Feasibility Trial for a Right Ventricular Failure Platform Trial

Inclusion Criteria: 1. Age ≥ 18 years. 2. Able to provide informed consent. 3. Able to comply with all study procedures. 4. History of RV dysfunction or RHF secondary to any of: a. Group 1 PH, pulmonary arterial hypertension b. Group 2 PH, left heart disease with normal left ventricular ejection fraction (LVEF) \> 50% and a previous RHC demonstrating combined pre and post-capillary PH, defined as: i. mPAP \>20 mmHg ii. PAWP \> 15 mmHg iii. PVR\> 2 WU c. Group 3 PH d. Group 4 PH, chronic thromboembolic PH that is either persistent after pulmonary endarterectomy or inoperable due to distal disease. 5. Symptomatic with current NYHA Functional Class II-IV 6. Biomarker and 2D echocardiogram evidence of RV dysfunction within 3 months: 1. NT-proBNP \>300 ng/L and qualitative evidence of at least 'mild' RV dysfunction on echocardiography OR NT-proBNP\<300 ng/L and qualitative evidence of at least moderate RV dysfunction and/or dilatation on 2D echocardiogram AND 2. A quantitative 2D echocardiogram with evidence of RV dysfunction defined as having both of the following: i. TAPSE ≤18 mm ii. RV dilatation (RV diameter \> 42 mm at the base). 7. Receiving loop diuretics or mineralocorticoid receptor antagonists for at least 4 weeks. 8. Access to an iOS or android smart phone or tablet. Exclusion Criteria: 1. Estimated glomerular filtration rate (eGFR) \<30 ml/min. 2. LVEF \< 50% 3. Normal RV size and function 4. Severe aortic or mitral valvular disease 5. Moderate or severe hepatic dysfunction (Child-Pugh Class B or C) 6. Participants requiring augmentation of diuretics or otherwise not meeting definition for clinical stability 7. Pregnancy or lactation 8. Unable to provide consent and comply with follow-up visits 9. Listed for lung, heart or heart/lung transplantation 10. Myocardial infarction or acute coronary syndrome within 90 days of screening 11. Enrolled in another interventional trial 12. Planned cardiac or thoracic surgical intervention in the next 6 months. 13. Known hypersensitivity to empagliflozin or ranolazine. 14. Concurrent treatment with: * strong inhibitors of Cytochrome P450 3A4 (CYP 3A4), (e.g., ketoconazole, itraconazole, voriconazole, posaconazole, clarithromycin, nelfinavir, ritonavir, indinavir, saquinavir and grapefruit juice) * class IA antiarrhythmics (e.g., quinidine, procainamide, disopyramide) or class III antiarrhythmics (e.g., sotalol, ibutilide, amiodarone, dronedarone) * inducers of CYP 3A4 (e.g., rifampin, rifabutin, rifapentine, phenobarbital, phenytoin, carbamazepine, and St. John's wort) 15. Congenital long QT syndrome or a QTc interval \>500 ms