Skin microcirculation dynamics are impaired in patients with rheumatoid arthritis and no cardiovascular comorbidities

Rheumatoid arthritis (RA) is associated with increased cardiovascular disease (CVD) risk. Microvascular endothelial dysfunction contributes to the development of vascular injury and subsequent CVD. We hypothesised that RA patients exhibit blunted microvascular reactivity regardless of CVD risk factors and investigated potential associations with coronary microvascular perfusion and surrogate markers of CVD. This case-control study recruited RA patients and non-RA individuals in the absence of cardiovascular comorbidities. Skin microvascular reactivity was dynamically assessed using laser speckle contrast imaging coupled with post-occlusive reactive hyperaemia protocol. Applanation tonometry was applied to assess subendocardial viability ratio, an index of myocardial microvascular perfusion, and central arterial stiffness [carotid-femoral pulse wave velocity (PWV), augmentation index]. Peripheral arterial stiffness (carotid PWV, β-stiffness index) and carotid atherosclerosis (intima-media thickness) were assessed with carotid ultrasound software. Skin microvascular responses before and following reperfusion [baseline flux, occlusion flux, time-to-peak, peak magnitude, peak-to-baseline magnitude, baseline cutaneous vascular conductance (CVC), and percentage increase in CVC] were significantly impaired in RA patients (n=35) compared to controls (n=35). Presence of RA independently predicted altered microvascular reactivity in multivariate analysis. Skin microcirculation dynamics significantly correlated with coronary microvascular perfusion and peripheral arterial stiffness, yet not carotid atherosclerosis, even after adjustment for CVD risk factors. Patients with RA present impaired microvascular reactivity regardless of CVD risk factors at a preclinical stage preceding CVD. Assessment of skin microvascular dysfunction may reflect a state of generalised vasculopathy, including myocardial microvascular abnormalities, and serve as a non-invasive surrogate indicator of CVD risk in RA.