title: Sildenafil reduces pulmonary vascular resistance in single ventricular physiology.
abstract: BACKGROUND
  High pulmonary vascular resistance (PVR) may be a risk factor for early and late mortality in both Glen shunt and Fontan operation patients. Furthermore, PVR may increase long after the Fontan operation. Whether pulmonary vasodilators such as phosphodiesterase 5 inhibitors can decrease PVR in patients with single ventricular physiology remains undetermined.
  
  
  RESULTS
  This was a prospective, multicenter study. Patients with single ventricular physiology who have a PVR index higher than 2.5 Wood units·㎡ (WU) were enrolled. Cardiac catheterization was performed before and after administration of sildenafil in all patients. After the Fontan operation, a six minute walk test (6MWT) was also performed. A total of 42 patients were enrolled. PVR was significantly decreased in each stage of single ventricular physiology after sildenafil administration: from 4.3±1.5WU to 2.1±0.6WU (p<0.01) in patients before a Glenn shunt, from 3.2±0.5WU to 1.6±0.6WU (p<0.001) in patients after a Glenn shunt, and from 3.9±1.7WU to 2.3±0.8WU (p<0.001) in patients after Fontan. In patients after Fontan, the 6MWT increased from 416±74m to 485±72m (p<0.01), and NYHA functional class improved significantly (p<0.05) after sildenafil administration. No major side effects were observed in any patients.
  
  
  CONCLUSIONS
  Sildenafil reduced PVR in patients with single ventricle physiology. Sildenafil increased exercise capacity and improved NYHA functional class in patients after a Fontan operation. This implies that pulmonary vasodilation is a potential therapeutic target in selected patients with elevated PVR with single ventricle physiology. Long-term clinical significance warrants further study.
authors.affiliation: Tokyo Women's Medical University, Pediatric Cardiology, 8-1, Tokyo.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Mori
authors.affiliation: Tokyo Women's Medical University, Pediatric Cardiology, 8-1, Tokyo.
authors.forename: In-Sam
authors.initials: IS
authors.lastname: Park
authors.affiliation: Tokyo Women's Medical University, Pediatric Cardiology, 8-1, Tokyo.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Yamagishi
authors.affiliation: Tokyo Women's Medical University, Pediatric Cardiology, 8-1, Tokyo.
authors.forename: Makoto
authors.initials: M
authors.lastname: Nakamura
authors.affiliation: Tokyo Women's Medical University, Pediatric Cardiology, 8-1, Tokyo.
authors.forename: Shiro
authors.initials: S
authors.lastname: Ishikawa
authors.affiliation: Tokyo Women's Medical University, Pediatric Cardiology, 8-1, Tokyo.
authors.forename: Kiyohiro
authors.initials: K
authors.lastname: Takigiku
authors.affiliation: Tokyo Women's Medical University, Pediatric Cardiology, 8-1, Tokyo.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Yasukochi
authors.affiliation: Tokyo Women's Medical University, Pediatric Cardiology, 8-1, Tokyo.
authors.forename: Tomotaka
authors.initials: T
authors.lastname: Nakayama
authors.affiliation: Tokyo Women's Medical University, Pediatric Cardiology, 8-1, Tokyo.
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Saji
authors.affiliation: Tokyo Women's Medical University, Pediatric Cardiology, 8-1, Tokyo. Electronic address: pnakanis@hij.twmu.ac.jp.
authors.forename: Toshio
authors.initials: T
authors.lastname: Nakanishi
mesh_terms: D000293:Adolescent; D002675:Child, Preschool; D005260:Female; D018729:Fontan Procedure / Q000009:adverse effects* / Q000379:methods; D006330:Heart Defects, Congenital / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery; D006352:Heart Ventricles / Q000002:abnormalities / Q000503:physiopathology / Q000601:surgery; D006439:Hemodynamics / Q000187:drug effects* / Q000502:physiology; D006801:Humans; D006976:Hypertension, Pulmonary / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control; D007231:Infant, Newborn; D007564:Japan; D008297:Male; D010043:Outcome and Process Assessment, Health Care; D058986:Phosphodiesterase 5 Inhibitors / Q000008:administration & dosage / Q000009:adverse effects; D011183:Postoperative Complications / Q000503:physiopathology / Q000517:prevention & control; D000068677:Sildenafil Citrate / Q000008:administration & dosage / Q000009:adverse effects; D014655:Vascular Resistance / Q000187:drug effects / Q000502:physiology; D014665:Vasodilator Agents / Q000008:administration & dosage / Q000009:adverse effects
chemical_list: D058986:Phosphodiesterase 5 Inhibitors; D014665:Vasodilator Agents; D000068677:Sildenafil Citrate