Background: Current guidelines emphasize the indispensability of high-quality chest compression for improving survival in patients who experience out-of-hospital cardiac arrest (OHCA). However, chest compression can cause thoracic injuries that may contribute to poor prognosis; therefore, the purpose of this study is to identify the predictors of thoracic injuries and evaluate the association between thoracic injuries and prognosis.

Methods and Results: Between June 2017 to July 2019, Utstein-style data on 384 consecutive adult patients who experienced non-traumatic OHCA and who were transferred to our hospital (Aso Iizuka Hospital) were collected. Each patient underwent a full-body computed tomography scan. Two-hundred and thirty-four patients (76%) had thoracic injuries (Group-T). The duration of chest compression was significantly longer in Group-T than in patients without thoracic injuries (Group-N; 43 vs. 32 min, respectively, P<0.001). Multivariate analysis revealed that older age and longer chest compression duration were predictors of thoracic injuries (odds ratios 1.03 and 1.07, respectively, P≤0.005). Among patients who achieved return of spontaneous circulation, Kaplan-Meier curves showed a significantly higher cumulative survival rate in Group-N than in Group-T at the 30-day follow up (log-rank test P=0.009).

Conclusions: Older age and longer chest compression duration were independent predictors of thoracic injuries due to chest compression in patients who experienced non-traumatic OHCA. Moreover, the presence of thoracic injuries was associated with worse short-term prognosis.