The Role of Trimetazidine on Right Ventricle Function in Pulmonary Arterial Hypertension

Inclusion Criteria: * Pre-capillary Pulmonary Hypertension patients assessed by right heart catheterization * Signed informed consent Exclusion Criteria: * Patient belonging to post-capillary, Isolated post-capillary, or combined post -capillary and pre-capillary pulmonary hypertension according to 2015 ESC/ERS Guidelines for the diagnosis and treatment of pulmonary hypertension. * Moderate to severe chronic pulmonary obstructive disease * Right Ventricular Ejection Fraction \> 45% assessed by cardiac magnetic resonance. * Documented left ventricular dysfunction with left ventricular ejection fraction \< 50% assessed by cardiac magnetic resonance. * Severe renal impairment (Serum creatinine \> 2.5 mg/dL, eGFR \< 30ml/min/1.73 m\^2, or routine dialysis treatment). * Malignant arrhythmia such as total atrioventricular block or ventricular fibrillation or unstable ventricular tachycardia. * 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 * Females who are lactating or pregnant or those who plan to become pregnant during the study * Known Parkinson disease * Known hypersensitivity to any of the drug formulation