Comparison of coronary computed tomography angiography to invasive coronary angiography for coronary allograft vasculopathy surveillance in patients with orthotopic heart transplant

Background Invasive coronary angiogram (ICA) is considered the gold standard for diagnosing coronary allograft vasculopathy (CAV) in post-orthotopic heart transplant (OHT) patients. Coronary CT angiography (CCTA) has been used as an alternative modality, but outcome studies comparing CCTA to ICA are limited. Methods We studied consecutive OHT patients who underwent CCTA (n = 38) from 1/2010 to 1/2024 and compared them to an age- and sex-matched cohort who underwent ICA (n = 76). The outcomes of interest were clinical events (death, myocardial infarction, heart failure, and stroke) and testing-related adverse events or complications at 1 year. Secondary outcomes included test characteristics of CCTA in patients who also underwent ICA within 90 days (paired subgroup, n=20). Results Baseline characteristics were similar between CCTA and ICA groups. CAV presence was similar between groups (CCTA: 8/38 (21%), ICA: 20/76 (26%), P=0.54). There were 4 adverse events in the ICA group (coronary spasm (n = 1), access-site bleeding (n = 2), and radial artery spasm (n = 1)) and none in the CCTA group. Clinical events occurred in 16% (6/38) of the CCTA group versus 7% (5/76) of the ICA group (OR 2.74, 95% CI, 0.77–10.13, P=0.12). In the paired subgroup, CCTA demonstrated adequate diagnostic capabilities for detection of CAV (accuracy 95%, sensitivity 75%, specificity 100%, PPV 100%, NPV 94%). Conclusions CCTA showed strong agreement with ICA for CAV detection and severity assessment. CCTA may emerge as a safer, non-invasive alternative to ICA for CAV assessment.