The influence of therapeutic hypothermia on the outcomes of cardiac arrest survivors: a retrospective cohort study

AIM: To determine whether therapeutic hypothermia (TH) improves survival and neurological outcomes in out-of-hospital cardiac arrest (OHCA) survivors. METHODS: This retrospective cohort study enrolled patients treated for OHCA with a return of spontaneous circulation admitted to the Cardiac Intensive Care Unit from October 2000 until March 2019. Data were collected from medical archives. Propensity score matching was used. The primary endpoint was death during hospital stay and secondary endpoint was cerebral performance category (CPC) score at discharge. RESULTS: Out of 152 patients included in the study, 58 (38.7%) underwent TH treatment. After matching (which left 70 patients in the analysis), death during hospital stay occurred less often in TH group (28.6% vs 57.1%, P = 0.029), while the difference in CPC score was not significant. Cox proportional hazards model showed the predictors of death during hospital stay to be TH (hazard ratio [HR] 0.29, 95% confidence interval [CI] 0.13-0.68, P = 0.004), initial Glasgow Coma Scale score of 3 (HR 7.55, 95% CI 1.44-39.63, P = 0.017), and heart failure (HR 2.35, 95% CI 1.02-5.34, P = 0.045). TH was not an independent predictor of CPC score. Mann-Whitney U test and linear regression model showed that TH was associated with higher gain in GCS. CONCLUSION: TH was associated with better survival and certain variables suggesting improved neurological outcomes, suggesting that TH is a vital treatment option for comatose OHCA survivors.