Health disparities in heart failure with reduced ejection fraction among immigrants in Sweden: data from the Swedish Heart Failure Registry

Abstract Introduction Health disparities in HF related to being an immigrant have not been characterised, and the underlying potential mechanisms remain unclear. Purpose To investigate whether immigrant status is associated with all-cause and cardiovascular (CV) mortality and HF hospitalisation (HFH) in patients with HFrEF, and to assess the extent to which socioeconomic circumstances, clinical severity, comorbidity burden, guideline-directed medical therapy (GDMT) use, and healthcare utilisation explain these associations. Methods Patients with HFrEF enrolled in the Swedish Heart Failure Registry (2005-2023) were considered for the current analysis. Immigrant status was defined by a recorded date of immigration in the Total Population Register. Outcomes were all-cause mortality, CV mortality, and first HFH. GDMT consisted of pharmacological treatments with class I recommendations in the ESC guidelines on HF during the study period, i.e. ACEi/ARB or ARNI(from 2016), beta-blockers, MRA, and SGLT2i(from 2021). Univariable and multivariable Cox proportional hazards regression models were fitted to investigate the association between immigrant status and outcomes. Mediation analysis was conducted to estimate the impact of socioeconomic circumstances, clinical severity, comorbidity burden, GDMT, and healthcare utilisation on these associations (Figure 1). All models were adjusted for sex and age. Results 60,286 patients with HFrEF were included, of whom 9% were immigrants, most commonly originating from Nordic and other European countries, followed by Asia/Oceania and Africa. Compared with non-immigrants, immigrants were younger, more often male, had lower socioeconomic status, fewer comorbidities except for diabetes and ischaemic heart disease (IHD), a comparable HF clinical severity profile, and received similar GDMT. Over a median follow-up of 2.2 years (IQR 0.6–5.7), immigrants had 31% and 35% lower crude risks of all-cause and CV death, respectively, with no difference in HFH. After adjustment for age and sex, immigrant status was associated with a 11% higher all-cause mortality, 9% higher CV mortality, and 22% higher HFH risk (Figure 2). Most of these associations were mediated by lower income, which explained approximately 75% of the association with all-cause mortality, 86% with CV mortality, and 39% with HFH. Other relevant mediators included worse NYHA class (≈30–43%), more impaired renal dysfunction (eGFR