Background: Post mortem interrogation of implantable electrical devices (CIED) may contribute to determination of time of death in forensic autopsy. Recent studies aimed to improve the estimation of time of death by an approach combining findings from autopsy, CIED interrogation and patients´ medical history.

As no data are available about the validity of blinded post mortem analysis for this issue, the postmortal CIED trial sought to elucidate the value of blinded post mortem CIED interrogation in a cardiological core lab for determination of time of death

Methods: The postmortal CIED trial is a prospective multicentre cohort study. Legal medical departments in Germany, Austria and Switzerland conducting autopsy for determination of time of death in patients with CIED were invited. CIED from participating legal medicine departments were included, if time of death remained unclear after autopsy. As a proof of principle CIED explanted during autopsy at our local legal medicine department with known time of death were analysed as a control cohort. Explanted devices were sent to our device interrogation core lab and underwent analysis blinded for autopsy findings and medical history. The accuracy of determination time of death and the accuracy of determination time in the control cohort served as primary outcome.  General feasibility of analysis in a distant core lab as well as identification of device concern were secondary outcomes.

Results: A total of 87 CIED were analysed. Determination of time of death was possible in 54 CIED (62%, CI 52-72%). Time of death could be determined within an exact hour in 25 (28.7%) or within exact day in 29 CIED (33.3%). The accuracy of estimation was 92.3% in the control cohort. CIED type (ICD superior to PM; p<0.01) and certain CIED manufacturer (p<0.01) were associated with successful determination whereas time between autopsy and CIED interrogation (p=0.4) and the number of CIED leads (p=0.4) were not.

Conclusion: Blinded post mortem analysis enables valid determination of time of death in the majority of CIED. Analysis of explanted CIED in a cardiological core lab is feasible and should be implemented in forensic autopsy.