This multicentre trial involving 7001 patients from Canada, UK, Australia and New Zealand has failed to show any significant benefit in the provision of home defibrillators for those patients with a previous anterior MI who did not meet criteria for implantable cardioverter-defibrillator insertion.

In the study, patients were randomized to either automated external defibrillation at the scene by bystanders (+ callout of EMS + bystander CPR) or callout of EMS + bystander CPR. A follow up median of 3 years revealed a 6.5% mortality in the control group vs 6.4% in the intervention group (hazard ratio of 0.97%, 95%CI 0.81-1.17).

1/3rd of deaths resulted from sudden cardiac arrest. 3/4 of these occurred at home but only 50% of these were witnessed. Home defibrillation was attempted in only 32 patients. The investigators ascribe the negative result to a lower than expected event rate, high proportion of unwitnessed events and the underuse of defibrillators.