Correspondence
Low Diagnostic Yield of Elective Coronary Angiography
N Engl J Med 2010; 363:92-95July 1, 2010
- Article
To the Editor:
Patel and coworkers (March 11 issue)1 report that approximately two thirds of patients undergoing elective coronary angiography do not have obstructive epicardial stenoses. We think that this article reflects the common misconception that left cardiac catheterization is limited to the search for epicardial stenoses.
Hemodynamic testing can reveal undiagnosed conditions, such as valve disease or diastolic dysfunction, that can cause angina.2 Regional or global left ventricular dysfunction with nonobstructive coronary artery disease may suggest a cardiomyopathy that, again, can cause angina.3 The assessment of functional coronary alterations is also important. In patients with suspected vasospastic angina, the ergonovine test can be used to confirm the diagnosis.4 In patients with suspected microvascular angina, the diagnosis can be confirmed if reduced coronary flow reserve is shown with the use of an intracoronary Doppler wire.5,6 Finally the absence of obstructions may serve as reassurance for some patients and encourage others to search for additional (perhaps less common) causes of chest pain. In conclusion, it is superficial to label cardiac catheterization as unyielding simply because it does not show epicardial stenoses.
Antonio Abbate, M.D., Ph.D.
George Vetrovec, M.D.
Virginia Commonwealth University, Richmond, VA
abbatea@yahoo.com Filippo Crea, M.D., Ph.D.
Catholic University, Rome, ItalyNo potential conflict of interest relevant to this letter was reported.
6 References1
Patel MR ,Peterson ED ,Dai D , et al. Low diagnostic yield of elective coronary angiography. N Engl J Med 2010;362:886-895
Full Text | Web of Science | Medline2
Preik M ,Kelm M ,Strauer BE . Management of the hypertensive patient with coronary insufficiency but without atherosclerosis. Curr Opin Cardiol 2003;18:255-259
CrossRef | Web of Science | Medline3
Elliott PM ,Kaski JC ,Prasad K , et al. Chest pain during daily life in patients with hypertrophic cardiomyopathy: an ambulatory electrocardiographic study. Eur Heart J 1996;17:1056-1064
Web of Science | Medline4
Fox K ,Garcia MA ,Ardissino D , et al. Guidelines on the management of stable angina pectoris: executive summary: the Task Force on the Management of Stable Angina Pectoris of the European Society of Cardiology. Eur Heart J 2006;27:1341-1381
CrossRef | Web of Science | Medline5
Camici PG ,Crea F . Coronary microvascular dysfunction. N Engl J Med 2007;356:830-840
Full Text | Web of Science | Medline6
Lanza GA ,Buffon A ,Sestito A , et al. Relation between stress-induced myocardial perfusion defects on cardiovascular magnetic resonance and coronary microvascular dysfunction in patients with cardiac syndrome X. J Am Coll Cardiol 2008;51:466-472
CrossRef | Web of Science | Medline
To the Editor:
The call by Patel et al. for strategies to improve the diagnostic yield of coronary angiography is seriously misguided from the perspective of clinical epidemiology. In fact, the observations in this article can be explained fully by verification bias — the preferential referral of patients for diagnostic verification.1,2 As an example, suppose we have a test marker with 80% sensitivity and 80% specificity (typical of cardiac stress tests). In a sample of 100 persons with a 10% disease prevalence, there will be 8 true positive results (100×0.1×0.8) and 18 false positive results (100×0.9×0.2). If we refer only the 26 persons with positive results for angiography, the observed “diagnostic yield” is only 31% (8 of 26). Moreover, the sensitivity of the test will appear to be 100% (all subjects with disease having a positive test), and its specificity will appear to be 0% (all subjects without disease also having a positive test). Hence, the more we rely on a test, the less well it appears to perform. As Cassius once observed, “The fault, dear Brutus, is not in our stars, but in ourselves. . . .”
George A. Diamond, M.D.
Sanjay Kaul, M.D.
Cedars–Sinai Medical Center, Los Angeles, CA
gadiamond@pol.net No potential conflict of interest relevant to this letter was reported.
2 References1
Rozanski A ,Diamond GA ,Berman D ,Forrester JS ,Morris D ,Swan HJC . The declining specificity of exercise radionuclide ventriculography. N Engl J Med 1983;309:518-522
Full Text | Web of Science | Medline2
Diamond GA . How accurate is SPECT thallium scintigraphy? J Am Coll Cardiol 1990;16:1017-1021
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To the Editor:
Working in a nation with limited health care resources, we were surprised by the results in the article by Patel et al. A total of 31.5% of patients with coronary artery disease (and 29.1% of those without coronary artery disease) were asymptomatic. Given the fact that no study has shown a benefit of revascularization in asymptomatic patients, we question whether the decision to perform coronary angiography was appropriate.
Typical angina was reported by 26.7% of patients without coronary artery disease, reflecting the difficulty physicians face daily in the assessment of patients with chest pain. A normal coronary angiogram provides great reassurance to all concerned, and patients in whom disease of intermediate severity is noted can be safely evaluated by means of the measurement of fractional flow reserve, thereby avoiding unnecessary further investigation or percutaneous coronary intervention.1
Guidelines just published by the National Institute for Health and Clinical Excellence (NICE) in the United Kingdom2 recommend direct invasive angiography if the likelihood of coronary artery disease is 61 to 90% and noninvasive functional imaging if the likelihood is 30 to 60%. Application of these guidelines in clinical practice is likely to increase the diagnostic yield of coronary angiography in a cost-effective way.3
Florim Cuculi, M.D.
Rajesh Kharbanda, M.D.
Bernard Prendergast, M.D.
John Radcliffe Hospital, Oxford, United Kingdom
florim@gmx.net No potential conflict of interest relevant to this letter was reported.
3 References1
Kern MJ ,Samady H . Current concepts of integrated coronary physiology in the catheterization laboratory. J Am Coll Cardiol 2010;55:173-185
CrossRef | Web of Science | Medline2
National Clinical Guideline Centre for Acute and Chronic Conditions. Chest pain of recent onset: assessment and diagnosis of recent onset chest pain or discomfort of suspected cardiac origin. 2010. (Accessed June 10, 2010, at http://guidance.nice.org.uk/CG95.)
3
Hernandez R ,Vale L . The value of myocardial perfusion scintigraphy in the diagnosis and management of angina and myocardial infarction: a probabilistic economic analysis. Med Decis Making 2007;27:772-788
CrossRef | Web of Science | Medline
To the Editor:
Patel et al. report that only 38% of patients undergoing diagnostic invasive coronary angiography have obstructive coronary artery disease, and improved patient selection is advocated. In his accompanying editorial,1 Brenner examines the importance of noninvasive imaging, particularly myocardial perfusion scintigraphy and computed tomographic (CT) angiography but rightly highlights the increasing exposure to ionizing radiation with imaging techniques such as these.
Cardiovascular magnetic resonance imaging (MRI) is a noninvasive and x-ray–free test that is not mentioned as an alternative, despite the fact that it has been validated against coronary angiography and myocardial perfusion scintigraphy, with documented prognostic importance. The recently published Appropriateness Criteria for Coronary Revascularization2 also failed to incorporate cardiovascular MRI within the imaging armamentarium for assessing myocardial ischemic burden and viability, despite its well defined role in clinical practice.3
In addition, given its unique characterization of myocardial tissue, cardiovascular MRI has a diagnostic role in the case of patients with suspected coronary artery disease and unobstructed coronary arteries, confirming the diagnosis of myocarditis, myocardial infarction with spontaneous coronary recanalization, syndrome X, or stress-induced (takotsubo) cardiomyopathy.4
Cardiovascular MRI has an important and versatile role to play in identifying coronary artery disease and differential diagnoses without exposing patients to ionizing radiation.
Chiara Bucciarelli-Ducci, M.D.
Bristol Heart Institute, Bristol, United Kingdom
c.bucciarelli-ducci@rbht. nhs. uk Dudley J. Pennell, M.D.
National Heart and Lung Institute, London, United KingdomDr. Pennell reports having received consulting fees from Siemens.
No other potential conflict of interest relevant to this letter was reported.
4 References1
Brenner DJ . Medical imaging in the 21st century -- getting the best bang for the rad. N Engl J Med 2010;362:943-945
Full Text | Web of Science | Medline2
Patel MR ,Dehmer GJ ,Hirshfeld JW ,Smith PK ,Spertus JA . ACCF/SCAI/STS/AATS/AHA/ASNC 2009 appropriateness criteria for coronary revascularization: a report by the American College of Cardiology Foundation Appropriateness Criteria Task Force, Society for Cardiovascular Angiography and Interventions, Society of Thoracic Surgeons, American Association for Thoracic Surgery, American Heart Association, and the American Society of Nuclear Cardiology endorsed by the American Society of Echocardiography, the Heart Failure Society of America, and the Society of Cardiovascular Computed Tomography. J Am Coll Cardiol 2009;53:530-553
CrossRef | Web of Science | Medline3
Bucciarelli-Ducci C ,Di Mario C ,Pennell DJ . Perfusion cardiovascular magnetic resonance in the clinical scenario of patients with coronary artery disease. J Am Coll Cardiol 2009;55:78-79
CrossRef | Web of Science | Medline4
Assomull RG ,Lyne JC ,Keenan N , et al. The role of cardiovascular magnetic resonance in patients presenting with chest pain, raised troponin, and unobstructed coronary arteries. Eur Heart J 2007;28:1242-1249
CrossRef | Web of Science | Medline
Author/Editor Response
We fully agree with Abbate et al. that invasive cardiac catheterization can supply information beyond angiographic stenoses and provide reassurance to patients and their caregivers if no obstructive lesions are found. However, we also believe that often the primary reason the test is performed is to determine whether symptomatic patients have obstructive coronary disease and if so, whether it can best be treated with antianginal medication or coronary revascularization.
To that end, we fully support the important lesson in Bayes' theorem1 provided by Diamond and Kaul. Although our study found that up to two thirds of persons who underwent elective cardiac catheterizations had nonobstructive disease, this should not be interpreted as implying that interventional cardiologists had widely performed inappropriate procedures. On the contrary, we found that the overwhelming majority of these patients had had a positive noninvasive test before catheterization, and therefore performing cardiac catheterization would be considered appropriate according to current guidelines.2 Similarly, we agree that our findings are inconclusive with regard to the accuracy of noninvasive testing in community practice. As pointed out by Diamond and Kaul, even a reasonably sensitive and specific noninvasive test can result in more false positive findings than true positive results if the screening is performed in persons who are at a very low risk of disease. Thus, we believe that our study may have identified a more systemic issue resulting from the nonselective use of noninvasive screening studies. Improvement in the yield of catheterization could be accomplished either by physicians being more selective in deciding who undergoes initial noninvasive evaluation (i.e., by using current or improved clinical risk models3) or by the adoption of more discriminating screening tests.
This strategy of selective testing is also pointed out by Cuculi et al. Although in general we support the use of testing algorithms that are based on risk, as outlined by recent NICE guidelines,4 we do believe that such strategies need further empirical evaluation. Bucciarelli-Ducci and Pennell provide an argument for considering cardiac MRI as an important tool for the identification of obstructive coronary artery disease. However, a review of the evidence underlying recommendations for noninvasive imaging5 reveals few randomized studies that show a clinical benefit, a state reflected by the clinical use of multiple different imaging tests. Since any approach might potentially be a reasonable strategy, we have recently launched the Prospective Multicenter Imaging Study for Evaluation of Chest Pain (PROMISE), funded by the National Heart, Lung, and Blood Institute, in which patients with symptoms that may be related to coronary artery disease are randomly assigned to either usual care or noninvasive angiography with the use of cardiac CT angiography. We look forward to using the results of this trial and other ongoing studies involving patients with chest pain to better inform clinical practice.
Manesh R. Patel, M.D.
Eric D. Peterson, M.D., M.P.H.
Pamela S. Douglas, M.D.
Duke Clinical Research Institute, Durham, NC
manesh.patel@duke. edu Since publication of their article, the authors report no further potential conflict of interest.
5 References1
Bayes T. An essay towards solving a problem in the doctrine of chances. London: Philosophical Transactions of the Royal Society of London, 1763.
2
Patel MR ,Dehmer GJ ,Hirshfeld JW ,Smith PK ,Spertus JA . ACCF/SCAI/STS/AATS/AHA/ASNC 2009 appropriateness criteria for coronary revascularization: a report of the American College of Cardiology Foundation Appropriateness Criteria Task Force, Society for Cardiovascular Angiography and Interventions, Society of Thoracic Surgeons, American Association for Thoracic Surgery, American Heart Association, and the American Society of Nuclear Cardiology: endorsed by the American Society of Echocardiography, the Heart Failure Society of America, and the Society of Cardiovascular Computed Tomography. Circulation 2009;119:1330-1352[Erratum, Circulation 2009;119(15):e488.]
CrossRef | Web of Science | Medline3
Diamond GA ,Forrester JS . Analysis of probability as an aid in the clinical diagnosis of coronary-artery disease. N Engl J Med 1979;300:1350-1358
Full Text | Web of Science | Medline4
National Clinical Guideline Centre for Acute and Chronic Conditions. Chest pain of recent onset: assessment and diagnosis of recent onset chest pain or discomfort of suspected cardiac origin. 2010. (Accessed June 2, 2010, at http://guidance.nice.org.uk/CG95.)
5
Tricoci P ,Allen JM ,Kramer JM ,Califf RM ,Smith SC Jr . Scientific evidence underlying the ACC/AHA clinical practice guidelines. JAMA 2009;301:831-841[Erratum, JAMA 2009;301:1544.]
CrossRef | Web of Science | Medline
Author/Editor Response
Bucciarelli-Ducci and Pennell are absolutely right to suggest that cardiovascular MRI is a promising alternative1 to the x-ray–based tests (myocardial perfusion scintigraphy or, increasingly, CT) that are used as “gatekeeper” tests before invasive coronary angiography is performed. There is no exposure to ionizing radiation associated with cardiovascular MRI, which is an important advantage in light of the rapidly increasing radiation-dose burden to the population from medical imaging procedures.2
Cardiology is not the only field in which MRI is a potentially viable alternative to x-ray–based examinations such as CT — providing at least equal efficacy without exposing the patient to ionizing radiation. In particular, a significant proportion of head and spine CT examinations (which together constitute more than one third of all CT scans) could potentially be replaced by MRI.3,4 Of course the cost of the procedure, the availability of MRI machines, and the clinical expertise of those who perform the test and interpret the results remain important issues with regard to MRI, but there are indeed a number of common imaging situations in which MRI should be considered more often, especially for patients who are particularly sensitive to radiation, such as children and young adults.5
David J. Brenner, Ph.D., D.Sc.
Columbia University Medical Center, New York, NYSince publication of his editorial, the author reports no further potential conflict of interest.
5 References1
Schwitter J ,Wacker CM ,van Rossum AC , et al. MR-IMPACT: comparison of perfusion-cardiac magnetic resonance with single-photon emission computed tomography for the detection of coronary artery disease in a multicentre, multivendor, randomized trial. Eur Heart J 2008;29:480-489
CrossRef | Web of Science | Medline2
Brenner DJ ,Hall EJ . Computed tomography -- an increasing source of radiation exposure. N Engl J Med 2007;357:2277-2284
Full Text | Web of Science | Medline3
Oikarinen H ,Merilainen S ,Paakko E ,Karttunen A ,Nieminen MT ,Tervonen O . Unjustified CT examinations in young patients. Eur Radiol 2009;19:1161-1165
CrossRef | Web of Science | Medline4
Clarke JC ,Cranley K ,Kelly BE ,Bell K ,Smith PH . Provision of MRI can significantly reduce CT collective dose. Br J Radiol 2001;74:926-931
Web of Science | Medline5
Brenner DJ . Should computed tomography be the modality of choice for imaging Crohn's disease in children? The radiation risk perspective. Gut 2008;57:1489-1490
CrossRef | Web of Science | Medline
- Citing Articles (2)
Citing Articles
1
T. Thomas Zacharia, Sangam G. Kanekar, Dan T. Nguyen, Kevin Moser. (2011) Optimization of patient dose and image quality with z-axis dose modulation for computed tomography (CT) head in acute head trauma and stroke. Emergency Radiology 18:2, 103-107
CrossRef2
G. Biondi-Zoccai, A. Abbate, G. Sangiorgi. (2011) It's never too early! Evidence for rushing your acute coronary patients to the cath lab. European Heart Journal 32:1, 13-15
CrossRef
