Evaluating the Association Between Social Vulnerability and Outcomes of Heart Transplantation in the United States

Introduction

The Social Vulnerability Index (SVI) is a tool that was developed by the Centers for Disease Control and Prevention to help identify communities that are at risk of harm from social, economic, or environmental factors. This study evaluates the association between SVI and outcomes of adult heart transplantation (HT) in the United States.

Methods

The United Network for Organ Sharing registry was used to identify all isolated adult (≥18 y) HT recipients and their home address zip codes between 2010 and 2021. Recipients were classified into three SVI risk groups: low risk (SVI: <0.33), intermediate risk (SVI: 0.33-0.65), and high risk (SVI: ≥0.66). Kaplan–Meier analysis was used to estimate recipient survival probability based on SVI risk. Multivariable Cox proportional hazard models were built to evaluate the association of SVI with 1- and 5-y mortality.

Results

A total of 22,400 recipients distributed over 9753 zip codes were included. Unadjusted 1-y survival rates in the three risk groups were as follows: low risk: 90.5%, intermediate risk: 91.1%, high risk 90.9%, and Log-rank P = 0.550 and 5-y survival rates were as follows: low risk: 80.8%, intermediate risk: 78.6%, high risk: 76.1%, and Log-rank P < 0.001. Compared to low-risk recipients, risk-adjusted 1-y mortality hazard ratio was 1.02 (0.92-1.14, P = 0.657) for intermediate risk and 1.09 (0.95-1.24, P = 0.222) for high-risk recipients. Risk-adjusted 5-y mortality hazard ratio was 1.07 (0.99-1.16, P = 0.095) for intermediate-risk recipients and 1.17 (1.06-1.28, P = 0.002) for high-risk recipients.

Conclusions

Social vulnerability is associated with HT outcomes. The Centers for Disease Control and Prevention SVI may be a useful tool in identifying at-risk geographic areas where targeted efforts may be prudent for reducing disparities in HT outcomes.