Trends in the use of implantable cardioverter-defibrillators for prevention of sudden cardiac arrest: A South Korean nationwide population-based study

Background: The benefits of implantable cardioverter-defibrillators (ICDs) for the prevention of sudden cardiac arrest (SCA) are well established. However, a significant knowledge gap remains regarding current indications and utilization of ICDs in real-world settings in Asia. Methods: Patients who underwent ICD implantation in South Korea from 2007 to 2015 were identified using the Health Insurance Review and Assessment Service database. We investigated trends in use of ICD for the prevention of SCA. Results: A total of 4649 ICDs were implanted during 9 years. ICDs were implanted in 1448 (31.2%) patients for primary prevention and in 3201 (68.8%) for secondary prevention. The proportion of ICDs for primary prevention increased from 6.1% in 2007 to 41.9% in 2015. Primary prevention was more frequent in older (≥40 years) recipients (34.4% vs. 14.6%, P <.0001). The rates of ICD implantation for primary prevention were highest for nonischemic dilated cardiomyopathy (55.1%) and lowest (9.7%) for inherited primary arrhythmia syndrome (IPAS). Conclusion: Our data showed a trend of progressively increasing rates of ICD implantation in Asia, especially for primary prevention of SCA. Primary prevention as an indication for ICD in patients with IPAS remained low.