Postmortem ICD interrogation in mode of death classification

Background The definition of sudden death due to arrhythmia relies on the time interval between onset of symptoms and death. However, not all sudden deaths are due to arrhythmia. In patients with an implantable cardioverter defibrillator (ICD), postmortem device interrogation may help better distinguish the mode of death compared to a time‐based definition alone. Objective This study aims to assess the proportion of “sudden” cardiac deaths in patients with an ICD that have confirmed arrhythmia. Methods We conducted a literature search for studies using postmortem ICD interrogation and a time‐based classification of the mode of death. A modified QUADAS‐2 checklist was used to assess risk of bias in individual studies. Outcome data were pooled where sufficient data were available. Results Our search identified 22 studies undertaken between 1982 and 2015 with 23,600 participants. The pooled results (excluding studies with high risk of bias) suggest that ventricular arrhythmias are present at the time of death in 76% of “sudden” deaths (95% confidence interval [CI] 67–85; range 42–88). Conclusion Postmortem ICD interrogation identifies 24% of “sudden” deaths to be nonarrhythmic. Postmortem device interrogation should be considered in all cases of unexplained sudden cardiac death.