Society of Atherosclerosis Imaging (SAI) Responds to AHA/ACC Statement on Detection and Prognosis of Coronary Artery Disease using Electron Beam Computed Tomography [EBCT].

SAI Imaging/Prevention Experts Present A Differing and More Clinically Relevant View of the Importance and Immediate Application of this New and Accurate Measure of Subclinical Heart Disease

Phoenix AZ, July 5, 2000:  The Executive Board of the Society of Atherosclerosis Imaging (SAI), presided over by Dr Harvey Hecht of the Arizona Heart Institute, issued a strong statement today, challenging the conclusions of a joint ACC/AHA panel which had spent two years developing a “consensus position” on the use of Electron Beam Tomography (EBCT) for the detection and prognosis of coronary artery disease.  The SAI, whose membership comprises experts in all fields of Cardiac and Cardiovascular Imaging, Prevention, and Risk Reduction, has a mission to evaluate and apply modern methods for both detection and treatment of early heart disease. In the US there are1.5 million heart attacks annually, 2/3 of which do not have “chest pain” as their initial symptom, and one of two adults dies from heart and vascular disease, often without warning.

The SAI Executive Board stated, “The ACC/AHA opinion was an often biased, selective review which neither represented a “consensus” nor the opinion of “experts” on EBCT.”  There were publicly admitted biases by the chairman Dr. Robert O’Rourke against the Imatron EBCT technology from the outset and conflicts existed amongst committee members, one of who resigned in protest, leaving only one remaining panel member who had ever interpreted an EBCT study.

Dr. John Rumberger, recognized as one of the world’s experts in cardiac imaging using EBCT and currently the Director of Medical Affairs for SAI and chair of the AHA Committee on Cardiovascular Imaging and Intervention, said: “I speak with authority in my criticism of the panel’s position, as I was an original member of the Consensus Panel, chosen by the ACC/AHA as one of the sole “experts” on EBCT.  Nonetheless, after a very frustrating and discouraging 15-month effort plagued by posturing and maneuvering under the guise of scientific inquiry, I resigned in exasperation from the ACC/AHA Consensus panel.  Thus my name does not appear as a final contributor.”

                                A Scientific Statement from the AHA in 1996 indicated that EBCT had a potential role in evaluating patients with atypical chest pain and for refining risk assessment in patients at moderate conventional cardiac risk.  Furthermore it was recognized that the presence of coronary calcium was 100% specific for histopathologic coronary atherosclerosis.  Thus, there are NO false positive EBCT examinations for the diagnosis and extent of coronary plaque.  However, that statement suggested that further research was necessary before wide application of the technology was advised for screening.

                Since 1996 there have been almost 100 papers and editorials published supporting the clinical utility of EBCT for evaluating the extent of coronary calcification, a validated surrogate to atherosclerotic plaque burden.  SAI particularly found the current ACC/AHA position to be at odds with an announcement by the American Heart Association listing EBCT as one of the 10 most important developments in preventive heart research for the year 1999.  The current ACC/AHA document examined only approximately 60 out of more than 300 publications on EBCT and did not include a number of 1999-2000 publications or some “in press” publications, most of which were made available to the panel.  The SAI Executive Committee said “Their recommendation to delay clinical utilization in currently appropriate patients and wait for yet more data is not only unnecessary and misguided, but obstructs access to validated diagnostic resources by the concerned, at risk, public.”

                SAI agreed with the ACC/AHA panel in stating that EBCT “…should not be used to diagnose obstructive coronary disease”.  But they failed to note that it could be used to determine who does NOT have obstructive disease and thus avoid further unnecessary testing in those at low to intermediate risk.  The negative predictive value of a zero calcium score in ruling out the presence of obstructive disease in patients with symptoms is > 95 % and has approached 100 % in some studies.  The statement by the ACC/AHA panel that EBCT would result in additional expensive and unnecessary testing to rule out obstructive disease was frivolous and not supported by published data indicating the use of EBCT as a cost effective alternative to conventional stress testing.

                Most importantly, the ACC/AHA Panel did not accurately describe the benefit of the detection of subclinical disease by screening at-risk individuals, a majority of whom cannot be reliably identified by any other method. The consistent finding of ALL published studies is that EBCT calcium scores, in asymptomatic patients, provide an index of future cardiac risk ranging 2 to 10 times greater than that afforded by conventional [Framingham] risk analysis. ”

In particular, SAI emphasized, as did the ACC/AHA panel, the use of EBCT as a clinical case management tool for early detection, assessment of risk in the context of conventional risk factors, and aggressive risk intervention and follow-up in those found to have coronary atherosclerotic disease.  However, SAI’s Executive Board also stated support for the concept of increasing patient awareness and the availability of access to testing by the public, including screening of middle-aged individuals for coronary disease.

Recent [1999-2000] relevant EBCT Peer Reviewed Publications:

1. Schmermund, A, Rumberger JA, et al: An Algorithm for the Noninvasive Identification of Angiographic Three-Vessel and/or Left Main Coronary Artery Disease in Symptomatic Patients on the Basis of Cardiac Risk and Electron Beam Computed Tomographic Calcium Scores. J Am Coll Cardiol 1999;33:444-52        

2. McLaughlin V, et al: Utility of Electron Beam Computed Tomography to Stratify Patients Presenting to the Emergency Room with Chest Pain. Am J Cardiol 1999;84:327-328 

3.  O’Malley PG, et al: Prognostic Value of Coronary electron Beam Computed Tomography for Coronary Heart Disease Events in Asymptomatic Populations. Am J Cardiol 2000;85:945-948 

4.  Budoff MJ, et al. Rates of Progression of Coronary Calcification by Electron Beam Computed Tomography. Am J Cardiol 2000; 86:(July, in press).

5.  Shavelle DM, et al. Exercise testing and electron beam computed tomography in the evaluation of coronary artery disease. J Am Coll Cardiol 2000;36:32-38                                                                              

6. Arad Y, et al: Prediction of Coronary Events with Electron Beam Computed Tomography. J Am Coll Cardiol [in press]; September 2000

7. Bielak LF, Rumberger JA, et al: A Probabilistic Model for Prediction of Angiographically Defined Obstructive Coronary Artery Disease Using Electron Beam Computed Tomography Calcium Score Strata. Circulation 2000; [in press] September

Society of Atherosclerosis Imaging:  President - Harvey S. Hecht MD ; Secretary/Treasurer –George P. Rodgers MD ; Director of Medical Affairs – John A. Rumberger MD, PhD ; Board of Directors – Stephan Achenbach MD, Arthur A. Agatston MD,  Daniel S. Berman MD, B. Greg Brown MD, PhD,  Matthew J. Budoff MD,  Tracy Q. Callister MD,  William P. Castelli MD,  James Ehrlich,MD,  Alan D. Guerci MD,  Warren R. Janowitz MD,  David King,  Lewis H. Kuller MD, DrPH,  Daniel J. Rader MD,  Paolo Raggi MD,  William C. Roberts MD,  Patrick F. Sheedy II MD,  Alan G. Wasserman MD  

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