Authors' objectives:

The objective of this Assessment is to determine the usefulness of computed tomography angiography (CTA) as a substitute for coronary angiography for two indications: 1) in the diagnosis of coronary artery stenosis, and 2) in the evaluation of acute chest pain in the emergency room (ER). Uses of CTA for other indications are not addressed in this Assessment.

Authors' results and conclusions: Seven studies compared CTA to angiography for diagnosis of coronary artery stenosis, ranging in size from 30 to 84 patients. These studies enrolled essentially convenience samples of consecutive patients scheduled to undergo angiography, and thus may be subject to spectrum bias. No study specifically studied a lower-risk subset of those patients referred for angiography, which is the target population for this procedure. A high prevalence of coronary stenosis was noted in all studies. In 5 studies reporting a per-patient analysis, 3 studies excluded patients with indeterminate test results. The sensitivity of CTA in identifying a 50% stenosis ranged from 88-100%, with 4 of 5 studies reporting sensitivities of at least 95%. Specificity ranged from 86-100%. In a per-segment analysis, sensitivity ranged from 79-99%, and specificity ranged from 95-98%. Four of these studies excluded either patients or segments from the analysis. Two studies evaluated the use of CTA for patients with acute chest pain in the ER. The sample sizes of the studies were 31 and 69. The studies used a mixed reference standard of angiography, clinical data, and noninvasive testing, which allows a calculation of sensitivity and specificity, but does not allow a comparison of performance to an alternative strategy. No alternative strategies for diagnosis were evaluated. Sensitivity of CTA was 83% and 96%, and specificity was 89% and 96%. It is unknown whether this indicates better or worse performance than an alternative strategy.

Authors' recommendations: Based on the available evidence, the Blue Cross and Blue Shield Association Medical Advisory Panel made the following judgments about whether CTA for screening or diagnostic evaluation of the coronary arteries meets the Blue Cross and Blue Shield Association Technology Evaluation Center (TEC) criteria. 1. The technology must have final approval from the appropriate governmental bodies. Multiple manufacturers have received U.S. Food and Drug Administration (FDA) 510(k) clearance to market multi detectorrow computed tomography (MDCT) machines equipped with at least 16 detector rows and at least two models of electron beam computed tomography (EBCT) machines have been cleared through FDA 510(k) clearance. Intravenous iodinated contrast agents used for cardiac CTA have also received FDA approval. 2. The scientific evidence must permit conclusions concerning the effect of the technology on health outcomes. Current studies are inadequate to determine the effect of CTA on health outcomes for the diagnosis of coronary artery stenosis in patients referred for angiography or for evaluation of acute chest pain in the ER. 3. The technology must improve the net health outcome; and 4. The technology must be as beneficial as any established alternatives. The available evidence is inadequate to determine whether CTA improves the net health outcome or is as beneficial as established alternatives for diagnosis of coronary artery stenosis or for evaluation of acute chest pain in the ER. 5. The improvement must be attainable outside the investigational settings. Whether use of CTA improves health outcomes has not been established in the investigational setting. Based on the above, CTA as a substitute for coronary angiography in the diagnosis of coronary artery stenosis does not meet the TEC criteria. CTA in the evaluation of acute chest pain in the emergency room also does not meet the TEC criteria.

Authors' methods: Review

Project Status: Completed

URL for project: http://www.bcbs.com/blueresources/tec/contact-tec.html

Year Published: 2006

English language abstract: An English language summary is available

Publication Type: Not Assigned

Country: United States

Organisation Name: BlueCross BlueShield Association

Contact Address: BlueCross BlueShield Association, Technology Evaluation Center, 225 North Michigan Ave, Chicago, Illinois, USA. Tel: 888 832 4321

Contact Name: tec@bcbsa.com

Contact Email: tec@bcbsa.com

Copyright: BlueCross BlueShield Association (BCBS)