Letter by Hamon et al Regarding Article, “Coronary Multidetector Computed Tomography in the Assessment of Patients With Acute Chest Pain”
To the Editor:
We read with interest the article of Hoffmann et al1 regarding the ability of coronary multidetector computed tomography to rule out acute coronary syndrome in patients presenting to the emergency department with acute chest pain. A note of caution is required in the development of such a strategy. In our opinion, after the use of a single set of biochemical markers for myocardial necrosis exclusion (ideally, troponin measurement), coronary multidetector computed tomography without any significant stenosis detected may be falsely reassuring.
First, some acute coronary syndrome–related plaques are known to be mild stenoses,2 that are surrounded transiently by thrombus material, but are still associated with potential ischemic events. A second troponin measurement is still recommended between 6 and 12 hours after admission, to avoid the wrongful discharge of a high-risk patient.3 Indeed, with an average time from symptom onset to presentation to the emergency department of 3.8 hours, and a mean stay in the emergency department of 7.4 hours, there would be time to have a second troponin assessment; this can have proven prognostic value for the patient.4 The balance of benefit/risk and cost-effectiveness of multidetector computed tomography in this patient perspective is questionable.
Second, we agree that coronary multidetector computed tomography has good diagnostic performance in highly selected patients compared with invasive angiography at the coronary segment level, but it has only moderately high specificity at the patient level.5 This inevitably will lead to a large number of false-positive results requiring invasive angiography. Functional testing remains very useful for determining the suitability of low-risk patients (dual negative troponin assessment at admission and between 6 and 12 hours) to undergo anatomic assessment (invasively or not) and to guide revascularization requirements.
We congratulate Hoffmann and colleagues for having conducted this provocative study, but we think it is a little premature to claim that an inconclusive initial ECG in combination with a single troponin assessment might be a safe alternative to rule out significant coronary artery disease in patients admitted to the emergency department with acute chest pain.
Hoffmann U, Nagurney J, Moselewski F, Pena A, Ferencik M, Chae C, Cury R, Butler J, Abbara S, Brown D, Manini A, Nichols J, Achenbach S, Brady TJ. Coronary multidetector computed tomography in the assessment of patients with acute chest pain. Circulation. 2006; 114: 2251–2260.
Little WC, Constantinescu M, Applegate RJ, Kutcher MA, Burrows MT, Kahl FR, Santamore WP. Can coronary angiography predict the site of a subsequent myocardial infarction in patients with mild to moderate coronary artery disease? Circulation. 1988; 78: 1157–1166.
Bertrand ME, Simoons ML, Fox KA, Wallentin LC, Hamm CW, McFadden E, De Feuter P, Specchia G, Ruzyllo W; Task Force on the Management of Acute Coronary Syndromes of the European Society of Cardiology. Management of acute coronary syndromes in patients presenting without persistent ST-segment elevation. Eur Heart J. 2002; 23: 1809–1840.
Hamon M, Biondi-Zoccai GG, Malagutti P, Agostoni P, Morello R, Valgimigli M, Hamon M. Diagnostic performance of multislice spiral computed tomography of coronary arteries as compared with conventional invasive coronary angiography. A meta-analysis. J Am Coll Cardiol. 2006; 48: 1896–1910.