Endothelial function measured by peripheral arterial tonometry in patients with chronic myeloid leukemia on tyrosine kinase inhibitor therapy: a pilot study

BACKGROUND: Arterial occlusive events are an emerging problem in patients with chronic myeloid leukemia (CML) receiving tyrosine kinase inhibitor (TKI) therapy. Endothelial cell damage is thought to play an important role in the development of vascular events. Measurement of the peripheral vasodilator response by peripheral arterial tonometry (PAT) has reportedly been useful in the non-invasive assessment of endothelial dysfunction. To date, no studies have assessed endothelial function using PAT in patients with CML receiving TKIs. METHOD: We measured the reactive hyperemia index (RHI) using PAT in young patients with CML (men aged ≤ 55 years and women aged ≤ 65 years) receiving TKIs. RESULTS: Thirty patients with CML were examined (mean age, 43.5 ± 9.8 years; men, 57%). The median RHI was 1.81. Among these patients, 16.7% and 83.3% were taking imatinib and second- or third-generation TKIs, respectively. There were no differences in the baseline characteristics between the low RHI (< 1.67, n = 10), borderline RHI (≥ 1.67 and < 2.10, n = 14), and normal RHI (≥ 2.10, n = 6) groups. Serum uric acid (UA) levels and the RHI were significantly negatively correlated (r = -0.40, p = 0.029). CONCLUSION: One-third of young patients with CML receiving TKI therapy were classified as having a low RHI. The RHI was negatively correlated with serum UA level. Larger prospective studies are necessary to examine whether the RHI predicts cardiovascular events in such patients.