The Australian Genetic Heart Disease Registry: Insights into healthcare utilisation and outcomes for genetic heart disease

Abstract Background Genetic heart diseases, such as inherited cardiomyopathies and primary arrhythmia syndromes, cause significant morbidity and mortality, including sudden cardiac death at a young age. However, it is not well understood how these patients use health care services. Linking disease registry data to routinely collected health data can provide a more complete and unbiased clinical dataset. Purpose To investigate the health service use of individuals with genetic heart disease by linking a well-characterised cohort of patients from the Australian Genetic Heart Disease Registry (AGHDR) with routinely collected statewide health datasets. Descriptive analysis was used to compare participants by their genetic heart disease diagnosis. Methods Demographic, clinical, and genetic data for AGHDR participants recruited in New South Wales, between 2007-2019 were linked to statewide hospitalisations (available 2001-2019), emergency department (ED) presentations (2005-2019) and mortality registry (2007-2019) by the Centre for Health Record Linkage (CHeReL). Descriptive statistics were used to compare participants by their genetic heart disease diagnosis. Results A total of 1311 AGHDR participants were included, with the following diagnoses: hypertrophic cardiomyopathy (n=898), dilated cardiomyopathy (n=89), arrhythmogenic cardiomyopathy (n=46), left ventricular non-compaction (n=62), long QT syndrome (n=110), Brugada syndrome (n=65), and catecholaminergic polymorphic ventricular tachycardia (n=41). Mean age at diagnosis was 42 years (±18), and 585 (58%) were male. Participants had 8483 hospital admissions, with a median of 16 admissions per participant accounting for intra-hospital transfers (range 1-98). Mean age at first admission was 42 years (±17) (See Table 1 for breakdown by clinical diagnosis). Approximately one-third of hospital admissions were for circulatory system issues, with the remaining for other systems such as the digestive system (12%), musculoskeletal system and connective tissues (8%) and respiratory (5%). There was a total of 5213 ED presentations, with 32% of the cohort presenting >7 times (See Table 2 for breakdown by clinical diagnosis). Episodes were generally of suspected cardiac origin, with top diagnoses including chest pain (n=341, 43%), atrial fibrillation (n=190, 24%), palpitations (n=96, 12%), abdominal pain (n=74, 9%) and syncope (n=64, 8%). There were 49 deaths identified from the mortality registry, of which three occurred <50 years of age, 16 at 50-69 years and 30 at >70 years. Participants with a diagnosis of hypertrophic cardiomyopathy accounted for the majority of deaths (n=45 (92%)). Conclusion We provide important insights into real-world health service utilisation for individuals with genetic heart disease in Australia. Understanding the reasons for hospital admissions or ED presentations may help to identify potential disparities and opportunities for greater surveillance.