title: Influence of pulmonary vascular reserve on exercise-induced pulmonary hypertension in patients with systemic sclerosis.
abstract: BACKGROUND
  Exercise-induced pulmonary hypertension (PH) is considered as an early preclinical functional phase of resting PH in systemic sclerosis (SSc). In this study, we investigated the prevalence of exercise-induced PH in patients with SSc and evaluated the influence of pulmonary vascular reserve on exercise-induced PH.
  
  
  METHODS
  This prospective study included 568 SSc patients. The patients with interstitial lung disease and those with left ventricular dysfunction were excluded (n = 50); finally, 518 patients underwent simple exercise echocardiography using a Master's two-step. Systolic pulmonary artery pressure (SPAP), the ratio of early diastolic transmitral flow velocity to early diastolic mitral annular velocity (E/e') and pulmonary vascular resistance (PVR) were measured before and after exercise. ΔPVR (the difference between rest and post) was used for the assessment of pulmonary vascular reserve. All patients were stratified into the no exercise-induced PH (SPAP <50 mmHg) or exercise-induced PH (SPAP ≥50 mmHg, n = 133) group.
  
  
  RESULTS
  Of the study patients, 27% patients were identified as having exercise-induced PH. ΔPVR was higher in the exercise-induced PH than no exercise-induced PH group (0.2 ± 0.3 vs. 0.4 ± 0.4WU, P < 0.0001). A weak correlation was found between postexercise SPAP and postexercise E/e' (r = 0.31, P < 0.0001), whereas a strong correlation was found between postexercise SPAP and postexercise PVR (r = 0.62, P < 0.0001). The analyzed data demonstrated that ΔPVR was independently associated with exercise-induced PH (odds ratio, 3.435; 95% CI, 1.013-11.650, P = 0.033).
  
  
  CONCLUSIONS
  The present study demonstrated that exercise-induced PH was common in patients with SSc. Exercise-induced PH might be closely associated with the factors affecting reduced pulmonary vascular reserve in patients with SSc.
authors.affiliation: Division of Cardiology, Department of Internal Medicine, St. Marianna University School of Medicine, Kawasaki, Japan.
authors.forename: Kengo
authors.initials: K
authors.lastname: Suzuki
authors.forename: Masaki
authors.initials: M
authors.lastname: Izumo
authors.forename: Ryo
authors.initials: R
authors.lastname: Kamijima
authors.forename: Kei
authors.initials: K
authors.lastname: Mizukoshi
authors.forename: Manabu
authors.initials: M
authors.lastname: Takai
authors.forename: Keisuke
authors.initials: K
authors.lastname: Kida
authors.forename: Kihei
authors.initials: K
authors.lastname: Yoneyama
authors.forename: Sachihiko
authors.initials: S
authors.lastname: Nobuoka
authors.forename: Hidehiro
authors.initials: H
authors.lastname: Yamada
authors.forename: Yoshihiro J
authors.initials: YJ
authors.lastname: Akashi
mesh_terms: D015984:Causality; D015897:Comorbidity; D025401:Echocardiography, Stress / Q000379:methods / Q000706:statistics & numerical data*; D005080:Exercise Test / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D006976:Hypertension, Pulmonary / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D007564:Japan; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D015203:Reproducibility of Results; D018570:Risk Assessment / Q000379:methods; D012595:Scleroderma, Systemic / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D012680:Sensitivity and Specificity
keywords: exercise echocardiography; pulmonary hypertension