Application of severity classification after return of spontaneous circulation for predicting long-term outcomes in cardiac arrest survivors

BACKGROUND: Accurately predicting outcomes for cardiac arrest (CA) survivors is essential. Existing severity scores reliably predict outcomes at hospital discharge, but their prognostic performance for survival at 6 months and 1 year remains unexplored. METHODS: This retrospective observational study enrolled 1773 adult nontraumatic CA patients in the emergency department of National Taiwan University Hospital between January 2011 and June 2023 without interhospital transfer. Data on clinical variables, resuscitation events, post-arrest care, and outcomes were collected, and the severity was classified using the sCAHP, rCAST, and TIMECARD scores. The outcomes included 6-month and 1-year survival. Predictive ability was evaluated using receiver operating characteristic (ROC) curves. RESULTS: Among 1773 enrolled patients, 501 (28.3%) survived to discharge, 361 (20.4%) to 6 months, and 346 (19.5%) to 1 year. The area under the ROC curves (AUCs) for 6-month survival were 0.787, 0.733, and 0.810 for the sCAHP, rCAST, and TIMECARD scores, respectively. For 1-year survival, the AUC values were 0.788, 0.734, and 0.816, respectively. sCAHP and TIMECARD scores demonstrated better discriminatory performance than did the rCAST score for both 6-month and 1-year survival. Compared with the sCAHP and rCAST scores, TIMECARD score exhibited superior discrimination for 1-year survival, particularly in patients ≤65 years, those with in-hospital CA (IHCA), and those with good pre-arrest neurological status. CONCLUSION: The sCAHP, rCAST, and TIMECARD scores demonstrated good discrimination and calibration for long-term survival. The TIMECARD score exhibited better discriminatory performance for 1-year survival, particularly in the subgroup of younger age, IHCA, and good pre-arrest neurological function.