Trimetazidine in Pulmonary Artery Hypertension

Inclusion Criteria: * PAH patients belonging to the following subgroups of the updated Dana Point Classification Group 1 1. Idiopathic PAH 2. Heritable PAH 3. Drug or toxin-induced PAH 4. PAH associated with connective tissue disease 5. PAH associated to congenital heart disease with simple systemic-to-pulmonary shunt at least 1 year after surgical repair 6. PAH associated to HIV infection * Documented hemodynamic diagnosis of PAH by right ventricular catheterization performed any time prior to screening * Signed informed consent Exclusion Criteria: * Patients belonging to the subgroups of the updated Dana Point Classification Group I not listed in the inclusion criteria * Patients belonging to the groups 2-5 of the updated Dana Point Classification Group * Moderate to severe chronic pulmonary obstructive disease * Documented left ventricular dysfunction * Severe renal impairment (Serum creatinine \> 2.5 mg/dL) * Patients who are receiving or have been receiving any investigational drugs within 1 month before the baseline visit * Acute or chronic impairment (other than dyspnea) limiting the ability to comply with study requirements * Psychotic, addictive or other disorder limiting the ability to provide informed consent or to comply with study requirements * Life expectancy less than 12 months * Females who are lactating or pregnant or those who plan to become pregnant during the study * Known hypersensitivity to any of the excipients of the drug formulation