Coronary Artery Stents in Heart Failure With Preserved Ejection Fraction

Inclusion Criteria: 1\. A diagnosis of HFpEF, defined by the European Society of Cardiology (ESC) criteria, defined as: 1. Symptoms of heart failure (New York Heart Association (NYHA) class II-IV) and 2. Left ventricular ejection fraction ≥ 50% and 3. NT-pro-BNP \> 125 pg/ml in sinus rhythm or \> 365 pg/ml in atrial fibrillation and 4. One or more of the following objective signs of left ventricular diastolic dysfunction: i. Invasively measured left ventricular end diastolic pressure ≥ 15 mmHg at rest or ≥ 25 mmHg on exercise (directly measured or estimated via pulmonary capillary wedge pressure) ii. Estimated pulmonary artery systolic pressure \> 35mmHg or tricuspid regurgitation velocity \> 2.8 m/s on echocardiography iii. Left atrial volume index \> 34ml/m2 in patient in sinus rhythm or left atrial volume index \> 40ml/m2 in atrial fibrillation iv. Relative left ventricular wall thickness \> 0.42 v. Left ventricular mass index ≥ 95 g/m2 in females or ≥ 115 g/m2 in males vi. Mitral E/E' ratio \> 9 Exclusion Criteria: 1. Age \<18 years 2. People without capacity to provide informed consent 3. PCI contraindicated or not feasible on coronary angiography or screening CTCA 4. Contraindication to clopidogrel/dual antiplatelet therapy 5. Recent acute myocardial infarction or coronary revascularisation (within 90 days) 6. Enrolment in another interventional study which may affect study outcomes 7. Severe chronic obstructive pulmonary disease (GOLD stage ≥3) 8. Haemoglobin \<=80 g/L 9. Other cardiac diagnosis as a cause for HFpEF (hypertrophic cardiomyopathy, untreated severe left sided valvular disease, cardiac amyloidosis)