CORRESPONDENCE: LETTER TO THE EDITOR
Reply
Karl R. Karsch, MD, FACC*,
Duncan R. Coles, BSc, MB, BS,
Mary A. Smail, MSc,
Ian S. Negus, MSc,
Peter Wilde, BSc, BM, BCh,
Martin Oberhoff, MD and
Andreas Baumbach, MD
* Bristol Heart Institute, Marlborough Street, Upper Maudlin Street, Bristol BS2 8HW, United Kingdom (Email: K.R.Karsch{at}bristol.ac.uk).
We appreciate Dr. Conti’s letter regarding our recent publication (1). He is actually not only commenting on our study but also on the excellent accompanying editorial by Zanzonico et al. (2), who in fact are stating that, aside from the radiation exposure using multislice computed tomography (MSCT), the benefit of sequential procedures for identification of significant coronary lesions would result in an estimate of 355,000 sudden deaths that might be avoided. However, we fully agree with Dr. Conti that, although promising, cardiac catheterization and contrast cine angiography still remain the reference standard for patients with coronary artery disease (CAD).
Based on the current technology, we believe the selection of patients who should undergo an MSCT study is indeed very crucial. It has to be questioned whether patients who are asymptomatic and at low risk are indeed candidates to have this study. Currently, no conclusive evidence justifies the relatively high radiation exposure associated with MSCT as a noninvasive screening tool for this population. There is not enough data comparing the impact of a carefully taken patient’s history by cardiologists together with an exercise test. Even if MSCT studies may then be negative, the dilemma for the cardiologist is that, given the limited sensitivity, specificity, and negative predictive value of MSCT, this test does not exclude CAD.
The clinical value of MSCT coronary angiography has also to be discussed in the context of other available noninvasive imaging techniques. The value of both nuclear imaging and stress echocardiography has been nicely established in patients with CAD. It remains to be documented where, indeed, the MSCT coronary angiography is placed within this armamentarium.
In addition, it has to be questioned whether detection of a nonsignificant "soft" lesion may indeed be life-saving. It is well known that so-called soft plaques, which are prone to rupture, are in at least 40% to 50% of nonsignificant lesions. If such a lesion can be detected by MSCT coronary angiography, what would be the ultimate consequence? Would it lead to percutaneous coronary intervention as a means of prevention of plaque rupture or just intensified medical therapy? Again, we face the same dilemma in identifying patients at high risk for plaque rupture with noninvasive diagnostic imaging. Patients being at high risk to develop CAD are currently treated with aggressive medical therapy to avoid future vascular complications. Thus, the real question is where MSCT coronary angiography is of real help in clinical decision making and medical treatment.
 |
References
|
|---|
1. Coles DR, Smail MA, Negus IS, et al. Comparison of radiation doses from multislice computed tomography coronary angiography and conventional diagnostic angiography J Am Coll Cardiol 2006;47:1840-1845.[Abstract/Free Full Text]2. Zanzonico P, Rothenberg LN, Strauss HW. Radiation exposure of computed tomography and direct intracoronary angiography: risk has its reward J Am Coll Cardiol 2006;47:1846-1849.[Abstract/Free Full Text]
|
Top
References