P17 ARTERIAL STIFFNESS OF THE FOREARM IS ASSOCIATED WITH NAILFOLD CAPILLARY COUNT IN SYSTEMIC SCLEROSIS: A NOVEL MARKER OF EARLY VASCULOPATHY?

Background: Microvascular disease, with rarefaction of nailfold capillaries, is the hallmark of systemic sclerosis (SSc). Obliteration of the ulnar and radial artery is regularly observed, implicating involvement of the forearm arteries. Pulse wave velocity (PWV) may serve as early biomarker of forearm artery involvement, before occurrence of irreversible arterial obliteration. Objectives: The aim was to investigate arterial stiffness of the aorta and the upper extremities in SSc patients and to correlate these findings with nailfold capillary count and extent of disease. Methods: Aortic PWV was defined as carotid-femoral (cf). Upper extremity PWV was measured as carotid-brachial (cb) and carotid-radial (cr), the ratio between cbPWV/crPWV was used as an indication of the relative PWV change in the forearm. Capillary count was the mean capillary count per 3 mm of 8 fingers. The number of SSc classification criteria was used as surrogate for extent of disease. [1] Results: In total, 19 SSc patients (median age 51 years, 68% female) were included. CbPWV/crPWV ratio correlated strongly with capillary count (r = −0.55, p = 0.022, figure 1) in SSc patients, with a trend in regards to its relation with the extent of disease (r=0.48, p=0.053). Conclusions: Our findings demonstrate that arterial stiffness of the forearm has a relationship with nailfold capillary count and tends to be associated with the extent of disease in patients with SSc. These may suggest that vascular damage also occurs in larger arteries of the forearm, which potentially serves as novel tool for assessing early vascular involvement in SSc.