Effects of Exercise-Based Cardiac Rehabilitation on Risk Factors, Fitness, and Quality of Life in Patients Undergoing Percutaneous Coronary Intervention: Emergency Department Versus Outpatient Routes

<b>Background/Objectives:</b> Hospital visits for the treatment of coronary heart disease primarily consist of routine outpatient (OP) or unscheduled emergency room (ER) visits. This study compared the effectiveness of cardiac rehabilitation (CR) based on the routes of hospital visits after percutaneous coronary intervention (PCI). <b>Methods</b>: Only men who completed three CR center visits (baseline, 6 months, 12 months) during the 12 months after PCI were analyzed. A total of 300 male patients were analyzed, with 206 patients in the OP group and 94 in the ER group, and their socioeconomic status, blood lipids, blood pressure, volume of oxygen peak (VO₂ peak), physical activity, and quality of life (QoL) were compared. This study is a retrospective analysis. <b>Results</b>: The ER group was older and had lower economic income than the OP group (<i>p</i> < 0.05). In the OP and ER groups, total cholesterol (OP -10.4%, and ER -8.6%) and low-density lipoprotein cholesterol (OP -10.9% and ER -8.2%) improved in the third visit compared to the first visit (<i>p</i> < 0.05). Additionally, VO2 peak (OP 16.5%, and ER 14.3%), physical activity (OP 25.1%, and ER 4.4%), and body fat (OP -5.8%, and ER -4.5%) ultimately improved in both groups (<i>p</i> < 0.05). The interaction effect by time and group showed that the OP group significantly improved compared to the ER group in terms of high-density lipoprotein cholesterol, VO₂ peak, exercise duration, grip strength, physical activity, body fat, and quality of life (<i>p</i> < 0.05). <b>Conclusions:</b> The 12-month CR program tended to improve outcomes in both groups, but the OP group showed greater improvements in high-density lipoprotein cholesterol, VO₂ peak, and QoL compared to the ER group.