Cardiac Allograft Vasculopathy Assessment in Heart-transplanted Patients: The Value of Cardiac Computed Tomography Angiography

BACKGROUND: Noninvasive assessment of cardiac allograft vasculopathy (CAV) is desirable. This study evaluates cardiac computed tomography angiography (CCTA) for CAV assessment, including agreement with invasive coronary angiography (ICA), and correlation of mild vessel wall changes with optical coherence tomography (OCT). METHODS: In this prospective, observational, single-center study, adult heart transplant (HTx) recipients underwent CCTA 1 wk before protocol ICA, with 3-vessel OCT performed when feasible. CCTA and ICA were graded by the International Society for Heart and Lung Transplantation (ISHLT) criteria by blinded readers. OCT provided quantitative vessel wall metrics. Major adverse cardiac events (heart failure hospitalization, CAV progression/percutaneous coronary intervention/occlusion, or cardiovascular death) were assessed. RESULTS: Fifty patients (median age 51 y; 74% male; median 7.7 y post-HTx) completed imaging. CCTA provided diagnostic quality in 98% of segments and enabled classification in all patients. CCTA identified CAV in 70% of patients versus 42% by ICA. The negative predictive value (95% confidence interval) of CCTA for any ICA-defined CAV was 93% (68%-100%) at the patient level and 89% (81%-95%) at the vessel level. In patients with no CAV on ICA but with minor signs of CAV (ie, ISHLT class 1) on CCTA, OCT revealed lower lumen/intima ratio compared with patients without CCTA-detected CAV. Over a median 2.3-y follow-up, 18% experienced a major adverse cardiac event; risk was higher with moderate-to-severe CAV (ie, ISHLT class 2-3). CONCLUSIONS: CCTA is feasible for CAV surveillance in selected HTx recipients and reliably identifies ICA-defined CAV. CCTA also detects mild vessel wall abnormalities supported by OCT, suggesting potential value for earlier noninvasive CAV detection and risk stratification.