209C hina, a country in the midst of an epidemiological transition, faces many challenges in implementing evidence-based care to curb the growing burden of coronary disease. An aging population and increasing prevalence of cardiovascular risk factors have led to an epidemic of acute coronary syndrome (ACS) across China.1,2 Effective therapies for ACS care, however, continue to be variably used with widespread inequities.3 Furthermore, hospital human resources and adoption of technologies also vary substantially and are particularly limited in rural areas. 4,5 This suggests the presence of significant barriers to implementing change, yet our understanding of these barriers within the healthcare system of China is limited. Particularly, how system factors, that is, the organizational structures, health policies, and the wider social, economic, and political context, may affect efforts to implement evidence at the point of care is largely unknown.Understanding these system barriers is critical given their influence on quality of care. Organizational and wider system factors have been consistently shown to have a significant influence on organizational change, success or failure of implementation of interventions, and their effectiveness. [6][7][8][9] For example, in acute myocardial infarction care, differences in organizational values and goals, senior management involvement, and expertise in acute myocardial infarction care have been identified between high-and low-performing hospitals.10 However, much of our existing understanding about how system factors influence care comes from high-income countries. How they affect care in the unique and dynamic Background-Organizational and wider health system factors influence the implementation and success of interventions.Clinical Pathways in Acute Coronary Syndromes 2 is a cluster randomized trial of a clinical pathway-based intervention to improve acute coronary syndrome care in hospitals in China. We performed a qualitative evaluation to examine the system-level barriers to implementing clinical pathways in the dynamic healthcare environment of China. Methods and Results-A qualitative descriptive analysis of 40 in-depth interviews with health professionals conducted in a sample of 10 hospitals purposively selected to explore barriers to implementation of the intervention. Qualitative data were analyzed using the Framework method. In-depth interviews identified 5 key system-level barriers to effective implementation: (1) leadership support for implementing quality improvement, (2) variation in the capacity of clinical services and quality improvement resources, (3) fears of patient disputes and litigation, (4) healthcare funding constraints and high out-of-pocket expenses, and (5) patient-related factors. Conclusions-System-level barriers affect the ability of acute coronary syndrome clinical pathways to change practice.Addressing these barriers in the context of current and planned national health system reform will be critical for future improvements in the managemen...