P2775Evaluation of right ventricular function in patients with idiopathic and non-idiopathic interstitial pulmonary fibrosis: a speckle tracking echocardiography study
Authors: Buonauro A , Sorrentino R , Canora A , Bocchino M L , Esposito R , Santoro C , Fiorillo L , Sanduzzi Zamparelli A , Trimarco B , Galderisi M 
Published: October 2019

Abstract

Background
Pulmonary fibrosis (PF) is a heterogeneous group of diffuse parenchymal lung diseases, including idiopathic PF (IPF), which is the most frequent type in adults, and non-IPF. The impairment of right ventricular (RV) myocardial function of PF patients is not fully elucidated.

Purpose
To identify RV alterations in patients with interstitial PF and to evaluate possible differences between IPF and non-IPF by a combined assessment with standard and advanced echocardiography.

Methods
We enrolled 61 patients affected by interstitial PF (F/M: 16/45; age 67.9±8.1 years). 33 patients had IPF fibrosis and 28 non-IPF (bronchiolitis obliterans-organizing pneumonia and nonspecific interstitial pneumonia/fibrosis). Patients with coronary artery disease, overt heart failure, primary cardiomyopathies, other forms of diffuse parenchymal lung disease, history of pulmonary embolism and primary pulmonary hypertension were excluded. PF diagnosis was made by chest radiography, spirometry and chest high-resolution computed tomography. Lung cumulative damage was evaluated by diffusion capacity of the lung for carbon monoxide (DLco). Anthropometric parameters and blood pressure (BP) were recorded. All patients underwent a complete standard and advanced echo-Doppler exam including assessment of RV structure and function. RV global longitudinal strain (RVGLS), septal and lateral longitudinal strain (SLS and LLS respectively), were estimated by speckle tracking echocardiography (all strains were reported in absolute values).

Results
No significant difference was found in sex prevalence, systolic and diastolic BP and heart rate between the two groups, whereas IPF patients were older (65.2±8.1 vs. 70.1±7.6 years, p<0.01) than non-IPF. There was no difference in DLco between IPF and non-IPF patients. The two groups had similar left ventricular (LV) mass index, LV E/A ratio and E/e' ratio, and LV ejection fraction. RV diameters, tricuspid annulus plane systolic excursion (TAPSE) and pulmonary systolic artery pressure (PAPs) were not significantly different between the two groups, whereas IPF patients had lower RV GLS (20.2±3.1 vs. 23.0±3.6%, p=0.006), SLS (17.4±3.4 vs. 20.5±4.7%, p<0.01) and LLS (22.6±4.5 vs. 25.8±4.7%, p<0.02) compared to non-IPF patients. In the pooled population, DLco was related to RV GLS (r=0.51, p=0.004) and SLS (r=0.47, p<0.01), but not with age (p=0.121), TAPSE (p=0.532), and PAPs (p=0.875). In separate sub-analyses according to PF type, DLco was related to RVGLS in patients with IPF (r=0.52, p=0.03), but not in patients with non-IPF (r=0.41, p=0.16).

Conclusion
In patients with PF, RV systolic myocardial dysfunction is detectable by speckle tracking but not with standard echocardiography. In patients with IPF, RV dysfunction is associated with the degree of lung disease damage, as assessed by DLco.