Effects of inpatient and outpatient cardiac rehabilitation on the 5-year prognosis in patients with acute myocardial infarction

Aims Cardiac rehabilitation (CR) has been shown to improve the prognosis of patients with acute myocardial infarction (AMI). In Japan, the duration of hospitalization has shortened, resulting in a lower participation rate in CR among outpatients. Therefore, we evaluated the effects of CR, stratified into inpatient and outpatient phases, on the prognosis of patients with AMI in Japan. Methods and results A multi-centre, retrospective, cohort study in which extracted 4411 AMI patients from 72 institutes throughout Japan who were identified from a Japanese Registry Of All cardiac and vascular Diseases (JROAD) in 2014 was performed. JROAD is a database from Diagnosis Procedure Combination, and we additionally investigated the detailed information about severity, complications, treatment of AMI, the results of examinations, and the 5-year prognosis with respect to CR (JROAD-CR). The patients were divided into four groups, depending on their history of CR as inpatients and outpatients. The percentages of inpatients and outpatients who received CR were 66.1% (n = 2917) and 9.91% (n = 437), respectively. The groups in which only inpatients received CR [In(+)Out(−)] and in which both inpatients and outpatients received CR [In(+)Out(+)] showed significant reduction in all-cause mortality [In(+)Out(−) group; hazard ratio (HR): 0.720, 95% confidence interval (CI) (0.546–0.950) and In(+)Out(+) group; HR: 0.575, 95% CI (0.338–0.977)], although composite major adverse cardiovascular events did not show significant reduction. Conclusion This JROAD-CR study newly revealed that even short periods of CR during hospitalization are important, and continuing CR into the outpatient phase may further improve the prognosis of patients with AMI in this early reperfusion and short hospital staying era.