Long-Term Impact of the Kumamoto Earthquake on Out-of-Hospital Cardiac Arrest With Cardiac and Non-Cardiac Origins - An Interrupted Time Series Analysis.

Background: Possible etiologies of out-of-hospital cardiac arrest (OHCA), including aortic dissection, ruptured aortic aneurysms, and pulmonary embolism, may be classified as non-cardiac causes. We investigated whether cardiac and non-cardiac OHCAs increased following the Kumamoto earthquake and whether the impact on OHCAs extended to regions far from the epicenter.

Methods and results: We prospectively analyzed a nationwide registry of patients who experienced OHCAs between January 2013 and December 2019. Data from cases registered in 7 prefectures, including Kumamoto (Kyushu region; n=82,060), in the All-Japan Utstein Registry were analyzed for OHCAs of cardiac and non-cardiac origin. The numbers of OHCAs before and after the Kumamoto earthquake were compared using an interrupted time series analysis. The incidence of both cardiac (rate ratio [RR] 1.22) and non-cardiac (RR 1.27) OHCAs in Kumamoto Prefecture increased after the earthquake. The difference disappeared when the analysis was limited to patients with non-cardiac OHCAs with a clear cause of cardiac arrest. The number of cardiac and non-cardiac OHCAs did not increase in other prefectures within the Kyushu region.

Conclusions: The Kumamoto earthquake led to an increase in the incidence of cardiac and non-cardiac OHCAs. However, this was attenuated by increasing distance from the epicenter. Except for cardiac causes, cases complicated by earthquake-related events may include non-cardiac OHCAs due to vascular diseases that might be overlooked.