Treatment With Ambrisentan in Patients With Borderline Pulmonary Arterial Hypertension

"Titration:~Monotherapy using ambrisentan will be initialized at a beginning dose of 5 mg (once daily). Drug intake is scheduled at the morning. After 4 weeks monitoring, the dose of ambrisentan will be uptitrated to 10 mg once daily. Otherwise, if intolerability is indicated, a dose of 5 mg (once daily) will be maintained through the study duration.~Maximum dose allowed: not to exceed 10 mg/day.~Administration:~Ambrisentan will be administered orally with or without food intake."

"Placebo tablet (one to two tablets corresponding to one to two verum tablets).~Administration:~Placebo will be administrated orally with or without food intake in the morning."