IMproved exercise tolerance in patients with PReserved Ejection fraction by Spironolactone on myocardial fibrosiS in Atrial Fibrillation rationale and design of the IMPRESS-AF randomised controlled trial

INTRODUCTION: Patients with atrial fibrillation frequently suffer from heart failure with preserved ejection fraction. At present there is no proven therapy to improve physical capacity and quality of life in participants with permanent atrial fibrillation with preserved left ventricular contractility. OBJECTIVE: The single-centre IMproved exercise tolerance In heart failure With PReserved Ejection fraction by Spironolactone On myocardial fibrosiS In Atrial Fibrillation (IMPRESS-AF) trial aims to establish whether treatment with spironolactone as compared with placebo improves exercise tolerance (cardiopulmonary exercise testing), quality of life and diastolic function in patients with permanent atrial fibrillation. METHODS AND ANALYSIS: A total of 250 patients have been randomised in this double-blinded trial for 2-year treatment with 25 mg daily dose of spironolactone or matched placebo. Included participants are 50 years old or older, have permanent atrial fibrillation and ejection fraction >55%. Exclusion criteria include contraindications to spironolactone, poorly controlled hypertension and presence of severe comorbidities with life expectancy <2 years. The primary outcome is improvement in exercise tolerance at 2 years and key secondary outcomes include quality of life (assessed using the EuroQol EQ-5D-5L (EQ-5D) and Minnesota Living with Heart Failure (MLWHF) questionnaires), diastolic function and all-cause hospitalisation. ETHICS AND DISSEMINATION: The study has been approved by the National Research and Ethics Committee West Midlands—Coventry and Warwickshire (REC reference number 14/WM/1211). The results of the trial will be published in an international peer-reviewed journal. TRIAL REGISTRATION NUMBERS: EudraCT2014-003702-33; NCT02673463; Pre-results.