Device failure may contribute to sudden death with cardiac implanted devices

1. Amongst a group of 517 patients in San Francisco, CA who suffered from sudden cardiac death between 2011 and 2013, 22 had cardiac implantable electronic devices (CEIDs). More than half of these were thought to be from ventricular tachycardia or ventricular fibrillation.

2. Of the total number of deaths in this group of patients with CEIDs, half were related to device failure.

Evidence Rating Level: 4 (Limited)    

Study Rundown: Cardiac implantable electronic devices (CIEDs) have been instrumental in saving innumerable lives. However, even those who have these devices can suffer from sudden cardiac death. If these occur outside of the hospital, interrogation of the device to evaluate for device malfunction is rarely done. This study, which was conducted in San Francisco, CA from 2011 to 2013, was conducted to determine the causes of sudden cardiac death in people with CIEDs. Of the 517 patients who suffered from sudden cardiac death, 22 had cardiac implantable electronic devices (CEIDs). More than half of these were thought to be from ventricular tachycardia or ventricular fibrillation. Of the total number of deaths in this group of patients with CEIDs, half were related to device failure.

The strength of the study was the ability to capture all the SCDs in the city. However, since the geographic region was small and the time span of the study was short, the size of the cohort studied was relatively small. Moreover, despite thorough investigation, the exact rhythm at the time of death and the cause of death for some patients may be unclear.

Click to read the study, published today in JAMA Internal Medicine

Relevant Reading: Arrhythmic death in implantable cardioverter defibrillator patients: a long-term study over a 10 year implantation period

In-Depth [case series]: This study included all out-of-hospital sudden cardiac deaths (SCDs) that took place in San Francisco from 2011 to 2013. SCDs were all reported to the medical examiner, so most of these were likely captured. All SCDs in patients with CIEDs (pacemakers and implantable cardioverter defibrillators) were included. Pathologists, electrophysiologists, and neurologists had to agree on the cause of death after reviewing all of the patients’ medical records and the terminal rhythm captured by the CIED (i.e., determined after interrogation of the device).

There were 517 SCDs identified during the time period, of which 22 occurred in patients with CIEDs. Fourteen of these 22 patients had pacemakers, and eight had ICDs. Six of fourteen with pacemakers and seven of eight with ICDs died of ventricular tachycardia or ventricular fibrillation. Overall, 50% of the SCDs in these patients were related to device failure. These included hardware failure, under-sensing, and programming issues.

Image: PD

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