Abstract P95: A Comparison of Compliance and Effectiveness of Wearable Defibrillators and Home AEDs in Out-of-Hospital Sudden Cardiac Arrest
Background Early defibrillation of ventricular tachyarrhythmia (VT/VF) is effective treatment for sudden cardiac arrest (SCA) yet the Home AED Trial (HAT) did not show improved survival by having an automatic external defibrillator (AED) in the home over conventional emergency medical services. Bystander observance and location of SCA were factors limiting the strategies success. In contrast, wearable defibrillators (WD) do not depend on bystanders and are available in and out of the home. We compared HAT to WD commercial results.
Methods and Results WD data was extracted from medical orders and WD tracking database. Social Security Death Index was used to determine survival >15 days. 688 patients from 2002 through 2006 used WD after myocardial infarction an average of 48 days, range 1–333. Mean age was 62.5±11.9 and 79% were male. Unlike HAT, only 104 (15%) patients had EF >35%. Data from 585 patients who used WD > 7 days were used for compliance statistics. Mean daily use was 20.3±3.4 hours (85%). During use there were 15 unconscious VT/VF events (12 survived at least 15 days) and 7 documented asystole deaths. We estimated 4 patients died from VT/VF due to not wearing WD. WD results were then compared to HAT. WD compliance was equated to HAT proper AED use. All WD SCA were considered “witnessed” and “home” due to device autonomy and use.
Conclusion WD eliminated the bystander requirement and location restraint, providing prompt detection and delivery of defibrillation. WD provided better protection for patients at risk for SCA compared to home AED.