Effects of the Combination of Bosentan and Sildenafil Versus Sildenafil Monotherapy on Pulmonary Arterial Hypertension (PAH)

Kaplan-Meier estimate of percentage of participants without a morbidity/mortality event. A morbidity/mortality event is defined as the occurrence of a) death, b) hospitalization for worsening or complication of PAH or intravenous prostanoid initiation, c) atrial septostomy, d) lung transplantation, or e) worsening PAH, defined as moderately or markedly worsened PAH symptoms using a patient global self-assessment (PGSA) scale AND initiation of inhaled or subcutaneous prostanoids or the disease progression package (open-label bosentan). If a patient replied no change or mildly worse on the PGSA, a decrease in 6MWT of 20% versus last visit or 30% versus baseline is also required to confirm the event.

Time frame: From baseline to end of study, approximately 86 months

Population: All randomized set

Blood sampling for the measurement of NT-pro-BNP was performed and the plasma concentrations of NT-pro-BNP were determined by a certified centralized laboratory.

Time frame: Baseline to Month 20

Population: All randomized patients with a baseline and at least one post-baseline value. Assessments considered are those where at least 60% of the patients have a post-baseline value

The 6MWT is a non-encouraged test, which measures the distance covered over a 6 minute walk; the patient is instructed to walk as far as possible in a 30 m long flat corridor, back and forth around two cones, with the permission to slow down, rest, or stop if needed. Areas were to be well ventilated with air temperature controlled between 20 °C and 23 °C (68 °F to 76 °F). The test was to be administered at the same time of day and by the same tester throughout the study. The tester measured the distance walked by non-encouraged patients during the timed 6 minute period.

Time frame: From baseline to week 16

Population: All randomized set

The Borg dyspnea index was evaluated immediately after the 6MWT to obtain a rating of dyspnea at the end of the exercise using a scale from 0 ('Nothing at all') to 10 ('Very, very severe - maximal').

Time frame: Baseline to Week 16

Population: All randomized set

The EQ-5D questionnaire is a patient-reported outcome consisting of a 5 dimensional descriptive system and a visual analog scale (VAS). The descriptive system asks respondents to describe their health status. Health is defined in 5 dimensions: (1) mobility, (2) self care, (3) usual activities, (4) pain or discomfort, and (5) anxiety or depression. Each dimension is divided into 3 levels, indicating (a) no problem, (b) some or moderate problems, or (c) extreme problems. Respondents record their problem(s) in each of the 5 dimensions. Combinations of these levels define a total of 243 health states. A health state defined by the descriptive system of EQ-5D can be described by a 5-digit number with full health is indicated by 11111 and poorest health state by 33333. The EQ-5D calculated score was derived by re-assigning local scores for answers to each question and combining these local scores into a global score with ranges from 0 (worst possible outcome) to 1 (best possible outcome).

Time frame: From baseline to Week 16

Population: All randomized set

The EQ-5D questionnaire is a patient-reported outcome consisting of a 5 dimensional descriptive system and a visual analog scale (VAS) together with brief demographic questions. EQ-5D VAS asks respondents to rate their perception of their overall health on a vertical visual analogue scale with 'best imaginable health state' set at 100 and 'worst imaginable health state' set at 0.

Time frame: Baseline to Week 16

Population: All randomized set

Class I: no limitation of usual physical activity (PA) which does not increase dyspnea, fatigue, chest pain, or presyncope. Class II: mild limitation of PA. No discomfort at rest. Normal PA increases dyspnea, fatigue, chest pain, or presyncope. Class III: marked limitation of PA. No discomfort at rest. Less than ordinary activity increases dyspnea, fatigue, chest pain, or presyncope. Class IV: unable to perform any PA and who may have signs of right ventricular failure. Dyspnea and/or fatigue may be present at rest and symptoms are increased by almost any PA.

Time frame: From baseline to Week 16

Population: All randomized set

The PGSA is a questionnaire that allows the patient to compare his/her PAH status in response to the question How do you feel about your PAH today compared with your last visit? asked by the investigator. Patients use a seven-point scale to respond: markedly better, moderately better, mildly better, no change, markedly worse, moderately worse, or mildly worse.

Time frame: Week 16

Population: All randomized set, patients who completed the assessment

Kaplan-Meier estimate of percentage of participants without a mortality event.Time to death due to any cause.

Time frame: Baseline to End of Study, approximately 86 months

Population: All randomized set

Kaplan-Meier estimate of percentage of participants without an event of death, hospitalization (for worsening or complication of PAH or initiation of intravenous prostanoids), atrial septostomy or lung transplantation. Time to first confirmed death, hospitalization (for worsening or complication of PAH or initiation of intravenous prostanoids), atrial septostomy or lung transplantation from baseline to end of study was confirmed by an independent Clinical Endpoint Committee.

Time frame: Baseline to end of study, approximately 86 months

Population: All randomized set