Long-term Clinical Outcomes Following Cardiac Stress Testing After Percutaneous Coronary Intervention

Background: Cardiac stress testing (CST) is commonly performed after percutaneous coronary intervention (PCI), yet little is known whether such ischemic testing is associated with improved clinical outcomes. Methods: We studied patients who underwent their first PCI procedure from October 2008 to December 2016 in Ontario, Canada. Patients who underwent CST from 60 days to 1 year after PCI were compared with those who did not undergo CST. The primary outcome was a composite of cardiovascular death or hospitalisation for myocardial infarction (MI) at 3 years after CST. Inverse probability of treatment weighting was used to adjust for potential differences between the study groups. Results: Among the 86,150 included patients, 40,988 (47.6%) underwent CST within 60 days to 1 year after PCI. Patients who underwent CST had higher prescription rates of cardiac medications. At 1 year after CST, rates of cardiac catheterisation and coronary revascularisation were more than double those observed in the nontested group (13.4% vs 5.9%, standardised difference [SD] 0.26, for cardiac catheterisation; 6.6% vs 2.7%, SD 0.19, for PCI). The CST group had a significantly lower primary event rate at 3 years compared without CST (3.9% vs 4.5%, hazard ratio 0.87, 95% confidence interval 0.81-0.93). Conclusions: This population-based study of PCI patients found a small but significantly lower risk of cardiovascular events among patients who received CST. Further studies are needed to confirm these findings and determine the specific aspects of care that may be associated with the modestly improved outcomes.