Emergency medical services as a strategy for improving ST-elevation myocardial infarction system treatment times.

BACKGROUND: Reducing delays in time to treatment is a key goal of ST-elevation myocardial infarction (STEMI) emergency care. Emergency medical services (EMS) are a critical component of the STEMI chain of survival. STUDY OBJECTIVE: We sought to assess the impact of the careful integration of EMS as a strategy for improving systemic treatment times for STEMI. METHODS: We conducted a study of all 747 nontransfer STEMI patients who underwent primary percutaneous coronary intervention (PCI) in Dallas County, Texas from October 1, 2010 through December 31, 2011. EMS leaders from 24 agencies and 15 major PCI receiving hospitals collected and shared common, de-identified patient data. We used 15 months of data to develop a generalized linear regression to assess the impact of EMS on two treatment metrics-hospital door to balloon (D2B) time, and symptom onset to arterial reperfusion (SOAR) time, a new metric we developed to assess total treatment times. RESULTS: We found statistically significant reductions in median D2B (11.1-min reduction) and SOAR (63.5-min reduction) treatment times when EMS transported patients to the receiving facility, compared to self-transport. In addition, when trained EMS paramedics field-activated the cardiac catheterization laboratory using predefined specified protocols, D2B times were reduced by 38% (43 min) after controlling for confounding variables, and field activation was associated with a 21.9% reduction (73 min) in the mean SOAR time (both with p < 0.001). CONCLUSION: Active EMS engagement in STEMI treatment was associated with significantly lower D2B and total coronary reperfusion times.

Growth in percutaneous coronary intervention capacity relative to population and disease prevalence.

BACKGROUND: The access to and growth of percutaneous coronary intervention (PCI) has not been fully explored with regard to geographic equity and need. Economic factors and timely access to primary PCI provide the impetus for growth in PCI centers, and this is balanced by volume standards and the benefits of regionalized care. METHODS AND RESULTS: Geospatial and statistical analyses were used to model capacity, growth, and access of PCI hospitals relative to population density and myocardial infarction (MI) prevalence at the state level. Longitudinal data were obtained for 2003-2011 from the American Hospital Association, the U.S. Census, and the Centers for Disease Control and Prevention (CDC) with geographical modeling to map PCI locations. The number of PCI centers has grown 21.2% over the last 8 years, with 39% of all hospitals having interventional cardiology capabilities. During the same time, the US population has grown 8.3%, from 217 million to 235 million, and MI prevalence rates have decreased from 4.0% to 3.7%. The most densely concentrated states have a ratio of 8.1 to 12.1 PCI facilities per million of population with significant variability in both MI prevalence and average distance between PCI facilities. CONCLUSIONS: Over the last decade, the growth rate for PCI centers is 1.5× that of the population growth, while MI prevalence is decreasing. This has created geographic imbalances and access barriers with excess PCI centers relative to need in some regions and inadequate access in others.

Developing an ST-elevation myocardial infarction system of care in Dallas County.

BACKGROUND: The American Heart Association Caruth Initiative (AHACI) is a multiyear project to increase the speed of coronary reperfusion and create an integrated system of care for patients with ST-elevation myocardial infarction (STEMI) in Dallas County, TX. The purpose of this study was to determine if the AHACI improved key performance metrics, that is, door-to-balloon (D2B) and symptom-onset-to-balloon times, for nontransfer patients with STEMI. METHODS: Hospital patient data were obtained through the National Cardiovascular Data Registry Action Registry-Get With The Guidelines, and prehospital data came from emergency medical services (EMS) agencies through their electronic Patient Care Record systems. Initial D2B and symptom-onset-to-balloon times for nontransfer primary percutaneous coronary intervention (PCI) STEMI care were explored using descriptive statistics, generalized linear models, and logistic regression. RESULTS: Data were collected by 15 PCI-capable Dallas hospitals and 24 EMS agencies. In the first 18 months, there were 3,853 cases of myocardial infarction, of which 926 (24%) were nontransfer patients with STEMI undergoing primary PCI. D2B time decreased significantly (P < .001), from a median time of 74 to 64 minutes. Symptom-onset-to-balloon time decreased significantly (P < .001), from a median time of 195 to 162 minutes. CONCLUSION: The AHACI has improved the system of STEMI care for one of the largest counties in the United States, and it demonstrates the benefits of integrating EMS and hospital data, implementing standardized training and protocols, and providing benchmarking data to hospitals and EMS agencies.