Early Therapy of Pulmonary Arterial Hypertension

Overview

Exercise-induced increase of the pulmonary arterial pressure may be an early sign of pulmonary arterial hypertension. It has been shown that patients with normal pulmonary arterial pressure at rest but elevated pulmonary arterial pressure during exercise have a decreased exercise-capacity and may have a worse prognosis compared to patients with normal pulmonary arterial pressure values at rest and during exercise. According to the currently used definition pulmonary hypertension can be diagnosed if the mean pulmonary arterial pressure is higher than 25mmHg at rest or 30mmHg during exercise. In this study patients with a risk for pulmonary arterial hypertension (connective tissue disease) and increased pulmonary arterial pressure values during exercise are receiving a therapy with a dual endothelin receptor antagonist - bosentan, a therapy established for pulmonary arterial hypertension. The therapy effect is than compared to the recorded changes before the introduction of this therapy.

Bosentan is an established therapy in pulmonary arterial hypertension, which may be diagnosed when the mean pulmonary arterial pressure is \>25mmHg at rest or \>30mmHg at exercise. Bosentan has shown efficacy, if mean pulmonary arterial pressure was elevated at rest. However, there are no data available of the effects of such a therapy, if the mean pulmonary arterial pressure is normal at rest but elevated during exercise. The purpose of this study is to provide additional data on this group of patients. Our hypothesis is that patients with exercise-induced pulmonary hypertension may show a gradual worsening of pulmonary hemodynamics and potentially a development of manifest pulmonary arterial hypertension (elevated resting pulmonary arterial pressure values) without treatment, while the introduction of Bosentan may improve hemodynamics and exercise capacity in this patient group.