Circulating leukocyte and carotid atherosclerotic plaque telomere length: interrelation, association with plaque characteristics, and restenosis after endarterectomy.

Objective: Shorter leukocyte telomeres are associated with atherosclerosis and predict future heart disease. The goal of the present study was to determine whether leukocyte telomere length is related to atherosclerotic plaque telomere length and whether it is associated with plaque characteristics or recurrence of disease.
Methods and Results: Telomere length was measured by real-time quantitative polymerase chain reaction in atherosclerotic plaques and leukocytes in patients with carotid atherosclerosis undergoing carotid endarterectomy (n=684) and of leukocytes in age- and gender-balanced subjects without clinical atherosclerosis (n=780). Leukocyte telomere length was shorter in patients versus controls (0.99 [interquartile range (IQR): 0.79 to 1.26] versus 1.06 [0.80 to 1.39]; P=0.0007). Plaque telomeres were longer than leukocyte telomeres (1.42 [IQR: 1.21 to 1.77] versus 1.01 [IQR: 0.75 to 1.34]; P<1.00×10(-6)) and independent of age. Leukocyte and plaque telomere length were only weakly correlated (correlation coefficient r2=0.04, P=0.03). Patients, whose plaques showed marked macrophage infiltration and large lipid core, had longer plaque telomeres (1.61 [IQR: 1.32 to 2.04] versus 1.40 [IQR: 1.15 to 1.57]; P=0.006) and shorter leukocyte telomeres (0.88 [IQR: 0.75 to 1.20] versus 1.03 [IQR: 0.83 to 1.34]; P=0.02). Plaque telomere length was associated with restenosis 1 year after endarterectomy (OR 1.58±0.206; P=0.026 per SD decrease of plaque telomere length).
Conclusions: Leukocyte telomere length is associated with the presence of atherosclerotic carotid plaques but is not a proxy for local plaque telomere length. Plaque telomere length is related to plaque characteristics and development of restenosis following endarterectomy.