3CPR Top Research Advances, 2009: Hospital and Emergency Medical Services Variability in Cardiac Arrest Outcomes Offer Targets for Improved Implementation
Disclosure: Dana Edelson: National Institutes of Health/National Heart, Lung, and Blood Institute, significant research; Philips Healthcare, significant research; Philips Healthcare, modest speaker's bureau; Fowler vs. Brally, expert witness; Philips Healthcare, modest consultant. Mr. Yuen: None.
Pub Date: Wednesday, February 3, 2010
Author: Dana P. Edelson, MD, MS and Trevor C. Yuen, B
Using the Epistry registry data from the Resuscitation Outcomes Consortium (ROC), Graham Nichol and colleagues demonstrated a more than fivefold difference in survival following OOHCA cardiac arrest across 10 North American sites. These sites represented a catchment area of more than 21 million people serviced by 225 emergency medicine services (EMS) agencies, making Epistry the largest known OOHCA database to date. The census-adjusted median incidence of EMS-treated cardiac arrest during the study period was 96.8/100,000 people, correlating to an extrapolated annual incidence of almost 300,000 OOHCAs in the U.S. and more than 30,000 in Canada. Most notable about this study, however, was the broad range of survival to discharge among the 10 sites, which ranged from a low of 3.0% to a high of 16.3% for all EMS-treated cases and a range of 7.7% to 39.9% for ventricular fibrillation (VF) or pulseless ventricular tachycardia (pVT).
The variation in survival is not limited to OOHCA but was demonstrated for IHCA as well by our other top pick. Paul Chan and colleagues used the National Registry of Cardiopulmonary Resuscitation (NRCPR) database to conduct a study of racial disparities in IHCA survival of ventricular origin. The NRCPR is the largest known IHCA database, and the current study included 10,011 adult cases of VF or pVT occurring in 274 hospitals. Black patients had a significantly lower unadjusted survival (25.2% vs. 37.4%) compared with white patients. More striking than this disparity, however, is its etiology. The authors demonstrated that adjusting for individual hospitals accounted for much of the disparity in survival. In addition, they found that black patients tended to cluster in hospitals with lower survival for all patients and that the overall survival ranged from 26.9% in the quintile of hospitals with the highest proportion of black patients to a high of 41.2% in the quintile with the lowest proportion of black patients.
These two studies, both impressive in their size and rigor, demonstrate what realistic benchmarks for success might look like and how far away we are from those benchmarks. The ROC authors estimated that 15,000 premature deaths would be prevented each year in North America if survival in the highest performing site were extended across the entire population. Inhospital estimates are harder to generate because the incidence of IHCA is not known. However, it is safe to assume that improving survival from ventricular arrhythmias in the hospital from an average of 35.1% to the high of 41.2% would yield additional lives saved.
Interestingly, the upper end of survival to discharge for shockable rhythms in both studies was close to 40%, which sets up a fairly clear new target threshold for both IHCA and OOHCA. Strategies to reach this target should focus on improving time to defibrillation by improving emergency response times and public access defibrillation, improving both the quantity and quality of delivered CPR by increasing the rate of bystander CPR and emphasizing deep, uninterrupted chest compressions, and optimizing postresuscitation care, including use of cardiac catheterization and therapeutic hypothermia. The gauntlet has been thrown. If VF and pVT do not result in a 40% survival to discharge in an individual hospital or community, it's time to ask why not and then set about trying to fix it.
- 2005 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation 2005;112(24 Suppl):IV1-203.
- Weil MH, Fries M. In-hospital cardiac arrest. Critical Care Medicine 2005;33(12):2825-2830.
- Rea TD, Eisenberg MS, Becker LJ, et al. Temporal trends in sudden cardiac arrest: a 25-year emergency medical services perspective. Circulation 2003;107(22):2780-2785.
- Nichol G, Thomas E, Callaway CW, et al. Regional variation in out-of-hospital cardiac arrest incidence and outcome. JAMA 2008;300(12):1423-1431.
- Chan PS, Nichol G, Krumholz HM, et al. Racial differences in survival after in-hospital cardiac arrest. JAMA 2009;302(11):1195-1201.
-- The opinions expressed in this commentary are not necessarily those of the editors or of the American Heart Association --