Detection of cardiac allograft vasculopathy on dual source computed tomography in heart transplant recipients: comparison with invasive coronary angiography

Abstract

Objective: We aimed to evaluate the diagnostic accuracy (DA) of dual-source CT coronary angiography (DSCTCA) against invasive coronary angiography (ICA) in assessing stenotic cardiac allograft vasculopathy (CAV) in heart transplant (HTX) recipients. Methods: Consecutive HTX recipients(n = 38) on annual surveillance, underwent DSCTCA prior to ICA on a 192-detector 384-slice DSCT scanner. Cases were classified as no CAV (no stenosis), any CAV (any degree of stenosis) or significant CAV (>50% stenosis). Results: Mean age was 33.66 ± 11.45 years (M:F = 27:11, median time from HTX-23.5 months). Prevalence of any CAV on DSCTCA and ICA was 44.7%(n = 17) and 39.5%(n = 15), respectively and that of significant CAV was 21.1%(n = 8) and 15.8%(n = 6), respectively. 557 (96.7%) segments were interpretable on DSCTCA. Mean radiation dose was 4.24 ± 2.15 mSv. At patient-level, the sensitivity, specificity, positive-predictive value, negative-predictive value (NPV), and DA of DSCTCA for detection of any CAV and significant CAV were 100%, 91.3%, 88.2%, 100%, 94.73% and 100%, 94%, 75%, 100%, 95% respectively. The same on segment-based analysis were 96%, 97.6%, 80%, 99.6%, 97.5% and 100%, 99.6%,86.7%,100%, 99.6%, respectively. There was excellent agreement between the two modalities for detection of any CAV and significant CAV [κ = 0.892 and 0.826 (patient-level), 0.859 and 0.927 (segment-level)]. CAC score correlated significantly with the presence of any CAV on both modalities. A diagnosis of rejection on biopsy did not correlate with any/significant CAV on DSCTCA or ICA. Conclusion: High sensitivity and NPV of DSCTCA in the evaluation of stenotic CAV suggests that it can be an accurate and non-invasive alternative to ICA for routine surveillance of HTX recipients. Advances in knowledge: DSCTCA detects the stenotic CAV non-invasively in transplant recipients with high sensitivity, specificity and NPV when compared with catheter coronary angiography, at lower radiation doses. There is excellent agreement between CT angiography and catheter coronary angiography for detection of any CAV and significant CAV. A diagnosis of rejection on biopsy does not correlate with any/significant CAV on CT angiography or catheter angiography.