Background: Cardiac allograft vasculopathy (CAV) is characterized by diffuse thickening of the arterial intima. Statins reduce the incidence of CAV, but despite the use of statins, CAV remains one of the leading causes of long-term death after heart transplant. Inhibitors of proprotein convertase subtilisin-kexin type 9 (PCSK9) substantially reduce cholesterol levels but have not been tested in heart transplant recipients. Methods: The Cholesterol lowering with EVOLocumab to prevent cardiac allograft Vasculopathy in De-novo heart transplant recipients (EVOLVD) trial (ClinicalTrials.gov Identifier: NCT03734211) is a randomized, double-blind trial designed to test the effect of the PCSK9 inhibitor evolocumab on coronary intima thickness in heart transplant recipients. Adults who have received a cardiac transplant within the past 4-8 weeks are eligible. Exclusion criteria include an estimated glomerular filtration rate ' 20 mL/min/1.73 m², renal replacement therapy, or contraindications to coronary angiography with intravascular ultrasound. 130 patients will be randomized (1:1) to 12-month treatment with evolocumab or matching placebo. The primary endpoint is the coronary artery intima thickness as measured by intravascular ultrasound. Conclusion: The EVOLVD trial is a randomized clinical trial designed to show whether treatment with the PCSK9 inhibitor evolocumab can ameliorate CAV over the first year after heart transplant.