CAROTID ARTERY STIFFNESS, DIGITAL ENDOTHELIAL FUNCTION, AND CORONARY CALCIUM IN PATIENTS WITH ESSENTIAL THROMBOCYTOSIS, FREE OF OVERT ATHEROSCLEROTIC DISEASE

Background . Patients with myeloproliferative neoplasms (MPNs) often suffer atherothrombotic events. Aim . To determine, if patients with essential thrombocytosis (ET), a subtype of MPNs, free of symptomatic atherosclerosis, have greater carotid artery stiffness, worse endothelial function, greater coronary calcium and carotid plaque burden than control subjects. Pateints and methods . 40 ET patients without overt vascular disease, and 41 apparently healthy, age and sex-matched control subjects with comparable classical risk factors for atheroscklerosis and Framingham risk for coronary disease were enrolled. All subjects were examined by physical and laboratory testing, carotid echo-tracking ultrasound, digital EndoPat pletysmography and CT calcium scoring. Results . No significant differences were found between ET patients and controls in carotid plaque score (1 (0-1.25) vs. 0(0-2), p=0.30), beta-index of carotid stiffness (7.75(2.33) vs. 8.44(2.81), p=0.23), pulse wave velocity (6.21(1.00) vs. 6.45(1.04) m/s, p=0.46), digital reactive hyperemia index (2.10(0.57) vs. 2.35 (0.61), p=0.07), or augmentation index (19(3-30) vs. 13 (5-22)%, p=0.38). Overall calcium score did not differ between groups (Agatston score 0.1(0-16.85) vs. 0(0-8.55), p=0.26). However, significantly more ET patients had an elevated coronary calcium score of>160 (6/40 vs. 0/42, p 160, indicating high cardiovascular risk, not predicted by the Framingham equation.