Do Phosphodiesterase 5 Inhibitors Improve Exercise Capacity in COPD Patients with Pulmonary Hypertension?

INTERVENTION: Trade Name: Cialis Product Name: Tadalafil (Cialis)10mg Pharmaceutical Form: Capsule, hard CONDITION: Chronic obstructive pulmonary disease Pulmonary hypertension (secondary to chronic obstructive pulmonary disease) ; Level: LLT Classification code 10009033 Term: Contains ; Level: LLT Classification code 10037406 Term: Contains PRIMARY OUTCOME: Main Objective: Do these drugs make bronchitic patients able to walk further before they have to stop? Primary end point(s): Six minute walk test Secondary Objective: Do these drugs improve the quality of life of bronchitic patients? INCLUSION CRITERIA: INCLUSION CRITERIA Men and women age 35‐85 years suffering from moderate to severe COPD (FEV1 <80% of predicted), who are smokers or ex‐smokers with a history of at least 20 pack years (GOLD criteria stage II‐III). Echocardiography will be used to assess whether they have pulmonary hypertension or not. Two echo criteria will be used. The first one will be right ventricular systolic pressure (RVSP) which is considered equal to systolic pulmonary artery pressure in the absence of pulmonary valve stenosis. RVSP is recommended in guidelines from the ACCP to detect pulmonary hypertension. The precise technique of measuring RVSP by Doppler echocardiography is described by McGoon et al. Briefly, the velocity of the tricuspid regurgitant (TR) jet is calculated (v) and computed along with the right atrial pressure (RAP) as follows: RVSP = 4v2 + RAP. Patients will be included if their RVSP >30mmHg. The reliability of RVSP estimated from echo TR has been studied