Background: Prior studies of cardiac rhythm management devices (pacemakers [PM] and implantable cardioverter defibrillators [ICD]) utilization in the United States have been limited to the Medicare population. We evaluated the national trends for the implantation of PMs and ICDs including the burden of device replacement.
Methods: The Nationwide Inpatient Sample was queried to identify PM and ICD patients between 1993 and 2006 using ICD-9-CM codes, including demographics, health profile, and economic data. The Charlson Comorbidity Index (CCI) and replacement burden were calculated, and changes over time studied.
Results: From 1993 to 2006, 2.4 million patients received a primary PM and 0.8 million received an ICD, while there were 369,000 PM replacements and 74,000 ICD replacements. Women comprised 49% of PM and 24% of ICD patients. The mean ICD replacement burden was 8.4% (range 5-22%) and decreased significantly over time (P < 0.0001) while the replacement burden for PMs was constant (mean = 13.4%, range 11-16%). ICD patients had more comorbidities than PM patients (CCI: 0.8 vs 1.1, P < 0.0001).
Conclusions: The replacement burden for PMs has remained constant, while the replacement burden for ICDs has decreased. This is likely due to the stability of the patient population receiving PMs and technology maturity. Alternatively, the indications for ICD implantation have broadened, resulting in an increased number of primary ICD implantations. The age and comorbidities are increasing in those patients receiving ICDs while the PM population is stable. These data suggest that monitoring of replacement burden is warranted, given the changing populations, their disparate clinical outcomes, and economic implications to the health care system.