5) outreach coordinator and patient-level web-based feedback to the referring hospital.
Results A total of 101 STEMI patients transported in 2007 were compared with 442 STEMI patients transferred after starting these initiatives for STEMI from 2008 to 2011, with the median door-in to door-out time decreased from 44 to 35 min (p < 0.0001), the median 1st D2B decreasing from 109.5 to 88.0 min (p < 0.0001), and the percentage under 90 min increased from 22.8% to 55.9% (p < 0.0001). Overall, throughout the study period (2007 to 2011), the transport times remained consistent (median 36.5 vs. 36.0 min, p = 0.98), whereas the PCI hospital D2B decreased from 20.0 to 16.0 min (p < 0.0001). Length of stay and in-hospital mortality remained low at 3.0 days and under 4%, respectively.
Conclusions A system-wide network program can achieve sustained (over 4 years) 1st D2B times of <90 min.
Reducing transfer delays from regional hospitals to hospitals with percutaneous coronary intervention (PCI) is a major goal to improve ST-segment elevation myocardial infarction (STEMI) patient care outcomes in the United States and elsewhere. Indeed, the 2011 American College of Cardiology/American Heart Association/Society for Cardiovascular Angiography and Interventions Guideline for Percutaneous Coronary Intervention: Executive Summary recommends as a systems goal primary PCI for STEMI patients presenting to a hospital without PCI capability within 120 min of first medical contact (1). Even so, nationally, only about 25% of STEMI patients from regional transfer hospitals obtain first door-to-balloon time (1st D2B) within 2 h (2). Numerous papers have highlighted the criticality of reducing time to reperfusion (3–12), and the National Registry of Myocardial Infarction database indicated that there are 6.3 fewer deaths per 1,000 patients treated for each 15-min improvement in time to reperfusion (13). However, even among hospitals actively participating in the institutionally aware Acute Coronary Treatment and Intervention Outcomes Network Registry (ACTION Registry)–Get With the Guidelines reported in 2009, only 53% of patients receive 1st D2B within 2 h and only 21% within 90 min (14).
Although in 2008 the American College of Cardiology/American Heart Association Performance Measures for Acute Myocardial Infarction recommended 2 new performance measures: time spent at the first hospital (transfer center) with a goal of ≤30 min, and total time to primary PCI with a goal of ≤90 min (15); subsequent 2013 STEMI guidelines have further clarified a first medical contact to balloon goal of 120 min for transferred patients. (The 2013 STEMI guidelines specify “immediate transfer to a PCI-capable hospital for primary PCI is the recommended triage strategy for patients with STEMI who initially arrive or are transported to a non–PCI-capable hospital, with an ideal first medical contact to device time system goal of 120 min or less”) (16). In light of all of these, we programmatically instituted a systematic approach to regional transfer STEMI patients in our network to achieve consistent improved reperfusion times.
The PCI Center in this study, Carolinas Medical Center, is an 888-bed tertiary care academic hospital of the University of North Carolina, School of Medicine, in metropolitan Charlotte, North Carolina, serving 38 counties and a population >5 million people. Primary PCI services and an active STEMI program 24 h, 7 days a week have been ongoing since 2005. The PCI center is part of a network of hospitals (Carolinas Healthcare System) that own and operate 4 helicopter based at 4 sites in the region, as well as numerous ground ambulances. Carolinas Medical Center and all of the referral centers discussed in this report are accredited by the Society of Cardiovascular Patient Care as Chest Pain Centers (17). Ambulance transport versus helicopter transport was at the discretion of the treating emergency medicine physician in collaboration with the receiving physicians (cardiologist or emergency medicine) at the PCI center.
All consecutive STEMI patients who were transported to the PCI receiving hospital from a 9-hospital referral network with a median transport time <60 min and a minimum of 5 emergency regional transfers for primary PCI in 2007 (n = 101) were compared with those transported after institution of a comprehensive systematic approach to regional transfer of STEMI patients (n = 442) during a 4-year period from 2008 to 2011. Five components of an expedient system-wide approach to transfer STEMI care were identified and instituted between these time periods. Implementation included: 1) an established hospital referral system network with uniform transfer algorithms (Fig. 1); 2) a goal-oriented performance protocol emphasizing time at the regional transfer hospital ≤30 min (Fig. 2); 3) expedited transport by ground or air with median transport times ≤60 min within a 50-mile radius; 4) a single call system to activate the PCI catheterization laboratory by the regional transfer hospital; and 5) an outreach coordinator supervising real-time entry and worldwide web–based feedback of patient transport times and outcomes imminently available to the regional transfer hospital for programmatic and institutional improvement (Fig. 3).
Data collection and analysis
The following definitions (Table 1) and time metrics were recorded and provided for analysis and feedback:
1. Transfer hospital time—calculated from time of arrival at the transfer hospital to time of departure from the transfer hospital (also known as door-in to door-out [DIDO] time).
2. Transport time—calculated from transfer hospital departure time to arrival at PCI hospital.
3. PCI door-to-balloon (PCI D2B)—calculated from time of arrival at the PCI hospital to time of first device (balloon or aspiration catheter, not guidewire) deployment during PCI.
4. 1st D2B—calculated from time of arrival at the transfer hospital to time of first device (balloon or aspiration catheter, not guidewire) deployment during PCI.
In addition, we evaluated and compared patient outcomes, including length of stay and mortality, over the course of the study. The ACTION database collection and study were approved by the institutional review board of the primary PCI hospital and Carolinas Healthcare System.
Statistical analysis was performed utilizing standard tests for comparing 2 groups. The Kruskal-Wallis test was used to analyze median times by regional transfer patients in 2007 to median times for those from 2008 to 2011 after implementation of a system-wide approach. The Fisher's exact test was used to equate distribution of patients reaching time goals between these periods as well.
Implementation of system-wide initiatives for transfer STEMI after 2007
In 2007, the PCI hospital treated 377 STEMI patients, of which 101 were transferred from the network hospitals. During 2008 to 2011, the PCI hospital received 2,362 STEMI patients, with 442 from the network hospitals (Table 2). Following implementation of this systematic approach, the median DIDO time at the 9 transfer STEMI hospitals declined from 44 min to 35 min (p < 0.0001), whereas the median transport time remained consistent (36.5 min vs. 36.0 min, p = 0.98). PCI D2B median time decreased from 20 min to 16 min (p < 0.0001), and the overall percentage achieving this in <30 min increased from 72.3% in 2007 to 93.4% during 2008 to 2011 (Table 3). The 1st D2B decreased from a median of 109.5 min in 2007 to 88 min (p < 0.0001) by 2008 to 2011, and the percentage of patients treated within the 90-min goal more than doubled (22.8% to 55.9%, p < 0.0001) (Fig. 4). This happened with more helicopter transports (21% [n = 21] in 2007 vs. 48% [n = 214] in 2008 to 2011, p < 0.0001) and more patients from farther away (27% [n = 27] in 2007 from 25 to 50 miles vs. 49% [n = 218] in 2008 to 2011, p < 0.0001).
Length of stay and mortality
Despite these system and time improvements during the same time frame from 2007 until 2008 to 2011, length of stay remained unchanged at 3 days (p = 0.2207), and in-hospital mortality remained <4% (p = 0.96).
Although many cities and some regions worldwide have developed mature regional transfer STEMI programs, to date, only 2 studies have reported median 1st D2B under 90 min for transfers—only 37 and 187 patients, respectively, with significantly shorter transfer times (flight times <10 min and drive times <40 min) (18,19). Furthermore, helicopter transport was utilized in over 80% of these cases. Therefore, this is the first report of a regional network system of hospitals approaching the 2008 American College of Cardiology/American Heart Association recommendations of <30 min spent at the transfer hospital, DIDO (median 35 min), and total time 1st D2B within 90 min over a 4-year period (Table 3). We believe these goals were achieved through the implementation of 5 key strategies including establishing a mature hospital referral network; a time goal–oriented transfer protocol; a more responsive transport system by ground ambulance or helicopter ≤60 min a standard of empowering the transfer hospital physician to activate the PCI hospital catheterization laboratory; and an online feedback tracking system of transport times and patient outcomes available by the worldwide web to the transfer hospital. By accrediting all hospitals in our network by the Society of Cardiovascular Patient Care as Chest Pain Centers, we improved quality and outcomes by sharing best practices monthly (including committed and coordinated ambulance or helicopter transport), by activating the PCI catheterization laboratory through a central single call-in switchboard, and by delivering process improvement solutions to each team member for early heart attack care. Our uniform transport algorithm and performance protocol (Fig. 2) are in keeping with our participation in the North Carolina RACE-ER (Reperfusion of Acute Myocardial Infarction in Carolina Emergency Departments–Emergency Response) project and emphasized a DIDO goal of <30 min (20), and the ability of the PCI referring hospital to activate the STEMI catheterization laboratory team at the PCI receiving hospital. In addition, our improved arrival at the PCI hospital to reperfusion times were only achieved through a nonvarying “hard-wired direct trauma approach” from helicopter or ambulance straight to the catheterization laboratory. There, quick assessment and oral consent were obtained by the cardiologist from the patient on the gurney immediately before transfer to the catheterization laboratory table. Although we did not assess the relative contribution of each of these factors to overall system improvement, other reports have shown some importance to all of these strategies and the greatest gains with multiple achievements (12,21). This systematic approach has achieved sustainable 1st D2B times of 88 min, significantly shorter than the 120 min recently reported from the ACTION Registry–Get With the Guidelines database (22).
Limitations to this report include that this was a single “hub-and-spoke” system for our region and that mortality, length of stay, and other outcomes did not improve significantly despite multiple previous reports linking mortality to delay to PCI (23,24). This may have occurred because of the relatively good baseline time metrics in 2007, highlighted by a low initial median 1st D2B of 109.5 min, better than that reported by other programs after interventions for improvement were well in place (9,20). Although details regarding patient severity, clinical differences in those transported by helicopter, and incidence of shock were missing, basic demographics across the centers as noted in Table 2 were equivalent. In the earlier years of data collection in this report, as well as nationwide, first medical contact and total ischemia time for transported patients were not identified tracking elements. We began to collect these metrics in late 2009. Therefore, we were unable to compare these data between the 2 time frames. However, our data from 2011 indicate that the true median first medical contact to reperfusion was 87 min and is similar to our reported 1st D2B reperfusion of 88 min from 2008 to 2011, but still, the incompleteness of these data represent a limitation of this study. Because our total ischemia times could not be assessed and compared, this may explain the lack of improvement in length of stay and mortality despite the well-established fact that most transport time reductions usually lead to reduced mortality (mainly in those with infarctions of <3 h duration) (23,24). In any event, the significant improvements in the time metrics with our program highlight that it is possible to regularly achieve 1st D2B times <90 min for a regional transfer STEMI network. Future efforts for systems of care improvements should concentrate on reducing total ischemia time by public education of early signs and symptoms of heart attack, as well as calling 911 rather than using private vehicle transport to emergency departments.
The implementation of multiple system-wide initiatives for transfer STEMI along with advanced transport protocols and patient-level feedback can achieve durable 1st D2B times within 90 min for a transfer STEMI network having transport times consistently <60 min.
The authors acknowledge the following hospitals and their STEMI teams, and numerous emergency medical service agencies who were instrumental in facilitating the implementation of the transfer protocol: Carolinas Medical Center (CMC)-Lincoln, CMC-Union, CMC-Pineville, CMC-University, Cleveland Regional Medical Center, Kings Mountain Hospital, Iredell Memorial Hospital, Lake Norman Regional Medical Center, Rowan Medical Center, Mecklenburg EMS Agency, MEDIC, and Carolinas HealthCare System's MEDCENTER AIR. They also acknowledge the significant contribution of Romano Paul (Carolinas HealthCare System) for the web-based reporting tool, Anne Olsen (Blazon Productions) for the creation of the article's map, and Norma Wright for her technical manuscript support.
Dr. Wilson serves as a consultant for Boston Scientific; and has received speaker honoraria from Abiomed. Dr. Rinaldi is a consultant for Abbott Vascular. Dr. Garvey is a consultant for Philips Healthcare. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- Abbreviations and Acronyms
- 1st D2B
- first door-to-balloon
- Acute Coronary Treatment and Intervention Outcome Network
- door-in to door-out
- percutaneous coronary intervention
- ST-segment elevation myocardial infarction
- Received January 11, 2013.
- Revision received May 3, 2013.
- Accepted May 28, 2013.
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