Coronary artery disease (CAD) remains one of the leading causes of mortality and disability worldwide [1]. An estimated 126 million individuals—approximately 1.72% of the global population—are currently affected, and this burden continues to rise despite advancements in acute cardiac care [2]. Population ageing, persistent exposure to modifiable risk factors, and widening health disparities contribute to the escalating global impact of CAD, underscoring the urgent need for effective secondary prevention strategies [3, 4]. Cardiac rehabilitation (CR) is a cornerstone of such prevention, with robust evidence demonstrating reductions in recurrent cardiovascular events, hospital readmissions, morbidity, and mortality. Traditionally, CR is organised into sequential phases: Phase I (inpatient CR), delivered during the acute hospitalisation following a cardiac event, focuses on early mobilisation, clinical assessment, risk-factor education, and preparing patients for discharge; Phase II (outpatient CR), a medically supervised programme initiated shortly after discharge, emphasising structured exercise training, lifestyle and risk-factor modification, optimisation of cardioprotective therapies, and psychosocial support; and Phase III (maintenance), a long term maintenance programme guided by health professionals focusing on exercise, self-management, and lifestyle integration [5]. Contemporary CR has since expanded into a comprehensive, multidisciplinary framework that incorporates exercise training, lifestyle modification, psychosocial support, health education, therapeutic optimisation, and dietary and smoking-cessation counselling [6, 7]. Collectively, these components target key modifiable risk factors such as physical inactivity, obesity, and tobacco use [8].

Despite these benefits, CR utilisation remains suboptimal worldwide. Participation is frequently defined as attendance at the first outpatient CR session [9] or completion of at least one supervised session [10], while adherence refers to the proportion of enrolled patients who completed the prescribed programme (i.e., non-dropouts), with several studies classifying attendance of $\ge$75% of scheduled sessions as completion [11, 12]. Nonetheless, CR utilisation remains low despite the presence of standardised recommendations. Participation in many high-income countries ranged from 40% to 50% [13], while rates in low- and middle-income settings are even lower [14]. Among those who enrol, adherence is frequently inadequate, and lower completion has been associated with higher rehospitalisation rates and poorer long-term outcomes [15, 16].

Over the past two decades, research has gradually shifted from demonstrating the clinical efficacy of CR to investigating the complex, multifactorial barriers that limit patient engagement [17, 18]. These barriers span healthcare delivery factors, socioeconomic challenges, individual characteristics, and environmental constraints [19, 20]. Nevertheless, a critical gap remains in the literature. There is limited comparative evidence that examined differences in barriers to CR participation and adherence between industrialised and developing countries. Given the substantial structural and contextual discrepancies across health systems, such comparisons are essential for understanding the global variability in CR uptake and for informing context-appropriate strategies to improve access and adherence. The absence of this perspective restricts the applicability of existing evidence and hinders efforts to design scalable, equity-focused interventions.

Therefore, this scoping review aimed to (i) identify recent barriers to participation and adherence to CR among patients with CAD and (ii) compare these barriers between industrialised and developing countries. Understanding these differences will enable policymakers, healthcare providers, and stakeholders to prioritise actionable areas for intervention and to develop sustainable strategies to increase participation and adherence in CR, ultimately reducing the global burden of CAD.

Cardiac rehabilitation is fundamentally a multidisciplinary programme that integrates health education, psychosocial support, lifestyle counselling, and therapeutic optimisation. In this review, several barriers to CR were identified, including inadequate knowledge of the disease and the associated risk factors [30, 38], misaligned perceptions of needs and benefits [32, 34], and insufficient social support [15]. These findings reflected the areas for improvement across the broader CR pathway, instead of issues solely linked to exercise.

A study by Conte et al. [41] demonstrated that most patients began CR with limited awareness of key modifiable cardiovascular risk factors, often underestimating the significance of physical inactivity, smoking, and diabetes. These gaps can be addressed by strengthening the educational, psychosocial, and lifestyle components of CR to enhance patient understanding, build confidence, and support sustained engagement. For instance, personalised training plans and the integration of technological tools have been proposed to educate CR participants to improve their awareness and adherence. While supervised exercise mitigates adverse cardiac remodelling and restores physical function, comprehensive education on cardiovascular risk factors, therapies, lifestyle modification, and therapeutic optimisation is equally critical for reducing morbidity and mortality [7].

Beyond individual-level influences, the broader distribution of barriers across contexts reflects deeper systemic shortcomings that continue to undermine equitable access to CR. In industrialised countries, persistently lower participation among older adults, women, and individuals with limited education signals entrenched inequities that current programme designs have yet to address effectively. Meanwhile, the dominance of financial, geographical, and time-related barriers in developing countries indicated structural deficiencies in health system planning, resource allocation, and service integration.

Logistical challenges, such as long travel distances, unreliable transportation, and inflexible work demands, also impacted CR participation and highlighted infrastructural gaps that remained unresolved despite existing evidence in the literature. The convergence of participation and adherence barriers further suggested that attrition stems not simply from individual motivation, but from a complex interplay of clinical, socioeconomic, and systemic constraints. Collectively, these findings underscore the need for CR programmes to move beyond traditional exercise-centric approaches and adopt context-responsive strategies that address social determinants and structural barriers to sustained participation and adherence.

Home-based CR delivers training, education, and lifestyle counselling remotely, often relying on digital tools such as wearables, mobile applications, and telemonitoring systems. Within this model, 64.66% of patients demonstrated good adherence, but was slightly lower than previously reported rates (73%–95%) [42, 43]. This change suggested that the unique demands of home-based delivery may amplify some barriers not typically encountered in hospital-based programmes. Generally, participants of home-based CR are required to self-regulate without real-time oversight, rendering behavioural determinants such as motivation, self-efficacy, and perceived social support to become disproportionately influential [44]. Likewise, the digital infrastructure underpinning home-based CR means that adherence is highly sensitive to technological factors, including platform usability, digital literacy, and access to reliable devices [45]. In contrast, centre-based CR are packaged with structured schedules, supervised sessions, and immediate professional feedback. Despite contributing to sustained participant engagement, this traditional approach has barriers observed in different phases. In Phase I (inpatient), challenges are commonly related to early referral, inconsistent delivery of inpatient education, and gaps in communication [46]. Patients often reported being uninformed about CR, lacking clinician support, or not being contacted by the CR staff [39]. Failures in continuity contribute to weak enrolment into Phase II (outpatient) services, despite the high participation during hospitalisation. Once patients transition to Phase II, the dominant barriers shift toward logistical issues such as distance, transportation, time constraints, and work responsibilities, as reflected across many outpatient studies [15, 25, 28, 33, 35, 39].

Patient perceptions, beliefs, and preferences were recognised as key factors influencing participation and adherence to the CR programme. Studies have shown that CR participation was positively affected by perceived needs, benefits, severity, and vulnerability [32, 34, 35]. These findings align with earlier studies, where increased perceived vulnerability and severity prompted changes in health behaviour, such as routine health screenings, treatment adherence, and avoiding additional injury [47]. Perceived vulnerability and severity were also combined in several studies and were identified as perceived threats that motivated behavioural changes and responsibility for patients’ health [48, 49]. Additionally, collaborative approaches such as shared decision making potentially improved CR adherence [38]. In summary, recognising individuals’ perceptual factors and fostering shared decision-making may enhance CR engagement and efficacy.

Physician support and programme delivery design emerged as critical healthcare system–level determinants of CR participation and adherence. Several studies demonstrated that strong physician recommendations, comprehensive patient education, and consistent follow-up substantially increased CR participation [33, 39], reinforcing the longstanding importance of physician referral [50]. Patients often reported seeking medical reassurance before enrolling in CR and were more likely to attend when guided by a trusted provider. This finding indicated the importance of patient support, particularly robust referral pathways that position CR as a standard component of secondary prevention rather than an optional add-on in their recovery. Automated referral systems have become popular for streamlining enrolment, but this method cannot mimic the influence of personal endorsement from primary care physicians or cardiologists [15], whose recommendations carry significant weight in patients’ decision-making [51].

Programme delivery design shaped patient engagement. For instance, face-to-face models were associated with higher completion rates than phone-based approaches [15]. Meanwhile, telehealth CR was perceived as lacking adequate mental health support, supervised exercise training, and opportunities for peer interaction, despite reducing barriers related to distance, travel, cost, and scheduling [52]. These outcomes suggested that optimising CR delivery requires tailoring programme components to the needs of specific patient subgroups instead of relying on uniform, one-size-fits-all models, besides ensuring that professional endorsement and programme structure support long-term engagement effectively.

Logistical challenges significantly hampered CR participation among patients, particularly geographic distance, transportation difficulties, and travel time. Notable regional variation was observed within the same country, as reported in Malaysia (27–70%) [35, 37] and China (5–25%) [25, 30]. The Malaysian population is distributed across Peninsular Malaysia and East Malaysia. Issues such as living far from CR centres or lacking access to private transportation were more pronounced in East Malaysia, making patients less likely to participate in CR programmes [37]. Similar patterns exist in China, where substantial geographic diversity, a large rural population, and the concentration of CR services in urban tertiary hospitals create significant access barriers. Patients were often frustrated with restricted and paid hospital parking [25], compounding existing travel and logistical difficulties and contributing to low participation.

Accessible medical care is commonly defined as being within a 30-minute travel radius [53], but studies examining journey-time thresholds for CR discovered that travel periods exceeding 60 minutes significantly reduced the likelihood of patient referral and participation [37, 54]. Findings from broader Asian settings suggested that the relationship between transport mode and participation is context-dependent. While self-driving facilitates attendance in some regions [37], non-drivers in urban areas with reliable public transportation may be more likely to participate in CR [35] due to reduced parking constraints and easier access to hospital facilities. This outcome was consistent with reports from Malaysian public hospitals, where long parking waits and limited capacity create additional barriers for patients who rely on private vehicles [55].

Work- and time-related conflicts remain major barriers to CR participation, with non-participants frequently citing inflexible working hours, job demands, and scheduling constraints as reasons for non-attendance [11, 25, 27, 28]. These challenges underscore the need for flexible programme formats, including home-based, hybrid, and after-hours options to accommodate working adults. Comorbidities exert an additional influence on participation and adherence, as chronic conditions such as diabetes, chronic obstructive pulmonary disease, and other cardiovascular risk factors were consistently associated with reduced involvement or higher dropout rates [11, 12, 15, 38]. Interestingly, findings from Chong et al. [35] diverge from this pattern, reporting higher participation among patients with multiple comorbidities in a mobile-based CR programme. This discrepancy may reflect the role of delivery modality, indicating the potential of flexible, technology-enabled models in reducing physical and logistical burdens experienced by multimorbid patients. Taken together, personalised and flexible CR designs that address occupational demands and the complexity of patients’ health profiles are superior in promoting CR participation compared to uniform, centre-based models.

Participation in CR within multiracial settings, such as Malaysia, demonstrated notable ethnic disparities, with Chinese and Indian patients participating at substantially lower rates than their Malay counterparts [35, 37]. These gaps extend beyond demographic proportions, highlighting broader socioeconomic inequalities, differences in health literacy, cultural perceptions of CR, and unequal access to healthcare services [56]. Financial barriers further exacerbated these disparities and consistently influence CR uptake across regions. Underprivileged groups face limited access due to programme costs [25, 27], and European findings associated lower income with significantly lower participation [57, 58]. In China, the absence of CR reimbursement under the National Health Service restricted affordability for outpatient follow-up, contributing to low engagement [25].

Lower socioeconomic status and education levels impeded CR participation more broadly [29, 31, 33], highlighting the need for subsidised programmes and targeted educational interventions to improve awareness and access. Employment status adds to the complexity of CR participation. While employed individuals often report time constraints, some evidence suggests that unemployed individuals may be more willing to participate due to greater schedule flexibility [12]. Collectively, these findings demonstrated that socioeconomic inequities, financial barriers, and differing life circumstances were critical in shaping CR participation, underscoring the need for context-responsive strategies that promote equitable access across diverse populations.

Age is a consistent determinant of CR participation and adherence, with middle-aged adults engaging at higher rates than older individuals [29, 31]. Older adults, regardless of gender, were less likely to enrol in or sustain structured exercise programmes [59]. Meanwhile, the oldest cohorts, particularly octogenarians, remain markedly underrepresented in CR research and programme design despite their substantial potential to benefit [60]. Several factors contributed to reduced engagement among older adults, including misconceptions about the impact of CR in health improvement, greater emotional distress, social isolation, and socioeconomic or functional limitations [61]. In contrast, younger patients tend to be more proactive in managing risk factors and perceive CR as valuable for long-term health. The consistent decline in participation with increasing age underscores the need to adapt CR delivery models, such as through hybrid or telehealth options, tailored support, or caregiver involvement, to ensure that programmes are accessible, acceptable, and responsive to the needs of older adults.

Evidence on gender influence on CR participation remains inconclusive. Some studies report higher engagement among men [12, 31, 37], whereas others report greater participation among women [29]. These conflicting patterns may reflect contextual differences. For example, women face additional practical and sociocultural barriers that limit attendance in several Asian settings, including caregiving responsibilities, transportation, comorbidities, and family obligations [37, 62]. In contrast, increasing public awareness and gender-focused cardiovascular campaigns in parts of Europe may have enhanced women’s engagement with CR [29].

Contrary to the relatively larger number of included studies examining gender, only a small subset explored mental health, also reporting inconsistent findings in this area. Depression has been associated with non-completion and reduced participation in CR [15, 63] and empirical evidence suggested that emotional distress arising from long waiting times and limited peer support may further discourage engagement [15]. Conversely, patients with better mental health management demonstrated higher completion rates, particularly in home-based CR models [38]. Meanwhile, some studies reported that anxiety increased the likelihood of participation [35, 64], while others demonstrated a negative relationship [65]. Collectively, these inconsistencies—combined with the limited number of mental health–focused studies—indicated that the effects of gender and psychological factors on CR uptake were highly context-dependent and shaped by sociocultural, emotional, and health-system influences, highlighting the need for more nuanced, stratified research and tailored intervention strategies.

Social support consistently emerged as a strong facilitator of CR participation and adherence. Patients who received encouragement from family members, friends, or community networks were more likely to enrol in and complete CR [12, 33, 35], whereas those who lived alone or lacked social support showed higher rates of dropout or non-completion [15, 36]. Notably, family and peer endorsement can shape patients’ perceptions of CR and reinforce decisions to engage in rehabilitation [66]. Evidence from Zhang et al. [24] further illustrated the value of structured social support, demonstrating that participants involved in the “Life Club” initiative were significantly more likely to complete CR than those without such support. These findings underscore the need for formal or informal social support integration in CR programmes to strengthen motivation, accountability, and sustained engagement among participants.

This scoping review has several strengths and limitations. A key strength of this study was the inclusion of evidence from industrialised and developing countries, enabling a comprehensive understanding of barriers across diverse healthcare and socioeconomic contexts. Furthermore, this study addressed a gap in earlier studies on mental health as an underevaluated yet potentially important factor influencing CR engagement, highlighting the need for further research to clarify the role in CR. In addition, only studies reporting a minimum of 100 participants were included in this review to reduce small-sample bias and improve evidence robustness. Nonetheless, several limitations should be acknowledged. Some data that were utilised in this study lack quantitative indicators, such as standard errors, measures of variance, correlation coefficients, and effect sizes, which precluded the possibility of conducting a meta-analysis. A systematic review with sufficient homogeneous data would allow for pooled estimates and provide stronger global evidence to enhance understanding of barriers to CR utilisation.

Participation and adherence to CR remain suboptimal globally despite the proven benefits. This scoping review demonstrated that barriers to engagement were multifactorial and varied across contexts. Demographic and psychosocial challenges were predominant in industrialised settings, whereas developing regions face pronounced financial, geographical, and infrastructural limitations. Meanwhile, issues such as transportation, comorbidities, and work demands affect patients universally. Engagement is further shaped by patient perceptions, physician endorsement, programme design, and the availability of social and mental health support, yet evidence regarding gender and psychological influences remains limited and inconsistent. Addressing these disparities will require tailored, context-responsive approaches that strengthen individual support, incorporate flexible delivery models such as hybrid or telehealth CR, and implement policy-level measures to reduce financial and logistical barriers. These strategies are essential for improving equitable access and optimising the impact of CR worldwide.

AL conceptualized the review, developed the search strategy, conducted the literature search, performed data charting and analysis, and drafted the initial manuscript. EH contributed to the design of the review protocol, provided critical input on data interpretation, and substantively revised the manuscript for important intellectual content. AS supervised the overall project, provided methodological guidance throughout the review, critically revised the manuscript for important intellectual content, verified the analytical processes, and served as the corresponding author. All authors contributed to the final manuscript, approved the submitted version, and agreed to be accountable for all aspects of the work.

Not applicable.

Not applicable.

This study was funded by the Malaysian Ministry of Higher Education (MOHE) through the Fundamental Research Grant Scheme (FRGS/1/2023/SS10/UiTM/03/4). The funder had no involvement in the study design; data collection, analysis, or interpretation; manuscript preparation; or the decision to submit the article for publication.

The authors declare no conflict of interest.

The authors used ChatGPT-5, a form of AI writing tool, to improve the grammar and spelling in the manuscript. The content of the manuscript was reviewed and edited accordingly prior to submission. The AI tool was only used to help with language editing; it did not help with coming up with ideas, analysing them, or interpreting them scientifically. The authors made all intellectual contributions, critical evaluations, and final edits.

Supplementary material associated with this article can be found, in the online version, at https://doi.org/10.31083/RCM45898.