Diagnostics & Imaging Week Associate

The American College of Cardiology Foundation (ACCF; Bethesda, Maryland), along with key specialty and subspecialty societies, has released appropriateness criteria for two relatively new clinical cardiac imaging modalities — cardiac computed tomography (CCT) and cardiac magnetic resonance imaging (CMRI). The criteria were developed in order to address the growth in biomedical imaging to ensure that it is appropriate to patient needs.

"In response to the need for guidance in ordering and performing advance cardiac imaging procedures, such as CT and CMR, the ACCF has focused a great deal of resources in helping to determine if it is ‘reasonable' or appropriate to perform a test for a specific indication," said Robert Hendel, MD, chair of the writing group for the appropriateness criteria for CCT and CMR.

He added: "We aim to assist patients, clinicians, and payers when determining how best to use cardiac tests and procedures. It is now widely apparent that these imaging studies should be used only when the information provided will have a direct impact on patient care, as medical imaging has undergone tremendous growth in recent years."

Hendel said it also is hoped that the criteria "will generate discussion between physicians and payers regarding reimbursement."

An appropriate imaging study is defined as one in which the expected incremental information combined with clinical judgment, "exceeds the expected negative consequences by a sufficiently wide margin for a specific indication that the procedure is generally considered acceptable care and a reasonable approach for the indication." Negative consequences include the risks of the procedure (i.e., radiation or contrast exposure) and the downstream impact of poor test performance such as the delay in diagnosis (false negatives) or inappropriate diagnosis (false positives).

The 39 CCT and 33 CMR indications rated by a technical panel of experts encompassed the majority of clinical scenarios referred for CCT and CMR, respectively.

"This is the first information available to clinicians and payers to help guide decisions on when to use these two newer imaging procedures in certain clinical scenarios," said Christopher Kramer, MD, a member of the writing group for the appropriateness criteria. "With payment decisions being made daily and without any criteria to guide clinicians and payers, the ACCF and its partners felt it was critical to provide these criteria now."

These appropriateness reviews assessed the risks and benefits of the imaging tests for several indications or clinical scenarios and scored them based on a scale of 1-9, where the upper range (7-9) implies that the test is generally acceptable and is a reasonable approach, and the lower range (1-3) implies that the test is generally not acceptable and is not a reasonable approach. The mid range (4-6) indicates an uncertain clinical scenario.

The indications for these reviews were drawn from common applications or anticipated uses, as few clinical practice guidelines currently exist for these techniques. These indications were reviewed by an independent group of clinicians and modified by the working group, and then panelists rated the indications based on the ACCF methodology for evaluating the appropriateness of cardiovascular imaging, which it said blends a broad range of clinical experience and available evidence-based information.

For the 39 indications for CCT, 13 were found to be appropriate, and 12 were uncertain. Fourteen of these indications were felt to be inappropriate reasons for CT test performance. There was great variability in scores for the uncertain category, suggesting markedly differing opinions.

However, there was substantial agreement as defined by RAND Corporation (Santa Monica, California) in the RAND/UCLA Appropriateness Method User's Manual for a panel this size for the categories labeled as either appropriate or inappropriate, with 77% and 86%, respectively, showing agreement. CCT was considered reasonable for a number of scenarios beyond assessments of structure and function, but still more than 40% of the indications were for this area.

For CMR, 17 of the 33 indications were ranked as appropriate, with another seven being uncertain. Nine scenarios were considered to be inappropriate reasons for magnetic resonance test performance. Similar to the indications for CCT, uncertain scenarios showed wider dispersion of scores than those for indications at either end of the spectrum.

Agreement, as defined for a panel this size by RAND, was present for 82% of the appropriate indications and 89% for those felt to be inappropriate. Two-thirds of the appropriate and uncertain indications for CMR were related to assessment of structure and function. These results support the strengths of CMR as a tool for defining the etiology of complex patient presentations where the clinical suspicion is high. The scores for other uses reflect the evolving nature of the capabilities of the test.

The ACCF said it believes that the appropriateness criteria in these reports should be useful for clinicians, healthcare facilities and third-party payers in the delivery of quality cardiovascular imaging.

For example, individual clinicians could use the ratings as a supportive decision or educational tool when ordering a test or providing a referral to another qualified physician.

The criteria also may be used to respond to a referring physician who has ordered a test for an inappropriate indication. Facilities and payers can use the criteria either prospectively in the design of protocols and preauthorization procedures or retrospectively for quality reports. It is hoped that payers will use this document as the basis for their own strategies to ensure that their members receive quality, but cost-effective, cardiovascular care.

"We recommend that cardiovascular professionals use the CCT and CMR appropriateness criteria to avoid ordering tests deemed inappropriate in the clinical setting unless there are very unusual circumstances. In addition, clinical scenarios rated uncertain require more research before we understand whether a given test is appropriate or inappropriate for that particular scenario," said Michael Poon, MD, a member of the writing group for the appropriateness criteria for CCT and CMR.

The CT and CMR appropriateness criteria are the second and third sets of appropriateness criteria to be developed by the ACCF. In October 2005, the foundation, in collaboration with the American Society of Nuclear Cardiology, issued the appropriateness criteria for single-photon emission computed tomography myocardial perfusion imaging.

The CCT and CMR appropriateness criteria were developed in collaboration with the American College of Radiology (Reston, Virginia), Society of Cardiovascular Computed Tomography (Damascus, Maryland), Society for Cardiovascular Magnetic Resonance (Mt. Royal, New Jersey), American Society of Nuclear Cardiology (Bethesda, Maryland), North American Society for Cardiac Imaging (Salem, Massachusetts), Society for Cardiovascular Angiography and Interventions (Bethesda, Maryland) and Society of Interventional Radiology (Fairfax, Virginia).

The full report can be found on the American College of Cardiology web site at www.acc.org.