Agonal breathing upon hospital arrival as a prognostic factor in patients experiencing out-of-hospital cardiac arrest

Background: Agonal breathing is a relatively common symptom that follows cardiac arrest when the brainstem function is preserved. Agonal breathing is associated with favorable survival in patients experiencing out-of-hospital cardiac arrest (OHCA). While previous studies focused on agonal breathing observed in the pre-hospital setting for all study subjects, we focused on agonal breathing observed upon hospital arrival. In this multicenter prospective study, we aimed to assess the prognosis of patients exhibiting agonal breathing upon hospital arrival were compared. We hypothesized that agonal breathing at hospital arrival would be associated with favorable neurological outcomes among patients with OHCA. Methods: The data on incidence of agonal breathing were prospectively collected for all evaluable participants in a multicenter, observational study in Japan (SOS-KANTO [Survey of Survivors after Out-of-Hospital Cardiac Arrest in Kanto Area] 2017 Study). Groups with and without agonal breathing were compared upon hospital arrival. Propensity-score with inverse probability of treatment weighting (IPTW) analysis was performed to adjust for confounding factors. The primary outcome was a favorable neurological outcome (Cerebral Performance Category 1–2) at 1 month. Results: A total of 6,457 participants out of the 9,909 registered in SOS-KANTO 2017 (in which 42 facilities participated) were selected for the current study. There were 128 patients (2.0%) in the with-agonal breathing group and 6,329 (98.0%) in the withoutagonal breathing group. The primary outcome was 1.1% in the with-agonal breathing group and 0.6% in the without-agonal breathing group (risk difference, 0.55; 95% confidence interval, 0.23–0.87) after IPTW analysis. Conclusion: In this multicenter prospective study, agonal breathing at hospital arrival was significantly associated with better neurological outcomes and increased survival at 1 month. Thus, agonal breathing at hospital arrival may be a useful prognostic predictor for patients experiencing OHCA.