A noninvasive and simple ultrasound test might be a new tool to help predict artery damage and increased risk of cardiovascular events in ANCA-associated vasculitis patients with granulomatosis with polyangiitis (GPA), according to researchers.
Their study, “Endothelial dysfunction in patients with granulomatosis with polyangiitis: a case-control study,” was published in the journal Rheumatology International.
Atherosclerosis — the hardening and narrowing of arteries due to the deposition of fat and cholesterol in their walls — is one of the leading causes of death in patients with ANCA-associated vasculitis (AAV). But why these patients are particularly at risk for developing atherosclerosis is still unclear.
People with atherosclerosis can have any artery in the body affected and are at a higher risk of developing serious cardiovascular diseases such as coronary heart disease or life-threatening events like stroke.
Indeed, several cardiovascular disorders including coronary heart disease, arrhythmias, pericarditis, and nonbacterial thrombotic endocarditis can be present in patients with GPA, a subgroup of AAV patients with widespread blood vessel dysfunction.
Given the well-known relationship between atherosclerosis, inflammation, and malfunction of blood vessels, researchers sought to investigate whether GPA patients were more exposed to vessel wall damage, called endothelial damage.
Researchers conducted a retrospective case-control study where a group of 44 GPA patients was compared with 53 healthy controls matched for age, sex, and comorbidities, all recruited from the University Hospital in Krakow, Poland.
To address endothelial damage, researchers used ultrasound examinations, which enable the determination of several artery indicators: artery flow-mediated dilatation (FMD), artery thickness, and artery stiffness.
Serum levels of thrombomodulin and VCAM-1 were also measured as surrogate markers of endothelial damage, and interleukin-6 (IL-6) and C-reactive protein were used as inflammatory markers.
Results showed that GPA patients are characterized by vascular endothelial damage, which is reflected in these patients by a decrease in ultrasound-measured flow-mediated dilatation, and an increase in laboratory markers of endothelial injury and inflammation.
Indeed, GPA patients presented a 15.9% increase in serum levels of VCAM-1 and a 50.9% increase in thrombomodulin, compared to controls. IL-6 and CRP levels were also elevated in these patients, and correlated with levels of endothelial damage.
Importantly, in GPA patients the flow-mediated dilatation was 48.9% lower than in controls, with no significant differences between groups regarding artery thickness or stiffness.
Flow-mediated dilatation was also negatively associated with the duration of the disease, meaning that patients who were living with GPA longer also had lower values of flow-mediated dilation.
Overall, the results indicate that flow-mediated dilatation of arteries, assessed by ultrasound examination, may be a prognostic factor for atherosclerosis in the GPA population.
“Patients with GPA are characterized by endothelial dysfunction, which is likely related to the chronic systemic inflammation observed in autoimmune diseases,” researchers wrote.
“Although large observational studies are needed to verify whether lower FMD% [flow-mediated dilatation] is associated with increased risk of cardiovascular events in GPA patients, this noninvasive and simple ultrasound test seems to represent a new tool/predictor of endothelial injury for clinical practice,” they added.