Inflammatory suppression rapidly attenuates microvascular dysfunction in rheumatoid arthritis

Rheumatoid arthritis (RA) is associated with greater risk of cardiovascular morbidity and mortality, the inflammatory component of RA being strongly linked to this excess risk. Endothelial dysfunction is linked to atherosclerosis and has been demonstrated in larger vessels in RA. In this pilot study, we determined for the first time whether skin microvascular function was impaired in patients with active RA and also determined its response to anti-inflammatory treatment. This was assessed non-invasively using laser Doppler imaging combined with iontophoresis of the vasodilators acetylcholine (ACh, endothelium dependent) and sodium nitroprusside (SNP, endothelium independent) to the forearm. Eight RA patients admitted for acute flare-ups were assessed before and following anti-inflammatory treatment. Standard laboratory indices were obtained along with pain perception (VAS). A control group of eight subjects was included for baseline comparison. Compared to this group, vascular function was substantially and significantly (P<0.00001) lower in RA patients. Following treatment, as CRP and VAS decreased, vascular function improved for both ACh (P<0.00001) and SNP (P=0.001), this improvement being significantly greater for ACh (P<0.001). Vascular dysfunction is evident in RA patients, even at the level of the cutaneous microcirculation, but improves as inflammation regresses. Assessment of cutaneous vascular function may be a useful, non-invasive surrogate indicator of vascular risk in RA, inclusive of myocardial microvascular abnormalities.