Cardiovascular Implantable Device Analysis at Autopsy
What is the utility of systematic routine cardiovascular implantable electronic device (CIED) removal, interrogation, and analysis at autopsy?
Autopsy subjects with a CIED at a Johns Hopkins University medical institution underwent CIED removal and interrogation by an electrophysiologist. The CIED was then submitted for technical analysis by the manufacturer. The CIED interrogation, manufacturer’s technical analysis, and final autopsy report were all cataloged in the Johns Hopkins Post-Mortem CIED Registry.
From a total of 2,025 autopsies, 84 subjects had their CIEDs removed and analyzed. These included 37 pacemakers and 47 defibrillators. Overall, 43 had died suddenly and 41 had died nonsuddenly. Significant clinical alerts (sustained tachyarrhythmias or an elevated fluid index value) were seen in 62.8% of sudden deaths. In the nonsudden death cohort, 19.5% displayed a significant clinical alert. Significant association of CIED alerts was noted when comparing sudden deaths versus nonsudden deaths (p < 0.001), defibrillators versus pacemakers (p < 0.005), and cardiac versus noncardiac cause of death (p < 0.001). Manufacturer analyses revealed a case of premature pacemaker battery depletion, and a hard reset in a defibrillator due to cold exposure.
Post-mortem CIED analysis is clinically useful in assisting with the timing, mechanism, and cause of death in the majority of sudden deaths, and in almost 20% of nonsudden deaths. CIED removal and analysis may be an important diagnostic tool in all autopsies and to assist manufacturers in identifying potentially fatal device failure.
It is clear that as physicians and industry, we have failed to harness the full scope of the information available on CIEDs post-mortem. While CIEDs returned to the manufacturers undergo destructive testing with the goal of quality assurance, as far as one can tell, there is no attempt to collect and analyze clinical information with the goal of patient care quality improvement. In the study, the authors report that among seven subjects with defibrillators and documented ventricular tachycardia/ventricular fibrillation, there were four cases of ventricular undersensing, two cases with unsuccessful final internal shocks, and one case of withheld therapy due to a programmed heart rate cut-off for therapy set above the rate of the ventricular arrhythmia. These findings are consistent with a prior report from University of California at San Francisco, which is quoted in the article, and cautions us against being complacent in regard to the device reliability and optimization of programming. Much can be learned from the device life after a patient’s death.
< Back to Listings