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 J o u r n a l P r e -p r o o f 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.