Post mortem pro life - Should we analyse the implantable devices after death? A systematic review

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 I2 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.

[Cardiac implantable electric devices in forensic medicine : Overview from the forensic and cardiology perspective]

In 2021, about 75,000 persons in Germany died unnaturally or due to unexplained reasons. As a consequence, there are difficulties in more precisely identifying the time, cause and circumstances of death. Nevertheless, clarification is crucial not only from the clinical perspective, but these data are of considerable importance in the context of investigative procedures as they can be used to answer numerous legally relevant questions. Cardiac implantable devices (CIED) are of vital importance in the treatment of cardiac arrhythmias. In 2020 about 100,000 patients underwent CIED implantation in Germany. Therefore, CIED are present in a relevant proportion of the deceased mentioned above. The valuable source of information represented by postmortal CIED interrogation has been shown in numerous studies. Nevertheless, postmortal CIED interrogation is not routinely performed in the context of forensic medical examinations for reasons of practicability. This article summarizes benefits and limitations of postmortal CIED interrogation from the perspective of forensic medicine and cardiology and gives a recommendation for realization.

Forensic cardiac device analysis at the Los Angeles County Department of the Coroner: A 20-year experience

Cardiac implantable electronic devices (CIEDs) store information continuously; however, the log of these devices is rarely analyzed in forensic practice. We retrospectively reviewed all cases referred for CIED interrogation by the Los Angeles County Department of Medical Examiner-Coroner between 2001 and 2020. According to the Department's practice, CIED interrogation may be requested for decedents in which details or cause of death are not clear from autopsy and clinical history. The CIED analysis was considered informative for the coroner's investigation either if it detected an arrhythmia or malfunction likely related to decedent's terminal event or if it was essential to determine time of death or identity of decedent. A total of 57 CIEDs were evaluated during the 20-year period. In almost half of cases (26/57: 45.6%), device analysis was informative for coroner's investigation. Arrhythmias likely related to terminal event were commonly detected (21/57: 36.8%). Device malfunction was identified as the likely cause of death in almost 10% of decedents (5/57: 8.8%), including three cases of battery depletion (3/57: 5.3%), one case of misclassification of ventricular tachycardia as supraventricular tachycardia with failure to deliver therapy (1/57: 1.7%), and one case of lead failure due to a broken pacing wire (1/57: 1.7%). Not infrequently, CIED interrogation was essential for determination of time of death (9/57: 15.8%), and there was one case (1/57: 1.7%) in which interrogation was essential for identifying the decedent. Our study shows that postmortem CIED interrogation can provide unique information regarding mechanism and time of death, and decedent's identity.

Determination of time of death by blinded post-mortem interrogation of cardiac implantable electrical devices

Postmortal interrogation of cardiac implantable electrical devices (CIED) may contribute to the determination of time of death in forensic medicine. Recent studies aimed to improve estimation of time of death by combining findings from autopsy, CIED interrogation and patients´ medical history. CIED from deceased undergoing forensic autopsy were included, if time of death remained unclear after forensic assessment. CIED explanted from deceased with known time of death were analysed as a control cohort. CIED were sent to our device interrogation lab and underwent analysis blinded for autopsy findings, medical history and police reports. The accuracy of time of death determination and the accuracy of time of death in the control cohort served as primary outcome. A total of 87 CIED were analysed. The determination of time of death was possible in 54 CIED (62%, CI 52–72%). The accuracy of the estimated time of death was 92.3% in the control cohort. Certain CIED type and manufacturers were associated with more successful determination. Blinded postmortal analysis enables a valid determination of the 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 medicine.

Postmortem Interrogation of Cardiac Implantable Electronic Devices: A 15-Year Experience

OBJECTIVES

This study sought to define the feasibility and utility of postmortem cardiac implantable electronic device (CIED) interrogation.

BACKGROUND

The diagnostic yield of routine postmortem interrogation of CIEDs including pacemakers, defibrillators, and implantable loop recorders has not been established.

METHODS

The study reviewed all CIED interrogations in deceased individuals undergoing medicolegal investigation of sudden or unexplained death by the Victorian Institute of Forensic Medicine between 2005 and 2020.

RESULTS

A total of 260 patients (68.8% male, median age 72.8 years [interquartile range: 62.7-82.2 years]) underwent CIED interrogation (202 pacemakers, 56 defibrillators, and 2 loop recorders) for investigation of sudden (n = 162) or unexplained (n = 98) death. CIEDs were implanted for median of 2.0 years (interquartile range: 0.7-5.0 years), with 19 devices at elective replacement indicator and 5 at end of life. Interrogation was successful in 256 (98.5%) cases. Potential CIED malfunction was identified in 20 (7.7%) cases, including untreated ventricular arrhythmias (n = 13) and lead failures (n = 3, 2 resulting in untreated ventricular arrhythmia). Interrogation directly informed cause of death in 131 (50.4%) cases. A total of 72 (27.7%) patients had abnormalities recorded in 30 days preceding death: nonsustained ventricular tachycardia (n = 26), rapid atrial fibrillation (n = 17), elective replacement indicator or end-of-life status (n = 22), intrathoracic impedance alarms (n = 3), lead issues (n = 3), or therapy delivered (n = 1). In 6 cases in which the patient was found deceased after a prolonged period, interrogation determined time of death. In 1 case, CIED interrogation was the primary means of patient identification.

CONCLUSIONS

Postmortem CIED interrogation frequently contributes important information regarding critical device malfunction, premortem abnormalities, mechanism, and time of death or patient identity. Device interrogation should be considered for select patients with CIEDs undergoing autopsy.