Identifying Patients at Risk for Pre-Hospital Sudden Cardiac Arrest at the Early Phase of Myocardial Infarction: The e-MUST Study
Background—In-hospital mortality of ST-Segment Elevation Myocardial Infarction (STEMI) has decreased drastically. In contrast pre-hospital mortality by Sudden Cardiac Arrest (SCA) remains high and difficult to reduce. Identification of the STEMI patients at higher risk for pre-hospital SCA could facilitate rapid triage and intervention in the field.
Methods— Using a prospective population-based study evaluating all STEMI patients managed by Emergency Medical Services (EMS) in the Greater Paris Area (11.7 million inhabitants) between 2006 and 2010, we identified characteristics associated with an increased risk of pre-hospital SCA and used these variables to build a SCA prediction score which we validated internally and externally.
Results— In the overall STEMI population, (n=8112; median age 60years, 78% males), SCA occurred in 452 patients (5.6%). By multivariate analysis, younger age, absence of obesity, absence of diabetes, shortness of breath, and a short delay between pain onset and call to EMS were the main predictors of SCA. A score built from these variables predicted SCA, with the risk increasing 2-fold in patients with a score between 10 and 19, 4-fold with a score between 20 and 29, and more than 18-fold with a score ≥ 30, compared to those with scores <10. The SCA rate was 28.9% in patients with a score ≥30 compared to 1.6% in patients with a score ≤ 9 (P for trend<0.001). The Area Under the Curve values were 0.7033 in the internal validation sample, and 0.6031 in the external validation sample. Sensitivity and specificity varied between 96.9% and 10.5% for scores 10 and above, and 18.0% and 97.6% for scores 30 and above, with scores between 20 and 29 achieving the best sensitivity and specificity (65.4% and 62.6%, respectively).
Conclusions— At the early phase of STEMI, the risk of pre-hospital SCA can be determined through a simple score of five routinely assessed predictors. This score might help optimizing EMS dispatching and management of STEMI patients.
- Sudden cardiac arrest prediction
- STEMI management
- STEMI assessment
- myocardial infarction
- sudden cardiac death, atherosclerosis
- Received April 16, 2016.
- Revision received July 12, 2016.
- Accepted September 28, 2016.