PURPOSE: Heart transplantation (HT) and mechanical circulatory support (MCS) has improved heart failure (HF) patient (PT) outcomes; it has also led to increased caregiver (CG) responsibility pre and post-surgery. We assessed whether PT and CG factors were related to baseline CG perceived burden in 3 groups of CGs of HF PTs (60-80 years): (1) PT supported with MCS as a bridge to HT (HT BTT), (2) PT awaiting HT without MCS (HT non BTT), and (3) PT prior to MCS for destination therapy (DT MCS). METHODS: Between 10/1/15-12/31/18, we enrolled 302 CGs from 13 U.S. sites: 92 HT BTT, 101 HT non BTT, and 109 DT MCS. CG burden was measured with the Oberst Caregiving Burden Scale (OCBS:  time: higher score=more time spent on task and  difficulty: higher score=more difficulty of task). CGs also completed the EQ-5D-3L (Visual Analog Scale [VAS]: 0 [worst] to 100 [best] imaginable health state and 5 dimensions); STAI-State (higher score=more anxiety); PHQ-8 (score ≥10=significant depressive symptoms), and demographic/health history/impact of caregiving on own health questions. PTs completed the KCCQ-12, MoCA (measure of cognitive dysfunction) and all above measures except the OCBS. Analyses included multivariable logistic regression models in which the binary outcomes were whether individual OCBS difficulty and time scores were higher than the cohort median values of 1.20 and 2.26, respectively. RESULTS: CGs were 61.1±9.7 years, 85% spouses, 85% female, and 85% white. Overall CG difficulty was low and CG time spent was moderate. CGs who reported more difficulty on tasks perceived more impact on their own health and had more anxiety, with no differences by PT implant strategy (table). CGs with < a high school education and with more anxiety were likely to spend more time on CG tasks, with no differences by PT implant strategy (table). CONCLUSION: Only CG factors, and not PT factors, were related to CG perceived burden. Understanding factors that affect CG burden may aid in preoperative advanced therapies discussions.