title: Acute Vasodilator Response in Pediatric Pulmonary Arterial Hypertension: Current Clinical Practice From the TOPP Registry.
abstract: BACKGROUND
  In pulmonary arterial hypertension (PAH), acute vasodilator response testing (AVT) is considered important to identify adult patients with favorable prognosis using calcium-channel blocker (CCB) therapy. However, in pediatric PAH, criteria used to identify acute responders and CCB use are insufficiently studied.
  
  
  OBJECTIVE
  This study sought to describe current clinical practice of AVT and subsequent treatment decisions in pediatric PAH.
  
  
  METHODS
  From January 2008 to May 2013, 529 consecutive children with confirmed pulmonary hypertension were enrolled in an international registry. We analyzed those children with evaluable AVT.
  
  
  RESULTS
  Of 382 children with evaluable AVT, 212 had idiopathic/familial PAH (IPAH/FPAH) and 105 had PAH associated with congenital heart disease (PAH-CHD). In 70% of the patients, AVT was performed using inhaled nitric oxide; other agents were used in the remaining patients. In IPAH/FPAH patients, 78 (37%) patients were acute responders according to their physician, 62 (30%) according to REVEAL (Registry-to-Evaluate-Early-And-Long-term PAH disease management)-pediatric criteria, and 32 (15%) according to Sitbon criteria. For PAH-CHD patients, the numbers of AVT responders were 38 (36%), 14 (13%), and 7 (7%) respectively. Correlation between AVT responder status as judged by the treating physician and by published response criteria was poor. Moreover, of the IPAH/FPAH patients judged by the treating physician as acute responders, only 23% were treated with CCB without additional PAH-targeted therapy. The Sitbon criteria selected patients with better prognosis who had excellent outcome when treated with CCB.
  
  
  CONCLUSIONS
  The current practice of identifying responders to AVT and subsequent treatment with CCB therapy demonstrated large discrepancies with current international guidelines. Also, in pediatric IPAH, the Sitbon criteria are the criteria of choice to identify patients with excellent survival when treated with CCB therapy.
authors.affiliation: Centre for Congenital Heart Diseases, Pediatric Cardiology, Beatrix Children's Hospital, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands.
authors.forename: Johannes M
authors.initials: JM
authors.lastname: Douwes
authors.affiliation: Pediatric Cardiology and Critical Care Medicine, The Hospital for Sick Children University of Toronto, Toronto, Ontario, Canada.
authors.forename: Tilman
authors.initials: T
authors.lastname: Humpl
authors.affiliation: Centre de Référence Malformations Cardiaques Congénitales Complexes, M3C-Necker Hospital for Sick Children, Assistance Publique des Hôpitaux de Paris, Pediatric Cardiology, University Paris Descartes, Paris, France.
authors.forename: Damien
authors.initials: D
authors.lastname: Bonnet
authors.affiliation: Pediatric Cardiology Unit, Children's University Hospital, Geneva, Switzerland.
authors.forename: Maurice
authors.initials: M
authors.lastname: Beghetti
authors.affiliation: Department of Pediatric Cardiology, Children's Hospital Colorado, University of Colorado School of Medicine, Aurora, Colorado.
authors.forename: D Dunbar
authors.initials: DD
authors.lastname: Ivy
authors.affiliation: Centre for Congenital Heart Diseases, Pediatric Cardiology, Beatrix Children's Hospital, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands. Electronic address: r.m.f.berger@umcg.nl.
authors.forename: Rolf M F
authors.initials: RM
authors.lastname: Berger
mesh_terms: D000280:Administration, Inhalation; D000293:Adolescent; D002121:Calcium Channel Blockers / Q000627:therapeutic use*; D006328:Cardiac Catheterization; D002648:Child; D002675:Child, Preschool; D004305:Dose-Response Relationship, Drug; D045462:Endothelium-Dependent Relaxing Factors / Q000008:administration & dosage; D065627:Familial Primary Pulmonary Hypertension / Q000188:drug therapy / Q000503:physiopathology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D008297:Male; D009569:Nitric Oxide / Q000008:administration & dosage*; D011379:Prognosis; D011669:Pulmonary Wedge Pressure / Q000187:drug effects; D012042:Registries; D012189:Retrospective Studies; D014664:Vasodilation / Q000187:drug effects*; D014665:Vasodilator Agents / Q000627:therapeutic use
chemical_list: D002121:Calcium Channel Blockers; D045462:Endothelium-Dependent Relaxing Factors; D014665:Vasodilator Agents; D009569:Nitric Oxide
keywords: calcium-channel blocker therapy; congenital heart disease; mean arterial pressure; right heart catheterization