Blunted coronary flow reserve in systemic sclerosis

Objectives. We investigated whether the non-invasive determination of coronary flow reserve (CFR), as evaluated by transthoracic Doppler echocardiography, might be a potential method to detect early dysfunction of cardiovascular system in patients affected by systemic sclerosis (SSc) without clinical signs or symptoms of cardiac impairment. The possible correlations between the CFR values and the duration of the disease, specific autoantibodies and cutaneous involvement subsets were investigated. Methods. Forty-four consecutive patients affected by SSc were analysed. The CFR was detected in the distal left anterior descending coronary artery by contrast-enhanced transthoracic second harmonic Doppler in all SSc patients and in 16 healthy controls. CFR was assessed at rest and during hyperaemia induced by administration of adenosine at 0.14 mg/kg/min over 5 min. The CFR was calculated as the ratio between hyperaemic (peak adenosine infusion) and resting peak diastolic velocity (PdvCFR) and resting velocity time integral (VtiCFR). Past medical history was carefully investigated. Results. Both PdvCFR and VtiCFR were significantly reduced in SSc patients when compared with controls (P<0.0001). In particular, both PdvCFR and VtiCFR were significantly lower in patients with dSSc when compared with patients affected by lSSc (P<0.02 and P<0.04 respectively). No statistically significant correlation was found between CFR values and history of smoking, serum levels of cholesterol or triglycerides, blood pressure, age of patients, duration of SSc and serum autoantibody positivity for ANA, ACA and Scl70. Conclusions. CFR is often reduced in SSc patients. CFR was lower in patients with dSSc than in those affected by lSSc. A reduced CFR value should be considered an indirect sign of heart involvement in scleroderma, but its clinical and prognostic implications need to be clarified.