Implantable cardioverter-defibrillator therapy in Australia, 2002-2015

Objectives: Quantify hospitalisation trends for implantable cardioverter-defibrillator (ICD) procedures and costs. Design and setting: Retrospective observational study using Australian hospitalisation procedure data. Participants: Patients with an ICD insertion, replacement, adjustment or removal procedure code (2002-2014). Main outcome measures: Number of ICD procedures stratified by procedure year, patient age (0-34; 35-69; ≥70 years) and sex. Age-adjusted population procedure rates per 100,000 population. Number of procedures associated with a complication. Estimated annual hospitalisation costs for ICD procedures. Results: Between 2002 and 2014, the annual number of ICD procedures increased 2.5-fold (1,844 to 6,504). Across all procedures, patients aged ≥70 years had considerably higher rates than their younger counterparts. For example, in 2014, the ICD replacement rate was 70 times higher for those aged ≥70 years than patients aged 0-34 years (43.9 vs. 0.6/100,000 population). The complication rate decreased from 45% to 19%, due primarily to a coding change. Across all years and procedure types, males underwent the majority of procedures (67-86%). The annual number of removals represented ≥4% of the number of insertions per year. Between 2011 and 2013, the annual cost of ICD hospitalisations increased 7% (A$144,036,822 vs. A$154,555,814) and aggregate costs for these 3 years was A$445,644,566. Conclusion: ICD procedures are increasing in Australia across all age groups, particularly for Australians aged ≥70 years. Given these increases, further studies should examine patterns of care associated with ICD therapy, particularly examining patient and/or hospital factors associated with adverse events, such as removals, to better understand and ultimately improve patient outcomes.