Change in peak 6-minute walk distance from baseline to Week 12. Peak 6MWD was defined as a 6-minute walk test (6MWT) within 10 to 60 minutes after study drug inhalation

Intention to treat analysis

Clinical worsening was defined as the first incidence of clinical worsening from randomization to the first occurrence of death, transplantation, hospitalization for PAH, or initiation of additional approved PAH therapy.

Intention to treat population

The Borg dyspnea score is a patient reported number between 0 (no perceived shortness of breath) and 10 (maximum perceived shortness of breath), obtained at the completion of each 6MWT.

Intention to treat population. A Week 12 observation was not present for one subject and that data point is not included in the analysis.

Change in NYHA functional class at Week 12. NYHA classifications:

Class I - Patients with pulmonary hypertension but without resulting limitation of physical activity. Ordinary physical activity does not cause undue dyspnea or fatigue, chest pain or near syncope.

Class II - Patients with pulmonary hypertension resulting in slight limitation of physical activity. They are comfortable at rest. Ordinary physical activity causes undue dyspnea or fatigue, chest pain or near syncope.

Class III - Patients with pulmonary hypertension resulting in marked limitation of physical activity. They are comfortable at rest. Less than ordinary activity causes undue dyspnea or fatigue, chest pain or near syncope.

Class IV - Patients with pulmonary hypertension in the inability to carry out any physical activity without symptoms. These patients manifest signs of right heart failure. Dyspnea and/or fatigue may even be present at rest. Discomfort is increased by any physical activity.

Intention to treat population

Change in 6MWD from Baseline to trough 6MWD at Week 12. Trough was defined as a 6MWT conducted at least 4 hours following study drug inhalation.

Intention to treat population

Change in peak 6MWD between Baseline and Week 6.

Intention to treat

Quality of life as measured by the Minnesota Living With Heart Failure (MLWHF) questionnaire was evaluated at baseline and at Week 12. The MLWHF questionnaire consists of 21 questions assessing how the patient's heart failure has prevented them from living the way they wanted during the defined time period. Each question was graded by the patient with a numeric value between 0 (No/none) and 5 (very much). These scores were then summed across the 21 questions for a Global Score. Global scores ranged from 0 to 105. These questions were further grouped into Physical (8 of the questions) and Emotional (5 of the questions) dimensions to further characterize the effect of heart failure on the patient's life. Physical scores ranged from 0 to 40, and emotional scores ranged from 0 to 25. For all 3 categories, the lower the score, the better the outcome. Values presented as change from Baseline.

Intention to treat population.

Signs and symptoms of PAH (Loud P2 sound, Ascites, Right ventricular S3 sound, Dyspnea, Right ventricular S4 sound, Orthopnea, Right ventricular heave, Dizziness, Murmur of tricuspid insufficiency, Syncope, Murmur of pulmonic insufficiency, Chest pain, Hepatomegaly, Palpitations, Jugular venous distension at 45 degrees, Fatigue, Edema) were assessed at Baseline and Week 12. The status of each sign and symptom ("absent" or "present") was assessed at each visit. To assess overall change from baseline in signs and symptoms, a "1" was assigned for each sign and symptom that was "present" at the Week 12 but was "absent" at baseline, a "-1" was assigned for each sign and symptom that was "absent" at Week 12 but was "present" at baseline, and a "0" was assigned for no change. An overall change score at each post-baseline assessment was then calculated by summing these values for all signs and symptoms. The overall change score had the potential to range from -17 to 17.

Intention to treat population.

Change in NT pro-BNP from Baseline to Week 12. Plasma samples were collected from patients at Baseline and Week 12 in order to measure any change over time in circulating plasma levels of this biomarker.

Per protocol