Socio-Economic Status and the Effect of Guideline-Directed Medical Therapy in the STRONG-HF Study

AIMS: Acute heart failure (AHF) impacts millions globally, with outcomes varying based on socio-economic status (SES). METHODS: SES measured by annual household income, years of education and medical insurance coverage. Each patient's income and education level relative to the median or mean, respectively, in the country was calculated, and categorized into tertiles (0, 1 or 2 from lowest to highest). SES scores (0-5) were computed as the sum of these levels plus insurance coverage (0 = no or 1 = yes). Patients' baseline characteristics, outcomes (HF readmission, death and their composite) and the effect of high-intensity care (HIC) vs. usual care (UC) were examined by SES scores 0-2, 3 and 4-5. RESULTS: Lower SES patients, who were younger, predominantly female, Black and non-European, had fewer comorbidities such as atrial fibrillation, diabetes and ischaemic heart disease and exhibited milder HF, indicated by a lower NYHA class, lower creatinine and higher cholesterol before discharge. Despite having milder HF and less comorbidities, after adjusting for baseline characteristics, patients with higher SES had numerically better outcomes, though differences were not statistically significant. 180-day hazard ratios (HRs) for HF readmission or death were 0.75 (95% CI 0.48-1.16) for SES scores of 3 and 0.85 (95% CI 0.58-1.23) for scores of 4-5, compared to 0-2. Higher SES patients had numerically better treatment effect from HIC, with HRs of 0.69 for SES 0-2, 0.72 for SES 3 and 0.50 for SES 4-5. CONCLUSIONS: In this post hoc analysis of the STRONG-HF study, lower SES was associated with milder acute HF but similar 180-day outcomes. Higher SES patients benefitted more from HIC.