Medical Therapy and Coronary Revascularization for Patients With Stable Coronary Artery Disease and Unclassified Appropriateness Score.

Although the appropriate use criteria incorporate common clinical scenarios for coronary revascularization, a significant proportion of patients with stable coronary artery disease (CAD) cannot be assigned an appropriateness score. Our objective was to characterize these patients and to evaluate whether coronary revascularization is associated with improved outcomes. A population-based cohort of patients aged ≥66 years, who underwent cardiac catheterization in Ontario, Canada, were included. Clinical characteristics were compared between patients with and without an appropriateness score. Clinical outcomes between coronary revascularization and medical therapy in patients with unclassified appropriateness score were compared using the inverse probability of treatment-weighted propensity method for confounder adjustment. Of the 19,228 patients with stable CAD, 11.2% (2,153 patients) were not assigned to an appropriateness score, mostly (92.9%) because of a lack of ischemic evaluation or a noninterpretable test. These patients were older, had higher rate of severe angina, and had more medical co-morbidities compared to patients with an appropriateness score. The 2-year rate of death or myocardial infarction in patients with unclassified appropriateness score was 15.3% in the revascularization group versus 20.7% in the medical therapy group. After propensity weighting, revascularization was associated with significantly lower hazard ratio (0.70; 95% confidence interval 0.61 to 0.79) for death or myocardial infarction compared with medical therapy. In conclusion, in patients aged ≥66 years with stable CAD and unclassified appropriateness score, revascularization is associated with improved outcomes.