A modelling tool can estimate the longevity of a variety of cardiac implantable electronic devices (CIEDs) in different settings allowing clinicians to choose the most appropriate device for each patient, a study finds.
Clinicians have found it challenging to compare the life of different pacemakers, the researchers wrote in the journal PLOS One, yet device longevity is of key importance to patients and payers.
The research team from the University of Leeds in the UK, Grenoble Alpes University and Grenoble Alpes University Hospital in France, built on previous work to design the Power Consumption Index (PCI). This would allow clinicians to estimate and then compare the longevities of CIEDs across models, manufacturers, settings and pacing options.
The PCI aimed to describe the intrinsic power consumption of the overall pacing system coupled with the battery over one hour, they said.
PCI was equal to t x I/C, the researchers explained, where ‘t’ was a constant of one hour, ‘I’ was the current required by the device and ‘C’ was battery capacity.
For the study, the research team used published data from the user manuals of all commonly used pacemakers including single chamber, dual chamber, cardiac resynchronisation and leadless devices to inform each device’s PCI calculation.
They aimed to determine which of the features used the most power, how they affected the longevity of the battery and how many years of battery power could be gained by deactivating them.
Comparing CIED longevity and programming options
To test the index, a set of fictitious patient data sets were created via a Monte-Carlo simulation and used to model CIED survival curves, which were then compared with real-life data from a Swedish pacemaker register, before the model was used to forecast survival curves for contemporary devices.
Importantly, the researchers found more than 50% of the PCI, and a significant contributor to energy consumption, was accounted for by background current.
Pacing current was found the second most significant contributor to energy consumption, they said, accounting for 20% of the PCI for standard single and dual chamber devices, 30% for CRT-P and 40% for leadless devices.
In addition, certain pacing algorithms and Intracardiac Electrogram (IEGM) storage also considerably impacted specific devices with longevity losses of up to one year.
‘The Monte-Carlo analysis demonstrated consistency between projected longevities by the PCI model and real-life data for historical devices and the calculated longevities that stemmed from this were consistent with the real-world data from Sweden,’ they wrote.
They concluded that the PCI model combining power consumption and battery capacity allowed a comparison of longevity across CIEDs and programming options.
‘Such a tool could help implanters improve personalisation of device prescription for their patients and payers to make more informed decisions about tailoring device purchases and programming most appropriate for their population,’ they added.
Benefits for patients and health systems
Study co-author Dr Klaus Witte, senior lecturer at the University of Leeds School of Medicine and consultant cardiologist at Leeds Teaching Hospitals NHS Trust, said the research was the ‘first step towards helping doctors to decide which pacemaker to choose and which programmes to activate’ for each patient so they have the device and battery life they need.
‘This will hopefully delay battery replacements or maybe avoid them altogether – which is good for patients, the NHS and wider society as a whole,’ he said.
Dr Witte explained clinicians often feel unsure about how different pacemaker options impacted the device’s battery life.
‘Together, the patient and the doctor can discuss which functions are necessary, and which are “nice to have”, as well as what cost to the battery there is for each option,’ he said.
‘Combining this with our previous publications that show how careful programming can help extend battery life, we are closer to providing patients with truly personalised care.’