Changes in treatments and outcomes among elderly patients with out-of-hospital cardiac arrest between 2002 and 2012: A post hoc analysis of the SOS-KANTO 2002 and 2012

Background: Little is known about recent changes in pre- and in-hospital treatments and outcomes for elderly patients with out-of-hospital cardiac arrest (OHCA). Methods: We compared data collected for the SOS-KANTO study in 2002 and 2012. We included patients aged ≥65 years who experienced OHCA of cardiac aetiology. The primary endpoint was favourable neurological outcomes 1 month after cardiac arrest. Results: A total of 8,964 (2002 vs. 2012: 3,544 vs. 5,420) patients were eligible for the current analysis. The proportion of pre-hospital return of spontaneous circulation (ROSC) increased significantly (3.8 vs. 5.6%, p<. 0.001). Among patients achieving ROSC, the proportion of advanced in-hospital treatments (i.e. extracorporeal membrane oxygenation, therapeutic hypothermia, and/or percutaneous coronary angiogram/intervention) provided increased significantly in 2012 (1.2 vs. 5.5%, p<. 0.001; 2.6 vs. 15.1%, p<. 0.001; 4.9 vs. 16.5%, p<. 0.001; respectively). The proportion of favourable neurological outcomes at 1 month increased significantly in 2012 (1.6 vs. 2.7%, p= 0.001). A logistic regression analysis that did not consider advanced in-hospital treatments showed a significantly higher rate of favourable neurological outcomes in the 2012 group than that in the 2002 group (OR, 2.2; 95% CI, 1.4-3.5). However, this difference was no longer observed in the second regression model that accounted for advanced in-hospital treatments (OR, 1.6; 95% CI, 0.9-2.9). Conclusion: There was an increased proportion of aggressive treatment, both pre- and in-hospital, for elderly patients with cardiogenic OHCA in the Kanto area, Japan. Favourable neurological outcomes improved significantly over 10 years.