Coronary computed tomography in heart transplant patients: detection of significant stenosis and cardiac allograft vasculopathy, image quality, and radiation dose. (September 2018)

• Record Type: Journal Article
• Authors: Günther, Anne; Aaberge, Lars; Abildgaard, Andreas; Ragnarsson, Asgrimur; Edvardsen, Thor; Jakobsen, Jarl; Andersen, Rune
• Is Part Of: Acta radiologica. Volume 59:Number 9(2018:Nov.)
• Page Start: 1066
• Page End: 1073
• Publication Date: 2018-09
• Subjects: Computed tomography angiography -- cardiac -- transplantation; Radiology, Medical -- Periodicals; Radiography, Medical -- Periodicals; Radiotherapy -- Periodicals; 616.0757
• DOI: 10.1177/0284185117748354
• Languages: English
• ISSNs: 0284-1851

Abstract

Background: Cardiac allograft vasculopathy (CAV) is an accelerated form of atherosclerosis unique to heart transplant (HTX) patients. Purpose: To investigate the detection of significant coronary artery stenosis and CAV, determinants of image quality, and the radiation dose in coronary computed tomography angiography (CCTA) of HTX patients with 64-slice multidetector CT (64-MDCT). Material and Methods: Fifty-two HTX recipients scheduled for invasive coronary angiography (ICA) were prospectively enrolled and underwent CCTA before ICA with intravascular ultrasound (IVUS). Results: Interpretable CCTA images were acquired in 570 (95%) coronary artery segments ≥2 mm in diameter. Sensitivity, specificity, and positive and negative predictive values of CCTA for the detection of segments with significant stenosis (lumen reduction ≥50%) on ICA were 100%, 98%, 7.7%, and 100%, respectively. Twelve significant stenoses were located in segments with uninterpretable image quality or vessel diameter <2 mm; only one was eligible for intervention. IVUS detected CAV (maximal intimal thickness ≥0.5 mm) in 33/41 (81%) patients; CCTA and ICA identified CAV (any wall or luminal irregularity) in 18 (44%) and 14 (34%) of these 33 patients, respectively. The mean estimated radiation dose was 19.0 ± 3.4 mSv for CCTA and 5.7 ± 3.3 mSv for ICA ( P < 0.001). Conclusion: CCTA with interpretable image quality had a high negative predictive value for ruling out significant stenoses suitable for intervention. The modest detection of CAV by CCTA implied a limited value in identifying subtle CAV. The high estimated radiation dose for 64-MDCT is of concern considering the need for repetitive examinations in the HTX population.