Abstract Body (Do not enter title and authors here): Introduction
Neighborhood residence and health literacy are associated with cardiovascular outcomes, however their interactions in minoritized populations are unknown. We evaluated the association between neighborhood social vulnerability, heart failure hospitalization (HFH), and all cause mortality in a cohort of older Black and Hispanic individuals with prior diagnosis of HF in the northeastern US.

Hypothesis
Individuals living in the most socially vulnerable neighborhoods have the highest HFH and 12-month mortality, and having limited health literacy will exacerbate these effects.

Methods
We recruited individuals >60 years self-identified as Black race or Hispanic ethnicity with heart failure as part of the Screening for Cardiac Amyloidosis with Nuclear Imaging in Minority Population (SCAN-MP) study. We assessed their social vulnerability index (SVI) at the census-tract level; health literacy (HL) with the Newest Vital Sign; and symptom burden with the Kansas City Cardiomyopathy Questionnaire (KCCQ). Cox proportional hazards ratio models evaluated the association between participants’ SVI and HFH (with death as competing risk) and 12-month mortality. We assessed interaction of HL with SVI. Outcomes were stratified for those with limited health literacy.

Results
Of 619 participants (mean age 73y, 51% women, 85% Black race), 50% lived in neighborhoods of extreme vulnerability (>89^th percentile national ranking of SVI). Individuals in the highest quartile (versus lowest) of SVI had increased HF symptoms (KCCQ Overall Score 64.8 vs. 70.6) and lower adequate health literacy (10% vs. 19%). After adjusting for age, sex, ethnicity, and gait speed, the highest quartile of SVI (vs. lowest) experienced higher HFH with death as competing risk (HR 1.71 [1.06, 2.76], p=0.03) and higher 12-month mortality (HR [95% CI] 5.17 [1.13, 23.69], p=0.03). Formal test of interaction for health literacy was significant for HFH (p=0.04), but not mortality (p=0.99). In stratified analysis of those with limited health literacy, living in the most vulnerable neighborhood was especially associated with higher HFH (HR 2.69 [1.48, 4.88], p=0.001).

Conclusion
Older Black or Hispanic individuals with HF residing in neighborhoods with higher SVI had increased HFH and 12-month mortality. HL modified the association with HFH. These results suggest that addressing health literacy may impact the risk of HFH among those in the most vulnerable neighborhoods.