Background: Battery longevity is an important factor in cardiac implantable electronic devices (CIEDs). Over the years, longevity has improved since devices started coming onto the market in the 1980s.
As well as particular algorithms a device might have, longevity can highly influence the implant of certain devices. However, there is a lack of research on actual longevity of these devices. In reality – how long are they actually lasting? How does this compare to their predicted longevity? This study looks at the true-life span of CIEDs.
Objectives: A retrospective study looking at predicted longevity to actual longevity in cardiac resynchronisation therapy devices.
Methods: Forty patients who have either a cardiac resynchronisation therapy defibrillator (CRTD) or a cardiac resynchronisation therapy pacemaker (CRTP) and have undergone a generator change, were included in this study.
The device companies have very specific prerequisites for the device to achieve its predicted longevity. In order to adhere to this, certain characteristics from each device were recorded so the predicted longevity could then be calculated. These characteristics included: threshold, lead impedance, capacitor reform and percentage paced, as well as any therapies that have been delivered. Some predicted longevities were available on the company’s websites. 75% (28) of devices were Medtronic, 25% (10) Abbott, and 5% (2) Boston Scientific.
Results: Seventy-two percent (29) of the devices did not reach their predicted longevity. The average longevity of the devices was 60.95 months. With a minimum longevity of 37 months in a Medtronic CRTD (patient received 28 shocks) and maximum of 103 months in a Medtronic CRTP. CRTPs had an average longevity of 82 months compared to the CRTDs with 55 months, one boosting a predictive longevity of 127 months but only reaching 74 months. Further analysis of the predicted longevity revealed that the maximum longevity stated by one particular company was based on a CRTP with 100% sensing – this figure is redundant in most patients as they require 100% pacing. Other factors that greatly affected longevity was the lead impedance, devices with 1000 ohms lasted longer than devices with 500 ohms.
Conclusion: Very few CIEDs reach their predicted longevity. Unknown factors such as the amount of therapies that are given, add another complication in predicting how long the device shall last. In an ideal world, companies should display only the longevities that are relevant and realistic. Should compensation from the companies be received for any device that has fallen short of its predicted longevity? Further analysis on the newer generation of devices is needed