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Diagnostic-therapeutic cascade revisited: coronary angiography, coronary artery bypass graft surgery, and
F L Lucas1, A E Siewers, D J Malenka
1Center for Outcomes Research and Evaluation, Maine Medical Center, 22 Bramhall St, Portland, ME 04102, USA. lucasl@mmc.org
Circulation
|December 10, 2008
Summary
Coronary angiography strongly predicts percutaneous coronary intervention but shows a threshold effect for coronary artery bypass graft surgery. Patients in high-testing areas may receive unneeded coronary artery disease treatments.
Area of Science:
- Cardiovascular Medicine
- Health Services Research
- Medical Economics
Background:
- Significant geographic disparities exist in coronary revascularization procedures within the United States.
- Coronary angiography rates are strongly correlated with revascularization rates.
Purpose of the Study:
- To examine the relationship between coronary angiography utilization and coronary artery revascularization by procedure type: coronary artery bypass graft surgery (CABG) and percutaneous coronary intervention (PCI).
Main Methods:
- Analysis of Medicare Part B claims data from a 20% sample of the US population.
- Calculation of population-based rates of cardiac catheterization and revascularization by geographic region.
- Statistical adjustment for regional demographic differences using the indirect method.
Main Results:
- Cardiac catheterization rates varied widely (16-77 per 1000 beneficiaries).
- A strong association was observed between coronary angiography and total revascularization (R(2)=0.84).
- Coronary angiography showed a strong linear relationship with PCI (R(2)=0.78) but a modest, threshold-dependent relationship with CABG (R(2)=0.41).
Conclusions:
- The diagnostic-to-therapeutic pathway for coronary artery disease differs significantly between PCI and CABG.
- PCI appears to be directly driven by angiography, while CABG may have a testing threshold.
- High rates of diagnostic testing in certain regions may lead to overtreatment for stable coronary artery disease.
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