Temporal Trends in Identification, Management, and Clinical Outcomes After Out-of-Hospital Cardiac Arrest: Insights From the Myocardial Ischaemia National Audit Project Database.

BACKGROUND

There is wide variation in survival rates from out-of-hospital cardiac arrest (OHCA) and overall survival remains poor. There is an expert consensus that early reperfusion therapy in ST-elevation reduces mortality. The management of patients without ST-elevation, however, is controversial.

METHODS AND RESULTS

The Myocardial Ischaemia National Audit Project database is a national registry of all hospital admissions in England and Wales treated as an acute coronary syndrome (ACS). We examined temporal trends, over a 5-year period, of OHCAs identified by Myocardial Ischaemia National Audit Project, admitted to hospital and treated as ACS, the interventional management of these patients and clinical outcomes. Four hundred ten thousand four hundred sixty-two patients were admitted to hospital in England and Wales with ACS. Of these, 9421 presented with OHCA (2.30%). There was an increase in OHCA cases as a proportion of ACS between 2009 and 2013 (1.79% in 2009 versus 2.74% in 2013; <0.001). The rate of coronary angiography+percutaneous coronary intervention increased in ACS patients presenting with OHCA (54.9% in 2009 [876/1595] versus 66.3% in 2013 [884/1334]; <0.001). Cox proportional hazards model with time-varying exposure to coronary angiography demonstrated a significant reduction in mortality in both the ST-elevation (hazard ratio, 0.30; 95% confidence interval, 0.28-0.32; <0.05) and non-ST-elevation cohort (hazard ratio, 0.44; 95% confidence interval, 0.42-0.46; <0.001). Predictors of favorable outcome were synonymous with the selection criteria for patients undergoing coronary angiography±percutaneous coronary intervention.

CONCLUSIONS

This observational study showed that selection for coronary angiography±percutaneous coronary intervention was associated with reduced mortality in OHCA patients diagnosed with ACS. These data support the need for a randomized controlled trial.