Appropriateness Criteria for Coronary Angiography in Angina: Reliability and Validity

BACKGROUND: Evaluated criteria for tailoring the decision to perform coronary angiography in specific clinical scenarios are lacking. OBJECTIVE: To determine the reliability and prognostic validity of patient-specific appropriateness criteria for coronary angiography among patients with suspected angina pectoris. DESIGN: Prospective observational study. Two independent panels of clinicians scored 2400 patient-specific indications for coronary angiography as inappropriate, uncertain, or appropriate. Using a simple computer algorithm, patients were matched to 1 of these indications. SETTING: 6 urban ambulatory care clinics in the United Kingdom. PATIENTS: 9356 consecutive patients with recent-onset chest pain in whom stable angina was suspected. MEASUREMENTS: Appropriateness ratings and clinical outcomes (coronary death and acute coronary syndrome events) over a median of 3 years of follow-up. RESULTS: 660 coronary deaths or acute coronary syndrome events occurred. Agreement between the 2 panels (reliability) on appropriateness category was moderate (weighted kappa = 0.58; P < 0.001). Use of subsequent angiography was strongly related to appropriateness category (P for linear trend <0.001) according to scores from either panel. Among patients judged as appropriate candidates for angiography, underuse was common (57% according to panel A and 71.3% according to panel B), and not undergoing coronary angiography was associated with higher coronary event rates than was undergoing the procedure. The hazard ratio after adjustment for age, sex, exercise electrocardiography result, and secondary prevention medication was similar according to panel A (2.78 [95% CI, 1.77 to 4.37]) and panel B (2.47 [CI, 1.72 to 3.55]). LIMITATION: The study was too small to assess the relationship of angiography with coronary death and did not assess the reasons why patients did not receive angiography. CONCLUSION: Appropriateness scores offer prognostically valid criteria for judging which specific patients might benefit from coronary angiography. Patient-specific appropriateness scores help pinpoint areas where judgments diverge and are a promising tool for making guidelines more effective.