Background: Cardiac rehabilitation (CR) after acute myocardial infarction (AMI) is recommended as a mandatory intervention in several national clinical practice guidelines published in America, Europe, and Korea to reduce recurrence and mortality. However, underutilization of CR is an established worldwide issue. In Korea, the promotion of CR is expected due to coverage by National Health Insurance. Nevertheless, the national status of CR use has not been reported. This retrospective cohort study aimed to investigate the current status of CR use in patients with AMI using nationwide data from the National Health Insurance Service of Korea. Methods: Patients with AMI admitted with the diagnosis of 'I21' code (from International Classification of Diseases, 10th revision, Clinical Modification) from July 1st, 2017 to June 30th, 2018 were included. CR use was defined as CR treatment or evaluation being performed during an outpatient follow-up period within 6 months after discharge. Participation rate and density were calculated nationally and by administrative division. Logistic regression analysis was performed to identify the influencing factors of CR participation. Results: Nationally, 1.5% of AMI patients (960/64,982) underwent CR during outpatient treatment after discharge. CR density was approximately 10. Logistic regression analysis revealed that influencing factors included old age, female sex, rural residence, and low Charlson comorbidity index. Conclusion: Hospital-based CR after AMI is underutilized despite its coverage by the National Health Insurance. More CR facilities have to be installed according to the needs of CR in various regions.

Aims Physical activity (PA) and systematic efforts, such as cardiac rehabilitation, are recommended by several national guidelines for those who have received heart valve surgery. However, only a few studies have demonstrated real-world situations, such as changes in the PA level after heart valve surgery, and their effects on long-term outcomes. We designed this study to investigate the changes in PA after heart valve surgery and their associations with mortality using nationwide representative data. Methods This study was performed using the Korean National Health Insurance Service database. We included patients who received heart valve surgery from 2009 to 2015 and underwent regular health checkups before and after surgery. Subjects were grouped according to their PA level before and after the surgery. Information on all-cause mortality was obtained until 31 December 2016, with a maximum follow-up period of 5 years. Results Of the 6587 subjects, 3258 (49.5%) were physically inactive after surgery. Among patients who were physically active ( n = 3070), 1196 (39.0%) became inactive after surgery. The postoperative ‘inactive’ group showed higher mortality than the ‘active’ group (hazard ratio (HR): 1.41, 95% confidence interval (CI): 1.08–1.83). The ‘inactive/inactive’ group showed the highest risk of mortality (HR: 1.69, 95% CI: 1.19–2.40) compared with the ‘active/active’ group. Conclusions Insufficient PA level after heart valve surgery is associated with higher risk of mortality. However, maintaining sufficient PA after heart valve surgery may be challenging for many patients. Therefore, systematic efforts, such as cardiac rehabilitation, should be considered in those who received heart valve surgery.