Abstract 15292: Quantitative Waveform Measures Predict Survival From Out-of-hospital Cardiac Arrest Independent of Prior Cardiovascular Disease

Abstract

Introduction: Quantitative waveform measures (QWM) of ventricular fibrillation (VF) can predict survival from out-of-hospital cardiac arrest (OHCA). However, cardiovascular disease (CVD) can change QWM as well as outcome from OHCA. We assessed the hypothesis that risk factors for and the presence of CVD were associated with changes in VF amplitude spectrum area (AMSA) and survival from OHCA. Methods: Data from ARREST, a registry of all OHCAs in North-Holland, the Netherlands, were used. Medical history was collected from the general practitioner using a questionnaire. AMSA was calculated for the first artifact free VF segment (mean segment duration 4.8 sec, sample frequency 125 Hz) and prior to every shock. Linear regression was used to assess the association between AMSA, risk factors and CVD, adjusting for resuscitation characteristics. Logistic regression was used to associate AMSA, resuscitation characteristics, risk factors and CVD with survival to hospital discharge. Results: We included 693 patients with an OHCA between 2006 and 2010, available medical history and VF on ECG recording with AED (n=163) or manual defibrillator (n=530), receiving a total of 2675, median 3 defibrillation shocks. Time from EMS call to first rhythm recording was median (IQR) 8.8 min (5.7-11.6), and 295 patients survived to hospital discharge (43%). Mean AMSA for the first analyzable segment was 12.7 (±16.0) mV-Hz, significantly lower for cardiomyopathy and obesity, and higher for known familial sudden cardiac death (SCD) (Table 1). Higher AMSA per mV-Hz increase (adjusted for resuscitation characteristics, risk factors and CVD) was significantly associated with higher survival to discharge (OR 1.04; 95% CI 1.02-1.06; P<0.001). Conclusions: Changes in AMSA due to reported CVD and risk factors are of small magnitude. AMSA remains an independent predictor of survival to hospital discharge, even when adjusting for resuscitation characteristics, risk factors and CVD.