Patients suffering from pulmonary arterial hypertension (PAH) frequently remain symptomatic despite medical therapy. Symptoms include breathlessness, poor exercise capacity and reduced quality of life.

In many other serious heart or lung diseases it has been shown that physical rehabilitation improves patient's fitness and quality of life. In PAH there are no clear guidelines and in general physical activity has traditionally been discouraged, although evidence for this advice is lacking. Interesting research project in Germany showed significant benefit for in-patient rehabilitation in PAH patients.

In this study we will perform a controlled clinical study of out-patient rehabilitation of patients with PAH. We hypothesize that physical training of patients will result in increased exercise capacity and improved quality of life.

Inclusion Criteria:

• All patients must satisfy current diagnostic criteria for pulmonary artery hypertension based on their historical right heart catheter data (within 4 years of study enrollment): Mean PAP >25mmHg at rest or >30mmHg with exercise, by a PCWP <= 15mmHg and by PVR >3 Wood Units.
• Willing and able to participate in 24 bi-weekly rehabilitation sessions, and medical follow-up.
• Stable dose of current PAH-specific medication for 3 months prior to enrollment.
• New York Heart Association (NYHA) Class II-III.
• Women of child-bearing age must demonstrate adequate contraception or undergo a pregnancy test.

Exclusion Criteria:

• Functional Class NYHA Class I or IV.
• PAH due to congenital heart disease, left heart disease, chronic lung diseases (VC or FEV1 < 60% of predicted) or chronic hypoxia.
• Acute intercurrent illness requiring hospital admission in the month proceeding screening.
• Any non-PAH medical condition likely to interfere with participation in rehabilitation, e.g. musculoskeletal disorders.
• Any uncontrolled or terminal non-PAH medical condition likely to interfere with completion of the study, according to the judgment of the study physician.
• Participation in another rehabilitation scheme within 6 months of enrollment in the study.
• Current participation in another clinical trial.
• Pregnancy or planned pregnancy during the study period.