Increased fibrosis and microvessel disease in allograft endomyocardial biopsies of children with chronic graft failure due to cardiac allograft vasculopathy

•There is increased fibrosis and microvessel disease (MVD) on endomyocardial biopsies (EMB) in pediatric heart transplant patients with chronic graft failure secondary to moderate- severe cardiac allograft vasculopathy (M-S CAV)•Fibrosis and MVD correlate with each other and are present even before angiographic diagnosis of CAV•Findings of fibrosis and MVD in EMB may have the potential to be used to modify the follow-up and treatment for this high-risk patients