Hybrid myocardial imaging for risk stratification prior to kidney transplantation : added value of coronary calcium and epicardial adipose tissue

BACKGROUND: Patient selection and optimal approach to risk stratification prior to kidney transplantation remain uncertain. We sought new predictors of an abnormal myocardial perfusion (MYP) stress test result. METHODS: Retrospective study of 411 consecutive chronic kidney disease stages 4-5D patients awaiting kidney transplantation referred for risk stratification. PET-CT or SPECT-CT was used to assess MYP and quantify coronary artery calcium (CAC) and epicardial adipose tissue (EAT). Abnormal MYP was defined as a perfusion defect involving ≥5% of the left ventricular myocardium. RESULTS: Fixed or reversible MYP defects were present in 41 patients (10%). Male sex, smoking, and history of cardiovascular disease were more prevalent; age was higher and CAC and EAT were greater in patients with MYP defects than in those with normal MYP. On multivariate logistic regression, EAT and CAC were independent predictors of abnormal MYP while diabetes mellitus showed a borderline association (P = .08). EAT added incremental diagnostic value to a model including age, CAC and diabetes mellitus [AUC 0.73 (95% CI 0.64-0.81) to 0.76 (95% CI 0.68-0.84; P = .02)]. Furthermore, the model containing EAT showed improved diagnostic discrimination. CONCLUSIONS: Abnormal MYP on screening stress testing appears to be rare in patients awaiting kidney transplantation suggesting an excess of testing. EAT and CAC may help predict what patients are at higher risk of developing abnormalities of MYP under stress. Comment in Does hybrid imaging have a role in cardiac risk evaluation of the pre-renal transplant patient? [J Nucl Cardiol. 2013]