Leukocyte telomere length is associated with high-risk plaques on virtual histology intravascular ultrasound and increased proinflammatory activity

OBJECTIVE

Leukocyte telomere length (LTL), a marker of cellular senescence, is inversely associated with cardiovascular events. However, whether LTL reflects plaque extent or unstable plaques, and the mechanisms underlying any association are unknown.

METHODS AND RESULTS

One hundred seventy patients with stable angina or acute coronary syndrome referred for percutaneous coronary intervention underwent 3-vessel virtual histology intravascular ultrasound; 30 372 mm of intravascular ultrasound pullback and 1096 plaques were analyzed. LTL was not associated with plaque volume but was associated with calcified thin-capped fibroatheroma (OR, 1.24; CI, 1.01-1.53; P=0.039) and total fibroatheroma numbers (OR, 1.19; CI, 1.02-1.39; P=0.027). Monocytes from coronary artery disease patients showed increased secretion of proinflammatory cytokines. To mimic leukocyte senescence, we disrupted telomeres and binding and expression of the telomeric protein protection of telomeres protein-1, inducing DNA damage. Telomere disruption increased monocyte secretion of monocyte chemoattractant protein-1, IL-6, and IL-1β and oxidative burst, similar to that seen in coronary artery disease patients, and lymphocyte secretion of IL-2 and reduced lymphocyte IL-10.

CONCLUSIONS

Shorter LTL is associated with high-risk plaque morphology on virtual histology intravascular ultrasound but not total 3-vessel plaque burden. Monocytes with disrupted telomeres show increased proinflammatory activity, which is also seen in coronary artery disease patients, suggesting that telomere shortening promotes high-risk plaque subtypes by increasing proinflammatory activity.

Peri-operative atrioventricular block as a result of chemotherapy with epirubicin and paclitaxel

A 47-year-old woman presented for mastectomy and immediate latissimus dorsi flap reconstruction having been diagnosed with carcinoma of the breast 6 months previously. In the preceding months she had received neo-adjuvant chemotherapy with epirubicin, paclitaxel (Taxol) and cyclophosphamide. This had been apparently uncomplicated and she had maintained a remarkably high level of physical activity. She was found to be bradycardic at pre-operative assessment but had no cardiac symptoms. Second degree Mobitz type II atrioventricular block was diagnosed on electrocardiogram, and temporary transvenous ventricular pacing instituted in the peri-operative period. We discuss how evidence-based guidelines would not have been helpful in this case, and how chemotherapy can exhibit substantial cardiotoxicity that may develop over many years. We suggest that patients who have received chemotherapy at any time should have a pre-operative electrocardiogram even if they are asymptomatic.