We evaluated temporal trends and geographic variation in choice of stress testing modality post-PCI, as well as associations between modality and procedure use after testing.
Stress testing is frequently performed post-PCI, but the choices amongst available modalities (electrocardiogram [ECG]-only, nuclear, or echocardiography; pharmacologic or exercise stress) and consequences of such choices are not well characterized.
CathPCI Registry® data were linked with identifiable Medicare claims to capture stress testing use between 60 and 365 days post-PCI and procedures within 90 days after testing. Testing rates and modality used were modeled based on patient, procedure, and PCI facility factors, calendar quarter, and Census Divisions using Poisson and logistic regression. Post-test procedure use was assessed using Gray’s test.
In 284,971 patients, the overall stress testing rate after PCI was 53.1 per 100 person-years. Testing rates declined from 59.3 in Quarter 1 (2006) to 47.1 in Quarter 4 (2008), but the relative use of modalities changed little. Among exercise testing recipients, adjusted proportions receiving ECG-only testing varied from 6.8%-22.8% across Census Divisions and among exercise testing recipients having an imaging test, the proportion receiving echocardiography (versus nuclear) varied from 9.4%-34.1%. Post-test procedure use varied among modalities; exercise ECG-only testing was associated with more subsequent stress testing (13.7% vs. 2.9%; p<0.001), but less catheterization (7.4% vs. 14.1%; p<0.001) than imaging-based tests.
Modest reductions in stress testing after PCI occurring between 2006 and 2008 cannot be ascribed to trends in use of any single modality. Additional research should assess whether this trend represents better patient selection for testing or administrative policies (e.g., restricted access for patients with legitimate testing needs). Geographic variation in utilization of stress modalities and differences in downstream procedure use among modalities suggest a need to identify optimal use of the different test modalities in individual patients.