- withdrawal from active therapy - pregnancy (non-pregnancy confirmed by patient being postmenopausal (age 60 or above) or having a negative urine- or plasma-hcg) - known hypersensitivity to iloprost or to any of the other ingredients. - previously included in this trial or a prostacyclin trial within 30 days - consent cannot be obtained - life-threatening bleeding defined by the treating physician - known severe heart failure (nyha class iv) - suspected acute coronary syndrome

- withdrawal from active therapy - pregnancy (non-pregnancy confirmed by patient being postmenopausal (age 60 or above) or having a negative urine- or plasma-hcg) - known hypersensitivity to iloprost or to any of the other ingredients. - previously included in this trial or a prostacyclin trial within 30 days - consent cannot be obtained - life-threatening bleeding defined by the treating physician - known severe heart failure (nyha class iv) - suspected acute coronary syndrome