Abstract 13061: Right Atrial Strain Combined With Ve/vco ₂ in Early Detection of Systemic Sclerosis Pulmonary Vascular Involvement

Introduction: Systemic sclerosis (SSc) is at risk of developing pulmonary vasculopathy (PV) leading to pulmonary arterial hypertension (PAH), right heart failure and death. Early detection of this life-limiting complication may allow timely therapy and improve patients’ survival. Nevertheless, standard non-invasive screening tests are not fully adequate to identify milder degrees of vascular disease and right heart catheterization is reserved to hemodynamic confirmation. An integrating strategy including reliable specific echocardiographic and CPET parameters may identify “pre-clinic” PV and better characterize patients that warrant further attention. Hypothesis: The aim of this study was to test the value of right atrial (RA) two-dimensional strain echocardiography (2D-STE) combined with VE/VCO2 slope in the early detection of PV in SSc patients. Methods: We recruited 57 asymptomatic, consecutive, SSc patients without previous diagnosis of PAH, referred to our specialized out-patients clinic from April 2015 to March 2016. Six patients were excluded because unsuitable for CPET. The remaining 51 patients (48 female and 3 male - mean age 61±11years) had normal resting pulmonary function, chest X-ray, BNP, blood routine test and standard echo parameters. RA 2D STE was assessed by averaging all segments in dedicated 4-chamber view. During an incremental CPET we analyzed: minute ventilation, workload, peak oxygen uptake, oxygen pulse, anaerobic threshold, ventilatory reserve and VE/VCO2 slope. We also studied 11 matched controls. Results: Despite normal standard CPET parameters, we found that SSc patients had higher VE/VCO2 slope (mean 31,4±5,1 vs. 24,3±3,7; p <0.001) and lower RA strain (mean 21,4±9.0% vs. 27,5±6.0%; p=0,01) than controls. Moreover, VE/VCO2 slope, but not traditional parameters as BNP, RA area, PAPs and TAPSE, showed a significant correlation with RA strain (r=-0.32 p< 0.002). In particular, patients with VE/VCO2 slope >34 had lower strain than patients with VE/VCO2 slope ≤34 (mean 15,6±3,8% vs. 23,8±9,5%; p<0,001). Conclusions: In asymptomatic SSc patients, combined approach with VE/VCO2 slope and RA strain could unmask milder forms of PV, improve SSc patients’ characterization and minimize diagnosis delay.