Assessing Appropriateness of Coronary Angiography: Another Step in Improving Quality

Coronary angiography has been the principal means of assessing coronary disease in patients who may need coronary revascularization (1). Introduced in the 1960s, the test has become one of the most frequently performed procedures in the United States. The American Heart Association estimates that more than 1.3 million procedures were done in 2005, an increase of 342% since 1979 (2). With the phenomenal growth of this expensive test and the small but significant morbidity and mortality associated with it, many have questioned the appropriateness of the present rates of use of the procedure.

Over the past 20 years, studies have shown that use of coronary angiography varies widely (3). Overuse is somewhat easy to determine, because registries of patients who have undergone catheterization provide the denominator for calculating the proportion that was appropriate. Underuse is more difficult to assess, because procedural databases do not record patients who need the procedure but do not get it.

Measuring appropriateness became easier in 1986, when RAND Corporation investigators used a modified Delphi process to develop appropriateness criteria for medical and surgical procedures (4). The RAND–University of California at Los Angeles appropriateness method uses an expert panel to review the evidence for the benefits and risks of a procedure, rates the appropriateness of doing the procedure in many clinical situations, and develops consensus about which situations are the most appropriate indications for the procedure.

Deciding on appropriateness criteria is similar to developing practice guidelines but differs in several important ways. The guideline process relies heavily on randomized clinical trial evidence and uses expert opinion only when good evidence is not available. The American College of Cardiology/American Heart Association (ACC/AHA) guidelines committee uses a particularly rigorous guideline development process (5, 6). However, translating an ACC/AHA guideline into a tool for …