Peripheral Arterial Stiffness and Endothelial Dysfunction in Idiopathic and Scleroderma Associated Pulmonary Arterial Hypertension

Abstract

Objective.Pulmonary endothelial dysfunction and increased reflection of pulmonary pressure waves have been reported in pulmonary arterial hypertension (PAH). However, the systemic vascular involvement is not fully understood. Our study focused on the systemic arterial stiffness and endothelial involvement in idiopathic and scleroderma associated PAH.Methods.Peripheral arterial stiffness and endothelial function were evaluated in 38 patients with idiopathic (n = 28) and scleroderma associated (n = 10) PAH, and 21 control subjects (13 healthy; 8 with scleroderma and normal pulmonary pressure). All participants underwent clinical and cardiopulmonary evaluation. Arterial stiffness was measured through the fingertip tonometry derived augmentation index (AI), which is the boost increase in the late systolic pressure wave after the initial systolic shoulder. Endothelial function was measured by forearm blood flow dilatation response to brachial artery occlusion by a noninvasive plethysmograph (EndoPAT 2000), which is associated with nitric oxide-dependent vasodilatation and yields a peripheral arterial tone (PAT) ratio.Results.Mean systolic pulmonary pressure was 70.5 ± 21.6 mm Hg (idiopathic-PAH) and 69.3 ± 20 mm Hg (scleroderma-PAH). AI was higher in scleroderma patients (10.5% ± 19.6% in healthy controls, 9.0% ± 21.5% in idiopathic-PAH, 20.1% ± 19.1% in scleroderma-PAH, and 24.4% ± 18.9% in scleroderma-controls; nonsignificant). PAT ratio was significantly lower (p < 0.05) than control values in idiopathic-PAH and scleroderma-PAH (PAT ratio: control 2.20 ± 0.25; idiopathic 1.84 ± 0.51; scleroderma 1.66 ± 0.66). AI was not correlated to endothelial dysfunction. There were no differences between the 2 PAH patient groups in age, body mass index, New York Heart Association classification, or 6-min walk test.Conclusion.Our study shows a trend towards increased arterial stiffness in scleroderma (nonsignificant), and also peripheral endothelial dysfunction in idiopathic-PAH and in scleroderma-PAH. These findings suggest involvement of different vessels in scleroderma-PAH compared to idiopathic-PAH.