Spironolactone Therapy in Chronic Stable Right HF Trial

- Provide a personally signed and dated inform consent form.

- Male or female ≥ 18 years.

- Able to comply with all study procedures.

- History of right heart failure (RHF) secondary to either: i) WHO, group 1 pulmonary arterial hypertension PAH OR ii) WHO group II PH with normal LV systolic function OR iii) WHO group III or IV PH OR iv) primary RV cardiomyopathy.

- Current NYHA II-IV

- RV dysfunction as measured by 2D echocardiogram: i)defined as a tricuspid annular plane systolic excursion (TAPSE) <16 mm ii) and /or a two dimensional fractional area change <35% on screening echo plus

- NT-proBNP>400 pg/ml

- Chronic use of diuretics

- Clinical stability: defined as no need for increased diuretics, hospitalization or emergency room visit 3 months prior to enrollment

- Patients on chronic MRA therapy or other potassium sparing diuretics.

- Baseline serum potassium>5 ummol/l.

- Estimated glomerular filtration rate <30 ml/min.

- LV ejection fraction <45%,

- Moderate or severe LV diastolic function,

- Moderate or severe aortic or valvular disease.

- Patients requiring augmentation of diuretics or otherwise not meeting definition for clinical stability.

- Severe Liver Failure (Child-Pugh Class C)

- Claustrophobia or inability lie still in a supine position

- Patients with contraindications to either PET or CMR imaging

- Pregnancy or lactation.

- Unable to provide consent and comply with follow up visits.