Prevalence and prognostic value of acute pulmonary vasodilator response in children and adults with pulmonary arterial hypertension

  • J Menno Douwes, Center for Congenital Heart Diseases, Dept of Pediatric Cardiology, University Medical Center Groningen, The Netherlands
  • Rosa Laura van Loon, Center for Congenital Heart Diseases, Dept of Pediatric Cardiology, University Medical Center Groningen
  • Elke Hoendermis, Center for Congenital Heart Diseases, Dept of Cardiology, University Medical Center Groningen
  • Melle Talsma, Center for Congenital Heart Diseases, Dept of Pediatric Cardiology, University Medical Center Groningen
  • Rolf Berger, Center for Congenital Heart Diseases, Dept of Pediatric Cardiology, University Medical Center Groningen

    • Objective
    To investigate the prevalence and prognostic value of acute pulmonary vasodilator response in children and adults with pulmonary arterial hypertension (PAH).
    Methods
    Sixty-six PAH patients (38 children, 28 adults; 20 with and 46 without post-tricuspid shunt) underwent acute pulmonary vasodilator challenge. Responders were identified according to three currently used criteria:
    1) Rich-criteria,1992: decrease in mean pulmonary arterial pressure (mPAP) and pulmonary vascular resistance (PVR) of >20%;
    2) Barst-criteria,1986: decrease in mPAP of >20%, unchanged or increased cardiac index and decreased or unchanged pulmonary to systemic vascular resistance ratio (PVR/SVR);
    3) Sitbon-criteria,2005: decrease in mPAP of >10mmHg reaching a mPAP of ≤40mmHg and an increased or unchanged cardiac output.
    We evaluated the prevalence of acute response in all patients, separately in children versus adults and separately in patients with versus without post-tricuspid shunt. Next, we analyzed whether responders had better survival.
    Results
    The prevalence of acute pulmonary vasodilator response in all groups depended on the criteria used (Figure). “Sitbon-responders” tended to have better survival than non-responders (5-year survival 100% vs 77.4% respectively, p=0.29), whereas “Rich- and Barst-responders” showed no difference in survival compared to non-responders. Lower PVR/SVR and mPAP/mSAP ratio both at baseline and after vasodilator challenge predicted improved survival.
    Conclusions
    The prevalence of acute pulmonary vasodilator response is highly dependent on the criteria used, appears to be higher in children, but absent in patients with a post-tricuspid shunt. Only responders according to the strict Sitbon-criteria showed improved survival. PVR/SVR and mPAP/mSAP ratio appear good predictors of survival in PAH.