The aim of this prospective, randomized, controlled study in patients with pulmonary hypertension, who are under stable optimized treatment for at least 2 months, is to examine the effect of an additional exercise and respiratory therapy.

The aim criteria measures the clinical parameters to record the effect of the training plus molecular parameter to evaluate the effectiveness of the training. The molecular parameters are composed of laboratory parameter and inflammatory parameter as well as genetic analyses, measurements of epigenetic changes measured by microRNA Expressions and DNA-methylation.

The study parameters will be assessed in the patient's routine examinations. Clinical parameters comprise of hemodynamic assessment of pulmonary arterial pressure during exercise, pump function of left and right ventricle, and further echocardiographic parameters. Improvement of exercise capacity will be measured by the change of six-minute walking distance, the breathing economics, the world health organization functional class (WHO functional class), peak oxygen consumption and blood gas analysis. The quality of life will be assessed with the SF-36 questionnaire. Data for survival analysis will be gained by structured phone interviews . The safety of the training is warranted by long-term, rest- and stress-ECG, safety laboratory, systemic blood pressure, heart frequency, oxygen saturation and occurrence of adverse events.

Patients will be examined in the Thoraxklinik Heidelberg. Patients of the training group will take part in a specific, 3-week inpatient training program at the rehabilitation center Knigstuhl Heidelberg. The training program consists of exercise and respiratory therapy as well as a mental gait training. Respiratory therapy will be performed 5 times/week for 30 minutes. Furthermore, 15-25 minutes low dosed interval training on a bicycle ergometer, dumbbell training of particular muscle groups with low weights and supervised walks on ground-level will be scheduled 5-7 times/week. Three- to five times a week a "mental gait training" is conducted to estimate the patient's individual physical abilities and limitations. The heart rate during exerciseand the intensity of the training will be closely monitored and individually adjusted. After three weeks of in-hospital rehabilitation the patients are asked to continue the training for twelve further weeks at home. All patients will be examined before the training program, at the end of the in-hospital phase after three weeks and after 15 weeks.

The control examinations cover the medical history, WHO functional class, physical examination, ECG, echocardiography at rest and during exercise, spiroergometry, quality of life, blood-gas analysis, lung function, 6-minute walking distance, oxygen saturation, blood pressure and heart rate, laboratory tests. An optional magnet resonance imaging at the beginning and after three months may also be conducted. At baseline, an optional genetic assessment will be performed; and at the beginning, after three and 15 weeks the expression levels of micro RNA and methylation of the DNA will be assessed. Medication will remain stable throughout the study.