Analysis of terminal arrhythmias stored in the memory of pacemakers from patients dying suddenly

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.

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.

Analysis of causes of death in patients with implanted defibrillators

AIMS

Implantable cardioverter defibrillators (ICDs) are used for primary or secondary prevention of sudden cardiac death. We sought to clarify prognosis and causes of death after ICD implantation.

METHODS AND RESULTS

A total of 2743 patients with ICDs implanted during 1990-2020 were analyzed. Median age was 68.5 (59.6-74.6) years; 21% women, median left ventricular ejection fraction (LVEF) was 30 (23-35), 52% had an ischemic etiology and 77% had a primary preventive indication. Mortality rate after 10 years was 22, 44, 55, and 72% in the 1st, 2nd, 3rd, and 4^th age quartile, respectively. The calculated median sex and age adjusted loss of life years compared to the average German population was 9.7 (6.1-14.0) years. Prognosis was independently related to sex, age, LVEF, and glomerular filtration rate. 713 out of 852 deaths could be classified to a specific cause. Congestive heart failure (CHF) accounted for death in 214 (30%) and sudden death (SD) for 144 patients (20%). Postmortem interrogation of devices in 74 patients revealed VT/VF in 39 and no episodes in 35 patients. Cancer was identified as the cause of death in 121 patients (17% of cases), of which 36 were bronchial carcinomas. 73 (10%) of patients died due to infection. 67 patients (9%) died within 24 h of procedures. Compared to other causes, significantly more life years were lost associated with procedures and SD: 9.3 (5.7-12.9) versus 12.1 (7.4-15.2) and 11.9 (7.6-17.8) years.

CONCLUSION

Life expectancy of ICD patients is lower than for the general population. Mortality is predominantly due to CHF, but there is still a considerable rate of SD. The occurrence of cancers, most importantly bronchial carcinomas, and infections, warrants protective measures. Some deaths during procedures are possibly preventable. Patients with ICDs comprise a vulnerable cohort, and treatment has to be optimized in many directions to improve prognosis.

Cardiac Implantable Electronic Device Interrogation at Forensic Autopsy: An Underestimated Resource?

BACKGROUND

Postmortem interrogations of cardiac implantable electronic devices (CIEDs), recommended at autopsy in suspected cases of sudden cardiac death, are rarely performed, and data on systematic postmortem CIED analysis in the forensic pathology are missing. The aim of the study was to determine whether nonselective postmortem CIED interrogations and data analysis are useful to the forensic pathologist to determine the cause, mechanism, and time of death and to detect potential CIED-related safety issues.

METHODS

From February 2012 to April 2017, all autopsy subjects in the department of forensic medicine at the University Hospital Charité who had a CIED underwent device removal and interrogation. Over the study period, 5368 autopsies were performed. One hundred fifty subjects had in total 151 CIEDs, including 109 pacemakers, 35 defibrillators, and 7 implantable loop recorders.

RESULTS

In 40 cases (26.7%) time of death and in 51 cases (34.0%) cause of death could not be determined by forensic autopsy. Of these, CIED interrogation facilitated the determination of time of death in 70.0% of the cases and clarified the cause of death in 60.8%. Device concerns were identified in 9 cases (6.0%), including 3 hardware, 4 programming, and 2 algorithm issues. One CIED was submitted to the manufacturer for a detailed technical analysis.

CONCLUSIONS

Our data demonstrate the necessity of systematic postmortem CIED interrogation in forensic medicine to determine the cause and timing of death more accurately. In addition, CIED analysis is an important tool to detect potential CIED-related safety issues.

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

AIM

Post-mortem interrogation of the cardiac implantable electronic devices (CIEDs) in combination with autopsy findings can provide additional information regarding device functioning after implantation or the mechanism of death. The aim of the study is to review the available data on the post-mortem interrogation of CIEDs and its possible clinical implications.

METHODS AND RESULTS

A systematic review of the published studies has been performed. Out of 762 unique citations 14 have been retained for final analysis. Post-mortem CIED interrogation reliably detects both serious device malfunctions and lead disorders but also improper device programming. As the need for CIED implantation is growing in the low-income countries, currently available data on battery longevity of devices explanted and destined for re-use have been reviewed.

CONCLUSIONS

Post-mortem CIED interrogation provides a unique opportunity to explore different mechanisms of death, often unavailable for distinction during regular in-hospital observation or in autopsy analysis.

Postmortem interrogation of cardiac implantable electrical devices may clarify time and cause of death

BACKGROUND

Postmortem interrogation of cardiac implantable electrical devices (CIED) in autopsy is not routinely performed. Thus, it remains unclear whether an interrogation might clarify time and cause of death.

METHODS

Seventy of 4401 patients (1.6%) undergoing autopsy in 2014 and 2015 presented with a CIED. The explanted CIED were interrogated with respect to time and possible cause of death. Battery and lead parameters, clinical and technical alerts, and arrhythmia episodes were reviewed and afterwards correlated with the results of autopsy and clinical data.

RESULTS

Twenty-five implantable cardioverter defibrillators (ICD) and 45 pacemaker (PM) devices were analyzed. Death was classified as cardiac by autopsy in 17 of 70 patients. Accordingly, presumably lethal ventricular arrhythmias were documented in six patients (8.6%; 5 ICD, 1 PM). In two of 30 patients with unknown cause of death after autopsy (6.7%), interrogation revealed ventricular tachycardia as potential reason for decease (1 ICD, 1 PM). Postmortem CIED interrogation additionally allowed to make a statement regarding the day of death in 36 patients (51%; 13 ICD, 23 PM). This was in accordance with clinical data or the results of autopsy in nine patients (25%; 3 ICD, 6 PM) or could even clarify the time of death in six patients (16.7%; 4 ICD, 2 PM).

CONCLUSION

Interrogation of CIED revealed potentially lethal ventricular arrhythmias in 9 of 70 patients investigated and enabled valid estimation of the day of death in 15 patients. We therefore conclude that routinely performed postmortem CIED interrogation may clarify time and cause of death.

Clinical Inferences of Cardiovascular Implantable Electronic Device Analysis at Autopsy

BACKGROUND

Cardiovascular implantable electronic device (CIED) removal and interrogation are recommended at autopsy in suspected cases of sudden cardiac death, but data on the role of nonselective post-mortem CIED (pacemaker or defibrillator) analysis in this setting are lacking.

OBJECTIVES

This study undertook an institutional registry analysis to determine the utility of systematic routine CIED removal, interrogation, and analysis at autopsy.

METHODS

From May 19, 2009, to May 18, 2015, autopsy subjects with a CIED at a Johns Hopkins University medical institution (Baltimore, Maryland) underwent CIED removal and interrogation by an electrophysiologist for clinical alerts. The CIED was then submitted for technical analysis by the manufacturer. The CIED interrogation, the manufacturer's technical analysis, and the final autopsy report were all cataloged in the Johns Hopkins Post-mortem CIED Registry.

RESULTS

A total of 2,025 autopsies were performed; 84 subjects had CIEDs removed and analyzed. These devices included 37 pacemakers and 47 defibrillators. Overall, 43 subjects had died suddenly, and 41 had not died suddenly. Significant clinical alerts (sustained tachyarrhythmias or an elevated fluid index value) were seen in 62.8% cases of sudden deaths. In the nonsudden death cohort, 19.5% displayed a significant clinical alert. Significant association of CIED alerts were noted when comparing sudden deaths versus nonsudden deaths (p < 0.001), defibrillators versus pacemakers (p < 0.005), and cardiac versus noncardiac causes of death (p < 0.001). Manufacturer analyses revealed a case of premature pacemaker battery depletion, as well as a hard reset in a defibrillator as a result of cold exposure.

CONCLUSIONS

Post-mortem CIED analysis was clinically useful in assisting with determination of the timing, mechanism, and cause of death in the majority of sudden deaths and in almost 20% of nonsudden deaths. The authors advocate CIED removal with analysis as an important diagnostic tool in all autopsies and to assist manufacturers in identifying potentially fatal device failures.

Sudden cardiac arrest in patients with severe nonischemic heart failure: risk stratification with the heart failure survival score

The authors wanted to investigate whether the heart failure survival score (HFSS) is useful for sudden cardiac arrest (SCA) risk stratification and whether there is a difference with regard to congestive heart failure (CHF) etiology. Data of 712 severe CHF patients (New York Heart Association III/IV 58%/42%, mean age 62+/-8 years, mean left ventricular ejection fraction 26%+/-11%) during the period from 1993-2003 were analyzed. The HFSS was calculated using the Aaronson formula. SCA-free survival was calculated using Kaplan-Meier analysis according to the etiology of CHF: coronary artery disease (CAD) (n=317) vs no CAD (n=395). In regard to SCA risk, the authors found no significant overall difference between patients with or without CAD. Non-CAD HFSS high-risk patients had a significantly higher risk for SCA than all the other groups ( P<.001). The HFSS is useful for the detection of a subgroup of non-CAD severe CHF patients at very high risk for SCA.

The mystery of sudden death: mechanisms for risks

This review addresses the possible overlapping mechanisms that may apply to the risk of sudden unexpected death occurring in epilepsy and in cardiac disease. It explores the interaction between the central and peripheral autonomic nervous systems and the cardiopulmonary systems. Included is a discussion of the potential interactive role of genetically determined subtle cardiac risk factors for arrhythmias with a predisposition for seizure-related cardiac arrhythmias. We address the possible mechanisms that are operant in producing both epileptogenic and cardiogenic arrhythmias. Finally, we speculate about potential preventive measures to minimize the risk of both sudden unexpected death in epilepsy and sudden cardiac death.