Coronary microvascular dysfunction in asymptomatic patients affected by systemic sclerosis: Limited vs. diffuse form

BACKGROUND This observational study was designed to evaluate the prevalence of coronary microvascular dysfunction (CMD) in asymptomatic patients affected by systemic sclerosis (SSc), stratifying the results according to the limited (lcSSc) and the diffuse (dcSSc) forms of the disease. METHODS AND RESULTS We enrolled 19 consecutive asymptomatic patients with dcSSc (n=7) or lcSSc (n=12). In all subjects, coronary flow reserve (CFR) was assessed by measuring diastolic coronary flow velocities in the left anterior descending artery by pulsed wave Doppler at baseline and after dipyridamole infusion (0.84 mg·kg(-1)·6 min(-1)). Wall motion score index was evaluated at baseline and during stress. We enrolled 20 healthy subjects as controls. Mean CFR was 1.96±0.62 in patients and 2.69±0.47 in controls (P