Low-Density Lipoprotein Cholesterol Trends and the Development of Cardiac Allograft Vasculopathy after Heart Transplantation

Abstract

<h3>Purpose</h3> The relationship between low-density lipoprotein cholesterol (LDL-C) and cardiac allograft vasculopathy (CAV) is unclear. The objectives of this study were to characterize lipid profiles early after heart transplant (HT), and to evaluate the relationship between early serum LDL-C and the development of CAV. <h3>Methods</h3> We retrospectively reviewed consecutive adults who underwent HT at the University of Ottawa Heart Institute (Ottawa, Canada) and Toronto General Hospital (Toronto, Canada) from 2010-2018. The primary outcome was the incidence of CAV (ISHLT grade 1-3). The relationship between LDL-C and CAV was assessed using Cox proportional hazards and logistic regression models adjusted <i>a priori</i> for clinically important covariates including recipient and donor age, recipient sex, ischemic time and pre-HT diabetes. <h3>Results</h3> 386 patients followed for 4.4 (2.8-6.8) years were included. LDL-C at baseline (2.11±0.86 mmol/L) and at 1-year after HT (2.20±0.88 mmol/L) was similar (p=0.21) but was significantly lower at the end of study follow-up (1.89±0.74 mmol/L) (p<0.01). Of 309 patients who underwent angiography, 54% developed CAV. The risk of CAV did not vary according to baseline, 1-year or change from baseline to 1-year pre-specified LDL-C thresholds (Figure). The odds of CAV at 1-year was equally likely across LDL-C values (adjusted OR 1.00, 95% CI: 0.61-1.63 for baseline and adjusted OR 1.25, 95% CI: 0.74-2.10 for 1-year LDL-C). <h3>Conclusion</h3> There was no relationship between early LDL-C and the development of CAV after HT. Our findings do not support targeting a specific LDL-C for patients who do not otherwise meet criteria for non-HT guideline recommended LDL-C targets. Randomized studies are warranted to determine if lipid-lowering to a specific LDL-C target decreases the development and progression of CAV.