Cardiac rehabilitation (CR) has been shown to improve functional status, quality of life, and recurrent cardiovascular disease (CVD) events. Despite its demonstrated compelling benefits and guideline recommendation, CR is underutilized, and there are significant disparities in CR utilization particularly by race, ethnicity, sex, and socioeconomic status. The purpose of this review is to summarize the evidence and drivers of these disparities and recommend potential solutions. Methods: In this review, key studies documenting disparities in CR referrals, enrollment, and completion are discussed. Additionally, potential mechanisms for these disparities are summarized and strategies are reviewed for addressing them. Summary: There is a wealth of literature demonstrating disparities among racial and ethnic minorities, women, those with lower income and education attainment, and those living in rural and dense urban areas. However, there was minimal focus on how the social determinants of health contribute to the observed disparities in CR utilization in many of the studies reviewed. Interventions such as automatic referrals, inpatient liaisons, mitigation of economic barriers, novel delivery mechanisms, community partnerships, and health equity metrics to incentivize health care organizations to reduce care disparities are potential solutions.

Background HIV + people are at increased risk of coronary artery disease, but the responsible mechanisms are incompletely understood. Proprotein convertase subtilisin/kexin type 9 ( PCSK 9) is traditionally recognized for its importance in cholesterol metabolism; however, recent data suggest an additional, low‐density lipoprotein receptor–independent adverse effect on endothelial cell inflammation and function. We tested the hypotheses that PCSK 9 levels are increased and that abnormal coronary endothelial function is related to PCSK 9 serum levels in HIV + individuals. Methods and Results Forty‐eight HIV + participants receiving antiretroviral therapy with suppressed viral replication, without coronary artery disease, and 15 age‐ and low‐density lipoprotein cholesterol–matched healthy HIV− subjects underwent magnetic resonance imaging to measure coronary endothelial function, quantified as percentage change in coronary artery cross‐sectional area during isometric handgrip exercise, an endothelial‐dependent stressor; and blood was obtained for serum PCSK 9 and systemic vascular biomarkers. Data are presented as mean±SD. Mean serum PCSK 9 was 65% higher in the HIV + subjects (302±146 ng/ mL ) than in the HIV − controls (183±52 ng/ mL , P <0.0001). Coronary endothelial function was significantly reduced in the HIV + versus HIV − subjects (percentage change in coronary artery cross‐sectional area, 2.9±9.6% versus 11.1±3.7%; P <0.0001) and inversely related to PCSK 9 ( R =−0.51, P <0.0001). Markers of endothelial activation and injury, P‐selectin and thrombomodulin, were also significantly increased in the HIV + subjects; and P‐selectin was directly correlated with serum PCSK 9 ( R =0.31, P =0.0144). Conclusions Serum PCSK 9 levels are increased in treated HIV + individuals and are associated with abnormal coronary endothelial function, an established measure of vascular health.