Characteristics, outcomes, and prognostic factors in patients with hanging-induced out-of-hospital cardiac arrest: An analysis of a nationwide registry in Japan.

Aim: To investigate the characteristics, outcomes, and prognostic factors of patients with hanging-induced out-of-hospital cardiac arrest (OHCA).

Methods: We analysed data from a population-based Japanese nationwide OHCA registry (2021-2022), comparing patients aged ≥18 years with hanging-induced OHCA to those with other OHCA causes. The primary outcome was 1-month favourable neurological outcomes. Prognostic factors for hanging-induced OHCA were identified using multivariable logistic regression analysis.

Results: Of 263,426 OHCAs, 7,878 (3.0 %) were hanging-induced, with an incidence of 3.1 per 100,000 person-years. Patients with hanging-induced OHCA were younger (median age; 58 vs. 81 years), more frequently males (60.2 % vs. 57.5 %), and less likely to have a witness (1.7 % vs. 42.1 %) and initial shockable rhythm (0.4 % vs. 5.9 %). The chance of 1-month favourable neurological outcomes was significantly lower in patients with hanging-induced OHCA than those with other OHCA causes (0.4 % vs. 2.5 %). Factors associated with favourable neurological outcomes included younger age, witnessed arrest, initial non-asystole cardiac rhythm, and prehospital return of spontaneous circulation (ROSC). Patients with initial non-asystole rhythm and prehospital ROSC had an 11.1 % probability of favourable neurological outcomes, whereas 97.1 % of patients lacking these characteristics had only a 0.1 % probability.

Conclusions: Prognosis following hanging-induced OHCAs was significantly worse compared to OHCAs of other causes. While some patients with initial non-asystole rhythm and prehospital ROSC may benefit from cardiopulmonary resuscitation, most lack these favourable features and have an exceedingly low chance of achieving favourable neurological outcomes at 1-month post-arrest.