- Email: [email protected]
Triage of Patients with Suspected Coronary Artery Disease using Multislice Computed Tomography
Original Investigations
Triage of Patients with Suspected Coronary Artery Disease using Multislice Computed Tomography1 Hans Hoffmann, MD, Hans-Peter Dübel, MD, Horst Laube, MD, Bernd Hamm, MD, Marc Dewey, MD
Rationale and Objectives. Several studies have shown that multislice computed tomography (MSCT) has a high sensitivity and specificity for detecting coronary artery stenoses. The aim of the present study was to investigate whether MSCT can reliably triage patients with suspected coronary artery disease (CAD) to coronary artery bypass grafting (CABG), percutaneous coronary intervention (PCI), or no revascularization. Materials and Methods. A total of 123 patients with suspected CAD who were referred for conventional coronary angiography (CATH) additionally underwent MSCT (16*0.5 mm detector collimation). Therapeutic decisions made on the basis of CATH and MSCT strictly following current guidelines for treatment of CAD were compared with decisions made by a cardiac surgeon and an interventional cardiologist. Only MSCTs with at least adequate image quality in all coronary segments were included in the analysis (94/123). Results. Decisions made on the basis of MSCT and CATH according to guidelines did not differ significantly (agreement of 88%, 82 of 94, P ⫽ .319). The therapeutic decisions made by the interventional cardiologist and the cardiac surgeon based on CATH differed significantly (overall agreement of 79%, 74 of 94 cases, P ⬍ .001; cardiologist: 78% PCI and 22% CABG versus surgeon: 38% PCI and 62% CABG), whereas there was 100% agreement regarding decisions for or against invasive treatment. Conclusions. MSCT shows good agreement with CATH in triaging patients with suspected CAD to CABG, PCI, or no revascularization. The choice of revascularization procedure is significantly more strongly influenced by whether an interventional cardiologist or a cardiac surgeon makes the decision than by the diagnostic test on which the decision is based. Key Words. Computed tomography; coronary artery imaging; revascularization; management; angiography. ©
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Coronary artery disease (CAD) is one of the most common diseases in industrialized countries (1). It is diagnosed noninvasively using resting electrocardiography (ECG), exercise ECG, scintigraphy, echocardiography, and stress echocardiography. These diagnostic tests vary
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From the Departments of Radiology (H.H., B.H., M.D.) and Cardiology (H.-P.D.), Charité, Humboldt University Medical School, Berlin, Germany; Department of Medicine I (Cardiology, Angiology, and Pulmology), Klinikum Brandenburg, Germany (H.H.); and Department of Cardiac Surgery, German Heart Center, Berlin, Germany (H.L.). Received April 2, 2007; accepted May 6, 2007. Address correspondence to: M.D. e-mail: [email protected]
© AUR, 2007 doi:10.1016/j.acra.2007.05.005
in their sensitivities and specificities (2). CAD is confirmed or excluded invasively by conventional coronary angiography (CATH), which has a mortality of 0.11% and a complication rate of 1.7% for major adverse cardiac and cerebrovascular events (MACCE) when performed as an elective diagnostic procedure (3). Multislice computed tomography (MSCT) involves the same radiation exposure and reliably depicts the coronary vessels with a sensitivity and specificity for the detection of hemodynamically significant stenoses of 85% and 95%, respectively. The technical advances made in recent years have continuously improved image analysis (4,5). The aim of the present study was to determine how well a therapeutic decision for either coronary artery bypass grafting
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(CABG), percutaneous coronary intervention (PCI), or no revascularization can be made on the basis of the MSCT findings in comparison with CATH (gold standard). To this end, we compared the therapeutic decisions made on the basis of MSCT and CATH in accordance with current guidelines with the therapeutic decisions made by specialists for PCI (interventional cardiologist) and CABG (cardiac surgeon).
MATERIAL AND METHODS Patients One hundred and twenty-three (92 men and 31 women, mean age 62.3 ⫾ 8.7 years) with suspected CAD who were referred to our institution by outpatient centers were investigated by elective CATH and MSCT as part of an investigator-initiated study comparing MSCT and magnetic resonance coronary angiography (6). Inclusion criteria were age at least 40 years and a sinus rhythm. Patients with contraindications to iodinated contrast agents, renal insufficiency, cardiac arrhythmia, coronary artery stents, or bypass grafts were excluded. The study was approved by the institutional review board and all patients gave written informed consent. MSCT Protocol Noninvasive coronary angiography with MSCT (Aquilion, Toshiba, Otawara, Japan) was performed during one breath-hold on a 16-slice CT scanner with 0.5-mm detector collimation (Aquilion 16, Toshiba), after intravenous injection of a nonionic, iso-osmolar contrast agent (iodixanol, 320 mg of iodine per mL [Visipaque, GE Healthcare Biosciences, Buckinghamshire, United Kingdom]) at a rate of 3.5 mL/second. Further details of the protocol and the results have been published elsewhere (6). All 15 coronary artery segments according to the classification of the American Heart Association (7) with a diameter of at least 1.5 mm on conventional coronary angiography constituted the basis of analysis. If at least one coronary artery segment was deemed to be nondiagnostic with MSCT, the patient was considered to be nondiagnostic for the current analysis according to the intention-to-diagnose design (8) because coverage of the entire coronary artery tree is necessary to adequately assess the potential of MSCT for triaging patients. Overall image quality in the remaining patients was rated as very good, good, satisfactory, or adequate.
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Conventional Coronary Angiography CATH was performed after MSCT within 5 days using standard techniques (Integris 3000, Philips Medical Systems, Best, The Netherlands) with the transfemoral approach. Using two orthogonal projections, quantitative coronary angiography was performed (in the projection showing the tightest view of stenoses) to measure diameter reductions. All 15 coronary artery segments were analyzed (7). The diameter of the reference vessel on conventional coronary angiography had to measure at least 1.5 mm for a stenosis to be included in the analysis, thus comprising all stenoses amenable to revascularization treatment. Guideline-Based Triage Using a Flow Chart The flow chart used for deciding about the most suitable therapeutic strategy was based on the current guidelines of the American College of Cardiology/ American Heart Association’s “For the Management of Patients With Chronic Stable Angina” (9), “For Percutaneous Coronary Intervention” (10), and in collaboration with the American Association for Thoracic Surgery and the Society of Thoracic Surgeons’ “For Coronary Artery Bypass Graft Surgery” (11). Only the recommendations of the Classification of Recommendations I with a Level of Evidence A and B were considered in the decision-making process. Therapy was indicated for a stenosis grade of at least 70%. The threshold for a stenosis of the left main coronary artery was 50% (Fig 1). Therapeutic Decision-Making by an Interventional Cardiologist and a Cardiac Surgeon The findings obtained by CATH and MSCT in each patient were assessed by an interventional cardiologist and a cardiac surgeon (both with more than 20 years of experience) blinded to patient data and the type of diagnostic test performed. To ensure blinding, the results were presented in the form of structured written reports supplemented by the patients’ characteristics. Further information available to the readers were type and intensity of chest pain, results of exercise ECG, stress myocardial scintigraphy or stress echocardiography, global left ventricular function, and diabetes mellitus. Statistical Analysis A level of P ⱕ .05 was considered significant. The overall per-patient agreement, the agreement in the decision between CABG and PCI, and the agreement in the
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Figure 1. Flow chart for triage of patients with suspected coronary artery disease established on the basis of the current guidelines of the American College of Cardiology/American Heart Association “For the Management of Patients With Chronic Stable Angina,” “Update for Coronary Artery Bypass Graft Surgery,” and “For Percutaneous Coronary Intervention, Recommendations I and Level of Evidence A and B.” Interventional treatment is indicated when the degree of stenosis is at least 70%, or 50% for left main coronary artery. (CABG: coronary artery bypass graft; EF: ejection fraction; LAD: left anterior descending coronary artery; LCX: left circumflex coronary artery; PCI: percutaneous coronary intervention; RCA: right coronary artery).
recommendation of revascularization versus no revascularization based on MSCT and CATH according to the current guidelines were compared using the pairwise McNemar’s test. In addition, kappa values were calculated. The same tests were applied for the comparison of the therapeutic decisions made by the interventional cardiologist and the cardiac surgeon and for comparing the therapeutic decisions with the therapies actually performed in the study patients. Accuracy of MSCT for and against revascularization and the predictive value of MSCT for revascularization were calculated. Agreement for MSCT scans with different image quality was assessed using Fisher’s test. The chi-square test served to compare the prevalence of CAD in different study populations. Statistical analyses were conducted using SPSS version 12.0. (SPSS, Inc, Chicago).
RESULTS A total of 123 MSCT scans were performed. Artifacts in at least one of the 15 coronary artery segment precluded evaluation of the entire coronary artery tree in 29 patients (24%). Thus 94 of 123 patients examined (76%) could be included in the analysis. In this group, the prevalence of coronary artery disease requiring intervention diagnosed by invasive tests was 49% (46 of 94 patients), which was not significantly different from the prevalence in the total study population (51%, 63 of 123 patients, P ⫽ .85). Image quality in the 94 patients included in the analysis was very good in 19 cases, good in 38, satisfactory in 35, and adequate in 2. The therapeutic decisions made on the basis of MSCT according to the guidelines for the treatment of coronary
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Table 1 Agreement of Therapeutic Decisions Based on MSCT and CATH Made According to the Guidelines for the Treatment of Coronary Artery Disease MSCT
CATH CABG PCI No revascularization Total
CABG
PCI
No Revascularization
Total
9 3 0 12
1 27 2 30
0 5 47 52
10 35 49 94
The statistical results were as follows: agreement: 88%; Kappa: 0.798; McNemar’s test: P ⫽ .319; agreement for decision between PCI and CABG: 90%; agreement for decision between revascularization and no revascularization: 93%; accuracy for decision for revascularization: 89%; accuracy for decision against revascularization: 96%; predictive value of MSCT for revascularization: 95%. CABG: coronary artery bypass graft; CATH: conventional coronary angiography; MSCT: multislice computed tomography; PCI: percutaneous coronary intervention.
artery disease (Fig 1) showed 88% agreement with the decisions based on CATH (Table 1). No patient who required operative management according to CATH was assigned to conservative treatment based on MSCT, and no patient assigned to the conservative management group by CATH would have been operated on according to MSCT. Regarding the decision between revascularization and no revascularization there was 93% agreement between CATH and MSCT (87 of 94, Table 1). Both tests also agreed in the exclusion of coronary artery disease (Fig 2). Agreement between CATH and MSCT was 90% for the decision between PCI and CABG (36 of 40, Table 1). In the cases in which there was agreement, MSCT correctly diagnosed four stenoses in the left main (Fig 3) and did not miss any left main stenosis. Disagreement between PCI and CABG was mainly the result of false-negative or false-positive diagnoses of left main stenosis equivalents. For MSCT scans with very good image quality (n ⫽ 19), agreement of guideline-based therapeutic decisions made on the basis of MSCT and CATH regarding guidelinebased therapeutic decisions increased to 100%, but the difference in comparison to cases with less than very good image quality was not significant (63 of 75 versus 19 of 19, P ⫽ .062). The overall agreement regarding therapeutic decisions made by the interventional cardiologist and the cardiac surgeon based on CATH was 79% (74 of 94). The rec-
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ommendation for invasive treatment showed 100% agreement. However, there was only 60% agreement (30 of 50) regarding the decision as to the therapeutic procedure. The cardiologist more often opted for PCI than CABG (39 versus 11/50, 78% versus 22%) as compared with the cardiac surgeon (19 versus 31/50, 38% versus 62%) the difference was significant in McNemar’s test (Table 2). For the therapeutic decisions based on MSCT, there was also good agreement between the interventional cardiologist and the cardiac surgeon with regard to the need for invasive treatment (99%), but only little agreement regarding the type of revascularization (52%, 23 of 44). There was significant disagreement between the interventional cardiologist and the cardiac surgeon with regard to the treatment strategy recommended (McNemar test P ⬍ .001, Table 3). It has to be noted that this difference was greater than the difference in guideline-based therapeutic decisions made on the basis of the MSCT and CATH findings (Table 1). Actual treatment of the patients performed on the basis of the CATH findings was in agreement with the current guidelines in 81% of the cases (76 of 94). The therapeutic decisions based on MSCT agreed with actual treatment in 83% of the patients (77 of 94). All left main stenoses were operated on. In patients with proximal left anterior descending coronary stenoses with simultaneous stenosis of the left circumflex coronary artery, the physician actually treating the patient repeatedly opted for a revascularization technique which was not in accordance with the guidelines. These decisions were made regardless of left ventricular function or the presence of diabetes mellitus or left main equivalent. Figure 4 shows an example of cardiosurgical management of a proximal left anterior descending coronary stenosis in two-vessel disease. Figure 5 shows a stenosis of the proximal left anterior descending coronary diagnosed by CATH and MSCT and successfully treated by PCI. Altogether, seven patients did not undergo revascularization although they had relevant coronary artery stenoses (⬎70%). Reasons for medical therapy in these cases were small vessel diameter, myocardial scars in the supply area, and patient’s personal decision. Coronary stenoses associated with 50%–70% diameter reduction were treated invasively when ischemia was demonstrated.
DISCUSSION MSCT coronary angiography has shown a high sensitivity and specificity for the detection of coronary steno-
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Figure 2. Exclusion of coronary artery disease in a 67-year-old woman. MSCT with curved multiplanar reformation of the LAD (a), LCX (b), and RCA (d). CATH of the coronary artery tree showing no significant stenoses: LCA (c) and RCA (e). (CATH: conventional coronary angiography; LAD: left anterior descending coronary artery; LCA: left coronary artery; LCX: left circumflex artery; MSCT: multislice computed tomography; RCA: right coronary artery).
ses (5). In the present study, we compared therapeutic decision-making (no intervention, PCI, or CABG) on the basis of MSCT and CATH. There was good agreement between CATH and MSCT regarding therapeutic decisions made in accordance with current guidelines (Table 1). Moreover, MSCT may be the basis for the kind of therapy in patients with CAD. The technical advances of MSCT in recent years have led to an ever-increasing diagnostic accuracy of MSCT coronary angiography (12). In our study, 15% of the coronary MSCT scans were of very good image quality. These scans allow analysis with the same accuracy as CATH. It is therefore expected that further improvements in image quality, for example through the use of 64-slice scanners (13–18), might further increase the number of scans with improved vessel depiction and fewer artifacts at the same spatial solution (19) for reliable interpretation and therapeutic decisionmaking.
The agreement of therapeutic decisions made by the cardiac surgeon and the interventional cardiologist was lower than the agreement between therapeutic decisions made on the basis of MSCT and CATH. There were significant differences between the cardiac surgeon and the interventional cardiologist in the type of invasive therapy recommended: there was only 60% agreement with regard to PCI versus CABG, whereas guideline-based therapeutic decisions on the basis of MSCT and CATH agreed in 90% of cases. The discrepancies between the interventional cardiologist and the cardiac surgeon may in part be explained by the fact that more and more stenoses of an unprotected left main have been treated interventionally since the advent of drug-eluting stents although they are an indication for CABG according to the guidelines (20,21). Studies directly comparing stenting of unprotected left main versus bypass are currently under way (22). Recent results from the Euro Heart Survey show that, as in our study, good agreement with current guidelines
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Figure 3. Examples of left main stenoses detected by MSCT in comparison to CATH. CATH showing 55% distal stenosis of left main (a, arrow) in a 69-year-old patient. MSCT diagnosis a 65% stenosis (e, arrow), three-dimensional view. Left main stenosis demonstrated by CATH (b, arrowhead) and multiplanar reformation of MSCT (f, arrowhead). High-grade stenosis of the left main on CATH (c, arrow), which is confirmed on oblique view of MSCT and shown to be due to a large plaque (g, arrow). A 63-year-old patient with 85% stenosis of left main on CATH (d, arrow) as compared with appearance on angiographic emulation of MSCT of nearly the same view (h, arrow). (CATH: conventional coronary angiography; MSCT: multislice computed tomography). Table 2 Agreement Between Interventional Cardiologist and Cardiac Surgeon Based on CATH
Interventional cardiologist CABG PCI No revascularization Total
Table 3 Agreement Between Interventional Cardiologist and Cardiac Surgeon Based on MSCT
Cardiac Surgeon
Cardiac Surgeon
No CABG PCI Revascularization Total
No CABG PCI Revascularization Total
11 20 0 31
0 19 0 19
0 0 44 44
11 39 44 94
Interventional cardiologist CABG PCI No revascularization Total
6 21 0 27
0 17 1 18
0 0 49 49
6 38 50 94
The statistical results were as follows: agreement: 79%; McNemar’s: P ⬍ .001 (indicating significant differences between the two physicians); Kappa: 0.677; agreement for decision between PCI and CABG: 60%; and agreement for decision between revascularization and no revascularization: 100%. CABG: coronary artery bypass graft; CATH: conventional coronary angiography; MSCT: multislice computed tomography; PCI: percutaneous coronary intervention.
The statistical results were as follows: agreement: 77%; McNemar’s test: P ⬍ .001 (indicating significant differences between the two physicians); Kappa: 0.672; agreement for decision between PCI and CABG: 52%; and agreement for decision between revascularization and no revascularization: 99%. CABG: coronary artery bypass graft; CATH: conventional coronary angiography; MSCT: multislice computed tomography; PCI: percutaneous coronary intervention.
are found and greatest differences are encountered in patients with severe coronary disease, impaired left ventricular function, and diabetes mellitus (23). Our results suggest that the crucial decision whether a patient should undergo CABG
is influenced more strongly by who makes the decision and not by the diagnostic test (CATH or MSCT) performed. Using MSCT as a diagnostic test might reduce the incidence of catheter-related complications in those
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Figure 4. Example of correct triage to bypass surgery by MSCT of a 48-year-old patient with diabetes mellitus. Occlusion of the RCA on CATH (a, arrow), on three-dimensional MSCT (b, arrow), and angiographic emulation of MSCT (c, arrow). Corresponding images of the proximal stenosis of the LAD (d, e, f). Follow-up by MSCT 18 months after CABG demonstrates occlusion of the venous bypass at the site of attachment (g, arrowhead) and a patent LIMA (h, i). (CABG: coronary artery bypass graft; CATH: conventional coronary angiography; LAD: left anterior descending coronary artery; LIMA: left internal mammary artery bypass; MSCT: multislice computed tomography; RCA: right coronary artery).
cases where no additional coronary interventions are necessary. In Germany, the incidence of MACCE is reported to be 0.23% for diagnostic cardiac catheterization (24) and peripheral arterial pseudoaneurysm occurs in 0.43% of cases (25), whereas rare complications such as abdominal ischemia (26) or cholesterol embolism syndrome (27) occur in isolated cases only. Based on an annual number of 652,781 catheter angiographies
performed in Germany (28), the use of MSCT could theoretically prevent about 1,200 MACCE and about 2,200 peripheral vascular complications every year. Disease of the left main is an independent factor that increases mortality during diagnostic cardiac catheterization to 0.7% (29,30). That all stenoses of left main were correctly identified by MSCT in our study clearly underlines the benefit of this noninvasive diagnostic test.
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Figure 5. CATH and MSCT of an LAD stenosis (arrow) in a 72-year-old patient before and after PCI. Depiction of the LAD stenosis on CATH (a) and curved multiplanar reformation of MSCT (b). Good primary result after PCI (c) and no restenosis on follow-up MSCT after stenting (d). (CATH: conventional coronary angiography; LAD: left anterior descending coronary artery; MSCT: multislice computed tomography; PCI: percutaneous coronary intervention).
We investigated how therapeutic decisions based on CAD and MSCT might differ in patients with suspected CAD referred for elective CATH. In a study of 22 patients with acute coronary syndrome, Dorgelo et al (31) found an 86% agreement regarding therapeutic decisions between MSCT and CATH and a 100% agreement for the decision between revascularization and no revascularization. To our knowledge, there are no further studies comparing therapeutic management based on MSCT versus CATH. Our study including the CT technology we used has some limitations. Therapeutic decisions were based on the degree and site of the stenosis, demonstration of ischemia, type and severity of symptoms, left ventricular function, and the presence of diabetes mellitus. Other criteria to be considered when deciding about revascularization are the vessel diameter and the morphology of the stenosis. It is possible in
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principle to assess these factors by MSCT, but they were not included in the decision-making process in the present study because of their complexity. Future studies might include these factors as well. Also, the results presented here are based on the findings obtained in a single center. MSCT of the coronary arteries is limited by a high rate of patients who cannot be analyzed because image quality is degraded by artifacts. The rate of 24% of unanalyzable patients corresponds to the incidence reported for 16-slice CT by other investigators (32). The rate of unanalyzable MSCT scans has been reduced with the advent of 64-slice scanners. The study population presented here was the last one examined using 16-slice CT at our department. CT is also limited in patients without sinus rhythm (33) and high heart rates (34). In conclusion, MSCT could be established as a diagnostic tool to replace catheter angiography in specific patient
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groups and to thus reduce the incidence of catheter-related complications. The results presented here suggest that MSCT would allow reliable triage of patients with suspected coronary artery disease. Technical advances have improved the image quality of MSCT in recent years, resulting in good agreement of the findings with invasive catheter angiography and increasing acceptance of this new technique for the assessment of patients presenting with unclear chest pain (35). However, the method has to be evaluated further using data obtained with 64-slice CT and from multicenter studies. REFERENCES 1. Tunstall-Pedoe H, Kuulasmaa K, Mahonen M, et al. Contribution of trends in survival and coronary-event rates to changes in coronary heart disease mortality: 10-year results from 37 WHO MONICA project populations. Monitoring trends and determinants in cardiovascular disease. Lancet 1999; 353:1547–1557. 2. Dewey M, Richter WS, Lembcke A, et al. Noninvasive diagnosis of coronary artery disease. Med Klin (Munich) 2004; 99:57– 64. 3. Noto TJ Jr, Johnson LW, Krone R, et al. Cardiac catheterization 1990: a report of the Registry of the Society for Cardiac Angiography and Interventions (SCA&I). Cathet Cardiovasc Diagn 1991; 24:75– 83. 4. Garcia MJ, Lessick J, Hoffmann MH. Accuracy of 16-row multidetector computed tomography for the assessment of coronary artery stenosis. JAMA 2006; 296:403– 411. 5. Schuijf JD, Bax JJ, Shaw LJ, et al. Meta-analysis of comparative diagnostic performance of magnetic resonance imaging and multislice computed tomography for noninvasive coronary angiography. Am Heart J 2006; 151:404 – 411. 6. Dewey M, Teige F, Schnapauff D, et al. Noninvasive detection of coronary artery stenoses with multislice computed tomography or magnetic resonance imaging. Ann Intern Med 2006; 145:407– 415. 7. Austen WG, Edwards JE, Frye RL, et al. A reporting system on patients evaluated for coronary artery disease. Report of the Ad Hoc Committee for Grading of Coronary Artery Disease, Council on Cardiovascular Surgery, American Heart Association. Circulation 1975; 51:5– 40. 8. Knottnerus JA, Muris JW. Assessment of the accuracy of diagnostic tests: the cross-sectional study. J Clin Epidemiol 2003; 56:1118 –1128. 9. Gibbons RJ, Abrams J, Chatterjee K, et al. ACC/AHA 2002 guideline update for the management of patients with chronic stable angina— summary article: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee on the Management of Patients With Chronic Stable Angina). Circulation 2003; 107:149 –158. 10. Smith SC Jr, Dove JT, Jacobs AK, et al. ACC/AHA guidelines for percutaneous coronary intervention (revision of the 1993 PTCA guidelines)— executive summary: a report of the American College of Cardiology/American Heart Association task force on practice guidelines (Committee to revise the 1993 guidelines for percutaneous transluminal coronary angioplasty) endorsed by the Society for Cardiac Angiography and Interventions. Circulation 2001; 103:3019 –3041. 11. Eagle KA, Guyton RA, Davidoff R, et al. ACC/AHA 2004 guideline update for coronary artery bypass graft surgery: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee to Update the 1999 Guidelines for Coronary Artery Bypass Graft Surgery). Circulation 2004; 110:e340 – e437. 12. Mollet NR, Cademartiri F, Krestin GP, et al. Improved diagnostic accuracy with 16-row multi-slice computed tomography coronary angiography. J Am Coll Cardiol 2005; 45:128 –132. 13. Leschka S, Alkadhi H, Plass A, et al. Accuracy of MSCT coronary angiography with 64-slice technology: first experience. Eur Heart J 2005; 26:1482–1487.
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14. Leber AW, Knez A, von Ziegler F, et al. Quantification of obstructive and nonobstructive coronary lesions by 64-slice computed tomography: a comparative study with quantitative coronary angiography and intravascular ultrasound. J Am Coll Cardiol 2005; 46:147–154. 15. Raff GL, Gallagher MJ, O’Neill WW, et al. Diagnostic accuracy of noninvasive coronary angiography using 64-slice spiral computed tomography. J Am Coll Cardiol 2005; 46:552–557. 16. Pugliese F, Mollet NR, Runza G, et al. Diagnostic accuracy of non-invasive 64-slice CT coronary angiography in patients with stable angina pectoris. Eur Radiol 2006; 16:575–582. 17. Mollet NR, Cademartiri F, van Mieghem CA, et al. High-resolution spiral computed tomography coronary angiography in patients referred for diagnostic conventional coronary angiography. Circulation 2005; 112:2318–2323. 18. Ropers D, Rixe J, Anders K, et al. Usefulness of multidetector row spiral computed tomography with 64- ⫻ 0.6-mm collimation and 330-ms rotation for the noninvasive detection of significant coronary artery stenoses. Am J Cardiol 2006; 97:343–348. 19. Dewey M, Hoffmann H, Hamm B. CT coronary angiography using 16 and 64 simultaneous detector rows: intraindividual comparison. Rofo 2007; 179(6):581–586. 20. Lee MS, Kapoor N, Jamal F, et al. Comparison of coronary artery bypass surgery with percutaneous coronary intervention with drug-eluting stents for unprotected left main coronary artery disease. J Am Coll Cardiol 2006; 47:864 – 870. 21. Raja SG. Drug-eluting stents and the future of coronary artery bypass surgery: facts and fiction. Ann Thorac Surg 2006; 81:1162–1171. 22. Ong AT, van der Giessen WJ. Drug-eluting stents for interventional revascularization of coronary multivessel disease. J Interv Cardiol 2005; 18:447– 453. 23. Breeman A, Hordijk-Trion M, Lenzen M, et al. Treatment decisions in stable coronary artery disease: insights from the Euro Heart Survey on Coronary Revascularization. J Thorac Cardiovasc Surg 2006; 132:1001–1009. 24. Behrenbeck W. Koronarangiographie und perkutane koronarangioplastie. Available from http://www.bqs-qualitaetsreport.de/Webs/ bqs/qualrep/2004/ergebnisse/. Accessed September 2006. 25. Scanlon PJ, Faxon DP, Audet AM, et al. ACC/AHA guidelines for coronary angiography. A report of the American College of Cardiology/ American Heart Association Task Force on practice guidelines (Committee on Coronary Angiography). Developed in collaboration with the Society for Cardiac Angiography and Interventions. J Am Coll Cardiol 1999; 33:1756 –1824. 26. ter Woorst FJ, Berry LL, de Swart HJ, et al. A rare complication of coronary arteriography. Cathet Cardiovasc Diagn 1998; 43:455– 456. 27. Brunner M, Trebing D, Goring HD. Cholesterol embolism syndrome after coronary angiography. Hautarzt 2005; 56:854 – 859. 28. van Buuren F, Mannebach H, Horstkotte D. 20th report of performance data from heart catheterization laboratories in Germany. 2003 results of a collaborative survey by the Committee of Clinical Cardiology and the Interventional Cardiology (for ECS) and Angiology Study Groups of the German Society of Cardiology-Cardiovascular Research. Z Kardiol 2005; 94:212–215. 29. Devlin G, Lazzam L, Schwartz L. Mortality related to diagnostic cardiac catheterization. The importance of left main coronary disease and catheter induced trauma. Int J Card Imaging 1997; 13:379 –386. 30. Porzionato A, Zancaner S, Ramondo A, et al. Onset and progression of fatal coronary dissection during angiography. Can J Cardiol 2006; 22:77–78. 31. Dorgelo J, Willems TP, Geluk CA, et al. Multidetector computed tomography-guided treatment strategy in patients with non-ST elevation acute coronary syndromes: a pilot study. Eur Radiol 2005; 15:708 –713. 32. Hoffmann MH, Shi H, Schmitz BL, et al. Noninvasive coronary angiography with multislice computed tomography. JAMA 2005; 293:2471–2478. 33. Kovacs A, Probst C, Sommer T, et al. [CT coronary angiography in patients with atrial fibrillation]. Rofo 2005; 177:1655–1662. 34. Hoffmann MH, Shi H, Manzke R, et al. Noninvasive coronary angiography with 16-detector row CT: effect of heart rate. Radiology 2005; 234:86 –97. 35. Schroeder S, Kuettner A, Beck T, et al. Usefulness of noninvasive MSCT coronary angiography as first-line imaging technique in patients with chest pain: initial clinical experience. Int J Cardiol 2005; 102:469 – 475.
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Triage of Patients with Suspected Coronary Artery Disease using Multislice Computed Tomography1 Hans Hoffmann, MD, Hans-Peter Dübel, MD, Horst Laube, MD, Bernd Hamm, MD, Marc Dewey, MD
Rationale and Objectives. Several studies have shown that multislice computed tomography (MSCT) has a high sensitivity and specificity for detecting coronary artery stenoses. The aim of the present study was to investigate whether MSCT can reliably triage patients with suspected coronary artery disease (CAD) to coronary artery bypass grafting (CABG), percutaneous coronary intervention (PCI), or no revascularization. Materials and Methods. A total of 123 patients with suspected CAD who were referred for conventional coronary angiography (CATH) additionally underwent MSCT (16*0.5 mm detector collimation). Therapeutic decisions made on the basis of CATH and MSCT strictly following current guidelines for treatment of CAD were compared with decisions made by a cardiac surgeon and an interventional cardiologist. Only MSCTs with at least adequate image quality in all coronary segments were included in the analysis (94/123). Results. Decisions made on the basis of MSCT and CATH according to guidelines did not differ significantly (agreement of 88%, 82 of 94, P ⫽ .319). The therapeutic decisions made by the interventional cardiologist and the cardiac surgeon based on CATH differed significantly (overall agreement of 79%, 74 of 94 cases, P ⬍ .001; cardiologist: 78% PCI and 22% CABG versus surgeon: 38% PCI and 62% CABG), whereas there was 100% agreement regarding decisions for or against invasive treatment. Conclusions. MSCT shows good agreement with CATH in triaging patients with suspected CAD to CABG, PCI, or no revascularization. The choice of revascularization procedure is significantly more strongly influenced by whether an interventional cardiologist or a cardiac surgeon makes the decision than by the diagnostic test on which the decision is based. Key Words. Computed tomography; coronary artery imaging; revascularization; management; angiography. ©
AUR, 2007
Coronary artery disease (CAD) is one of the most common diseases in industrialized countries (1). It is diagnosed noninvasively using resting electrocardiography (ECG), exercise ECG, scintigraphy, echocardiography, and stress echocardiography. These diagnostic tests vary
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From the Departments of Radiology (H.H., B.H., M.D.) and Cardiology (H.-P.D.), Charité, Humboldt University Medical School, Berlin, Germany; Department of Medicine I (Cardiology, Angiology, and Pulmology), Klinikum Brandenburg, Germany (H.H.); and Department of Cardiac Surgery, German Heart Center, Berlin, Germany (H.L.). Received April 2, 2007; accepted May 6, 2007. Address correspondence to: M.D. e-mail: [email protected]
© AUR, 2007 doi:10.1016/j.acra.2007.05.005
in their sensitivities and specificities (2). CAD is confirmed or excluded invasively by conventional coronary angiography (CATH), which has a mortality of 0.11% and a complication rate of 1.7% for major adverse cardiac and cerebrovascular events (MACCE) when performed as an elective diagnostic procedure (3). Multislice computed tomography (MSCT) involves the same radiation exposure and reliably depicts the coronary vessels with a sensitivity and specificity for the detection of hemodynamically significant stenoses of 85% and 95%, respectively. The technical advances made in recent years have continuously improved image analysis (4,5). The aim of the present study was to determine how well a therapeutic decision for either coronary artery bypass grafting
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(CABG), percutaneous coronary intervention (PCI), or no revascularization can be made on the basis of the MSCT findings in comparison with CATH (gold standard). To this end, we compared the therapeutic decisions made on the basis of MSCT and CATH in accordance with current guidelines with the therapeutic decisions made by specialists for PCI (interventional cardiologist) and CABG (cardiac surgeon).
MATERIAL AND METHODS Patients One hundred and twenty-three (92 men and 31 women, mean age 62.3 ⫾ 8.7 years) with suspected CAD who were referred to our institution by outpatient centers were investigated by elective CATH and MSCT as part of an investigator-initiated study comparing MSCT and magnetic resonance coronary angiography (6). Inclusion criteria were age at least 40 years and a sinus rhythm. Patients with contraindications to iodinated contrast agents, renal insufficiency, cardiac arrhythmia, coronary artery stents, or bypass grafts were excluded. The study was approved by the institutional review board and all patients gave written informed consent. MSCT Protocol Noninvasive coronary angiography with MSCT (Aquilion, Toshiba, Otawara, Japan) was performed during one breath-hold on a 16-slice CT scanner with 0.5-mm detector collimation (Aquilion 16, Toshiba), after intravenous injection of a nonionic, iso-osmolar contrast agent (iodixanol, 320 mg of iodine per mL [Visipaque, GE Healthcare Biosciences, Buckinghamshire, United Kingdom]) at a rate of 3.5 mL/second. Further details of the protocol and the results have been published elsewhere (6). All 15 coronary artery segments according to the classification of the American Heart Association (7) with a diameter of at least 1.5 mm on conventional coronary angiography constituted the basis of analysis. If at least one coronary artery segment was deemed to be nondiagnostic with MSCT, the patient was considered to be nondiagnostic for the current analysis according to the intention-to-diagnose design (8) because coverage of the entire coronary artery tree is necessary to adequately assess the potential of MSCT for triaging patients. Overall image quality in the remaining patients was rated as very good, good, satisfactory, or adequate.
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Conventional Coronary Angiography CATH was performed after MSCT within 5 days using standard techniques (Integris 3000, Philips Medical Systems, Best, The Netherlands) with the transfemoral approach. Using two orthogonal projections, quantitative coronary angiography was performed (in the projection showing the tightest view of stenoses) to measure diameter reductions. All 15 coronary artery segments were analyzed (7). The diameter of the reference vessel on conventional coronary angiography had to measure at least 1.5 mm for a stenosis to be included in the analysis, thus comprising all stenoses amenable to revascularization treatment. Guideline-Based Triage Using a Flow Chart The flow chart used for deciding about the most suitable therapeutic strategy was based on the current guidelines of the American College of Cardiology/ American Heart Association’s “For the Management of Patients With Chronic Stable Angina” (9), “For Percutaneous Coronary Intervention” (10), and in collaboration with the American Association for Thoracic Surgery and the Society of Thoracic Surgeons’ “For Coronary Artery Bypass Graft Surgery” (11). Only the recommendations of the Classification of Recommendations I with a Level of Evidence A and B were considered in the decision-making process. Therapy was indicated for a stenosis grade of at least 70%. The threshold for a stenosis of the left main coronary artery was 50% (Fig 1). Therapeutic Decision-Making by an Interventional Cardiologist and a Cardiac Surgeon The findings obtained by CATH and MSCT in each patient were assessed by an interventional cardiologist and a cardiac surgeon (both with more than 20 years of experience) blinded to patient data and the type of diagnostic test performed. To ensure blinding, the results were presented in the form of structured written reports supplemented by the patients’ characteristics. Further information available to the readers were type and intensity of chest pain, results of exercise ECG, stress myocardial scintigraphy or stress echocardiography, global left ventricular function, and diabetes mellitus. Statistical Analysis A level of P ⱕ .05 was considered significant. The overall per-patient agreement, the agreement in the decision between CABG and PCI, and the agreement in the
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Figure 1. Flow chart for triage of patients with suspected coronary artery disease established on the basis of the current guidelines of the American College of Cardiology/American Heart Association “For the Management of Patients With Chronic Stable Angina,” “Update for Coronary Artery Bypass Graft Surgery,” and “For Percutaneous Coronary Intervention, Recommendations I and Level of Evidence A and B.” Interventional treatment is indicated when the degree of stenosis is at least 70%, or 50% for left main coronary artery. (CABG: coronary artery bypass graft; EF: ejection fraction; LAD: left anterior descending coronary artery; LCX: left circumflex coronary artery; PCI: percutaneous coronary intervention; RCA: right coronary artery).
recommendation of revascularization versus no revascularization based on MSCT and CATH according to the current guidelines were compared using the pairwise McNemar’s test. In addition, kappa values were calculated. The same tests were applied for the comparison of the therapeutic decisions made by the interventional cardiologist and the cardiac surgeon and for comparing the therapeutic decisions with the therapies actually performed in the study patients. Accuracy of MSCT for and against revascularization and the predictive value of MSCT for revascularization were calculated. Agreement for MSCT scans with different image quality was assessed using Fisher’s test. The chi-square test served to compare the prevalence of CAD in different study populations. Statistical analyses were conducted using SPSS version 12.0. (SPSS, Inc, Chicago).
RESULTS A total of 123 MSCT scans were performed. Artifacts in at least one of the 15 coronary artery segment precluded evaluation of the entire coronary artery tree in 29 patients (24%). Thus 94 of 123 patients examined (76%) could be included in the analysis. In this group, the prevalence of coronary artery disease requiring intervention diagnosed by invasive tests was 49% (46 of 94 patients), which was not significantly different from the prevalence in the total study population (51%, 63 of 123 patients, P ⫽ .85). Image quality in the 94 patients included in the analysis was very good in 19 cases, good in 38, satisfactory in 35, and adequate in 2. The therapeutic decisions made on the basis of MSCT according to the guidelines for the treatment of coronary
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Table 1 Agreement of Therapeutic Decisions Based on MSCT and CATH Made According to the Guidelines for the Treatment of Coronary Artery Disease MSCT
CATH CABG PCI No revascularization Total
CABG
PCI
No Revascularization
Total
9 3 0 12
1 27 2 30
0 5 47 52
10 35 49 94
The statistical results were as follows: agreement: 88%; Kappa: 0.798; McNemar’s test: P ⫽ .319; agreement for decision between PCI and CABG: 90%; agreement for decision between revascularization and no revascularization: 93%; accuracy for decision for revascularization: 89%; accuracy for decision against revascularization: 96%; predictive value of MSCT for revascularization: 95%. CABG: coronary artery bypass graft; CATH: conventional coronary angiography; MSCT: multislice computed tomography; PCI: percutaneous coronary intervention.
artery disease (Fig 1) showed 88% agreement with the decisions based on CATH (Table 1). No patient who required operative management according to CATH was assigned to conservative treatment based on MSCT, and no patient assigned to the conservative management group by CATH would have been operated on according to MSCT. Regarding the decision between revascularization and no revascularization there was 93% agreement between CATH and MSCT (87 of 94, Table 1). Both tests also agreed in the exclusion of coronary artery disease (Fig 2). Agreement between CATH and MSCT was 90% for the decision between PCI and CABG (36 of 40, Table 1). In the cases in which there was agreement, MSCT correctly diagnosed four stenoses in the left main (Fig 3) and did not miss any left main stenosis. Disagreement between PCI and CABG was mainly the result of false-negative or false-positive diagnoses of left main stenosis equivalents. For MSCT scans with very good image quality (n ⫽ 19), agreement of guideline-based therapeutic decisions made on the basis of MSCT and CATH regarding guidelinebased therapeutic decisions increased to 100%, but the difference in comparison to cases with less than very good image quality was not significant (63 of 75 versus 19 of 19, P ⫽ .062). The overall agreement regarding therapeutic decisions made by the interventional cardiologist and the cardiac surgeon based on CATH was 79% (74 of 94). The rec-
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ommendation for invasive treatment showed 100% agreement. However, there was only 60% agreement (30 of 50) regarding the decision as to the therapeutic procedure. The cardiologist more often opted for PCI than CABG (39 versus 11/50, 78% versus 22%) as compared with the cardiac surgeon (19 versus 31/50, 38% versus 62%) the difference was significant in McNemar’s test (Table 2). For the therapeutic decisions based on MSCT, there was also good agreement between the interventional cardiologist and the cardiac surgeon with regard to the need for invasive treatment (99%), but only little agreement regarding the type of revascularization (52%, 23 of 44). There was significant disagreement between the interventional cardiologist and the cardiac surgeon with regard to the treatment strategy recommended (McNemar test P ⬍ .001, Table 3). It has to be noted that this difference was greater than the difference in guideline-based therapeutic decisions made on the basis of the MSCT and CATH findings (Table 1). Actual treatment of the patients performed on the basis of the CATH findings was in agreement with the current guidelines in 81% of the cases (76 of 94). The therapeutic decisions based on MSCT agreed with actual treatment in 83% of the patients (77 of 94). All left main stenoses were operated on. In patients with proximal left anterior descending coronary stenoses with simultaneous stenosis of the left circumflex coronary artery, the physician actually treating the patient repeatedly opted for a revascularization technique which was not in accordance with the guidelines. These decisions were made regardless of left ventricular function or the presence of diabetes mellitus or left main equivalent. Figure 4 shows an example of cardiosurgical management of a proximal left anterior descending coronary stenosis in two-vessel disease. Figure 5 shows a stenosis of the proximal left anterior descending coronary diagnosed by CATH and MSCT and successfully treated by PCI. Altogether, seven patients did not undergo revascularization although they had relevant coronary artery stenoses (⬎70%). Reasons for medical therapy in these cases were small vessel diameter, myocardial scars in the supply area, and patient’s personal decision. Coronary stenoses associated with 50%–70% diameter reduction were treated invasively when ischemia was demonstrated.
DISCUSSION MSCT coronary angiography has shown a high sensitivity and specificity for the detection of coronary steno-
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Figure 2. Exclusion of coronary artery disease in a 67-year-old woman. MSCT with curved multiplanar reformation of the LAD (a), LCX (b), and RCA (d). CATH of the coronary artery tree showing no significant stenoses: LCA (c) and RCA (e). (CATH: conventional coronary angiography; LAD: left anterior descending coronary artery; LCA: left coronary artery; LCX: left circumflex artery; MSCT: multislice computed tomography; RCA: right coronary artery).
ses (5). In the present study, we compared therapeutic decision-making (no intervention, PCI, or CABG) on the basis of MSCT and CATH. There was good agreement between CATH and MSCT regarding therapeutic decisions made in accordance with current guidelines (Table 1). Moreover, MSCT may be the basis for the kind of therapy in patients with CAD. The technical advances of MSCT in recent years have led to an ever-increasing diagnostic accuracy of MSCT coronary angiography (12). In our study, 15% of the coronary MSCT scans were of very good image quality. These scans allow analysis with the same accuracy as CATH. It is therefore expected that further improvements in image quality, for example through the use of 64-slice scanners (13–18), might further increase the number of scans with improved vessel depiction and fewer artifacts at the same spatial solution (19) for reliable interpretation and therapeutic decisionmaking.
The agreement of therapeutic decisions made by the cardiac surgeon and the interventional cardiologist was lower than the agreement between therapeutic decisions made on the basis of MSCT and CATH. There were significant differences between the cardiac surgeon and the interventional cardiologist in the type of invasive therapy recommended: there was only 60% agreement with regard to PCI versus CABG, whereas guideline-based therapeutic decisions on the basis of MSCT and CATH agreed in 90% of cases. The discrepancies between the interventional cardiologist and the cardiac surgeon may in part be explained by the fact that more and more stenoses of an unprotected left main have been treated interventionally since the advent of drug-eluting stents although they are an indication for CABG according to the guidelines (20,21). Studies directly comparing stenting of unprotected left main versus bypass are currently under way (22). Recent results from the Euro Heart Survey show that, as in our study, good agreement with current guidelines
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Figure 3. Examples of left main stenoses detected by MSCT in comparison to CATH. CATH showing 55% distal stenosis of left main (a, arrow) in a 69-year-old patient. MSCT diagnosis a 65% stenosis (e, arrow), three-dimensional view. Left main stenosis demonstrated by CATH (b, arrowhead) and multiplanar reformation of MSCT (f, arrowhead). High-grade stenosis of the left main on CATH (c, arrow), which is confirmed on oblique view of MSCT and shown to be due to a large plaque (g, arrow). A 63-year-old patient with 85% stenosis of left main on CATH (d, arrow) as compared with appearance on angiographic emulation of MSCT of nearly the same view (h, arrow). (CATH: conventional coronary angiography; MSCT: multislice computed tomography). Table 2 Agreement Between Interventional Cardiologist and Cardiac Surgeon Based on CATH
Interventional cardiologist CABG PCI No revascularization Total
Table 3 Agreement Between Interventional Cardiologist and Cardiac Surgeon Based on MSCT
Cardiac Surgeon
Cardiac Surgeon
No CABG PCI Revascularization Total
No CABG PCI Revascularization Total
11 20 0 31
0 19 0 19
0 0 44 44
11 39 44 94
Interventional cardiologist CABG PCI No revascularization Total
6 21 0 27
0 17 1 18
0 0 49 49
6 38 50 94
The statistical results were as follows: agreement: 79%; McNemar’s: P ⬍ .001 (indicating significant differences between the two physicians); Kappa: 0.677; agreement for decision between PCI and CABG: 60%; and agreement for decision between revascularization and no revascularization: 100%. CABG: coronary artery bypass graft; CATH: conventional coronary angiography; MSCT: multislice computed tomography; PCI: percutaneous coronary intervention.
The statistical results were as follows: agreement: 77%; McNemar’s test: P ⬍ .001 (indicating significant differences between the two physicians); Kappa: 0.672; agreement for decision between PCI and CABG: 52%; and agreement for decision between revascularization and no revascularization: 99%. CABG: coronary artery bypass graft; CATH: conventional coronary angiography; MSCT: multislice computed tomography; PCI: percutaneous coronary intervention.
are found and greatest differences are encountered in patients with severe coronary disease, impaired left ventricular function, and diabetes mellitus (23). Our results suggest that the crucial decision whether a patient should undergo CABG
is influenced more strongly by who makes the decision and not by the diagnostic test (CATH or MSCT) performed. Using MSCT as a diagnostic test might reduce the incidence of catheter-related complications in those
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Figure 4. Example of correct triage to bypass surgery by MSCT of a 48-year-old patient with diabetes mellitus. Occlusion of the RCA on CATH (a, arrow), on three-dimensional MSCT (b, arrow), and angiographic emulation of MSCT (c, arrow). Corresponding images of the proximal stenosis of the LAD (d, e, f). Follow-up by MSCT 18 months after CABG demonstrates occlusion of the venous bypass at the site of attachment (g, arrowhead) and a patent LIMA (h, i). (CABG: coronary artery bypass graft; CATH: conventional coronary angiography; LAD: left anterior descending coronary artery; LIMA: left internal mammary artery bypass; MSCT: multislice computed tomography; RCA: right coronary artery).
cases where no additional coronary interventions are necessary. In Germany, the incidence of MACCE is reported to be 0.23% for diagnostic cardiac catheterization (24) and peripheral arterial pseudoaneurysm occurs in 0.43% of cases (25), whereas rare complications such as abdominal ischemia (26) or cholesterol embolism syndrome (27) occur in isolated cases only. Based on an annual number of 652,781 catheter angiographies
performed in Germany (28), the use of MSCT could theoretically prevent about 1,200 MACCE and about 2,200 peripheral vascular complications every year. Disease of the left main is an independent factor that increases mortality during diagnostic cardiac catheterization to 0.7% (29,30). That all stenoses of left main were correctly identified by MSCT in our study clearly underlines the benefit of this noninvasive diagnostic test.
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Figure 5. CATH and MSCT of an LAD stenosis (arrow) in a 72-year-old patient before and after PCI. Depiction of the LAD stenosis on CATH (a) and curved multiplanar reformation of MSCT (b). Good primary result after PCI (c) and no restenosis on follow-up MSCT after stenting (d). (CATH: conventional coronary angiography; LAD: left anterior descending coronary artery; MSCT: multislice computed tomography; PCI: percutaneous coronary intervention).
We investigated how therapeutic decisions based on CAD and MSCT might differ in patients with suspected CAD referred for elective CATH. In a study of 22 patients with acute coronary syndrome, Dorgelo et al (31) found an 86% agreement regarding therapeutic decisions between MSCT and CATH and a 100% agreement for the decision between revascularization and no revascularization. To our knowledge, there are no further studies comparing therapeutic management based on MSCT versus CATH. Our study including the CT technology we used has some limitations. Therapeutic decisions were based on the degree and site of the stenosis, demonstration of ischemia, type and severity of symptoms, left ventricular function, and the presence of diabetes mellitus. Other criteria to be considered when deciding about revascularization are the vessel diameter and the morphology of the stenosis. It is possible in
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principle to assess these factors by MSCT, but they were not included in the decision-making process in the present study because of their complexity. Future studies might include these factors as well. Also, the results presented here are based on the findings obtained in a single center. MSCT of the coronary arteries is limited by a high rate of patients who cannot be analyzed because image quality is degraded by artifacts. The rate of 24% of unanalyzable patients corresponds to the incidence reported for 16-slice CT by other investigators (32). The rate of unanalyzable MSCT scans has been reduced with the advent of 64-slice scanners. The study population presented here was the last one examined using 16-slice CT at our department. CT is also limited in patients without sinus rhythm (33) and high heart rates (34). In conclusion, MSCT could be established as a diagnostic tool to replace catheter angiography in specific patient
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groups and to thus reduce the incidence of catheter-related complications. The results presented here suggest that MSCT would allow reliable triage of patients with suspected coronary artery disease. Technical advances have improved the image quality of MSCT in recent years, resulting in good agreement of the findings with invasive catheter angiography and increasing acceptance of this new technique for the assessment of patients presenting with unclear chest pain (35). However, the method has to be evaluated further using data obtained with 64-slice CT and from multicenter studies. REFERENCES 1. Tunstall-Pedoe H, Kuulasmaa K, Mahonen M, et al. Contribution of trends in survival and coronary-event rates to changes in coronary heart disease mortality: 10-year results from 37 WHO MONICA project populations. Monitoring trends and determinants in cardiovascular disease. Lancet 1999; 353:1547–1557. 2. Dewey M, Richter WS, Lembcke A, et al. Noninvasive diagnosis of coronary artery disease. Med Klin (Munich) 2004; 99:57– 64. 3. Noto TJ Jr, Johnson LW, Krone R, et al. Cardiac catheterization 1990: a report of the Registry of the Society for Cardiac Angiography and Interventions (SCA&I). Cathet Cardiovasc Diagn 1991; 24:75– 83. 4. Garcia MJ, Lessick J, Hoffmann MH. Accuracy of 16-row multidetector computed tomography for the assessment of coronary artery stenosis. JAMA 2006; 296:403– 411. 5. Schuijf JD, Bax JJ, Shaw LJ, et al. Meta-analysis of comparative diagnostic performance of magnetic resonance imaging and multislice computed tomography for noninvasive coronary angiography. Am Heart J 2006; 151:404 – 411. 6. Dewey M, Teige F, Schnapauff D, et al. Noninvasive detection of coronary artery stenoses with multislice computed tomography or magnetic resonance imaging. Ann Intern Med 2006; 145:407– 415. 7. Austen WG, Edwards JE, Frye RL, et al. A reporting system on patients evaluated for coronary artery disease. Report of the Ad Hoc Committee for Grading of Coronary Artery Disease, Council on Cardiovascular Surgery, American Heart Association. Circulation 1975; 51:5– 40. 8. Knottnerus JA, Muris JW. Assessment of the accuracy of diagnostic tests: the cross-sectional study. J Clin Epidemiol 2003; 56:1118 –1128. 9. Gibbons RJ, Abrams J, Chatterjee K, et al. ACC/AHA 2002 guideline update for the management of patients with chronic stable angina— summary article: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee on the Management of Patients With Chronic Stable Angina). Circulation 2003; 107:149 –158. 10. Smith SC Jr, Dove JT, Jacobs AK, et al. ACC/AHA guidelines for percutaneous coronary intervention (revision of the 1993 PTCA guidelines)— executive summary: a report of the American College of Cardiology/American Heart Association task force on practice guidelines (Committee to revise the 1993 guidelines for percutaneous transluminal coronary angioplasty) endorsed by the Society for Cardiac Angiography and Interventions. Circulation 2001; 103:3019 –3041. 11. Eagle KA, Guyton RA, Davidoff R, et al. ACC/AHA 2004 guideline update for coronary artery bypass graft surgery: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee to Update the 1999 Guidelines for Coronary Artery Bypass Graft Surgery). Circulation 2004; 110:e340 – e437. 12. Mollet NR, Cademartiri F, Krestin GP, et al. Improved diagnostic accuracy with 16-row multi-slice computed tomography coronary angiography. J Am Coll Cardiol 2005; 45:128 –132. 13. Leschka S, Alkadhi H, Plass A, et al. Accuracy of MSCT coronary angiography with 64-slice technology: first experience. Eur Heart J 2005; 26:1482–1487.
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