PURPOSE: Involvement of caregivers (CGs) is crucial to successful outcomes of patients (PTs) awaiting heart transplantation (HT) and scheduled for durable mechanical circulatory support (MCS). Importantly, CG quality of life (QOL) may be impacted by providing care for older PTs with advanced heart failure (HF) awaiting these surgeries. We sought to identify both PT and CG factors related to QOL for CGs providing care to pts (60-80 years old (yo)) awaiting HT (with and without MCS) and destination therapy (DT) MCS. METHODS: Between 10/1/15-12/31/18, we enrolled 302 CGs of HF PTs from 13 U.S. sites: 193 awaiting HT (92 HT with MCS [HT BTT] and 101 HT without MCS [HT non BTT]), and 109 DT MCS. At baseline, CGs completed the EQ-5D-3L (Visual Analog Scale [VAS]: 0 [worst] to 100 [best] imaginable health state); STAI-State (range=20-80, higher score=more anxiety); PHQ-8 (range=0-24; score >10=significant depressive symptoms); and Oberst Caregiving Burden Scale (OCBS): 15 items (2 subscales, 1-5 range each): (1) time: higher score=more time spent on task, and (2) difficulty: higher score=more difficulty of task. CG demographics and clinical history (medical and surgical) were also collected. PTs completed the KCCQ-12 (an HF-specific QOL measure) and all above measures except the OCBS. Analyses included multivariable logistic regression models in which the binary outcome was whether the CG EQ-5D-3L VAS score was less than the cohort median value of 90. RESULTS: CGs (n=302) were 61.1±9.7 yo, 85% white, 85% female, and 85% spouses. CGs reported high overall QOL at baseline (mean/median VAS=83.8±14.0 and 90) with no significant differences between groups. CG EQ-5D VAS score less than 90 was correlated with number of CG comorbidities (p=0.001) and STAI-state (p=0.002) after adjusting for other covariates in the model. See table. CONCLUSION: CG- and not PT-specific factors were related to CG QOL prior to HT and DT MCS. Awareness of these factors may foster support of CGs.