Leaders in Pharmaceutical Business Intelligence (LPBI) Group

What is the risk of infection?

With no standard definition or reporting system, infection rates vary widely, and the commonly quoted risk of 0.5% for new implants and 1-5% for replacement procedures may be wrong.4 Infection, even if it seems superficial, usually necessitates extraction of the entire system. Simply treating the infection with antibiotics results in a much poorer outcome.5 The increased risk of infection associated with battery replacement makes it critical that we prolong the life of implantable devices as much as possible. The health economic grounds for minimising the number of replacements are also compelling.6

The current financial model discourages the development of longer life devices. Increasing longevity would reduce profits for manufacturers, implanting physicians, and their institutions. With financial disincentives for both manufacturers and purchasers it is hardly surprising that longer life devices do not exist.

Patients are often assumed to prefer smaller devices, but when offered the choice, over 90% would opt for a larger, longer lasting device over a smaller one that would require more frequent operations to change the battery.7 And given the risks that patients are exposed to during replacement, there is an urgent need to improve longevity by developing longer life batteries and using those in current devices more prudently.

What can be done now?

At present the main drive to improving longevity of pacemakers has been through programming changes aimed at reducing the amount of pacing8 or minimising the drain of current during pacing—for example, using high impedance leads. But devices are usually replaced when there is still substantial life left in the battery. For example, when a pacemaker reaches elective replacement indication, it is usually 3-12 months before it will reach its end of life. And even then, the battery may continue to function for several months. Early replacement may be reasonable for high risk patients (such as those who are entirely dependent on their pacemaker). However, we could delay replacement of the pulse generator until the batteries are virtually depleted in lower risk patients. The increasingly popular innovation of home monitoring of devices would facilitate this.

For ICDs the waste is even more striking; devices reach their elective replacement indication when they are still capable of delivering at least six full energy shocks. Each shock reduces the battery longevity by about 30 days. So for patients who receive no shock therapy we are prematurely discarding a device costing up to £25 000 (€33 000; $36 000), which could last at least another six months (current devices last four to seven years on average). We need to review the timing of replacement of implantable devices in all patients.