Cholesterol efflux capacity of high-density lipoprotein correlates with survival and allograft vasculopathy in cardiac transplant recipients

Aims Cardiac allograft vasculopathy (CAV) is an important cause of mortality after cardiac transplantation. High-density lipoprotein (HDL) cholesterol efflux capacity (CEC) is inversely associated with coronary artery disease. In two independent studies, we tested the hypothesis that reduced CEC is associated with mortality and disease progression in CAV. Methods and Results We tested the relationship between CEC and survival in a cohort of patients with CAV (n=35). Multivariable Cox proportional hazard models demonstrated that higher levels of CEC were associated with improved survival (HR, 95% CI 0.26, 0.11-0.63) per standard deviation CEC, p=0.002). To determine whether reduced CEC is associated with CAV progression, we utilized samples from the Clinical Trials in Organ Transplantation 05 (CTOT05) study to determine the association between CEC and CAV progression and status at 1 year (n=81), assessed by average change in maximal intimal thickness (MIT) on intravascular ultrasound. Patients who developed CAV had reduced CEC at baseline and 1-year post transplant. We observed a significant association between pre-transplant CEC and the average change in MIT, particularly amongst patients who developed CAV at one year (β= -0.59, p = 0.02, R2 = 0.35). Conclusion Reduced CEC is associated with disease progression and mortality in CAV patients. These findings suggest the hypothesis that interventions to increase CEC may be useful in cardiac transplant patients to prevent or treat CAV.