Emergency medical services management of ST-segment elevation myocardial infarction in the United States--a report from the American Heart Association Mission: Lifeline Program.

OBJECTIVE: ST-segment elevation myocardial infarction (STEMI) is a major cause of morbidity and mortality in the United States. Emergency medical services (EMS) agencies play a critical role in its initial identification and treatment. We conducted this study to assess EMS management of STEMI care in the United States. METHODS: A structured questionnaire was administered to leaders of EMS agencies to define the elements of STEMI care related to 4 core measures: (1) electrocardiogram (ECG) capability at the scene, (2) destination protocols, (3) catheterization laboratory activation before hospital arrival, and (4) 12-lead ECG quality review. Geographic areas were grouped into large metropolitan, small metropolitan, micropolitan, and noncore (or rural) by using Urban Influence Codes, with a stratified analysis. RESULTS: Data were included based on responses from 5296 EMS agencies (36% of those in the United States) serving 91% of the US population, with at least 1 valid response from each of the 50 states and the District of Columbia. Approximately 63% of agencies obtained ECGs at the scene using providers trained in ECG acquisition and interpretation. A total of 46% of EMS systems used protocols to determine hospital destination, cardiac catheterization laboratory activation, and communications with the receiving hospital. More than 75% of EMS systems used their own agency funds to purchase equipment, train personnel, and provide administrative oversight. A total of 49% of agencies have quality review programs in place. In general, EMS systems covering higher population densities had easier access to resources needed to maintain STEMI systems of care. Emergency medical services systems that have adopted all 4 core elements cover 14% of the US population. CONCLUSIONS: There are large differences in EMS systems of STEMI care in the United States. Most EMS agencies have implemented at least 1 of the 4 core elements of STEMI care, with many having implemented multiple elements.

A composite model of survival from out-of-hospital cardiac arrest using the Cardiac Arrest Registry to Enhance Survival (CARES).

OBJECTIVE: Using CARES data, to develop a composite multivariate logistic regression model of survival for projecting survival rates for out-of-hospital arrests of presumed cardiac etiology (OHCA). METHODS: This is an analysis of 25,975 OHCA cases (from October 1, 2005 to December 31, 2011) occurring before EMS/first responder arrival and involving attempted resuscitation by responders from 125 EMS agencies. RESULTS: The survival-at-hospital discharge rate was 9% for all cases, 16% for bystander-witnessed cases, 4% for unwitnessed cases, and 32% for bystander-witnessed pVT/VF cases. The model was estimated separately for each set of cases above. Generally, our first equation showed that joint presence of a presenting rhythm of pVT/VF and return of spontaneous circulation in the pre-hospital setting (PREHOSPROSC) is a substantial direct predictor of patient survival (e.g., 55% of such cases survived). Bystander AED use, and, for witnessed cases, bystander CPR and response time are significant but less sizable direct predictors of survival. Our second equation shows that these variables make an additional, indirect contribution to survival by affecting the probability of joint presence of pVT/VF and PREHOSPROSC. The model yields survival rate projections for various improvement scenarios; for example, if all cases had involved bystander AED use (vs. 4% currently), the survival rate would have increased to 14%. Approximately one-half of projected increases come from indirect effects that would have been missed by the conventional single-equation approach. CONCLUSION: The composite model describes major connections among predictors of survival, and yields specific projections for consideration when allocating scarce resources to impact OHCA survival.

Systems of care for ST-segment-elevation myocardial infarction: a report From the American Heart Association's Mission: Lifeline.

BACKGROUND: National guidelines call for participation in systems to rapidly diagnose and treat ST-segment-elevation myocardial infarction (STEMI). In order to characterize currently implemented STEMI reperfusion systems and identify practices common to system organization, the American Heart Association surveyed existing systems throughout the United States. METHODS AND RESULTS: A STEMI system was defined as an integrated group of separate entities focused on reperfusion therapy for STEMI within a geographic region that included at least 1 hospital that performs percutaneous coronary intervention and at least 1 emergency medical service agency. Systems meeting this definition were invited to participate in a survey of 42 questions based on expert panel opinion and knowledge of existing systems. Data were collected through the American Heart Association Mission: Lifeline website. Between April 2008 and January 2010, 381 unique systems involving 899 percutaneous coronary intervention hospitals in 47 states responded to the survey, of which 255 systems (67%) involved urban regions. The predominant funding sources for STEMI systems were percutaneous coronary intervention hospitals (n = 320, 84%) and /or cardiology practices (n = 88, 23%). Predominant system characteristics identified by the survey included: STEMI patient acceptance at percutaneous coronary intervention hospital regardless of bed availability (N = 346, 97%); single phone call activation of catheterization laboratory (N = 335, 92%); emergency department physician activation of laboratory without cardiology consultation (N = 318, 87%); data registry participation (N = 311, 84%); and prehospital activation of the laboratory through emergency department notification without cardiology notification (N = 297, 78%). The most common barriers to system implementation were hospital (n = 139, 37%) and cardiology group competition (n = 81, 21%) and emergency medical services transport and finances (n = 99, 26%). CONCLUSIONS: This survey broadly describes the organizational characteristics of collaborative efforts by hospitals and emergency medical services to provide timely reperfusion in the United States. These findings serve as a benchmark for existing systems and should help guide healthcare teams in the process of organizing care for patients with STEMI.

A model of survival from out-of-hospital cardiac arrest using the Boston EMS arrest registry.

OBJECTIVES: To characterize the survival rate for out-of-hospital arrests of cardiac aetiology and predictor variables associated with survival in Boston, MA, and to develop a composite multivariate logistic regression model for projecting survival rates. METHODS: This is a retrospective analysis of all arrests of presumed cardiac aetiology (from January 1, 2004 to December 31, 2007) where resuscitation was attempted (n=1156) by 911 emergency responders. RESULTS: The survival-at-hospital discharge rate was 11% (vs. 1-10% often reported). The coefficients and odds ratios in the first equation of the model show that joint presence of presenting rhythm of ventricular fibrillation/tachycardia (VF/VT) and return of spontaneous circulation in the pre-hospital setting (ROSC) is a substantial direct predictor of survival (e.g., 54% of such cases survive). Response time, public location, witnessed, and age are significant but less sizable direct predictors of survival. A second equation shows that these four variables make an additional indirect contribution to survival by affecting the probability of joint presence of VF/VT and ROSC; bystander CPR also makes such an indirect contribution but no significant direct one as shown in the first equation. The projected survival rate if cases had always experienced bystander CPR and rapid response time of less than four minutes is 21%. CONCLUSIONS: The unique model describes the major contribution of VF/VT and ROSC, and key relationships among predictors of survival. These connections may have otherwise gone underreported using standard approaches and should be considered when allocating scarce resources to impact cardiac arrest survival.