Forensic perspectives on postmortem CIED interrogation: A systematic review and meta-analysis.

Background: Cardiac implantable electronic devices (CIED) are a heterogeneous group of medical devices with increasingly sophisticated diagnostic capabilities, which could be exploited in forensic investigations. However, current guidelines are lacking clear recommendations on the topic. The first aim of this systematic review is to provide an updated assessment of the role of postmortem CIED interrogation, and to give practical recommendations, which can be used in daily practice. Secondly, the authors aim to determine the rates of postmortem CIED interrogation and autopsy investigations, the type of final rhythm detected close to death (with a focus on the significance of documented arrhythmias), as well as the role of postmortem CIED interrogation in the determination of final cause/time of death, and any potentially fatal device malfunctions.

Methods: A systematic search in MEDLINE and Scopus aiming to identify reports concerning postmortem human CIED interrogation was performed, including a systematic screening of reference lists. Case reports, letters to the editors, commentaries, review articles or guidelines were excluded, along with studies related to cardiac devices other than CIED. All data were pooled and analyzed using fixed-effects meta-analysis models, and the I statistic was used to assess heterogeneity.

Results: A total of 25 articles were included in the systematic review, enrolling 3194 decedent CIED carriers. Ten studies (40%) had a 100% autopsy rate, whereas in further 6 studies autopsy findings were variably reported; CIED interrogation was available from 22 studies (88%), and it was never performed prior to autopsy. The overall rate of successful postmortem CIED interrogation was 89%, with high heterogeneity among studies, mainly due to device deactivation/battery discharge. Twenty-four percent of CIED carriers experienced sudden cardiac death (SCD), whereas non-sudden cardiac and non-cardiac death (NSCD, NCD) were reported in 37% and 30% of decedents, respectively. Ventricular tachyarrhythmias were recorded in 34% of overall successfully interrogated CIED, and in 62% of decedents who experienced a SCD; of all ventricular tachyarrhythmias recorded, 40% was found in NSCD or NCD. A clear interpretation of the etiological role of recorded arrhythmias in the causation of death required integration with autopsy findings. Overall, potentially fatal device malfunctions were detected in 12% of cases.

Conclusions: Postmortem CIED interrogation is a valuable tool for the determination of the cause of death, and may complement autopsy. Forensic pathologists need to know the potential utility, pitfalls, and limitations of this diagnostic examination to make this tool as much reliable as possible.