Background: Identification of elevation in pulmonary pressures during
exercise may provide prognostic and therapeutic implications in patients
with connective tissue disease (CTD). Interstitial lung disease (ILD) is
common in CTD patients and subtle interstitial abnormalities detected by
lung ultrasound could predict exercise-induced pulmonary hypertension
(PH). Methods and Results: Echocardiography and lung ultrasound were
performed at rest and bicycle exercise in CTD patients (n=41) and
control subjects without CTD (n=24). Ultrasound B-lines were quantified
by scanning four intercostal spaces in the right hemithorax. We examined
the association between total B-lines at rest and the development of
exercise-induced PH during ergometry exercise. Compared to controls, the
number of total B-lines at rest was higher in CTD patients (0 [0, 0]
vs. 2 [0, 9], p<0.0001) and was correlated with
radiological severity of ILD assessed by computed tomography (fibrosis
score, r=0.70, p<0.0001). Pulmonary artery systolic pressure
(PASP) was increased with ergometry exercise in CTD compared to controls
(48±14 vs. 35±13 mmHg, p=0.0006). The number of total B-lines at rest
was highly correlated with higher PASP (r=0.52, p<0.0001) and
poor right ventricular pulmonary artery coupling (tricuspid annular
plane systolic excursion/PASP ratio, r=-0.31, p=0.01) during peak
exercise. The number of resting B-lines predicted the development of
exercise-induced PH with an area under the curve 0.79 (p=0.0003).
Conclusions: These data may suggest the value of a simple resting
assessment of lung ultrasound as a potential tool for assessing the risk
of exercise-induced PH in CTD patients.
Significant Clinical Indexes of Exercise-Induced Pulmonary Hypertension in Patients With Connective Tissue Disease
