Differentiation of primary and secondary Raynaud's disease by carotid arterial stiffness.

Introduction: primary Raynaud's disease may be difficult to differentiate clinically from the secondary form with an underlying connective tissue, haematological, neurovascular or drug-induced disorder. We undertook a study to determine the elastic carotid and muscular femoral arterial biomechanical properties and intima-media thickness (IMT) in subjects with primary and secondary Raynaud's disease, to assess whether these parameters could differentiate the two conditions.
Methods: twenty patients with primary Raynaud's disease and 53 subjects with secondary Raynaud's associated with scleroderma (systemic sclerosis, SSc) had measurements of their carotid and femoral wall mechanics with a duplex scanner coupled to a Wall Track system. Their age, gender, body mass index, heart rate, systolic and diastolic blood pressures, presumed cardiovascular load, plasma creatinine, fasting cholesterol, triglyceride and glucose concentrations were also measured.
Results: the carotid elastic properties [mean (SD): elastic modulus: 560 (180) vs 1204 (558) mmHg,p <0.001 and stiffness index: 5.69 (1.35) vs 11.92 (6.4), p<0.001 for primary and secondary Raynaud's respectively] were significantly impaired in patients with secondary Raynaud's disease even after adjustment for potentially influencing physiological and biochemical variables. There were no statistical differences in the femoral elastic properties or the carotid and femoral IMTs between the two groups.
Conclusion: Duplex determination of the carotid elasticity or stiffness is different in primary Raynaud's phenomenon compared with secondary Raynaud's associated with SSc. This may be a useful non-invasive tool, in addition to autoantibody markers and nail-fold capillaroscopy, to differentiate between the two forms of Raynaud's phenomenon.