Response to Letter Regarding Article, “Usefulness of 64-Slice Cardiac Computed Tomographic Angiography for Diagnosing Acute Coronary Syndromes and Predicting Clinical Outcome in Emergency Department Patients With Chest Pain of Uncertain Origin”
We thank Dr Gaibazzi for his interest in our article describing the potential benefits of cardiac multidetector computed tomography (MDCT) in patients referred to the emergency department (ED) for assessment of an acute chest pain syndrome.1 We agree that other modalities may have negative predictive value similar to MDCT, and indeed, comparative studies may be in order. Unfortunately, at the present time, it remains the case that a high proportion of patients with chest pain are hospitalized to “rule out” an acute coronary syndrome,2 and it is useful to bear in mind that our study refers not to population screening, but to symptomatic patients who present real diagnostic difficulty, and encompasses some 20% of ED chest pain patients. In this population, we have shown that almost 50% of hospitalizations could be avoided by use of MDCT,3 which would represent considerable savings to any healthcare system.
Ongoing multicenter trials are assessing the predictive value of MDCT for major adverse cardiovascular events in various settings including the ED (the Study of Myocardial Perfusion and Coronary Anatomy Imaging Roles in CAD [SPARC] trial and the Coronary Computed Tomography for Systematic Triage of Acute Chest Pain Patients to Treatment [CT-STAT] trial). MDCT is also invaluable for diagnosing noncoronary origins for acute chest pain. Presenting the potential role of MDCT as “1% gain in negative predictive value paid for by radiation exposure and unbelievably high financial costs” is in our opinion incorrect. Preliminary data on the costs of MDCT as compared with standard ED triage showed lower costs with MDCT,4 whereas radiation dose is comparable to myocardial scintigraphy. We also disagree that referral to stress test is mandatory to assess functional significance in symptomatic ED patients if MDCT shows significant coronary stenosis. MDCT therefore has the potential to change clinical practice with respect to ED triage, and further studies to examine the logistics and risk–benefit ratio are needed.
Sources of Funding
Drs Halon and Peled have received research grants from Philips Medical Systems.
Drs Gaspar and Peled have received travel grants for speaking engagements from Philips Medical Systems. Dr Peled is a member of the medical advisory board for Philips Medical Systems. The remaining authors report no conflicts.
Rubinshtein R, Halon DA, Gaspar T, Jaffe R, Karkabi B, Flugelman MY, Kogan A, Shapira R, Peled N, Lewis BS. Usefulness of 64-slice cardiac computed tomographic angiography for diagnosing acute coronary syndromes and predicting clinical outcome in emergency department patients with chest pain of uncertain origin. Circulation. 2007; 115: 1762–8.
Christenson J, Innes G, McKnight D, Boychuk B, Grafstein E, Thompson CR, Rosenberg F, Anis AH, Gin K, Tilley J, Wong H, Singer J. Safety and efficiency of emergency department assessment of chest discomfort. CMAJ. 2004; 170: 1803–1807.
Rubinshtein R, Halon DA, Gaspar T, Jaffe R, Karkabi B, Flugelman MY, Kogan A, Peled N, Lewis BS Triage and management of patients presenting to the emergency room with chest pain of uncertain etiology using 64-slice cardiac CT. Circulation. 2005 (Suppl); 112: II-680.