Abstract
Participation and adherence to cardiac rehabilitation (CR) remain low worldwide; meanwhile, differences in barriers between industrialized and developing countries have not been well synthesized. A scoping review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) guidelines to map recent evidence (2014-2025) on barriers to CR participation and adherence in industrialized and developing settings. Searches conducted in major databases identified 538 records, of which 19 met the inclusion criteria for thematic analysis. Participation in CR ranged from 12.3% to 81% in industrialized countries and from 5% to 70% in developing settings, while adherence ranged from 70.8% to 90.3% and from 20.4% to 71.3%, respectively. Reported barriers can be clustered into patient-level beliefs and perceptions, logistical and work-related constraints, comorbidities and health status, socioeconomic and demographic factors, psychological characteristics, and health-system and environmental limitations. A wide variation in CR utilization persists globally, with distinct patterns of barriers across industrialized and developing contexts. These findings highlight the need for setting-specific strategies to improve CR participation and adherence.