['The impact of Quilty (sub-endocardial infiltration of lymphocytes) on the development of stenotic microvasculopathy and outcome after heart transplantation has not yet been evaluated.', 'Biopsies (n = 9,713) obtained within the first post-transplant year from 873 patients (722 men, age 49.3 +/- 0.3 years) were evaluated by light microscopy (hematoxylin-eosin) for Quilty and cellular rejection (ISHLT), stenotic microvasculopathy (luminal radius:medial thickness ratio <1) and endothelial disease (core diameter:cell diameter ratio < or =1). Risk factors for stenotic microvasculopathy were analyzed by logistic regression. Overall survival and freedom from graft failure (cardiac re-transplantation, myocardial infarction and sudden cardiac death) were estimated by the Kaplan-Meier method and tested using a Cox proportional hazard model.', 'We found 1,830 (19%) Quilty-positive biopsies in 481 (55%) Quilty-formers and stenotic microvasculopathy in 866 (9%) biopsies of 379 (43%) patients. Evidence of Quilty (odds ratio [OR] 1.77; 95% confidence interval [CI] 1.26 to 2.57) and endothelial disease (OR 4.98; 95% 95% CI 3.31 to 7.49) indicated higher risk, whereas post-transplant statin therapy was associated with lower risk for stenotic microvasculopathy (OR 0.68; 95% CI 0.48 to 0.97). Freedom from graft failure was lower in Quilty-formers (p = 0.0060) and even worse if patients suffered from both Quilty and stenotic microvasculopathy (p = 0.0017). Both factors were confirmed in multivariate regression analysis (stenotic microvasculopathy risk ratio [RR] 1.90, 95% CI 1.23 to 2.95; Quilty RR 1.77, 95% CI 1.11 to 2.82, p = 0.0430).'] Does quilty indicate increased risk for microvasculopathy and poor survival after heart transplantation?