075 Echocardiographic Determinants of Diffusing Lung Capacity in Patients with Cardiovascular Disease

BackgroundAlterations of diffusion lung carbon monoxide (DLco) and alveolar-capillary membrane gas conduction (Dm) are associated with poor prognosis in patients with heart failure (HF) or stable coronary artery disease (CAD) even when LV systolic function is preserved. However, the impact of LV function on diffusing lung capacity is poorly understood.Methods and ResultsTwelve healthy subjects were compared to 19 patients with stable HF and LV systolic dysfunction and to 12 patients with stable CAD and preserved LV systolic function. Diffusing lung capacity was assessed by DLco and Dm, using single breath technique and Roughton-Forster method. Comprehensive transthoracic echocardiography was performed to evaluate LV ejection fraction (EF), Sa velocity, global longitudinal strain (GLS), E and Ea velocities and E/Ea ratio. Demographic and clinical data were similar between the 3 groups. However, HF group were significantly older than control or CAD groups (65±7 vs. 54±12 or 56±7yrs, p<0.01). Compared to control subjects, patients with CAD or HF had lower DLco and Dm (33±6 vs. 25±6 vs. 20.5±6, p<0.01; 55±17 vs. 37±10 vs. 30±11ml.min-1.mmHg-1, p<0.01). In the whole cohort, DLco was correlated with systolic and diastolic parameters (LVEF: r=0.47, p=0.001; GLS: r=0.35, p=0.02; Sa: r=0.49, p=0.0007; E/Ea: r=-0.30, p=0.05; Ea: r=0.51, p=0.0006). Similar results were found with Dm (LVEF: r=0.44, p=0.004; GLS: r=0.33, p=0.03; Sa: r=0.47, p=0.001 and E/Ea: r=-0.36, p=0.02; Ea: r=0.49, p=0.0009). On multivariate analysis, after adjustment for age, sex and BMI, independent predictors of DLco as well as Dm were Ea (r2=0.27, p=0.0006; r2=0.25, p=0.001) and LVEF