Joint association of social determinants of health and congestive heart failure with mortality in U.S. adults.

Congestive heart failure (CHF) and social determinants of health (SDoH) are each associated with increased mortality risk, but their combined effects are not well understood. This study investigated the joint association of CHF and cumulative SDoH burden with all-cause and cardiovascular disease (CVD) mortality. Data were obtained from 38,937 U.S. adults aged ≥ 18 years participating in the National Health and Nutrition Examination Survey (NHANES) from 2003 to 2018. CHF was identified by self-reported physician diagnosis. Eight SDoH indicators across five domains were assessed and categorized into low (≤ 2) or high (> 2) burden. Cox proportional hazards models estimated the independent and joint associations of CHF and SDoH with mortality. Restricted cubic spline (RCS) models assessed non-linear associations. Subgroup and sensitivity analyses were performed, and Kaplan-Meier (KM) curves illustrated survival. Among 38,937 participants (mean age 47.1 years; 51.9% female), 3.4% had CHF and 54.0% had high SDoH burden. During a median follow-up of 8.1 years, 4,730 all-cause deaths and 1,224 CVD deaths were recorded. CHF was associated with elevated all-cause (HR = 2.31, 95% CI: 2.03-2.62) and CVD mortality (HR = 3.52, 95% CI: 2.90-4.26). High SDoH burden also increased the risk of all-cause (HR = 1.84, 95% CI: 1.69-1.99) and CVD mortality (HR = 1.92, 95% CI: 1.62-2.28). The highest risks were observed among individuals with both CHF and high SDoH burden (HR = 3.47 and 5.27, respectively). RCS analysis demonstrated significant non-linear, dose-response relationships (p for nonlinearity < 0.001). Joint risks were particularly elevated in younger adults (< 65 years), those with hypertension, and individuals lacking routine healthcare. Sensitivity analyses confirmed the robustness of findings. CHF and high SDoH burden are independently and jointly associated with increased mortality. Addressing both clinical and social risk factors is essential to reduce disparities and improve cardiovascular outcomes.