BACKGROUND: Coronary heart disease seriously jeopardizes human health and has become a principal public health problem of global concern. While percutaneous coronary intervention (PCI) repairs narrowed arteries and extends patients' lives, cardiac rehabilitation offers additional benefits post-PCI. Numerous previous studies have shown that cardiac rehabilitation can inhibit the progression of atherosclerotic plaques in patients after coronary intervention, effectively controlling patients' clinical symptoms and improving their quality of life. However, the current status of adherence to phase I cardiac rehabilitation is poor, and the variation in adherence to phase I cardiac rehabilitation among post-PCI patients in China are not well understood. This study aimed to identify the heterogeneity of adherence to phase I cardiac rehabilitation and its influencing factors in post-PCI patients through latent class analysis (LCA) to support individualized interventions. METHODS: PCI patients ( RESULTS: Adherence to phase I cardiac rehabilitation in post-PCI patients was classified into three groups: Good Adherence (31.2%), Poor Nutritional and Psychological Management (32.0%), and Lack of Exercise (36.8%). Limited social support, poor utilization of chronic disease resources, low education level, a history of alcohol consumption, and kinesiophobia are factors influencing the different latent subgroups ( CONCLUSION: Heterogeneity exists in the adherence to phase I cardiac rehabilitation of post-PCI patients. Healthcare professionals should implement targeted interventions based on the characteristics of each category to improve adherence.