Assessing the Association of Appropriateness of Coronary Revascularization and Clinical Outcomes for Patients With Stable Coronary Artery Disease
What is the appropriateness of coronary revascularization in Ontario, Canada, and what is the association with longer-term outcomes?
A population-based cohort of stable patients undergoing cardiac catheterization was assembled from April 1, 2006, to March 31, 2007. The appropriateness for coronary revascularization at the time of coronary angiography was retrospectively adjudicated using the appropriate use criteria. Clinical outcomes between coronary revascularization and medical treatment without revascularization, stratified by appropriateness categories, were compared.
In 1,625 patients with stable coronary artery disease (CAD), 61% had appropriate indications for coronary revascularization, 20% had uncertain indications, and 19% had inappropriate indications. Percutaneous coronary intervention or coronary artery bypass grafting was only performed in 69% who had an appropriate indication for coronary revascularization. Coronary revascularization was associated with a lower adjusted hazard of death or acute coronary syndrome (11.8% vs. 16%; hazard ratio [HR], 0.61; 95% confidence interval [CI], 0.42-0.88) at 3 years compared with medical therapy in appropriate patients. The rate of coronary revascularization was 54% in the uncertain category and 45% in the inappropriate category. No significant difference in death or acute coronary syndrome between coronary revascularization and no revascularization in the uncertain category (HR, 0.57; 95% CI, 0.28-1.16) and the inappropriate category (HR, 0.99; 95% CI, 0.48-2.02) was observed.
Using the appropriateness use criteria, there was substantial underutilization and overutilization of coronary revascularization in contemporary clinical practice. Underutilization of coronary revascularization is associated with significantly increased risks of adverse outcomes in patients with appropriate indications.
The Ontario Ministry of Health is to be congratulated for funding this study demonstrating that underutilization of coronary revascularization in stable CAD patients with appropriate indications is a significant health care problem that is likely related to local practice culture. Interestingly, in this national single payer system, as in the United States, approximately 40% of patients referred for coronary arteriography for stable CAD had normal or mildly abnormal coronary arteries.
Keywords: Coronary Artery Disease, Acute Coronary Syndrome, Cardiac Catheterization, Canada, Ontario, Coronary Artery Bypass, Percutaneous Coronary Intervention
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