Implantable Cardioverter-Defibrillators: Is There Life after 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.

Cardiovascular implantable electronic device function and longevity at autopsy: an underestimated resource

BACKGROUND

The feasibility and safety of postmortem cardiovascular implantable electronic device (CIED; pacemaker or defibrillator) retrieval for reuse has been shown. To date, studies indicate a low yield of reusable postmortem CIEDs (17%-30%).

OBJECTIVE

The purpose of this study was to test the hypothesis that a higher rate of reusable CIEDs would be identified upon postmortem retrieval when an institutional protocol for systematic and routine acquisition, interrogation, reprogramming, and manufacturer analysis was used.

METHODS

Over a 6-year period, all subjects referred for autopsy underwent concomitant CIED pulse generator retrieval and enrollment in the Johns Hopkins Post-Mortem CIED Registry. CIEDs were interrogated, reprogrammed, and submitted for manufacturer analysis.

RESULTS

In total, 84 autopsies had CIEDs (37 pacemakers, 47 implantable cardioverter-defibrillators). CIEDs were implanted 2.84 ± 2.32 years before death, with 30% implanted <1 year before death. Overall, CIED postmortem longevity was 4.79 ± 3.41 years, with 56% demonstrating longevity ≥4 years (this group had an estimated mean longevity of 7.37 ± 2.44 years). Manufacturer analyses uncovered 2 falsely triggered elective replacement indication alerts, confirmed 5 correctly triggered elective replacement indication alerts, identified a recalled pacemaker, and verified that a defibrillator had undergone nonprogrammable hard reset.

CONCLUSION

When a protocol for systematic and routine postmortem CIED retrieval, interrogation, reprogramming, and analysis was used, we noted that >60% of pacemakers and >50% of defibrillators demonstrated normal functional status with projected longevities >7 years on average. Formation of a national hospital-based "CIED donor network" would facilitate larger scale charitable efforts in underserved countries.