Predicting survival in out-of-hospital cardiac arrest patients undergoing targeted temperature management: The Polish Hypothermia Registry Risk Score

BACKGROUND: Prompt reperfusion and post-resuscitation care, including targeted temperature management (TTM), improve survival in out-of-hospital cardiac arrest (OHCA) patients. To predict in-hospital mortality in OHCA patients treated with TTM, the Polish Hypothermia Registry Risk Score (PHR-RS) was developed. The use of dedicated risk stratification tools may support treatment decisions. METHODS: Three hundred seventy-six OHCA patients who underwent TTM between 2012 and 2016 were retrospectively analysed and whose data were collected in the Polish Hypothermia Registry. A multivariate logistic regression model identified a set of predictors of in-hospital mortality that were used to develop a dedicated risk prediction model, which was tested for accuracy. RESULTS: The mean age of the studied population was 59.2 ± 12.9 years. 80% of patients were male, 73.8% had shockable rhythms, and mean time from cardiac arrest (CA) to cardiopulmonary resuscitation (CPR) was 7.2 ± 8.6 min. The inputs for PHR-RS were patient age and score according to the Mild Therapeutic Hypothermia (MTH) Scale. Criteria for the MTH score consisted of time from CA to CPR above 10 min, time from CA to the return of spontaneous circulation above 20 min, in-hospital CA, unwitnessed CA, and non-shockable rhythm, each counted as 1 point. The predictive value of PHR-RS was expressed as an area under the curve of 0.74. CONCLUSIONS: PHR-RS is one of the simplest and easiest models to use and enables a reliable prediction of in-hospital mortality in OHCA patients treated with TTM.