Abstract 256: Temporal Trends In Survival From Sudden Cardiac Arrest Based On Presenting Rhythm: Prospective Study In A Large US Community

Abstract

Background: The proportion of non-shockable out-of-hospital sudden cardiac arrest (SCA) (pulseless electrical activity [PEA] and asystole) remains higher than shockable SCA (ventricular fibrillation [VF], ventricular tachycardia [VT]). More recently, survival from non-shockable rhythms may have improved, but there is little data available on temporal trends in the community. Aim: To investigate community-based temporal trends in SCA survival based on presenting rhythm. Methods: We prospectively evaluated survival outcomes for out-of-hospital SCA in the Portland, OR metro area (Pop. approx. 1 million, 2002-2017). Detailed lifetime clinical records were reviewed to only include cases of likely cardiac etiology who were resuscitated by emergency medical services. Results: Of 3,723 SCA cases, 908 (24%) presented with PEA, 1,302 (35%) with asystole, and 1,513 (41%) with VF/VT. The mean age was 68.9±21.8 in PEA, 62.2±21.8 in asystole, and 63.2±15.3 in VF/VT. The proportion of PEA decreased over 4-yr time periods (29.2% in 2002-2005, 24.7% in 2006-2009, 20.4% in 2010-2013, 23.3% in 2014-2017) while the proportion of asystole increased (26.2%, 30.3%, 36.8%, 44.1%); and the proportion of VF/VT decreased over time (44.6%, 45.0%, 42.8%, 32.6%). Survival increased over time for PEA (5.7%, 4.3%, 9.6%, 13.6%; p for trend <0.001) and for VF/VT (27.5%, 29.8%, 37.9%, 36.6%; p for trend <0.001), but not for asystole SCA (1.7%, 1.6%, 4.0%, 2.4%; p for trend 0.37). Bystander CPR increased in all 3 presenting rhythms (p for trend for each rhythm <0.001). In a multivariable model including age, sex and Utstein variables the following were significant determinants of survival: young age, female sex, witnessed arrest, and public location in PEA; young age and witnessed arrest in asystole; young age, female sex, public location, witnessed arrest and bystander CPR in VF/VT. Conclusions: Over a 16-year period, survival outcomes improved for SCA presenting with PEA and VF/VT, but not with asystole. Determinants of survival varied between the 3 presenting rhythms. These findings highlight the beneficial effects of the growing bystander-EMS relationship and the potential for further improvements in outcome with ongoing evaluation and enhancement.