Cardiac CT and PET for Surveillance of Heart Transplant Recipients: Systematic Review and Bayesian Meta-Analysis

Background: For noninvasive surveillance of cardiac allograft vasculopathy (CAV), cardiac computed tomography (cardiac computed tomography [CT]) and positron emission tomography (PET) received a Class IIa recommendation by the 2023 ISHLT (International Society for Heart and Lung Transplantation) guidelines. However, implementation has lagged behind because of concerns about their ability to rule out disease and stratify risk. Objectives: The purpose of this study was to define the diagnostic and prognostic ability of PET and cardiac CT in cardiac transplant recipients. Methods: Electronic databases were searched for studies evaluating CT or PET for their diagnostic (for detecting angiographic CAV) and prognostic (for predicting major adverse cardiovascular outcomes) value. Sensitivity and specificity were pooled using Bayesian bivariate binormal-normal models with random-effects. HRs were pooled using Bayesian normal random-effects models. Results: In total, 44 studies (32 CT and 12 PET) enrolling 3,049 patients were included. Coronary computed tomography angiography (CTA) showed high sensitivity (97.6%; 95% credible interval [CrI]: 93.7%-99.1%) and specificity (82.3%; 95% CrI: 75.3%-88.3%) for detecting any CAV. Coronary CTA also showed high sensitivity (92.6%; 95% CrI: 86.2%-96.2%) and specificity (92.6%; 95% CrI: 89.8%-94.9%) for significant CAV. The PET CAV algorithm for detecting significant CAV showed good sensitivity (83.9%; 95% CrI: 69.1%-92.4%) and specificity (89.6%; 95% CrI: 82.2%-94.2%). PET-derived parameters including myocardial flow reserve, stress myocardial blood flow, PET CAV score, and summed stress score, predicted future major adverse cardiovascular outcomes. Conclusions: Both coronary CTA and PET can rule out significant CAV; however, at higher pretest probabilities, coronary CTA may be preferrable. Multiple PET-derived parameters may have prognostic value, whereas there is insufficient evidence for the long-term prognostic value of CT.