Editor's Note: Commentary based on Bradley SM, Chan PS, et al. Validation of the appropriate use criteria for percutaneous coronary intervention in patients with stable coronary artery disease (from the COURAGE trial). Am J Cardiol 2015;116(2):167-73.

Aims/Objectives

Validation of appropriate use criteria for revascularization in patients with stable ischemic heart disease.

Methods

This was a post hoc analysis of patients enrolled in COURAGE trial, which compared outcomes of PCI+OMT vs OMT alone.¹ Using clinical and angiographic data, authors mapped patients to "Appropriate", "Inappropriate", and "Uncertain" category, based on 2012 AUC for PCI.² Within each appropriateness category, they compared outcomes, death, non-fatal MI and revascularization, for PCI + OMT vs OMT alone, using Kaplan-Meir survival curves and log rank tests. They also compared angina-specific health status, as determined by Seattle Angina Questionnaire scores for angina frequency, physical limitations, and quality of life domains over time (1, 3, 6, 12, 24, 30 months) within each appropriateness category, for PCI + OMT vs OMT alone, using t-test. They also conducted repeated-measure analyses of the scores and change from baseline over time using maximum likelihood methods to estimate the average benefit of PCI over time.

Results

Total of 1,987 (88% of 2,287) patients could be mapped to AUC appropriateness category. In PCI group 66% patients were classified appropriate, 28% uncertain and 5% inappropriate. There were no significant differences in rates of death, non-fatal MI or composite of both comparing PCI vs. OMT alone within appropriateness categories. Revascularization rates were significantly lower in PCI + OMT group who were classified as appropriate (24% vs 34%, hazard ratio 0.65, 95% CI 0.53 to 0.80, p <0.001), and uncertain (11% vs 21%, hazard ratio 0.49, 95% CI 0.32 to 0.76, p 0.001).

There were significant differences noted in health status outcomes by appropriateness category. Patients classified as appropriate, Seattle Angina Questionnaire scores at one month were significantly higher in the PCI group compared with the OMT alone group (80 ± 23 vs 75 ± 24 at one month for angina frequency, persisted throughout the first two years follow-up; 73 ± 24 vs 68 ± 24 for physical limitations at one month, persisted through 6 months; and 68 ± 23 vs 60 ± 24 for quality of life at one month, persisted through six months; all p <0.01). In contrast, health status scores for all three SAQ domains were similar throughout the first year of follow-up in PCI + OMT patients compared with OMT alone in patients classified as uncertain or inappropriate.

Conclusion

Initial PCI strategy for SIHD, when appropriate is associated with lower rate of revascularizaton and better health status, whereas uncertain PCI's are associated with lower revascularizaton rates, but similar health status compared to OMT, and inappropriate PCI's are associated with similar revascularization and health status compared to OMT alone. These findings support the validity of AUC for revascularization.

Commentary/Perspective

Results of this post-hoc analysis of COURAGE trial provide empirical evidence to support the validity of appropriate use criteria for PCI. For stable ischemic heart disease, PCI when done for appropriate indications is associated with lower revascularization rates and better health status outcomes. However, due to strict inclusion and exclusion criteria of COURAGE trial, these results lack generalizability. Also, the results obtained from a study of bare metal stents are of uncertain applicability in an era of 2nd generation drug eluting stents and FFR guided PCI. Regardless, this study provides first evidence to validate AUC, and hopefully will enhance compliance.

References

1. Bradley SM, Chan PS, et al. Validation of the appropriate use criteria for percutaneous coronary intervention in patients with stable coronary artery disease (from the COURAGE trial). Am J Cardiol 2015;116(2):167-73.
2. Patel MR, Dehmer GJ, et al. ACCF/SCAI/STS/AATS/AHA/ASNC/HFSA/SCCT 2012 Appropriate use criteria for coronary revascularization focused update: a report of the American College of Cardiology Foundation Appropriate Use Criteria Task Force, Society for Cardiovascular Angiography and Interventions, Society of Thoracic Surgeons, American Association for Thoracic Surgery, American Heart Association, American Society of Nuclear Cardiology, and the Society of Cardiovascular Computed Tomography. J Am Coll Cardiol 2012;59(9):857-81.

Keywords: Angina Pectoris, Area Under Curve, Coronary Artery Disease, Coronary Disease, Drug-Eluting Stents, Follow-Up Studies, Health Status, Likelihood Functions, Metals, Myocardial Ischemia, Percutaneous Coronary Intervention, Quality of Life

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