European Heart Journal Advance Access originally published online on February 16, 2006
European Heart Journal 2006 27(9):1127-1128; doi:10.1093/eurheartj/ehi805
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Gatekeeper for coronary angiography
Department of Cardiology
Thoraxcenter
University Medical Center Groningen
University of Groningen
Postbus 30001
Hanzeplein 1
9700 RB Groningen
The Netherlands
Tel: +31 50 3612355
fax: +31 50 3614391
E-mail address: c.a.geluk{at}thorax.umcg.nl
Department of Cardiology
Thoraxcenter
University Medical Center Groningen
University of Groningen
Postbus 30001
Hanzeplein 1
9700 RB Groningen
The Netherlands
We would like to compliment Hoilund-Carlsen and colleagues on their well-designed study on myocardial perfusion scintigraphy (MPS) as gatekeeper for coronary angiography.1 However, we have some doubts with regard to the use of MPS in a not-low-risk population. In this selection of patients scheduled for coronary angiography, obstructive coronary artery disease (CAD) was present in half of the population. This is more than twice the prevalence found in populations screened for acute chest pain.2 In such not-low-risk populations, it has been advised to use a test with high sensitivity to identify all patients with the most severe forms of disease in order to improve event-free survival and cost-effectiveness at a long term.3 In our opinion, a sensitivity of 81% for obstructive CAD and 94% for three-vessel disease, as was found by Hoilund-Carlsen and colleagues, is too low to incorporate MPS as effective gatekeeper in a pre-coronary angiography strategy.
Furthermore, we share their concern that too many coronary angiographies are performed in patients with normal coronary arteries. A diagnostic test with a high-negative predictive value could therefore best serve as a filter for coronary angiography, but the estimated negative predictive value of MPS for obstructive CAD was only 82%. We suggest that other imaging modalities, such as electron beam computed tomography (EBCT), may better serve as an initial filter for coronary angiography. Absence of coronary calcium on EBCT has a negative predictive value of >95% for the presence of obstructive CAD and the occurrence of future coronary events.4,5 Although for measurement of coronary calcium EBCT no contrast is used and thus no information on luminal obstructions is provided, increasing amounts of coronary calcium are associated with the future risk of coronary events. Detection of coronary calcium may therefore also serve as guide for the initiation of preventive treatment, such as lifestyle modification and aspirin or statin therapy.6
We suggest to use a two-staged diagnostic approach for risk stratification prior to coronary angiography, with EBCT as first step and selective use of non-invasive stress tests (MPS, cardiac stress magnetic resonance imaging, or stress echocardiography) in patients with intermediate calcium scores as second step. Patients with low calcium scores do not need coronary angiography, and patients with high calcium scores should undergo coronary angiography without non-invasive stress testing. This approach will result in a low rate of coronary angiographies in patients without obstructive CAD, in combination with a more optimal identification of patients requiring revascularization therapy. Given the costs of EBCT and MPS, a two-staged approach will certainly be more cost-effective.
References
- Hoilund-Carlsen PF, Johansen A, Christensen HW, Vach W, Moldrup M, Bartram P, Veje A, Haghfelt T. Potential impact of myocardial perfusion scintigraphy as gatekeeper for invasive examination and treatment in patients with stable angina pectoris: observational study without post-test referral bias. Eur Heart J 2006; 27: 2934.
[Abstract/Free Full Text] - deFilippi CR, Rosanio S, Tocchi M, Parmar RJ, Potter MA, Uretsky BF, Runge MS. Randomized comparison of a strategy of predischarge coronary angiography versus exercise testing in low-risk patients in a chest pain unit: in-hospital and long-term outcomes. J Am Coll Cardiol 2001; 37: 20422049.
[Abstract/Free Full Text] - Garber AM, Solomon NA. Cost-effectiveness of alternative test strategies for the diagnosis of coronary artery disease. Ann Intern Med 1999; 130: 719728.
[Abstract/Free Full Text] - Haberl R, Becker A, Leber A, Knez A, Becker C, Lang C, Bruning R, Reiser M, Steinbeck G. Correlation of coronary calcification and angiographically documented stenoses in patients with suspected coronary artery disease: results of 1764 patients. J Am Coll Cardiol 2001; 37: 451457.
[Abstract/Free Full Text] - Keelan PC, Bielak LF, Ashai K, Jamjoum LS, Denktas AE, Rumberger JA, Sheedy II PF, Peyser PA, Schwartz RS. Long-term prognostic value of coronary calcification detected by electron-beam computed tomography in patients undergoing coronary angiography. Circulation 2001; 104: 412417.
[Abstract/Free Full Text] - Rumberger JA, Brundage BH, Rader DJ, Kondos G. Electron beam computed tomographic coronary calcium scanning: a review and guidelines for use in asymptomatic persons. Mayo Clin Proc 1999; 74: 243252.[ISI][Medline]
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