Follow-up tests and outcomes for patients undergoing percutaneous coronary intervention: analysis of a Japanese administrative database

Follow-up tests after percutaneous coronary intervention (PCI) are considered inappropriate for asymptomatic patients. Despite this perception, many cardiologists conduct follow-up tests as routine practice. The objective of this study was to investigate the survival benefits of follow-up testing after PCI in a real-world setting in Japan. A nationwide Japanese administrative database was used to identify unselected patients who underwent PCI with stent implantation between January 2010 and December 2013. We used time-dependent Cox proportional hazards models to evaluate the association between follow-up testing and outcomes. The primary outcome was the composite of all-cause death and acute myocardial infarction (AMI). Among a total of 21,409 patients, 15,095 (70.5%) completed follow-up testing, of whom 9814 (45.0%) underwent coronary angiography. During a median of 2.7 years of observation, the primary outcome occurred less frequently for patients who underwent follow-up testing (1.21 vs. 4.51% per year; adjusted hazard ratio, 0.59; 95% CI 0.52–0.67; p < 0.001). Individual rates of all-cause death and AMI were also lower for the patients who underwent follow-up testing. Follow-up testing was associated with a lower risk of all-cause death and/or AMI. However, because of the unexpectedly large effect and many limitations of the administrative data, our findings should be further investigated to assess the net benefit of follow-up tests. In addition, we do not intend to encourage routine follow-up tests for patients without clear clinical indications. Follow-up tests should be conducted in accordance with clinical indications.