Detection of myocardial infarction by dual-source coronary computed tomography angiography using quantitated myocardial scintigraphy as the reference standard
- R Rubinshtein1,
- T D Miller1,
- E E Williamson2,
- J Kirsch2,
- R J Gibbons1,
- A N Primak2,
- C H McCollough2,
- P A Araoz2
- 1Department of Medicine, division of Cardiovascular Diseases, Mayo Clinic, Rochester Minnesota, USA
- 2Department of Radiology, Mayo Clinic, Rochester Minnesota, USA
- Correspondence to Dr Ronen Rubinshtein, Division of Cardiovascular Diseases, MB 4-506, 200 First Street SW, Rochester, MN 55905, USA; rubinshtein.ronen{at}mayo.edu
- Accepted 27 January 2009
- Published Online First 5 February 2009
Abstract
Background: Dual-source coronary computed tomography angiography (DS-CTA) has the potential to assess both coronary anatomy and myocardial perfusion. We studied the ability of DS-CTA to detect myocardial infarction (MI) compared to a reference standard of technetium Tc99m sestamibi single photon emission computed tomography (SPECT).
Methods: 122 patients with suspected or known coronary artery disease (age 60 (SD 11) years, 36% females) were evaluated by both DS-CTA and SPECT. SPECT-MI size was quantitated using a threshold value of 60% of peak counts on the resting images. MI on DS-CTA was defined as transmural or subendocardial hypoenhancement (<50% of surrounding myocardium), which persisted in both diastolic and systolic reconstructions and was concordant with a coronary artery territory. The performance of DS-CTA to detect SPECT-MI was determined in a blinded, vessel-based analysis.
Results: 366 vessel territories were analysed (122 patients ×3). SPECT revealed 20 vessel territories with MI (involving 17 patients). 15/20 (75%) of these vessel territories were also detected by DS-CTA. An additional seven MIs were detected by DS CTA only (considered as false positive). Thus, the sensitivity of DS-CTA for detection of SPECT-MI was 75% (95% CI 56% to 94%), specificity 98% (97% to 100%), positive predictive value 68% (49% to 88%) and negative predictive value 99% (97% to 100%). DS-CTA detected 10/11 (91%) larger MIs (involving >5% of left ventricular (LV) mass by SPECT). For the 15 concordant MIs (in both SPECT and DS-CTA) the mean difference in MI size between modalities was 0.5% (4.6%) of LV mass (95% CI −8.6% to 9.5%).
Conclusions: DS-CTA myocardial perfusion imaging showed moderate sensitivity and positive predictive value but high specificity and negative predictive value for detection of SPECT-MI. Most large infarcts (>5% of LV mass) were detected by DS-CTA. When MI was detected by both modalities, there was a good correlation between infarct sizes quantitated by DS-CTA vs SPECT.
Footnotes
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The authors had full access to data and take full responsibility for the integrity of the data. All authors have read and agree to the manuscript as written.
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Funding TDM received research grants from Lantheus Medical Imaging and Molecular Insight Pharmaceuticals and has acted as a consultant to TherOx, Inc and The Medicines Company. RJG received research grants from Radiant Medical, KAI Pharmaceuticals, TargeGen, TherOx and King Pharmaceuticals, and has acted as a consultant for Hawaii Biotech, Cardiovascular Clinical studies (WOMEN study), Consumers Union and the TIMI 37A study. EEW received research grants from Siemens Medical Solutions and Bayer Health care and participated in expert panels for both. ANP is partially supported by a research grant from Siemens Medical Solutions. CHMcC received research grants from Siemens Medical Solutions, Bayer Health care, and RTI electronics.
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Competing interests None.
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The authors had full access to data and take full responsibility for the integrity of the data. All authors have read and agree to the manuscript as written.
