Abstract Body (Do not enter title and authors here): Background
Social health, including social isolation and kinlessness, has important implications for older adults. Social isolation and lack of traditional kin networks has been associated with adverse health outcomes including long-term facility placement, healthcare utilization, and all-cause mortality. Prior studies report 6-10% of older adults in the US are kinless. However, little is known about the prevalence and impact of kinlessness on older patients with advanced heart failure (HF), particularly given the psychosocial requirements for advanced therapies.

Aim
To describe the social support structures and their association with clinical outcomes in older adults with advanced HF at a large academic advanced HF center.

Methods
We abstracted data from the electronic medical records of adults >70 referred for management of advanced HF from 2012-2022. Patients were excluded if they did not have clinical HF or were not seen by an advanced HF physician.

Results
834 older adults were referred for management of advanced HF. Median age was 75 years (IQR 7), 68% were male, and 71% were white. Mean ejection fraction was 35 (SD 17.4), and most were NYHA class III-IV (62%) at time of referral. In terms of social support, 574 (69%) were married and 734 (88%) had living children, whereas only 28 (3.3%) had no documented living 1^st degree relatives. One hundred twenty (14%) lived alone. Overall, 35 (4.2%) received a left ventricular assist device (LVAD) and 23 (2.8%) received a heart transplant (HT). LVAD recipients were more likely to be married (89%, p<0.001) and have living children (83%, p<0.001). All HT recipients had living children (100%, p=0.03), and they were more likely to be married (70%, p=0.01). No patients without a spouse or living child received an advanced therapy. Overall, 298 (36%) of patients died during the study period. While mortality did not vary by kin status, married adults were more likely to die on hospice (49% vs. 39%), and those with children were less likely to die in the hospital or ICU (38% vs. 43%).

Conclusion
Very few (3.3%) older adults referred to an academic advanced HF center lack a living spouse or child, suggesting that kinless older adults are under-referred. Having a living spouse or child was associated with greater rates of LVAD and HT, as well as rates of hospice and out-of-hospital death. These data may identify important disparities in advanced therapies and end-of-life care for older adults with advanced HF who are kinless.