The Low Yield of Stress Imaging in a Population-Based Study of Asymptomatic Patients Post PCI
Background—Little is known about the clinical value of stress imaging studies in asymptomatic patients post percutaneous coronary intervention (PCI).
Methods and Results—Residents of Olmsted County, MN, who underwent PCI were followed for the occurrence of stress imaging (stress nuclear or stress echocardiography), coronary angiography, or coronary artery bypass grafting (CABG) (without angiography) as initial procedures after PCI. Patients whose first follow-up procedure was a stress imaging test were evaluated for their symptom status at the time of the study and whether they underwent angiography or revascularization (PCI or CABG) within 90 days. Of 1848 patients who underwent PCI during the study period, 710 (38%) had stress imaging as their initial procedure after PCI, and 241 (13% of the entire cohort) were asymptomatic at the time of testing. The majority (86%) of these 241 patients underwent PCI for acute myocardial infarction or unstable angina. Within 90 days of stress imaging, 16 of the 241 asymptomatic patients underwent angiography and two patients were revascularized. Stratified by timing after PCI, none of 138 asymptomatic patients tested within two years of PCI underwent revascularization. Two of 103 asymptomatic patients tested after two years from PCI underwent revascularization. Compared to patients who were asymptomatic at the time of stress imaging, patients who did not undergo any follow-up procedures (stress imaging, angiography, or CABG) after the index PCI were older, more likely to have co-morbidities, and had significantly greater all-cause mortality (p<0.001).
Conclusions—In a population-based sample of patients undergoing PCI primarily for acute coronary syndromes, 1 in 8 had subsequent stress imaging when they were asymptomatic. These stress imaging tests resulted in further revascularization in less than 1% of patients. The very low rate of downstream revascularization suggests that stress imaging in asymptomatic patients post PCI has low value.
- Received June 23, 2013.
- Accepted January 30, 2014.