Speckle tracking assessment of the atrial function in patients with systemic sclerosis

Background Systemic sclerosis (SSc) is a chronic autoimmune disease characterized by small vessel vasculopathy, autoantibodies production and exaggerated extracellular matrix deposition, leading to extensive tissue fibrosis. Cardiac involvement in SSc, albeit often asymptomatic, is frequent and represents a negative prognostic factor. Speckle tracking global longitudinal strain (GLS) has proved itself to be an effective tool to identify the presence and the progression of subclinical SSc-related cardiomyopathy. The aim of our study was to assess whether SSc-related cardiomyopathy affects not only the ventricles but also the right (RA) and left atria (LA) in patients with SSc and no overt cardiac disease nor pulmonary hypertension. Materials and methods Observational prospective study enrolling all consecutive patients with SSc age- and gender-matched 1:1 to healthy controls. Patients with structural heart disease, heart failure, atrial fibrillation and pulmonary hypertension were excluded. For every patient, standard echocardiographic parameters and speckle-tracking derived variables were registered. The reservoir function (from the end of ventricular contraction to mitral valve opening), conduit function (from mitral valve opening through the onset of atrium contraction) and contraction function (from the onset of atrium contraction to the end of ventricular diastole) were assessed via GLS. Zero strain reference was set at left ventricular end diastole. Results Fifty-two SSc patients and 52 matched controls were consecutively enrolled. Left ventricular ejection fraction (66.5%±7.4% vs. 66.1%±5.9%; p=ns) right fractional area change (49.4%±9.6% vs. 49.2%±9.2%; p=ns) and mean sPAP (29.0%±5.3% vs. 24.4%±4.1%; p=ns) were well within the normal range and similar between SSc patients and controls. Right atrial reservoir function (35.0%±7.3% vs. 42.3%±8.5%; p=.024) and contraction function (14.8%±4.3% vs. 18.5%±4.1%; p=.034) were significantly lower in SSc patients when compared to matched controls. No difference was seen in right atrial conduit function or left atrial strain. In patients with SSc, RA reservoir (r=.194; p=.033) and conduit function (r=.174; p=.036) were directly associated to right ventricular GLS. LA reservoir (r=.260; p=.008) and conduit function (r=.271; p=.006) were directly associated with left ventricular GLS. No association was observed between contraction function and GLS in both left and right chambers. Moreover, RA and LA reservoir (r=.358; p=.02), conduit (r=.525; p=.004) and contraction functions (r=.30; p=.0.18) were directly correlated. Conclusions While no significant difference was seen between cases and controls in terms of common echocardiographic parameters, RA reservoir and contraction function assessed through GLS were significantly impaired in patients with SSc. The correlation between impaired atrial and ventricular GLS in SSc may represent another indirect evidence of SSc-related heart global involvement. Funding Acknowledgement Type of funding sources: None.