Background: Caregivers provide critical support for patients with chronic diseases, including heart disease, but often experience caregiver stress that negatively impacts their health, quality of life, and patient outcomes. Objectives: We aimed to inform health care teams on an evidence-based approach to supporting the caregivers of patients with heart disease. Methods and Results: We conducted a systematic review and meta-analysis of randomized controlled trials written in English that evaluated interventions to support caregivers of patients with heart disease. We identified 15,561 articles as of April 2, 2020 from 6 databases; of which 20 unique randomized controlled trials were evaluated, representing a total of 1570 patients and 1776 caregivers. Most interventions focused on improving quality of life, and reducing burden, depression, and anxiety; 85% (17 of 20) of the randomized controlled trials provided psychoeducation for caregivers. Interventions had mixed results, with moderate non-significant effects observed for depression (Hedges' g=-0.64; 95% CI, -1.34 to 0.06) and burden (Hedges' g=-0.51; 95% CI, -2.71 to 1.70) at 2 to 4 months postintervention and small non-significant effects observed for quality of life and anxiety. These results were limited by the heterogeneity of outcome measures and intervention delivery methods. A qualitative synthesis of major themes of the interventions resulted in clinical recommendations represented with the acronym "CARE" (Caregiver-Centered, Active engagement, Reinforcement, Education). Conclusions: This systematic review highlights the need for greater understanding of the challenges faced by caregivers and the development of guidelines to help clinicians address those challenges. More research is necessary to develop clinical interventions that consistently improve caregiver outcomes.