Study objective For out-of-hospital cardiac arrest, authoritative, evidence-based recommendations have been made for regionalization of postarrest care. However, system-wide implementation of these guidelines has not been evaluated. Our hypothesis is that statewide regionalization of postarrest interventions, combined with emergency medical services (EMS) triage bypass, is associated with improved survival and neurologic outcome.
Methods This was a prospective before-after observational study comparing patients admitted to cardiac receiving centers before implementation of the interventions ("before") versus those admitted after ("after"). In December 2007, the Arizona Department of Health Services began officially recognizing cardiac receiving centers according to commitment to provide specified postarrest care. Subsequently, the State EMS Council approved protocols allowing preferential EMS transport to these centers. Participants were adults (≥18 years) experiencing out-of-hospital cardiac arrest of presumed cardiac cause who were transported to a cardiac receiving center. Interventions included (1) implementation of postarrest care at cardiac receiving centers focusing on provision of therapeutic hypothermia and coronary angiography or percutaneous coronary interventions (catheterization/PCI); and (2) implementation of EMS bypass triage protocols. Main outcomes included discharged alive from the hospital and cerebral performance category score at discharge.
Results During the study (December 1, 2007, to December 31, 2010), 31 hospitals were recognized as cardiac receiving centers statewide. Four hundred forty patients were transported to cardiac receiving centers before and 1,737 after. Provision of therapeutic hypothermia among patients with return of spontaneous circulation increased from 0% (before: 0/145; 95% confidence interval [CI] 0% to 2.5%) to 44.0% (after: 300/682; 95% CI 40.2, 47.8). The post return of spontaneous circulation catheterization PCI rate increased from 11.7% (17/145; 95% CI 7.0, 18.1) before to 30.7% (210/684; 95% CI 27.3, 34.3) after. All-rhythm survival increased from 8.9% (39/440) to 14.4% (250/1,734; adjusted odds ratio [aOR]=2.22; 95% CI 1.47 to 3.34). Survival with favorable neurologic outcome (cerebral performance category score=1 or 2) increased from 5.9% (26/439) to 8.9% (153/1,727; aOR=2.26 [95% CI 1.37, 3.73]). For witnessed shockable rhythms, survival increased from 21.4% (21/98) to 39.2% (115/293; aOR=2.96 [95% CI 1.63, 5.38]) and cerebral performance category score=1 or 2 increased from 19.4% (19/98) to 29.8% (87/292; aOR=2.12 [95% CI 1.14, 3.93]).
Conclusion Implementation of a statewide system of cardiac receiving centers and EMS bypass was independently associated with increased overall survival and favorable neurologic outcome. In addition, these outcomes improved among patients with witnessed shockable rhythms.