Deprivation and device therapy: understanding the impact of socioeconomic status on ICD therapy outcomes

Abstract Introduction More socioeconomically deprived patients have worse cardiovascular outcomes. However, relationships between socioeconomic status (SES) and implantable cardioverter defibrillator (ICD) therapy have not been studied. Purpose To determine whether patients with more deprived SES experience different rates of ICD therapy. Methods Retrospective analysis of patients who received an ICD at a single tertiary cardiac centre from 2017 to 2020. SES was computed utilising the Indices of Multiple Deprivation (IMD) and patient’s postcode at date of implant. IMD is produced from the domains: income; employment; health deprivation and disability; education, skills training; crime; barriers to housing and services; living environment. Baseline variables included device type, implant indication, ICD programming, cardiovascular risk factors and medications. ICD therapies were classified as appropriate (AT) for ventricular tachycardia (VT) or ventricular fibrillation (VF), and inappropriate (IT) for all other therapies. Devices were programmed with ICD therapy zones enabled at 200 BPM or above. Univariate and multivariate Cox regressions were used to identify predictors, and Fine-Gray competing risk models to assess the thresholds of deprivation rank on therapy outcomes. Results The cohort included 844 patients with a follow-up duration of 625 ± 306 days. Lower SES (more deprived) patients showed a trend toward increased AT in the multivariate Cox model, with a hazard ratio (HR) of 1.000 (95% CI: 0.999–1.000, p = 0.023). The upper three SES quartiles showed a 48.4% reduction in the AT/annualised event rate compared to the lowest quartile (0.044 vs 0.085 events per patient-year). The Fine-Gray competing risks model confirmed these with a HR of 0.50 (95% CI: 0.32–0.77, p = 0.0017) for the lowest deprivation quartile (Figure 1). Interestingly, deprivation rank was not associated with IT in univariate or multivariate analyses. Conclusion Our findings indicate that patients who reside in the lowest quartile of deprived areas are more likely to experience AT from their ICD, without any association with IT. This suggests that SES factors are related to the occurrence of VT or VF. These could be related to chronic stress levels and increased sympathetic drive triggering arrhythmias as well as factors influencing cardiovascular risk, medical compliance and healthcare support. These data highlight the importance of considering SES in management of ICD patients. Clinicians, service managers and policymakers should be aware of the SES disparities to provide equity in ICD outcomes. Further research is needed to assess the specific factors and mechanisms causing this trend to create a more personalised care package for ICD patients to improve outcomes.Figure 1