Rating the appropriateness of coronary angiography, coronary angioplasty and coronary artery bypass grafting: the ACRE study

Background Previous studies investigating the appropriateness of invasive m anagement of coronary disease had not reported the internal consistency of their ratings and may now be out of date. The aim of this study was to meas ure the influence of clinical factors on contemporary ratings of the approp riateness of coronary angiography, percutaneous transluminal coronary angio plasty (PTCA) and coronary artery bypass graft (CABG) in the Appropriatenes s of Coronary Revascularisation (ACRE) study. Methods The Delphi-RAND technique was used, in which an expert panel (four cardiologists, three cardiothoracic surgeons, a general physician and a gen eral practitioner), meeting In 1995, rated mutually exclusive indications ( n = 2178 for angiography, n = 995 for PTCA and n = 984 for CABG). The main outcome measures were the appropriateness category (inappropriate, uncertai n or appropriate) for each of the three procedures and treatment preference . Results For revascularization, the strongest determinant of inappropriatene ss was coronary anatomy. The odds ratio (OR) for inappropriate PTCA was 10. 6 (95 per cent confidence interval (CI) 4.8-23.5) for the effect of left ma in stem or three-vessel disease versus single-vessel disease, and for CABG it was 0.06 (95 per cent CI 0.03-0.15). The number of diseased vessels was strongly related to preference for medical, PTCA or CABG treatment (p for l inear trend <0.001). Mild versus severe anginal symptoms were associated wi th inappropriate angiography (OR 2.0 (95 per cent CI 0.9-9.8), although thi s effect was stronger when only the cardiologists' ratings were considered (OR 10.1 (95 per cent CI 2.4-42.6)). Conclusion These are the first UK ratings of appropriateness covering all t hree procedures. The associations with clinical factors provide evidence of the internal consistency of these ratings. Prospective validation of these ratings against clinical outcomes is under way in the ACRE study.