Abstract 15867: Amplitude Spectrum Area (amsa) and Outcome: Role of Utstein and Comorbidities Factors

Introduction: Quantitative waveform measures of the ventricular fibrillation (VF) waveform predict outcome of out-of-hospital cardiac arrest (OHCA). We investigated whether Utstein characteristics and/or chronic health conditions relate to waveform measures to help understand the mechanisms by which waveform relates to outcome. Methods: We performed a cohort investigation of persons >=18 years who suffered VF OHCA between January 1, 2007 and December 31, 2013 in a large metropolitan emergency medical service (EMS) system and had a continuous defibrillator recording. The Amplitude Spectrum Area (AMSA) measure was determined immediately prior to first shock. We used logistic and multinomial regression to evaluate the relationship of AMSA, Utstein, and Charlson with survival to hospital discharge. Results: A total of 788 patients experienced VF OHCA and had an ECG recording. Although Utstein, AMSA, and Charlson were associated with survival in univarariate analyses, only AMSA and Charlson remained associated with survival in multivariable regression (Table 1). Using multinomial regression, Utstein characteristics of witness status, bystander CPR, public location, and shorter EMS response predicted more favorable AMSA quartile (p Discussion: AMSA predicts VF OHCA outcome and is mediated in part by health services characteristics but not chronic health conditions.