Tadalafil for Severe Pulmonary Hypertension Due to Chronic Obstructive Pulmonary Disease

This study tests whether tadalafil — a drug used for pulmonary arterial hypertension and other conditions — can help people with severe pulmonary hypertension caused by chronic obstructive pulmonary disease (COPD). In COPD, damaged lungs can cause dangerously high blood pressure in the lung blood vessels, making breathing and physical activity very difficult. **You may be eligible if...** - You are 18 to 84 years old - You have COPD confirmed by breathing tests - You have been diagnosed with severe precapillary pulmonary hypertension through a heart catheterization test - Your shortness of breath is classified as WHO functional class II to IV - You have never previously taken a PDE5 inhibitor (such as sildenafil or tadalafil) for pulmonary hypertension **You may NOT be eligible if...** - You have a different cause of pulmonary hypertension (not COPD-related) - You have already been treated with pulmonary vasodilator medications - You have severe heart failure with low pumping function - You are pregnant or breastfeeding Talk to your doctor to see if this trial is right for you.