Non-elective heart failure hospitalization in patients with cardiac resynchronisation therapy or dual chamber implantable cardioverter defibrillators in England: a retrospective cohort study

FUNDING ACKNOWLEDGEMENTS: Type of funding sources: Private company. Main funding source(s): BIOTRONIK SE & Co. KG BACKGROUND: Limited real-world data are available on the risk of non-elective heart failure-related hospitalization (HFH) in patients with de-novo cardiac implantable electronic devices. PURPOSE: The aim of this study was to quantify and compare the risk of HFH in two distinct HF cohorts: those with cardiac resynchronisation therapy devices including a defibrillator (CRT-D) and those with dual chamber implantable cardioverter defibrillators (DR-ICD). METHODS: Linked primary care data from the Clinical Practice Research Datalink (CPRD), secondary care data from Hospital Episode Statistics (HES) and mortality statistics from the Office of National Statistics (ONS) were used, reflecting a representative sample of patients treated within NHS England. Patients with a diagnosis or treatment for HF who received a de-novo CRT-D or DR-ICD between 1 April 2016 and 31 October 2019 were included. The study follow-up period extended to 31 October 2020. We calculated the median time to first post-implantation HFH and for those affected, the time from first-to-second and second-to-third admission. Univariable and multivariable Cox proportional hazards regression models were used to derive hazard ratios (HRs) and quantify the association between device type and admission. Results were adjusted for age, sex, and comorbidities. RESULTS: Data were analysed from 2,883 CRT-D (mean age 68.8 years, 79% male, median follow-up 39 months) and 1,643 DR-ICD (mean age 66.6 years, 80% male, median follow-up 41 months) patients. The CRT-D cohort had more baseline comorbidities. At 12 and 36-months post-implantation, the percentage of patients with at least one all-cause or CV-related hospital admission was similar between cohorts, but the percentage with a HFH differed. The risk of first HFH was greater in the CRT-D cohort than the DR-ICD cohort (HR=1.18; CI: 1.07–1.29; p<0.001). Median time to event was 19.8 months (IQR 4.9-38) for the CRT-D cohort and 26.6 months (IQR 6.5-44.6) for the DR-ICD cohort. However, there was no difference in the risk of subsequent HFH between the two cohorts (second admission: HR=0.99; CI: 0.88–1.17; p>0.9; third admission HR=1.05; CI: 0.86–1.27; p=0.6). The incident HFH risk for the CRT-D cohort increased from 17.3 per 100 person years for a first event to 46.6 per 100 person years for a second event and further increased to 76.3 per 100 patient years for the third event. CONCLUSIONS: Patients implanted with a CRT-D are at greater risk of first post-implant HFH, likely due to these patients having more severe HF. However, when the population is restricted to patients with a previous post-implant HFH, the risk is similar in patients with CRT-D and DR-ICD devices. For both devices, any HFH is associated with an increased risk of subsequent HFH. Future research should seek to identify strategies to reduce repeated HFH in these patient groups.