123/Complication rates associated with the replacement and upgrade of implantable cardiac devices – A single-centre experience

Introduction: Worldwide utilisation of cardiac implantable electronic devices has increased in the past two decades (Mond et al., 2008). In the time following implant generator replacements/system upgrades it may be necessary for generator replacements or system upgrades due to battery depletion, device malfunction or disease progression. To date, few studies have assessed the complication rates of these second procedures at specialist centres.
Methods: A total of 1,221 procedures were retrospectively extracted from the Royal Brompton Hospital’s pacing database. Records of complications were crosschecked with a central database to identify all complication rates within a 6-month follow up period. Once crosschecked complication rates were calculated, and associated variables assessed using chi squared tests. Procedures involving lead extractions were analysed separately.
Results: The overall complication rate was 7.8% (95% CI 6.1–9.9%) for procedures not involving lead additions and 16.4% (95% CI 12.5–20.9%) for procedures involving lead additions. Procedure involving lead additions resulted in high incidence rates of lead displacements requiring revision (X2(1) = 12.827, p=0.001), pneumothorax requiring drainage (X2(1) = 10.029, p<0.001) and phrenic nerve stimulation (X2(1) = 22.667, p<0.001), compared to procedure without lead additions. The overall system infection rate was low (0.7%, 95% CI 0.3–1.4%). The majority of complications (67%) were reported in the first 29 days. Lead additions, level of operator complex devices and longer procedure times were all associated with higher complication rates. Procedures involving lead extractions resulted in significantly higher complication rates (X2(1) = 9.647, p=0.002).
Conclusion: The complication rates reported are similar to those found in large registries elsewhere (Kirkfeldt et al., 2014 and Poole et al., 2010). Several predictive factors of complication incidence have been highlighted, but further prospective data is needed to improve risk stratification prior to system upgrades/generator replacement procedures.