Udenafil Therapy to Improve Symptomatology, Exercise Tolerance and Hemodynamics in Patients With Heart Failure (ULTIMATE-HF)

• VO2max with cardiopulmonary exercise test [ Time Frame: Baseline and 12th weeks ] [ Designated as safety issue: No ]

  VO2 max was defined as cardiopulmonary exercise capacity

  Comparison between groups and within groups

  
  

• The changes of left ventricle ejection fraction [ Time Frame: baseline and 12 th week ] [ Designated as safety issue: No ]
  comparison between groups and within groups
  
  
• serum BNP level [ Time Frame: Baseline, 4th week, and 12th week ] [ Designated as safety issue: No ]
  Comparison between groups and within groups
  
  
• Change of ventilator efficiency (VE/VCO2 slope) in cardiopulmonary exercise test [ Time Frame: Baseline and 12th week ] [ Designated as safety issue: No ]
  Comparison between groups and within groups
  
  
• Change of symptomatic status expressed as New York Heart Association (NYHA) functional class [ Time Frame: Baseline, 4th week, and 12th week ] [ Designated as safety issue: No ]
  Comparison between groups and within groups
  
  
• Change of pulmonary artery systolic pressure (PASP) in echocardiography at rest and during exercise [ Time Frame: Baseline and 12th week ] [ Designated as safety issue: No ]
  Comparison between groups and within groups.
  
  
• Admission for heart failure [ Time Frame: 12th week ] [ Designated as safety issue: No ]
  Admission due to congestive heart failure during 12 week follow-up
  
  
• Composite clinical endpoints [ Time Frame: 12th week ] [ Designated as safety issue: No ]

  Composite clinical endpoints during 12 week follow-up, are defined as follows:

  1. Composite of all-cause death and admission for heart failure
  2. Composite of cardiac death and admission for heart failure
  
  
• Safety endpoint [ Time Frame: 12th week ] [ Designated as safety issue: Yes ]

  Safety endpoint during 12 week follow-up, is defined as follows:

  1. Development of facial flushing, febrile sensation, eyeball pain, visual disturbance, headache, penile erection.
  2. Intolerance or development of other adverse drug reactions related with study drug.
  
  
• Change of symptomatic status expressed as Borg dyspnea index [ Time Frame: baseline, 4 weeks and 12 weeks ]
  Comparison between groups and within groups.
  
  

Udenafil (Zydena), a newly developed PDE-5 inhibitor, has been proved to have similar efficacy and safety profile, compared with other PDE-5 inhibitors. Also, laboratory data showed that udenafil inhibits ventricular hypertrophy and fibrosis in rat heart failure model. Based on these results, the investigators hypothesized that udenafil would improve symptom, exercise capacity and hemodynamic status in patients with systolic heart failure. In this 12-week, randomized, double-blind, placebo-controlled trial, patients with systolic heart failure will be enrolled according to the eligibility criteria. After randomization, study participants will be assigned to receive either 50mg of udenafil or placebo two times a day for 4 weeks, and then the dosage will be doubled to 100mg two times a day for next 8 weeks. Participants will attend study visits at baseline and weeks 4 and 12. Physical examination, medical history review, blood sample collection and electrocardiogram will be conducted on each study visits. At baseline and week 12, participants will undergo cardiopulmonary exercise test and exercise echocardiography. At every study visits,researchers will collect health information.