Background Nailfold capillaroscopy (NC) represents the method to analyze microvascular abnormalities in autoimmune rheumatic diseases, but the pathophysiological link between the microvascular derangement which is seen in NC and endothelial function is yet to be discovered.
Objectives We investigated the association between endothelial function which is assessed by brachial artery flow-mediated dilatation (FMD) and NC patterns in patients with Raynaud’s phenomenon (RP).
Methods 37 postmenopausal women with secondary RP and 23 controls suffering from hand numbness were evaluated with NC using a digital microscope at 400× and 100 × magnifications. The microvascular alterations were classified into three different patterns, early, active and late. Endothelial function was examined by brachial FMD (endothelium dependent) and response to 40 µg of sublingual nitroglycerine (NTG-induced dilatation, endothelium independent).
There were significant capillary loop dilatation (apical width; 14.1±5.6 vs. 10.4±1.7 μm, p=0.001 and total width; 40.6±15.1 vs. 31.6±4.6 μm, p=0.002) and length (316.0±78.5 vs. 270.4±34.7 μm, p=0.004) in secondary RP compared to controls. Giant capillaries, loss of capillaries, hemorrhage and background pallor were much more prevalent in secondary RP as compared to controls (all P’s< 0.05). Although there were no significant differences in NTG-induced dilatation between secondary RP and controls(16.1±5.9 % vs. 19.6±9.0%, P=0.091), significant decreases in the FMD value (6.1±3.5% vs. 9.0±2.2%, P<0.001) were noted. Both FMD and NTG-induced dilatation showed a significant inverse association with severity of NC findings (r=-0.355, p=0.005 and r=-0.285, p=028).
Conclusions Significantly impaired endothelial function was found in secondary RP and capillary enlargement was significantly associated with endothelial dysfunction. This result might implicate that the recognition of abnormal capillaroscopic patterns in the secondary RP might be prognostic for the early detection of microvascular heart involvement.
Disclosure of Interest: None Declared