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 between October 2008 and 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 (CV) death or hospitalization for myocardial infarction (MI) at 3 years after CST. Inverse probability of treatment weighting (IPTW) 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 catheterization and coronary revascularization were more than double observed in the non-tested group (13.4% vs 5.9%, standardized difference (SD) 0.26 for cardiac catheterization, 6.6% vs. 2.7%, SD 0.19 for PCI). The stress testing group had significantly lower primary event rate at 3 years compared with those not tested (3.9% vs. 4.5%; HR 0.87, 95% CI 0.81-0.93).

Conclusions — Our population-based study of PCI patients found a small, but significantly lower risk of cardiovascular events among patients who received stress testing. Further studies are needed to confirm these findings and determine the specific aspects of care that may be associated with the modestly improved outcomes.