Implementation of Specialty Centers for Patients with ST-Segment Elevation Myocardial Infarction

Background. Early percutaneous coronary intervention (PCI) has been shown to be superior to fibrinolytic therapy andis associated with reduced morbidity andmortality for patients with ST-segment elevation myocardial infarction (STEMI). Objective. To determine the performance of a regional system with prehospital 12-lead electrocardiogram (ECG) identification of STEMI patients anddirect paramedic transport to STEMI receiving centers (SRCs) for provision of primary PCI. Methods. This was a prospective study evaluating the first year of implementation of a regional SRC network to determine the key time intervals for patients identified with STEMI in the prehospital setting. Results. During the 12-month study period, 1,220 patients with a suspected STEMI were identified on prehospital 12-lead ECG, of whom 734 (60%) underwent emergency PCI. A door-to-balloon time of 90 minutes or less was achieved for 651 (89%) patients, and459 (62.5%) had EMS–patient contact-to-balloon times ≤ 90 minutes. Transport of suspected STEMI patients to an SRC resulted in ambulance diversion from a closer ED for 31% of patients anda median increase in transport time of 3.8 minutes. Conclusion. Door-to-balloon times within the 90-minute benchmark were achieved for almost 90% of STEMI patients transported by paramedics after implementing our regionalized SRC system     

Detection of STEMI Using Prehospital Serial 12-Lead Electrocardiograms

Objective: Repeated or serial 12-lead electrocardiograms (ECGs) in the prehospital setting may improve management of patients with subtle ST-segment elevation (STE) or with a ST-segment elevation myocardial infarction (STEMI) that evolves over time. However, there is a minimal amount of scientific evidence available to support the clinical utility of this method. Our objective was to evaluate the use of serial 12-lead ECGs to detect STEMI in patients during transport in a Canadian emergency medical services (EMS) jurisdiction. Methods: We performed a retrospective study of suspected STEMI patients transported by EMS in the Chaudière-Appalaches region (Québec, Canada) between August 2006 and December 2013. Patients were monitored by a serial 12-lead ECG system where an averaged ECG was transmitted every 2 minutes. Following review by an emergency physician, ECGs were grouped as having either a persistent STE or a dynamic STE that evolved over time. Results: A total of 754 suspected STEMI patients were transported by EMS during the study period. Of these, 728 patients met eligibility criteria and were included in the analysis. A persistent STE was observed in 84.3% (614/728) of patients, while the remaining 15.7% (114/728) had a dynamic STE. Among those with dynamic STE, 11.1% (81/728) had 1 ST-segment change (41 no-STEMI to STEMI; 40 STEMI to no-STEMI) and 4.5% (33/728) had ≥ 2 ST-segment changes (17 no-STEMI to STEMI; 16 STEMI to no-STEMI). Overall, in 8.0% (58/728) of the cohort, STEMI was identified on a subsequent ECG following an initial no-STEMI ECG. Conclusions: Through recognition of transient ST-segment changes during transport via the prehospital serial 12-lead ECG system, STEMI was identified in 8% of suspected STEMI patients who had an initial no-STEMI ECG.     

Cellular technology improves transmission success of pre-hospital electrocardiograms

Study objectiveIn rural settings, long distances and transport times pose a challenge for achieving early reperfusion goals in patients with ST-elevation myocardial infarction (STEMI). This study investigated the association between the method of pre-hospital 12-lead ECG transmission (radio transmission vs. cellular phone transmission) and the success of transmission and legibility of 12-lead ECGs in a rural setting.MethodsObservational study of pre-hospital 12-lead ECG transmission to the emergency department (ED) in a predominantly rural area. Success of transmission and the legibility of the 12-lead ECG were analyzed to identify barriers to 12-lead ECG transmission and reasons for failed transmission.ResultsEmergency medical services performed ECGs on 1140 patients, 917 of which they attempted to transmit, including 43 cases requiring emergent catheterization. Twelve-lead ECG transmission was successful in 236 (70%) of 337 radio attempts and 441 (76%) of 580 cellular attempts (difference 6.0%, 95% CI 1.1-12.1). Legibility increased from 164 (49%) of 337 radio attempts to 389 (67%) of 580 cellular attempts (difference 18.4%, 95% CI 11.8–24.9).ConclusionThe success of transmission and legibility of 12-lead ECGs was significantly higher with cellular technology by emergency medical service agencies in comparison to radio transmission. In rural settings with lengthy transport times, utilization of cellular technology for transmission of pre-hospital 12-lead ECGs may improve door-to-balloon times for STEMI patients.     

L ACERATIONS AND A CUTE W OUNDS,AN E VIDENCE -B ASED G UIDE

Abstract

Introduction. Few systems worldwide have achieved the benchmark time of less than 90 minutes from emergency medical services (EMS) contact to balloon inflation (E2B) for patients sustaining ST-segment elevation myocardial infarction (STEMI). We describe a successful EMS systems approach using a combination of paramedic and 12-lead electrocardiogram (ECG) software interpretation to activate a STEMI bypass protocol. Objectives. To determine the proportion of patients who met the benchmark of E2B in less than 90 minutes after institution of a regional paramedic activated STEMI bypass to primary PCI protocol. Methods. We conducted a before-and-after observational cohort study over a 24-month period ending December 31, 2009. Included were all patients diagnosed with STEMI by paramedics trained in ECG acquisition and interpretation and transported by EMS. In the “before” phase of the study, paramedics gave emergency departments (EDs) advance notification of the arrival of STEMI patients and took the patients to the ED of the PCI center. In the “after” phase of the study, paramedics activated a STEMI bypass protocol in which STEMI patients were transported directly to the PCI suite, bypassing the local hospital EDs. Transmission of ECGs did not occur in either phase of the study. Results. We compared the times for 95 STEMI patients in the before phase with the times for 80 STEMI patients in the after phase. The proportion for whom E2B was less than 90 minutes increased from 28.4% before to 91.3% after (p < 0.001). Median E2B time decreased from 107 minutes (interquartile range [IQR] = 30) before to 70 minutes (IQR = 24) after. Median D2B time decreased from 83 minutes (IQR = 34) before to 35 minutes (IQR = 19) after. Median E2D time increased from 21 minutes (IQR = 8) before to 32 minutes (IQR = 17) after. Median differences between phases were significant at p < 0.001. The rate of false-positive PCI laboratory activation during the after phase of the study was 12.4%. Conclusions. The proportion of patients with E2B times less than 90 minutes significantly improved through the implementation of a paramedic-activated STEMI bypass protocol. Further study is required to determine whether these benefits are reproducible in other EMS systems.     

The Positive Predictive Value of Paramedic Versus Emergency Physician Interpretation of the Prehospital 12-Lead Electrocardiogram

Background. Obtaining a prehospital 12-lead ECG may improve triage andexpedite care of patients with acute myocardial infarction (AMI). Whether the ECG should undergo physician review prior to activation of a percutaneous intervention (PCI) team is unclear. Objective. To document the positive predictive value (PPV) of the prehospital 12-lead ECG when interpreted by paramedics versus emergency physicians. Methods. This was a prospective, observational study. In November 2003, our local health care andemergency medical services (EMS) systems implemented a prehospital “cardiac alert” program in which patients suspected of having ST-elevation myocardial infarction (STEMI) based on the prehospital 12-lead ECG were diverted away from receiving facilities without emergent PCI capability andthe PCI team was mobilized. For the first year, a cardiac alert was activated by paramedics (Phase I). After the first year, the ECG was transmitted to the ED, with the emergency physician (EP) responsible for activation (Phase II). The PPV for cardiac alerts in Phases I andII were compared by using three different “gold standards”: cardiologist interpretation of the prehospital 12-lead ECG, disposition to emergent PCI, andcoronary lesions on angiography or arrest prior to emergent PCI. Results. A total of 110 patients were enrolled (54 in Phase I, 56 in Phase II). Cardiologist confirmation of a STEMI on the prehospital 12-lead EKG was 42/54 (78%) in Phase I and54/56 (96%) in Phase II. Disposition to emergent PCI occurred in 38/54 (70%) Phase I patients and51/56 (91%) Phase II patients. Lesions at catheterization or arrest prior to emergent PCI were observed in 41/54 (69%) of Phase I patients and50/56 (89%) of Phase II patients. All of these comparisons achieved statistical significance (p < 0.01). Conclusions. Transmission to the ED for EP interpretation improves the PPV of the prehospital 12-lead ECG for triage andtherapeutic decision-making.     

Accuracy of Paramedic Broselow Tape Use in the Prehospital Setting

Introduction. Previous literature has documented that prehospital 12-lead electrocardiography (ECG) decreases the time to reperfusion in patients with an acute ST-segment elevation myocardial infarction (STEMI). Objective. To compare time to ECG, time to angioplasty suite (laboratory), andtime to reperfusion in emergency medical services (EMS) STEMI patients, who received care through three different processes. Methods. The setting was a large suburban community teaching hospital with emergency department (ED)-initiated single-page acute myocardial infarction (AMI) team activation for STEMI patients. The population was STEMI patients transported by EMS from January 2003 to October 2005. Not all EMS agencies had prehospital 12-lead ECG capability. Paramedics interpret andverbally report clinical assessment andECG findings via radio. The AMI team is activated at the discretion of the emergency physician 1) before patient arrival to the ED based on EMS assessment, 2) after ED evaluation with EMS ECG, or 3) after ED evaluation andED ECG. Time intervals were calculated from ED arrival. To assess the impact of interventions on performance targets, we also report the proportion of patients who arrived in laboratory within 60 minutes andreperfusion within 90 minutes of arrival. Parametric andnonparametric statistics are used for analysis. Results. During the study period, there were 164 STEMI patients transported by EMS; mean age was 66.1 years, and56% were male. Of these, 93 (56.7%) had an EMS ECG and31 (33%) had AMI team activation before ED arrival. Mean time to laboratory for all patients was 49.8 ± 34.4 minutes andtime to reperfusion was 93.2 +/? 34.5 min. Patients with prearrival activation were transported to laboratory sooner (mean, 24.3 vs. 53. 4 minutes; p < 0.001) andreceived reperfusion sooner than all other patients (mean, 70.4 vs. 96.3 minutes; p = 0.007). More prearrival activation patients met performance targets to laboratory (96.7% vs. 73.7%; p = 0.009) andreperfusion (85.2% vs. 51.0%; p = 0.003). There was no difference in time to laboratory or to reperfusion for patients who received EMS ECG but no prearrival activation compared with those who received EMS transport alone. Conclusions. A minority of patients with EMS ECGs had prearrival AMI team activation. EMS ECGs combined with systems that activate hospital resources, but not EMS ECGs alone, decrease time to laboratory andreperfusion.     

The Role of Prehospital Electrocardiograms in the Recognition of ST-Segment Elevation Myocardial Infarctions and Reperfusion Times

Background

Clinical outcomes in ST-segment elevation myocardial infarction (STEMI) are related to reperfusion times. Given the benefit of early recognition of STEMI and resulting ability to decrease reperfusion times and improve mortality, current prehospital recommendations are to obtain electrocardiograms (ECGs) in patients with concern for acute coronary syndrome.

Objectives

We sought to determine the effect of wireless transmission of prehospital ECGs on STEMI recognition and reperfusion times. We hypothesized decreased reperfusion times in patients in whom prehospital ECGs were obtained.

Methods

We conducted a retrospective, observational study of patients who presented to our suburban, tertiary care, teaching hospital emergency department with STEMI on a prehospital ECG.

Results

Ninety-nine patients underwent reperfusion therapy. Patients with prehospital ECGs had a mean time to angioplasty suite of 43 min (95% confidence interval [CI] 31–54). Compared to patients with no prehospital ECG, mean time to angioplasty suite was 49 min (95% CI 41–57), p = 0.035. Patients with prehospital STEMI identification and catheterization laboratory activation had a mean time to angioplasty suite of 33 min (95% CI 25–41), p = 0.007. Patients with prehospital ECGs had a mean door-to-balloon time of 66 min (95% CI 53–79), whereas the control group had a mean door-to-balloon time of 79 min (95% CI 67–90), p = 0.024. Patients with prehospital STEMI identification and catheterization laboratory activation had a mean door-to-balloon time of 58 min (95% CI 48–68), p = 0.018.

Conclusions

Prehospital STEMI identification allows for prompt catheterization laboratory activation, leading to decreased reperfusion times.     

Prehospital Electrocardiographic Computer Identification of ST-segment Elevation Myocardial Infarction

Abstract

Background. Identifying ST-segment elevation myocardial infarctions (STEMIs) in the field can decrease door-to-balloon times. Paramedics may use a computer algorithm to help them interpret prehospital electrocariograms (ECGs). It is unknown how accurately the computer can identify STEMIs.

Objectives. To Determine the sensitivity and specificity of prehospital ECGs in identifying patients with STEMI.

Methods. Retrospective cross-sectional study of 200 prehospital ECGs acquired using Lifepak 12 monitors and transmitted by one of more than 20 emergency medical services (EMS) agencies to the emergency department (ED) of a Summa Akron City Hospital, a level 1 trauma center between January 1, 2007, and February 18, 2010. The ED sees more than 73,000 adult patients and treats 120 STEMIs annually. The laboratory performs 3,400 catheterizations annually. The first 100 patients with a diagnosis of STEMI and cardiac catheterization laboratory activation from the ED were analyzed. For comparison, a control group of 100 other ECGs from patients without a STEMI were randomly selected from our Medtronic database using a random-number generator. For patients with STEMI, an accurate computer interpretation was “acute MI suspected.” Other interpretations were counted as misses. Specificity and sensitivity were calculated with confidence intervals (CIs). The sample size was determined a priori for a 95% CI of ±10%.

Results. Zero control patients were incorrectly labeled “acute MI suspected.” The specificity was 100% (100/100; 95% CI 0.96–1.0), whereas the sensitivity was 58% (58/100; 95% CI 0.48–0.67). This would have resulted in 42 missed cardiac catheterization laboratory activations, but zero inappropriate activations. The most common incorrect interpretation of STEMI ECGs by the computer was “data quality prohibits interpretation,” followed by “abnormal ECG unconfirmed.”

Conclusions. Prehospital computer interpretation is not sensitive for STEMI identification and should not be used as a single method for prehospital activation of the cardiac catheterizing laboratory. Because of its high specificity, it may serve as an adjunct to interpretation.     

Diagnostic accuracy of prehospital electrocardiograms interpreted remotely by emergency physicians in myocardial infarction patients

BackgroundPrehospital 12‑lead electrocardiogram (ECG) is the most widely used screening tool for recognition of ST-segment elevation myocardial infarction (STEMI). However, prehospital diagnosis of STEMI based solely on ECGs can be challenging.ObjectivesTo evaluate the ability of emergency department (ED) physicians to accurately interpret prehospital 12‑lead ECGs from a remote location.MethodsAll suspected prehospital STEMI patients who were transported by EMS and underwent angiography between 2006 and 2014 were included. We reviewed prehospital ECGs and grouped them based on: 1) presence or absence of a culprit artery lesion following angiography; and 2) whether they met the 3rd Universal Definition of Myocardial Infarction. We also described characteristics of ECGs that were misinterpreted by ED physicians.ResultsA total of 625 suspected STEMI cases were reviewed. Following angiography, 94% (590/625) of patients were found having a culprit artery lesion, while 6% (35/625) did not. Among these 35 patients, 24 had ECGs that mimicked STEMI criteria and 9 had non-ischemic signs. Upon ECG reinterpretation, 92% (577/625) had standard STEMI criteria while 8% (48/625) did not. Among these 48 patients, 35 had ischemic signs ECGs and 13 did not. Characteristics of misinterpreted ECGs included pericarditis, early repolarization, STE > 1 mm (1‑lead only), and negative T-wave.ConclusionsRemote interpretation of prehospital 12‑lead ECGs by ED physicians was a useful diagnostic tool in this EMS system. Even if the rate of ECG misinterpretation is low, there is still room for ED physicians operating from a remote location to improve their ability to accurately diagnose STEMI patients.     

Implementation of an All-Day Artificial Intelligence–Based Triage System to Accelerate Door-to-Balloon Times

ObjectiveTo implement an all-day artificial intelligence (AI)–based system to facilitate chest pain triage in the emergency department.MethodsThe AI-based triage system encompasses an AI model combining a convolutional neural network and long short-term memory to detect ST-elevation myocardial infarction (STEMI) on electrocardiography (ECG) and a clinical risk score (ASAP) to prioritize patients for ECG examination. The AI model was developed on 2907 twelve-lead ECGs: 882 STEMI and 2025 non-STEMI ECGs.ResultsBetween November 1, 2019, and October 31, 2020, we enrolled 154 consecutive patients with STEMI: 68 during the AI-based triage period and 86 during the conventional triage period. The mean ± SD door-to-balloon (D2B) time was significantly shortened from 64.5±35.3 minutes to 53.2±12.7 minutes (P=.007), with 98.5% vs 87.2% (P=.009) of D2B times being less than 90 minutes in the AI group vs the conventional group. Among patients with an ASAP score of 3 or higher, the median door-to-ECG time decreased from 30 minutes (interquartile range [IQR], 7?59 minutes) to 6 minutes (IQR, 4?30 minutes) (P<.001). The overall performances of the AI model in identifying STEMI from 21,035 ECGs assessed by accuracy, precision, recall, area under the receiver operating characteristic curve, F1 score, and specificity were 0.997, 0.802, 0.977, 0.999, 0.881, and 0.998, respectively.ConclusionImplementation of an all-day AI-based triage system significantly reduced the D2B time, with a corresponding increase in the percentage of D2B times less than 90 minutes in the emergency department. This system may help minimize preventable delays in D2B times for patients with STEMI undergoing primary percutaneous coronary intervention.     

The Impact of Prehospital 12-Lead Electrocardiograms on Door-to-Balloon Time in Patients With ST-Elevation Myocardial Infarction

Introduction

Multiple strategies have been implemented to reduce door-to-balloon times. The purpose of this study was to compare door-to-balloon times between ST-elevation myocardial infarction (STEMI) patients who arrived at the emergency department by ambulance with a pre-hospital electrocardiogram (ECG), to those who self-transported and had an ECG on ED arrival.

Methods

This retrospective, comparative study evaluated differences in door-to-balloon times from October 2006 to December 2009 between STEMI patients that had a 12-lead ECG done in the ambulance prior to ED arrival and patients who self-transported and had an ECG on ED arrival.

Results

Of the 367 patients, 62% (n = 228) arrived by ambulance and 38% (n = 139) self-transported to the emergency department. Door-to-balloon times were 30 minutes less (P < .001) than patients who were self-transported.

Discussion

Door-to-balloon times can be reduced when chest pain patients are transported to the emergency department by ambulance. The paramedics are equipped to perform an ECG, thereby making a preliminary diagnosis of STEMI. The emergency department can them prepare for potential angioplasty or percutaneous coronary intervention. An opportunity exists for emergency nurses to educate the public about the importance of calling 911 for chest pain.     

Reperfusion rate and inhospital mortality of patients with ST segment elevation myocardial infarction diagnosed already in the prehospital phase: Results of the German Prehospital Myocardial Infarction Registry (PREMIR)

AimsWe sought to evaluate the in-hospital fate of patients with ST segment elevation myocardial infarction (STEMI) diagnosed already in the prehospital phase by physican equipped ambulances.MethodsA total of 2326 consecutive STEMI patients were included in PREMIR. For this analysis 218 patients with prehospital cardiopulmonary resuscitation were excluded.ResultsThe median time between symptom onset and 12-lead ECG was 85 min. The median time intervals between the diagnostic 12-lead ECG and prehospital fibrinolysis were 10 min, until inhospital fibrinolysis 52 min and until primar PCI 86 min, respectively. Reperfusion therapy with prehospital fibrinolysis (24%), inhospital fibrinolysis (13%) or primary PCI (45%) was performed in 82% of the patients. Inhospital mortality was 6.0% in patients with prehospital fibrinolysis (n = 504), 5.8% in patients with inhospital fibrinolysis (n = 278), 4.5% in patients with primary percutaneous coronary intervention (n = 962) and 16.2% in patients without early reperfusion therapy (n = 377), respectively. In the multivariate propensity score analysis comparing prehospital fibrinolysis and primary PCI we observed no significant difference in the odds for in-hospital mortality (odds ratio: 1.57, 95% CI: 0.94–2.63). The final discharge diagnosis was STEMI in 90% of the patients, in patients with prehospital fibrinolysis 95%.ConclusionsIn patients with STEMI already diagnosed in the prehospital phase the ischemic time is short, accuracy of the diagnosis is high and reperfusion therapy is performed in over 82%. Inhospital mortality was not different between prehospital fibrinolysis and primary PCI.     

Physician attitudes about prehospital 12-lead ECGs in chest pain patients

INTRODUCTION: The prehospital 12-lead electrocardiogram (ECG) has become a standard of care. For the prehospital 12-lead ECG to be useful clinically, however, cardiologists and emergency physicians (EP) must view the test as useful. This study measured physician attitudes about the prehospital 12-lead ECG. HYPOTHESIS: This study tested the hypothesis that physicians had "no opinion" regarding the prehospital 12-lead ECG. METHODS: An anonymous survey was conducted to measure EP and cardiologist attitudes toward prehospital 12-lead ECGs. Hypothesis tests against "no opinion" (VAS = 50 mm) were made with 95% confidence intervals (CIs), and intergroup comparisons were made with the Student's t-test. RESULTS: Seventy-one of 87 (81.6%) surveys were returned. Twenty-five (67.6%) cardiologists responded and 45 (90%) EPs responded. Both groups of physicians viewed prehospital 12-lead ECGs as beneficial (mean = 69 mm; 95% CI = 65-74 mm). All physicians perceived that ECGs positively influence preparation of staff (mean = 63 mm; 95% CI = 60-72 mm) and that ECGs transmitted to hospitals would be beneficial (mean = 66 mm; 95% CI = 60-72 mm). Cardiologists had more favorable opinions than did EPs. The ability of paramedics to interpret ECGs was not seen as important (mean = 50 mm; 95% CI = 43-56 mm). The justifiable increase in field time was perceived to be 3.2 minutes (95% CI = 2.7-3.8 minutes), with 23 (32.8%) preferring that it be done on scene, 46 (65.7%) during transport, and one (1.4%) not at all. CONCLUSIONS: Prehospital 12-lead ECGs generally are perceived as worthwhile by cardiologists and EPs. Cardiologists have a higher opinion of the value and utility of field ECGs. Since the reduction in mortality from the 12-lead ECG is small, it is likely that positive physician attitudes are attributable to other factors.     

Agreement between actual and synthesized right-sided and posterior electrocardiographic leads in identifying ischemia

ObjectiveA 12-lead electrocardiogram (ECG) is the standard of care for chest pain patients. However, 12-lead ECGs have difficulty detecting ischemia of the right ventricle or posterior wall of the heart. New technology exists to mathematically synthesize these leads from a 12-lead ECG; however, this technology has not been evaluated in the emergency department (ED). We assessed the level of agreement between synthesized 18-lead ECGs and actual 18-lead ECGs in identifying ST elevations, ST depressions, and T wave inversions in ED patients.MethodsActual 12- and 18-lead ECGs were acquired and synthesized 18-lead ECGs were produced based on waveforms from 12-lead ECGs. A blinded cardiologist interpreted the actual and synthesized 18-lead ECGs to identify the presence of abnormalities. Using actual 18-lead ECGs as the reference, the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and kappa of synthesized 18-lead ECGs in identifying abnormalities were determined.ResultsData from 295 patients were analyzed. There was 100% agreement between synthesized 18-lead ECGs and actual 18-lead ECGs in identifying ST elevations and ST depressions (sensitivity, specificity, PPV, and NPV of 100%, and kappa of 1.00). Synthesized 18-lead ECGs had 95% sensitivity, 80% specificity, 97% PPV, and 70% NPV in identifying T wave inversions, when compared with actual 18-lead ECGs (kappa: 0.70).ConclusionSynthesized 18-lead ECGs demonstrated 100% agreement with actual 18-lead ECGs in the identification of ST elevations and ST depressions and good agreement in the identification of T wave inversions in a sample of patients ED patients with complaints suspicious of cardiac origin.     

Prehospital time intervals and management of ischemic stroke patients

ObjectiveQuantify prehospital time intervals, describe prehospital stroke management, and estimate potential time saved if certain procedures were performed en route to the emergency department (ED).MethodsAcute ischemic stroke patients who arrived via emergency medical services (EMS) between 2012 and 2016 were identified. We determined the following prehospital time intervals: chute, response, on-scene, transport, and total prehospital times. Proportions of patients receiving the following were determined: Cincinnati Prehospital Stroke Scale (CPSS) assessment, prenotification, glucose assessment, vascular access, and 12-lead electrocardiography (ECG). For glucose assessment, ECG acquisition, and vascular access, the location (on-scene vs. en route) in which they were performed was described. Difference in on-scene times among patients who had these three interventions performed on-scene vs. en route was assessed.ResultsData from 870 patients were analyzed. Median total prehospital time was 39 min and comprised the following: chute time: 1 min; response time: 9 min; on-scene time: 15 min; and transport time: 14 min. CPSS was assessed in 64.7% of patients and prenotification was provided for 52.0% of patients. Glucose assessment, vascular access initiation, and ECG acquisition was performed on 84.1%, 72.6%, and 67.2% of patients, respectively. 59.0% of glucose assessments, 51.2% of vascular access initiations, and 49.8% of ECGs were performed on-scene. On-scene time was 9 min shorter among patients who had glucose assessments, vascular access initiations, and ECG acquisitions all performed en route vs. on-scene.ConclusionsOn-scene time comprised 38.5% of total prehospital time. Limiting on-scene performance of glucose assessments, vascular access initiations, and ECG acquisitions may decrease prehospital time.     

The impact of prehospital activation of the cardiac catheterization team on time to treatment for patients presenting with ST-segment-elevation myocardial infarction

Objective

We sought to evaluate the accuracy of emergency medical services (EMS) activation of the cardiac catheterization laboratory (CCL) for patients with ST-elevation myocardial infarction (STEMI) and its impact on treatment intervals from dispatch to reperfusion.

Methods

We conducted a before-and-after cohort study of patients presenting via EMS with prehospital electrocardiogram findings consistent with STEMI. Before August 20, 2007, percutaneous coronary intervention was initiated after patient arrival. Afterward, EMS providers could activate the CCL if the prehospital electrocardiogram automated interpretation indicated STEMI. All interval times from EMS dispatch to percutaneous coronary intervention were measured via synchronized timepieces.

Results

A total of 53 patients, 14 before and 39 after prehospital activation, were included. Emergency medical services CCL activation was 79.6% sensitive (95% confidence interval [CI], 65.2%-89.3%) and 99.7% specific (95% CI, 99.1%-99.9%). Mean door-to-hospital electrocardiogram and mean CCL-to-reperfusion times were unaffected by the intervention. Prehospital activation of the CCL significantly improved mean door-to-balloon (D2B) time by 18.2 minutes (95% CI, 7.69-28.71 minutes; P = .0029) and door-to-CCL by 14.8 minutes (95% CI, 6.20-23.39 minutes; P = .0024). Improvements in D2B were independent of presentation during peak hours (F ratio = 17.02, P < .0001). There were significant time savings reflected in all EMS intervals: 20.7 minutes (95% CI, 9.1-32.3 minutes; P = .0015) in mean dispatch-to-reperfusion time, 22.2 minutes (95% CI, 11.45-32.95 minutes; P = .0003) in mean first medical contact-to-reperfusion time, and 20 minutes (95% CI, 10.95-29.05 minutes; P = .0001) in recognition-to-reperfusion time.

Conclusions

Emergency medical service providers can appropriately activate the CCL for patients with STEMI before emergency department arrival, significantly reducing mean D2B time. Significant reduction is demonstrated throughout EMS intervals.     

Overall ED efficiency is associated with decreased time to percutaneous coronary intervention for ST-segment elevation myocardial infarction

Background

Performance of percutaneous coronary intervention (PCI) within 90 minutes of hospital arrival for ST-segment elevation myocardial infarction patients is a commonly cited clinical quality measure. The Centers for Medicare and Medicaid Services use this measure to adjust hospital reimbursement via the Value-Based Purchasing Program. This study investigated the relationship between hospital performance on this quality measure and emergency department (ED) operational efficiency.

Methods

Hospital-level data from Centers for Medicare and Medicaid Services on PCI quality measure performance was linked to information on operational performance from 272 US EDs obtained from the Emergency Department Benchmarking Alliance annual operations survey. Standard metrics of ED size, acuity, and efficiency were compared across hospitals grouped by performance on the door-to-balloon time quality measure.

Results

Mean hospital performance on the 90-minute arrival to PCI measure was 94.0% (range, 42-100). Among hospitals failing to achieve the door-to-balloon time performance standard, median ED length of stay was 209 minutes, compared with 173 minutes among those hospitals meeting the benchmark standard (P < .001). Similarly, median time from ED patient arrival to physician evaluation was 39 minutes for hospitals below the performance standard and 23 minutes for hospitals at the benchmark standard (P < .001). Markers of ED size and acuity, including annual patient volume, admission rate, and the percentage of patients arriving via ambulance did not vary with door-to-balloon time.

Conclusion

Better performance on measures associated with ED efficiency is associated with more timely PCI performance.     

Hospital Process Intervals,not Ems Time Intervals,are the Most Important Predictors of Rapid Reperfusion in Ems Patients with St-Segment Elevation Myocardial Infarction

Abstract

Objective. To assess the relationship of emergency medical services (EMS) intervals and internal hospital intervals to the rapid reperfusion of patients with ST-segment elevation myocardial infarction (STEMI). Methods. We performed a secondary analysis of a prospectively collected database of STEMI patients transported to a large academic community hospital between January 1, 2004, and December 31, 2009. EMS and hospital data intervals included EMS scene time, transport time, hospital arrival to myocardial infarction (MI) team activation (D2Page), page to catheterization laboratory arrival (P2Lab), and catheterization laboratory arrival to reperfusion (L2B). We used two outcomes: EMS scene arrival to reperfusion (S2B) ≤90 minutes and hospital arrival to reperfusion (D2B) ≤90 minutes. Means and proportions are reported. Pearson chi-square and multivariate regression were used for analysis. Results. During the study period, we included 313 EMS-transported STEMI patients with 298 (95.2%) MI team activations. Of these STEMI patients, 295 (94.2%) were taken to the cardiac catheterization laboratory and 244 (78.0%) underwent percutaneous coronary intervention (PCI). For the patients who underwent PCI, 127 (52.5%) had prehospital EMS activation, 202 (82.8%) had D2B ≤90 minutes, and 72 (39%) had S2B ≤90 minutes. In a multivariate analysis, hospital processes EMS activation (OR 7.1, 95% CI 2.7, 18.4], Page to Lab [6.7, 95% CI 2.3, 19.2] and Lab arrival to Reperfusion [18.5, 95% CI 6.1, 55.6]) were the most important predictors of Scene to Balloon ≤ 90 minutes. EMS scene and transport intervals also had a modest association with rapid reperfusion (OR 0.85, 95% CI 0.78, 0.93 and OR 0.89, 95% CI 0.83, 0.95, respectively). In a secondary analysis, Hospital processes (Door to Page [OR 44.8, 95% CI 8.6, 234.4], Page 2 Lab [OR 5.4, 95% CI 1.9, 15.3], and Lab arrival to Reperfusion [OR 14.6 95% CI 2.5, 84.3]), but not EMS scene and transport intervals were the most important predictors D2B ≤90 minutes. Conclusions. In our study, hospital process intervals (EMS activation, door to page, page to laboratory, and laboratory to reperfusion) are key covariates of rapid reperfusion for EMS STEMI patients and should be used when assessing STEMI care.     

Door-to-Balloon Times from Freestanding Emergency Departments Meet ST-Segment Elevation Myocardial Infarction Reperfusion Guidelines

Background

Freestanding emergency departments (FEDs) introduce a challenge to physicians who care for the patient with an ST-segment elevation myocardial infarction (STEMI) because treatment is highly time dependent. FEDs have no percutaneous coronary intervention (PCI) capabilities, which necessitates transfer to a PCI-capable facility or fibrinolysis.

Study Objective

Our aim was to determine the proportion of STEMI patients who arrived to an FED and were subsequently transferred for PCI and met the door-to-balloon reperfusion guidelines of 90 min.

Methods

This was a dual-center retrospective cohort review of all patients 18 years and older who were diagnosed with an STEMI and presented to the main hospital−affiliated FEDs. Electronic medical records and emergency medical services documentation were reviewed for all cases since the opening of the FEDs in July 2007 and August 2009, respectively. Key time points were abstracted and statistical evaluation was performed using Fisher's exact test.

Results

A total of 47 patients met inclusion criteria. Median door-to-transport time was 34 min (interquartile range [IQR] 15 min). Median transport time from the FEDs to the main hospital catheterization laboratory was 21 min (IQR 5 min). Median arrival at the catheterization laboratory-to-balloon time was 25 min (IQR 13 min). Median total door-to-balloon time was 83 min (IQR 10.5 min), with 78.7% meeting the American Heart Association's recommended guidelines of ≤ 90 min.

Conclusion

STEMI patients initially seen at two FEDs achieved door-to-balloon time goals of < 90 min.     

Using ECG-To-Activation Time to Assess Emergency Physicians’ Diagnostic Time for Acute Coronary Occlusion

BackgroundThere is no quality metric for emergency physicians’ diagnostic time for acute coronary occlusion.ObjectiveWe sought to quantify diagnostic time associated with automated interpretation, classic ST-elevation myocardial infarction (STEMI) criteria, STEMI-equivalents, and subtle occlusions, using electrocardiogram (ECG)-to-activation of catheterization laboratory time.MethodsThis multicenter retrospective study reviewed all code STEMI patients from the emergency department (ED) with confirmed culprit lesions from January 2016 to December 2018. We measured door-to-ECG (DTE) time and ECG-to-activation (ETA) time. We examined the first ED ECGs to determine whether automated interpretation labeled “STEMI,” and they met classic STEMI criteria, STEMI-equivalents, or rules for subtle occlusion. ECG analysis was performed by two emergency physicians blinded to clinical scenario, automated interpretation, and angiographic outcome.ResultsThere were 177 code STEMIs with culprit lesions, with a median DTE time of 9.0 min and a median ETA time of 16.0 min. Automated interpretation labeled 55.4% of first ECGs “STEMI” (ETA 6.5 min) and 44.6% not “STEMI” (ETA 66 min, p < 0.0001). Of first ECGs, 63.8% met classic STEMI criteria (ETA 8.0 min), 8.5% had STEMI-equivalents (ETA 32.0 min, p = 0.0026), 16.4% had subtle occlusions (ETA 89.0 min, p = 0.045), and 11.3% had no diagnostic sign of occlusion (ETA 68.0 min, p = 0.20).ConclusionsSTEMI criteria missed more than one-third of occlusions on first ECG, but most had STEMI-equivalents or rules for subtle occlusion. ETA time can serve as a quality metric for emergency physicians to promote new ECG insights and assess quality improvement initiatives.