Pharmacologic Stress Myocardial Perfusion Imaging with SPECT and PET in Liver Transplant Candidates: Physiologic Limitations, Current Evidence, and Future Directions.

PURPOSE OF REVIEW: Myocardial perfusion imaging with SPECT and PET is commonly used to assess coronary artery disease, but its role in liver transplant candidates remains incompletely defined. This review examines how cirrhotic physiology affects pharmacologic stress imaging and summarizes current evidence for the use of SPECT, PET, and quantitative perfusion measures in this population.

RECENT FINDINGS: Hyperdynamic circulation, elevated resting myocardial blood flow, impaired chronotropic response, and attenuated vasodilator reserve may reduce the diagnostic performance of relative perfusion imaging. Reported SPECT sensitivity for coronary artery disease in liver transplant candidates is substantially lower than the general population. Quantitative PET, particularly myocardial flow reserve, has shown possible prognostic value, although evidence is limited to small observational cohorts. SPECT should be interpreted cautiously in higher-risk candidates. PET may offer additional physiologic and prognostic information, but transplant-specific thresholds and clinical pathways remain unvalidated. Whether improved perfusion-based risk stratification changes management and improves outcomes remains to be determined.