Causes of Delay and Associated Mortality in Patients Transferred With

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1 Causes of Delay and Associated Mortality in Patients Transferred With ST-Segment Elevation Myocardial Infarction Michael D. Miedema, Marc C. Newell, Sue Duval, Ross F. Garberich, Chauncy B. Handran, David M. Larson, Steven Mulder, Yale L. Wang, Daniel L. Lips and Timothy D. Henry Circulation 2011, 124: : originally published online September 19, 2011 doi: /CIRCULATIONAHA Circulation is published by the American Heart Association Greenville Avenue, Dallas, TX Copyright 2011 American Heart Association. All rights reserved. Print ISSN: Online ISSN: The online version of this article, along with updated information and services, is located on the World Wide Web at: Subscriptions: Information about subscribing to Circulation is online at Permissions: Permissions & Rights Desk, Lippincott Williams & Wilkins, a division of Wolters Kluwer Health, 351 West Camden Street, Baltimore, MD Phone: Fax: journalpermissions@lww.com Reprints: Information about reprints can be found online at

2 Interventional Cardiology Causes of Delay and Associated Mortality in Patients Transferred With ST-Segment Elevation Myocardial Infarction Michael D. Miedema, MD; Marc C. Newell, MD; Sue Duval, PhD; Ross F. Garberich, MS; Chauncy B. Handran, BS; David M. Larson, MD; Steven Mulder, MD; Yale L. Wang, MD; Daniel L. Lips, MD; Timothy D. Henry, MD Background Regional ST-segment elevation myocardial infarction systems are being developed to improve timely access to primary percutaneous coronary intervention (PCI). System delays may diminish the mortality benefit achieved with primary PCI in ST-segment elevation myocardial infarction patients, but the specific reasons for and clinical impact of delays in patients transferred for PCI are unknown. Methods and Results This was a prospective, observational study of 2034 patients transferred for primary PCI at a single center as part of a regional ST-segment elevation myocardial infarction system from March 2003 to December Despite long-distance transfers, 30.4% of patients (n 613) were treated in 90 minutes and 65.7% (n 1324) were treated in 120 minutes. Delays occurred most frequently at the referral hospital (64.0%, n 1298), followed by the PCI center (15.7%, n 317) and transport (12.6%, n 255). For the referral hospital, the most common reasons for delay were awaiting transport (26.4%, n 535) and emergency department delays (14.3%, n 289). Diagnostic dilemmas (median, 95.5 minutes; 25th and 75th percentiles, minutes) and nondiagnostic initial ECGs (81 minutes; minutes) led to delays of the greatest magnitude. Delays caused by cardiac arrest and/or cardiogenic shock had the highest in-hospital mortality (30.6%), in contrast with nondiagnostic initial ECGs, which, despite long treatment delays, did not affect mortality (0%). Significant variation in both the magnitude and clinical impact of delays also occurred during the transport and PCI center segments. Conclusions Treatment delays occur even in efficient systems for ST-segment elevation myocardial infarction care. The clinical impact of specific delays in interhospital transfer for PCI varies according to the cause of the delay. (Circulation. 2011;124: ) Key Words: delays delivery of health care myocardial infarction angioplasty, balloon, coronary Timely reperfusion is the cornerstone of treatment in patients with ST-segment elevation myocardial infarction (STEMI). Improving door-to-needle time for fibrinolytic therapy and door-to-balloon time for primary percutaneous coronary intervention (PCI) has been shown to decrease mortality in a linear fashion. 1 3 PCI is the preferred method of reperfusion if it can be performed in a timely manner at high-volume centers. 4 7 Yet, only 25% of US hospitals have PCI capability. Both the American College of Cardiology/American Heart Association (ACC/AHA) and the European Society of Cardiology (ESC) guidelines currently recommend a door-to-balloon time of 90 minutes for primary PCI, although the ECS guidelines extend this to 120 minutes for transferred patients. 5,6 Clinical Perspective on p 1644 The mortality benefit achieved with primary PCI in STEMI patients is diminished by treatment delays. 8,9 It is therefore imperative to develop strategies that both increase access to primary PCI and improve door-to-balloon times The ACC launched the D2B Alliance 14 to improve time to treatment in PCI hospitals, and the AHA established Mission: Lifeline 15 to develop STEMI systems of care that will improve timely access to PCI. The Joint Commission includes door-to-balloon times as a core quality assurance measure. 16 Although transfer patients are currently excluded from this metric, the ACC/AHA 2008 performance measures recommend that they be included. 17 Although randomized trials comparing patients transferred for PCI with onsite fibrinolysis favor PCI, transport and reperfusion times were shorter than what are often achieved in routine practice. 18,19 A recent matched cohort suggests that the mortality benefit of PCI over fibrinolysis diminishes as the door-to-balloon time increases and is negated once the Continuing medical education (CME) credit is available for this article. Go to to take the quiz. Received November 9, 2009; accepted August 10, From the Minneapolis Heart Institute Foundation at Abbott Northwestern Hospital, Minneapolis, MN (M.D.M., M.C.N., S.D., R.F.G., C.B.H., D.M.L., S.M., Y.L.W., D.L.L., T.D.H.); University of Minnesota Cardiovascular Disease Division, Minneapolis (M.D.M., T.D.H.); Division of Epidemiology and Community Health, University of Minnesota, Minneapolis (S.D.); and Ridgeview Medical Center, Waconia, MN (D.M.L.). Correspondence to Timothy D. Henry, MD, Minneapolis Heart Institute Foundation, 920 E 28th St, Ste 100, Minneapolis, MN henry003@umn.edu 2011 American Heart Association, Inc. Circulation is available at DOI: /CIRCULATIONAHA Downloaded from at AZIENDA 1636 ULSS 20 DI VERONA on October 28, 2011

3 Miedema et al Delays in Patients Transferred for PCI 1637 door-to-balloon exceeds the door-to-needle time by 107 minutes. 20 Regional STEMI treatment systems using standardized transfer protocols have been shown to improve treatment times Despite these recent initiatives, disparities between guidelines and clinical performance persist. Door-to-balloon times have improved at PCI centers, but fewer than half of STEMI patients undergo PCI within the recommended 90-minute time frame. 25 Time to treatment in patients who require interhospital transfer for PCI remains an even greater challenge, with 10% of patients treated within 90 minutes and only 15% to 35% treated within 120 minutes. 26,27 Despite the increased focus on delays in STEMI care, no published data exist on the reason for delays in an established regional STEMI system. The purpose of this study was to determine the frequency, magnitude, and clinical impact of specific delays in a standardized regional system designed for the rapid transfer of STEMI patients for primary PCI in a real-world population. Methods The Minneapolis Heart Institute level 1 MI program is a regional transfer system using a standardized protocol designed to improve time to treatment and clinical outcomes in patients with STEMI presenting to community hospitals without PCI capability. The system design and initial results have previously been published. 22,28 Briefly, the diagnosis of STEMI was made by the emergency department physician at the referral hospital, and a single phone call activated the system. Thirty-one hospitals without onsite cardiology consultation participated, including 11 hospitals within 60 miles of the PCI center (designated zone 1) and 20 hospitals (zone 2) between 60 and 210 miles away. Standardized protocols and a predetermined transfer plan (ambulance or helicopter on the basis of locations and availability) were implemented for each site. Transferred patients bypass the PCI center emergency department and proceed directly to the catheterization laboratory. Patients were enrolled in a comprehensive, prospective database and followed up for 5 years. Inclusion criterion for the prospective registry was STEMI or new left bundle-branch block in patients with chest pain of 24 hours duration. There were no exclusions; thus, the registry includes patients with out-of-hospital cardiac arrest, cardiogenic shock, elderly patients, and patients with an initially nondiagnostic 12-lead ECG. Each patient s total door-to-balloon time (arrival at referral hospital to balloon at PCI center) was divided into 3 segments: referral hospital door-in to door-out time, transport time, and PCI center door-to-balloon time. A goal was initially established for hospitals in zone 1, setting a target time of 30 minutes at the referral hospital, 30 minutes for transport, and 30 minutes at the PCI center, for a total door-to-balloon time of 90 minutes. It became evident early in the evaluation period that a 30-minute goal was not realistic for the majority of patients at the referral hospitals. This was due largely to delays in time required for ground transport or in waiting for air transport, with an average of a 20- to 25-minute period from contacting air transport to the arrival of the helicopter. Given these unavoidable delays and the ESC guidelines, a goal was established, with a targeted total door-to-balloon time of 120 minutes for both zones 1 and 2. Detailed time data were recorded for each individual patient. Each patient s case was independently reviewed with a reason for delay recorded for each segment. If multiple sources of delay occurred within a single segment, the delay of the greatest magnitude was recorded. Referral hospital door-in to door-out delays ( 45 minutes) were categorized into 1 of 6 categories: nondiagnostic ECG, diagnostic dilemma, emergency department delay, cardiogenic shock and/or cardiac arrest, awaiting transport, and other. A delay resulting from nondiagnostic ECG was documented if the patient s initial ECG was nondiagnostic, with a subsequent ECG revealing a STEMI. A delay resulting from a diagnostic dilemma was coded for a patient with symptoms atypical for STEMI or if the emergency department physician investigated diagnoses other than STEMI, eg, a patient with back pain and ST-segment elevation who required a computed tomography scan to rule out aortic dissection before starting anticoagulation. An emergency department delay was documented if an EKG was not obtained, interpreted, and a call placed to activate the system within 15 minutes of the patient s arrival without other cause for delay. Delays caused by cardiac arrest and cardiogenic shock were placed in a single category because they frequently coexisted and represented similar high-risk patients. Cardiogenic shock was defined on the basis of definitions in the Should We Emergently Revascularize Occluded Coronaries for Cardiogenic Shock (SHOCK) trial. 29 For both cardiogenic shock and cardiac arrest, the location of onset was determined (prehospital, referral hospital, transport, PCI center). Delays awaiting transport were documented if 30 minutes elapsed from the time of the call to transport to the patient s departure from the referral hospital. The other category included patients with delays that did not fit into these definitions. Transport delays ( 45 minutes) were divided into 4 categories: weather, distance, traffic, and other. Distance delays were documented if the distance to be covered during transport was too great for the mode of transportation available ( 40 miles for ground transport and 125 miles for air transport). PCI center door-to-balloon delays ( 30 minutes) were separated into 5 categories: catheterization laboratory team delay, complex procedure, cardiogenic shock/cardiac arrest in the catheterization laboratory, diagnostic dilemma, and other. A catheterization laboratory team delay was considered if the PCI procedure did not begin within 15 minutes of the patient s arrival to the PCI hospital. A complex procedure was identified by reviewing the procedure note and laboratory log and identifying factors such as difficulty achieving vascular access or addressing the culprit lesion. Diagnostic dilemma was coded if the cardiologist felt that additional workup was warranted before proceeding with the procedure. For example, this category was selected if a patient with chest pain and subtle ST-elevation but no cardiac risk factors and recent unilateral leg swelling was sent for a computed tomography angiogram to rule out pulmonary emboli before angiography. Descriptive statistics are displayed as means and SDs for continuous variables; number and percentage with characteristic are given for categorical variables. When continuous variables had skewed distributions (delay times), data are summarized with medians and 25th and 75th percentiles. We used 2 or Fisher exact tests to compare inhospital, 30-day, and 1-year mortality in those with balloon times 120 minutes and those with times 120 minutes. A value of P 0.05 was considered significant, and 95% confidence intervals (CIs) were generated. All statistical calculations and plots were done with Stata 11.1 (College Station, TX). Institutional Review Board approval was obtained for data collection, follow-up, and data analysis. Results From March 2003 to December 2009, 2034 patients were transferred for PCI, including 1195 patients in zone 1 and 839 patients in zone 2 (Figure 1). At the referring hospital, 6 patients were excluded from the analyses: 5 patients who had unverifiable times and 1 patient who died in the emergency department. Seven patients were excluded from the transport analyses: 6 patients who had unverifiable times and 1 patient who died before transport. In the PCI center analysis, 21 patients were excluded: 3 who had unverifiable delays, 12 who died before the procedure, and 6 who did not undergo angiography. The distributions of total door-to-balloon times are shown in Figure 2A (zone 1) and 2B (zone 2) using the goal of 120 minutes as recommended by ESC guidelines. In zone 1, 43% of patients had total door-to-balloon times of 90 minutes, and 79% were treated in 120 minutes. In

4 1638 Circulation October 11, 2011 Figure 1. Flow chart of the number of patients in the study. PCI indicates percutaneous coronary intervention; ED, emergency department. zone 2, 12% and 47% were treated in 90 and 120 minutes, respectively. Overall in-hospital, 30-day, and 1-year mortality rates for all patients were 5.4%, 6.1%, and 9.9%, respectively. Compared with patients treated in 120 minutes, patients whose total door-to-balloon time was 120 minutes had increased in-hospital mortality (6.4% [95% CI, ] versus 4.1% [95% CI, ]; P 0.023) but only a trend at day 30 (6.8% [95% CI, ] versus 4.9% [95% CI ]; P 0.078) and no statistically significant difference at 1 year (10.2%; [95% CI, ] versus 8.8% [95% CI ]; P 0.29). The clinical characteristics of the patients treated in 120 minutes compared with 120 minutes are shown in Table 1. Older patients, diabetics, nonsmokers, and patients with cardiogenic shock were more likely to have delays. A summary of the median times for each delay at the 3 treatment segments is shown in Figure 3. Referral Hospital Door-in to Door-out Delays The distributions of door-in to door-out treatment times at the referral hospital are shown in Figure 4. The median door-in to door-out time was 54 minutes (25th and 75th percentiles, minutes) and was shorter in zone 1 (48 minutes; minutes) compared with zone 2 (61 minutes; minutes). Of the 2028 patients analyzed, 1298 (64.0%) had a delay (door-in to door-out 45 minutes). The frequency, magnitude, in-hospital mortality, and peak creatine kinase-mb for each specific type of delay are shown in Table 2. The most common reasons for delay at the referral hospital were awaiting transport (n 535, 26.4% of total patients; 41.2% of delays) and emergency department delay (n 289, 14.3% of total patients; 22.3% of delays). The longest delays occurred among patients with diagnostic dilemma (95.5 minutes; minutes) and nondiagnostic initial ECG (81 minutes; minutes). In-hospital mortality associated with individual delays was highest in patients with cardiogenic shock and/or cardiac arrest (34 of 111, 30.6%) and lowest in patients with initially nondiagnostic ECGs (0 of 181, 0%). Of the 34 patients who died with a delay from cardiogenic shock and/or cardiac arrest, 33 (97.1%) developed the cardiac complication before or within 30 minutes of their arrival to the referral hospital. One of the 2 patients categorized as other suffered from a fear of flying and had to Figure 2. Distribution of total door-to-balloon times in zones 1 (A) and 2(B). Goal door-to-balloon time was 120 minutes (dashed line). Median door-to-balloon time was 94 minutes in zone 1 (solid line) and 123 minutes in zone 2 (solid line). Eighteen patients had door-toballoon times 240 minutes in zone 1. Thirty-five patients had door-to-balloon times 240 minutes in zone 2.

5 Miedema et al Delays in Patients Transferred for PCI 1639 Table 1. Baseline Characteristics in Patients With Delays <120 and >120 Minutes Delay 120 min (n 1324) Delay 120 min (n 691) P Age, mean (SD), y 61.3 (14.1) 64.0 (14.4) Male, % Hypertension, % Diabetes mellitus, % Dyslipidemia, % Current smoker, % Family history of coronary artery disease, % Prior myocardial infarction, % Prior percutaneous coronary intervention, % Prior coronary artery bypass graft, % Left bundle-branch block, % Out-of-hospital cardiac arrest, % Cardiogenic shock, % Before PCI After PCI PCI indicates percutaneous coronary intervention. be reassigned to ground transport; the other patient initially refused transport but later agreed to being transferred. Transport Delays The distributions of transfer times for patients during the transport segment are shown in Figure 5A and 5B. Overall, 255 patients (12.6%) experienced a delay; 33 patients (2.8%) in zone 1 and 222 patients (26.6%) in zone 2 had transport times 45 minutes. The frequency, magnitude, in-hospital mortality, and peak creatine kinase-mb for each specific type of delay are shown in Table 3. The most common reason for delay in Zone 1 was weather (n 23, 1.9% of zone 1 patients; 69.7% of zone 1 transport delays). The longest zone 1 delays were due to distance (54 minutes; minutes). The most common reason for delay in zone 2 was distance (n 175, 21.0% of zone 2 patients; 78.8% of zone 2 transport delays). The longest zone 2 delays were due to weather (77 minutes; minutes). There were no traffic delays in zone 1 or 2. Mortality for patients with transport delays was similar to that for patients without delays. Delays categorized as other were due to the helicopter being unavailable and helicopter breakdown. PCI Center Door-to-Balloon Delays The distribution of door-to-balloon times at the PCI center is shown in Figure 6. Door-to-balloon delays 30 minutes occurred in only 317 patients (15.7%). The frequency, magnitude, in-hospital mortality, and peak creatine kinase-mb for each specific type of delay are shown in Table 4. The most common reason for delay included catheterization laboratory team delay (n 143, 7.1% of PCI center patients; 45.1% of PCI center delays) and complex procedure (n 117, 5.8% of PCI center patients; 36.9% of PCI center delays). The longest delay occurred in patients with diagnostic dilemmas (92.5 minutes; minutes). The highest mortality was seen in patients with cardiogenic shock and/or cardiac arrest (19 of 43, 44.2%). Of the 19 patients who died with a delay resulting from cardiogenic shock and/or cardiac arrest, 13 (68.4%) developed the complication before or within 30 minutes of arrival to the referral hospital, and 3 (15.8%) developed the complication during transport (within 90 minutes from arrival at the referral hospital). Discussion This is the first description of the frequency and magnitude of treatment delays in a regional STEMI system of transfer for primary PCI. An understanding of the specific reasons for delay is essential to continued improvement treatment times among transfer patients. Prolonged door-to-balloon times in STEMI patients undergoing PCI are associated with increased mortality, 3 especially in high-risk groups. 29 Data from observational registries have Figure 3. Median times for individual delays at each of the 3 treatment segments. PCI indicates percutaneous coronary intervention; ED, emergency department.

6 1640 Circulation October 11, 2011 Figure 4. Distribution of door-in to door-out times at the referral hospital. Goal door-in to door-out time was 45 minutes (dashed line) and median time was 54 minutes (solid line). Twenty-two patients had door-in to door-out times 240 minutes. shown that it has been difficult to achieve recommended door-to-balloon times of 90 minutes. 25 This is especially true for STEMI patients who are transferred for PCI. For example, Nallamothu et al 26 reported times to treatment in transferred STEMI patients from the National Registry of Myocardial Infarction and found the national average to be 180 minutes, with more than one quarter of the patients treated in 240 minutes. The ACC National Cardiovascular Data Registry data from 2005 and 2006 indicate that only 36.3% of patients were treated in 120 minutes. 27 In contrast, our results demonstrated that two thirds of patients were treated in 120 minutes, and that only 165 patients (8.2%) exceeded total door-to-balloon times of 180 minutes. Although these treatment times represent an improvement compared with previously published national averages, delays still occurred frequently. Recently published data from Denmark, a small country with an organized transfer system, indicate that 65% of transferred patients still had a system delay (time from emergency medical services contact to primary PCI) of 120 minutes. 30 The most frequent source of delays occurred at the referral hospital, where just over one quarter of the patients had a delay awaiting transport. The majority of these delays were of low magnitude (median, 14 minutes above goal), and were associated with a relatively low in-hospital mortality (3.9%). Standardizing transfer protocols, increasing the availability of transport vehicles, and implementing prehospital notification at referral hospitals may lead to earlier dispatching of transport services and improvements in treatment times. Emergency department delays were the second-mostcommon cause for delay at the referral hospital, and may be improved with continued clinical systems improvement and feedback/quality improvement. Patients with an initially nondiagnostic ECG had the second-longest delays. This delay is best addressed by serial ECGs. Although labeled as having a delay, many of these patients actually had an appropriate time from the diagnostic ECG to balloon inflation. In addition, the lower peak creatine kinase-mb seen in this group suggests that they represent a low-risk patient population in which prolonged treatment times may be less important. In fact, of the 182 patients with delay resulting from an initially nondiagnostic ECG, there were no in-hospital deaths. The importance of door-in to door-out time at referral hospitals was recently demonstrated in an analysis of the Acute Coronary Treatment and Intervention Outcomes Network (ACTION) Registry Get With the Guidelines. 31 The study included STEMI patients transferred for primary PCI from 2007 to 2010 and revealed only 11% of Table 2. Frequency, Magnitude, and Mortality Associations of Specific Delays at the Referral Hospital: Referring Hospital Door-in to Door-out Delays Patients, n (%) Magnitude (min), Median (25th 75th Percentile) In-Hospital 1-Year Peak CK, Median (25th 75th Percentile), U/L No delay ( 45 min) 730 (36.0) 35 (28 41) ( ) Awaiting transport 535 (26.4) 59 (51 72) ( ) ED delay 289 (14.3) 65.5 ( ) ( ) Nondiagnostic ECG 184 (9.1) 81 ( ) ( ) Diagnostic dilemma 177 (8.7) 95.5 (72 127) ( ) Cardiac arrest/shock 111 (5.5) 68 (56 86) ( ) Other 2 (0.1) 60.5 (58 63) Total 2028 CK indicates creatine kinase; ED, emergency department.

7 Miedema et al Delays in Patients Transferred for PCI 1641 Figure 5. Distribution of treatment times during transport in zones 1 (A) and2(b). Goal transport time was 45 minutes in zone 1 (dashed line) and in zone 2 (dashed line). Median transport time was 22 minutes in zone 1 (solid line) and 35 minutes in zone 2 (solid line). patients in the United States had a door-in to door-out time of 30 minutes. Patients with a door-in to door-out time of 30 minutes had increased mortality compared with those treated in 30 minutes. The median door-in to door-out time in this registry was 68 minutes ( minutes). In comparison, our median door-in to door-out time was shorter (54 minutes; minutes), especially in zone 1 (48 minutes; minutes), where patients receive primary PCI similar to those studied in the ACTION registry. Our data indicate that not only the delay but also the specific reason for delay and the magnitude affect mortality. Finally, with a median transport time of 25 minutes and a median PCI center time of 20 minutes, the majority of our patients with short referral hospital (door-in to door out) delays were still treated in 120 minutes. This reflects the benefit of a regional STEMI system using standardized protocols and transfer processes. The transport segment was the least common source of delays. Distance from the PCI center was the most frequent cause of delay, which, for air transfer, will be difficult to improve. The ideal way to improve these times may be to develop a national system of regional STEMI care centers of excellence to limit transfer distances. 11,12,32 Delays resulting from distance in patients transferred by ground could potentially be improved with greater use of helicopter transport. However, switching to air ambulance transfer for hospitals within close range of the PCI center should be considered cautiously, especially if ground transport is on site or in close proximity to the referral hospital. Although transfer times may be shortened with air transport, they may be at least partially offset by an extended time at the referring hospital awaiting arrival of air transport, and the cost-effectiveness of ground versus air transport needs to be considered. 33 The optimal mode of transport for each referral center should be predetermined on the basis of availability of ground and air transport, distance from PCI center, weather, and traffic patterns. At the PCI center, the majority of patients were treated within the 30-minute goal, reflecting preactivation of the catheterization laboratory team before the patient s arrival. Catheterization laboratory team delays and complex procedures were the most common reasons for delay at the PCI center and were both infrequent and of relatively short magnitude. The data presented are observational, so drawing conclusions about the clinical outcomes associated with individual delays should be done cautiously. However, as would be expected, delay resulting from cardiogenic shock/cardiac arrest was associated with the highest mortality. Current guidelines recommend PCI as the reperfusion method of choice in patients with cardiogenic shock. 5,6,34 In the majority Table 3. Frequency, Magnitude, and Mortality Associations of Specific Delays During Transport Patients, n (%) Magnitude (min), Median (25th 75th Percentile) Zone 1 Zone 2 In-Hospital 1-Year Peak CK, Median (25th 75th Percentile), U/L Patients, n (%) Magnitude (min), Median (25th 75th Percentile) In-Hospital 1-Year Peak CK, Median (25th 75th Percentile), U/L No delay 1160 (97.2) 22 (16 31) ( ) 612 (73.4) 29 (25 37) ( ) ( 45 min) Weather 23 (1.9) 52.5 (50 61) ( ) 45 (5.4) 77 (63 110) ( ) Distance 10 (0.8) 54 (52 58) ( ) 175 (21.0) 55.5 (51 63) ( ) Traffic Other (0.2) 61 (53 69) Total CK indicates creatine kinase.

8 1642 Circulation October 11, 2011 Figure 6. Distribution of treatment times at the percutaneous coronary intervention (PCI) center. Goal door-to-balloon time was 30 minutes (dashed line) and median door-to-balloon time was 20 minutes (solid line). ED indicates emergency department. of these patients, the critical nature of the patients condition at presentation led to the delay intubation, cardiopulmonary resuscitation, multiple shocks, and stabilization. Of the 53 patients in this study who died with a delay caused by cardiogenic shock or cardiac arrest, 46 patients (86.8%) developed the complication before or within 30 minutes of presentation, suggesting that only 7 patients potentially suffered the complication as a result of the delay itself. Only one quarter of the hospitals in the United States have PCI capability; therefore, the development of regional STEMI systems that include the transfer of patients from non-pci centers is a key strategy to improve timely access to PCI. 24 Although prehospital triage to PCI centers is another approach to increase timely access to PCI, only 50% of patients use emergency medical service; therefore, even in metropolitan areas, predetermined arrangements for transfer to a PCI center are important. The Joint Commission uses a door-to-balloon time of 90 minutes as a core measure, but currently transferred patients are excluded. Recently, the ACC/AHA Task Force on Performance Resources recommended that door-in/door-out times and first-door-to-pci times be included. 16,17 The ACC/AHA Task Force acknowledged that a total door-to-balloon time of 90 minutes for transferred STEMI patients may be difficult to achieve consistently. Although fibrinolytic therapy could be considered for patients who may not achieve targeted treatment times, many of these patients (including those with cardiogenic shock and cardiac arrest) may have contraindications to fibrinolytics. Healthcare systems may be hesitant to implement transfer for primary PCI in STEMI patients for fear of noncompliance with guidelines and future ramifications in terms of pay for performance. The ESC guidelines have recently adopted a goal for total door-to-balloon time of 120 minutes for transferred STEMI patients. 6 Our results would support this change and suggest that the cause of the delay may be more important than the actual length of delay. More than one third of the deaths from the entire cohort occurred in patients who developed cardiogenic shock and/or cardiac arrest before PCI. The vast majority of patients developed this complication before or shortly after their arrival to the referral hospital, indicating that the cardiac complication led to the delay rather than the delay contributing to the complication. The most recent update of the ACC/AHA guidelines for care of STEMI patients has acknowledged the inability to avoid delays in certain patients, stating some patients have clinically relevant non system-based delays that do not represent qualityof-care issues. 5 Study Limitations The study occurred within a single region with an established regional STEMI system and use of a pharmaco-invasive Table 4. Frequency, Magnitude, and Mortality Associations of Specific Delays at the Percutaneous Coronary Intervention Center: Door-to-Balloon Delays Patients, n (%) Magnitude (min), Median (25th 75th Percentile) In-Hospital 1 Year Peak CK, Median (25th 75th Percentile), U/L No delay ( 30 min) 1696 (84.3) 19 (15 23) ( ) Catheterization laboratory 143 (7.1) 38 (34 50) ( ) team delay Complex procedure 117 (5.8) 38 (34 45) ( ) Cardiac arrest/shock 43 (2.1) 41 (35 46) ( ) Diagnostic dilemma 14 (0.7) 92.5 (59 131) ( ) Total 2013 CK indicates creatine kinase.

9 Miedema et al Delays in Patients Transferred for PCI 1643 approach for patients transferred long distances (zone 2) and therefore may not be generally applicable to all regions. Although the individual segment delays recorded were arbitrary, they were based on an attempt to meet current treatment guidelines at the time of the program s initiation. Finally, the data presented are observational and nonrandomized. Assuming a direct cause-and-effect relationship for outcomes and each specific delay should be done cautiously. However, data from prospective registries have distinct advantages, including analysis of a higher-risk, real-world patient population not included in randomized trials. 35,36 Conclusion The development of a regional STEMI system that includes transfer of patients from non-pci centers is an important strategy to improve timely access to primary PCI. Our data indicate that clinical outcomes vary significantly according to the reason for the delay, and that not all delays are STEMI system dependent. These results have important implications for the design of regional STEMI systems, the inclusion of transferred STEMI patients in core measures, and potentially the current AHA/ACC guidelines. Sources of Funding This research was supported by the Minneapolis Heart Institute Foundation. None. Disclosures References 1. Goldberg RJ, Mooradd M, Gurwitz JH, Rogers WJ, French WJ, Barron HV, Gore JM. Impact of time to treatment with tissue plasminogen activator on morbidity and mortality follow acute myocardial infarction (the Second National Registry of Myocardial Infarction). Am J Cardiol. 1998;82: Cannon CP, Gibson CM, Lambrew CT, Shoultz DA, Levy D, French WJ, Gore JM, Weaver WD, Rogers WJ, Tiefenbrunn AJ. 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JAMA. 2010;303: CLINICAL PERSPECTIVE Regional ST-segment elevation myocardial infarction systems are being developed to improve timely access to primary percutaneous coronary intervention (PCI). System delays may diminish the mortality benefit achieved with primary PCI in ST-segment elevation myocardial infarction patients, but the specific reasons for and clinical impact of delays in patients transferred for PCI are unknown. We report the frequency, magnitude, and clinical impact of specific delays that occur at the referral hospital, during transport, and at the PCI hospital for 2034 patients transferred for PCI in a regional ST-segment elevation myocardial infarction system. Despite the use of evidence-based strategies to improve treatment times, delays still occurred frequently within the ST-segment elevation myocardial infarction system. Delays occurred most frequently at the referral hospital, and were most often due to awaiting transport and emergency department delays. Delays occurred less frequently during transport or at the PCI center. Diagnostic dilemmas and nondiagnostic initial ECGs led to delays of the greatest magnitude but had limited or no impact on mortality. Delays caused by out-of-hospital cardiac arrest and/or cardiogenic shock had the highest impact on in-hospital mortality. In these high-risk patients, the delay rarely led to the cardiac arrest or cardiogenic shock; instead, the critical nature of the patient s illness resulted in the delay. These results have implications for the design of regional ST-segment elevation myocardial infarction systems and may affect the current American College of Cardiology/American Heart Association guidelines for time to treatment in transferred patients. Go to to take the CME quiz for this article.