Letter by Schuster et al Regarding Article, “Selecting a Noninvasive Imaging Study After an Inconclusive Exercise Test”
To the Editor:
We read with interest the clinician update by Blankstein and DeVore,1 which aims to provide practical guidance on the selection of a noninvasive study after an inconclusive exercise test.
Although the scenario described may be commonly encountered, it should be emphasized that the best practice in this situation is controversial. First, the authors' initial statement that “Exercise treadmill testing (ETT) is an excellent initial test for the evaluation of patients with known or suspected cardiovascular disease who are able to exercise and have a normal baseline ECG” can be challenged.
Although it may historically have been the easiest test to perform, it is well recognized that it has poorer diagnostic accuracy in comparison with other noninvasive techniques, in particular, in women. Indeed, recent UK National Institute for Health and Clinical Excellence guidelines now recommend that the exercise treadmill testing is no longer used for the investigation of any patients with chest pain of recent onset, including atypical chest pain.2
Second, it is important to remember that there is more to coronary artery disease than epicardial anatomy. Although we completely agree that coronary computed tomographic angiography is appropriate to rule out coronary artery disease in patients with low pretest probability, we believe that in patients with an intermediate pretest probability of coronary artery disease, a functional test rather than an anatomic test should be the method of choice. In such patients, functional information should guide patient management. It has been shown that intervention based on fractional flow reserve confers a prognostic benefit over anatomically guided intervention. These data come from >1000 patients, and it is important to note that >38% of all interventions could have been avoided if patients with an anatomic lesion of >50% luminal diameter, but a nonsignificant functional test, had not proceeded to revascularization.3 In addition, it was shown that patients with a hemodynamically nonsignificant stenosis who were not revascularized had a better prognosis than those who were. Computed tomographic angiography is unable to provide such functional assessment, and thus should not be recommended in these patients.1 As the authors point out, a number of noninvasive tests can provide clinicians with this functional information.
We need to move away from the classic lumenography-driven—approach, include the more recent evidence into our decision-making process, and use the information gained by functional noninvasive testing.
Andreas Schuster, MD
Geraint Morton, MA, MRCP
Eike Nagel, MD, PhD
King's College London British Heart Foundation Centre of
National Institute of Health Research Biomedical Research Centre
at Guy's and St. Thomas' NHS Foundation Trust
Wellcome Trust and Engineering and Physical Sciences Research
Council Medical Engineering Centre
Division of Imaging Sciences and Biomedical Engineering
The Rayne Institute
St. Thomas Hospital
London, United Kingdom
Dr Nagel received significant grant support from Bayer Schering Pharma and Philips Healthcare.
- © 2011 American Heart Association, Inc.
- Blankstein R,
- Devore AD
- Skinner JS,
- Smeeth L,
- Kendall JM,
- Adams PC,
- Timmis A,
- Group CPGD
- Tonino PAL,
- Fearon WF,
- De Bruyne B,
- Oldroyd KG,
- Leesar MA,
- Ver Lee PN,
- Maccarthy PA,
- Van't Veer M,
- Pijls NHJ