Absence of epicardial coronary stenosis in patients with systemic sclerosis and severe impairment of coronary flow reserve

Systemic sclerosis (SSc) is known to be characterised by a diffuse microvascular pathological process leading to cutaneous and visceral changes and to related clinical manifestations. Both necropsy studies and in vivo investigations have shown that in a number of patients with SSc there is evidence of a coronary microvascular disease, while coronary artery disease does not exceed that seen in a control group. In particular, myocardial perfusion defects on thallium-201 scintigraphy usually occur in the absence of angiographic evidence of coronary stenosis. Recently, we used a new and non-invasive method of contrast enhanced, transthoracic, second harmonic echo Doppler in patients with SSc to evaluate the coronary flow reserve (CFR), a functional variable measuring the ability of the coronary microvasculature to adapt its lumen to a vasodilating stimulus.