Primary Outcomes

Description: Do patients with JAK2 V617F positive ET in comparison to age-and sex-matched, apparently healthy control subjects show more advanced progression of carotid artery stiffness (expressed as two interrelated parameters, the beta-stiffness index and the pulse wave velocity) in a 4 year observation period?

Description: Do patients with JAK2 V617F positive ET in comparison to age-and sex-matched, apparently healthy control subjects show more advanced progression of carotid plaque score in a 4 year observation period? Scoring of atherosclerotic plaques will be done according to the Rotterdam Study. The presence of at least one plaque in each segment of the extracranial carotid arterial bed, (the common carotid artery and the bulb, the internal carotid artery and the external carotid artery) on either side is scored 1 point. Thus, the carotid plaque score ranges from 0 (absence of plaques, best) to 6 (plaques present in all segments on both sides, worst outcome).

Description: Do patients with JAK2 V617F positive ET in comparison to age-and sex-matched, apparently healthy control subjects show more advanced progression of coronary calcium score in a 4 year observation period?

Description: Do patients with JAK2 V617F positive ET in comparison to age-and sex-matched, apparently healthy control subjects show greater changes digital endothelial function, expressed as the Reactive Hyperemia Index (RHI), in a 4 year observation period? The RHI is the ratio of the pletysmographic amplitude of the digital arteries during maximal reactive hyperemia and the basal amplitude. RHI ranges from 1 (no augmentation of pulsation with reactive hyperemia, i.e. worst outcome) to values above 2 (good endothelial response to reactive hyperemia).

Description: Quantification of JAK2 V617F mutation burden and its correlation with the coronary calcium burden.