Survival Benefits of Outpatient Cardiac Rehabilitation after Acute Myocardial Infarction: Propensity Analysis Using Japanese Administrative Database

Survival benefit of outpatient cardiac rehabilitation (CR) after acute myocardial infarction (AMI) has recently been contested under the current real-world clinical practice. We investi‐ gated whether outpatient CR was associated with lower mortality and morbidity risks among Japanese AMI patients. We analyzed patients who were admitted for AMI and received both percutaneous coronary intervention and inpatient CR from January 2011 to December 2014, using a nationwide administrative database in Japan (final date of follow-up: July 31, 2016). We compared patients who received outpatient CR and who did not, and the primary outcome was a com‐ posite of all-cause death and recurrence of AMI after the landmark time-point of day 180 after discharge. We applied Cox proportional hazards model to estimate outcomes, and propensity-score matching was applied to adjust for baseline imbalances. [0.87, 2.27] years), 730 (12.9%) participated in outpatient CR at least once within 180 days of discharge. Of 1,458 propensity-score matched patients, outpatient CR participation was associated with lower but statistically non-significant risks among the pri‐ mary outcome (1.38 vs. 2.12 per 100 patient-years; HR = 0.71; 95%CI, 0.32 to 1.61). Among Japanese patients who admitted for AMI and received both percutaneous coronary intervention and inpatient CR, outpatient CR was underutilized, and associated with a statistically non-significant mortality and morbidity benefits. Further study is necessary to reaffirm the real-world effectiveness of outpatient CR under the current real-world clinical practice.