Assessment of pulmonary arterial pressure during exercise-Doppler echocardiography in systemic sclerosis

Purpose: Pulmonary arterial hypertension (PAH) is common complication and established prognostic determinant in systemic sclerosis (SSc). Aims of the study were to verify whether a screening strategy with exercise-Doppler echocardiography (EDE) unmasks the presence of stress PAH and whether it was able to identify a subset of patients at high risk of future resting PAH. Methods: Seventy-four consecutive female patients (mean age 61±12 years) affected by SSc (66% limited) underwent a bicycle exercise test in the semi-supine position on a tilting exercise table with an increase in workload every 2 min by 25 W. Echocardiography examinations were performed simultaneously throughout the exercise with the evaluation of pulmonary artery systolic pressure (PASP) and right ventricle function. Clinical data, N-terminal pro-brain natriuretic peptide (NT-proBNP), and carbon dioxide diffusing capacity (DLCO) were collected. In 31 patients rest echocardiography was repeated after a mean follow-up of 12.6±4.9 months. Results: All patients had normal left ventricle ejection fraction and normal left ventricle filling pressures, estimated by E/E' ratio. Sixty (81%) patients had normal rest PASP (<=36mmHg); among these patients, 23 (38%) showed an increase during stress over 50 mmHg. The mean increase in PASP during exercise in overall population was 21±10 mmHg. The peak systolic velocity of tricuspidal lateral annulus on Doppler tissue imaging was normal at rest in the majority of patients (>0.12 m/sec in 92%), as well as the tricuspid annular plane systolic excursion (>18 mm in 95%), and right ventricle outflow tract acceleration time (>100 msec in 83%); no significant worsening of the above parameters during stress occurred with the exception of acceleration time (127±31 msec at rest vs 95±24 msec at stress, p<0.0001). Rest PASP, as well as peak PASP, is significantly and positively correlated with the number of years from diagnosis, functional class, and the presence of Raynaud's phenomenon, whilst negatively correlated with DLCO (p<0.05 for all). Rest PASP is also correlated with NT-proBNP (p=0.009, r=0.30) and exercise time (p=0.009, r= -0.31); peak PASP is correlated with rest right ventricle diastolic function (E'/A'; p=0.02, r= -0.29) and, strongly, with rest PASP at the follow-up (p<0.001, r=0.62). Conclusions: Rest and stress echocardiography provides useful information in SSc patients; an abnormal increase in PASP at EDE is frequent even in patients with rest PASP within normal limits. Peak PASP early detected patients with higher rest PASP after one-year.