Other considerations The committee decided only to review the evidence in the HF-REF and AF population, and not the HF-PEF and AF population, because there is no prognostic evidence for use of beta-blockers in HF-PEF. The committee were aware of the recent IPD published by Kotecha180 which looked at the effect of baseline heart rate on mortality in a subgroup of people with AF treated with beta-blockers. The committee agreed that the previously reported IPD data by Kotecha181 and the resulting data obtained directly from the trial authors was more appropriate for inclusion within the review as these summary statistics did not include the BEST trial of bucindolol versus placebo which is not licensed for any indication in the UK. Chronic Heart Failure Treating Heart Failure NICE 2018. All rights reserved. Subject to Notice of rights. ISBN: 978-1-4731-3093-7 6.2.3 Mineralocorticoid Receptor Antagonists in HFPEF Heart failure with preserved ejection fraction (HFpEF) is associated with myocardial stiffness and reduced ventricular filling. The mechanism for this is incompletely understood but cell hypertrophy and interstitial fibrosis can be found in myocardial biopsies of patients with HFpEF. A number of drugs affecting parts of the renin-angiotensin pathway have been developed and shown to be effective in the treatment of heart failure with reduced ejection fraction (HFREF). Many have also been investigated in HFpEF but have not shown similar benefits so currently none of these drugs are recommended for treatment of patients with HFpEF. The mineralocorticoid aldosterone, the neurohormone produced as the final product of the renin-angiotensin system is known to promote myocyte hypertrophy and fibrosis. Inhibition through mineralocorticoid receptor antagonism has been hypothesised to counteract the underlying pathological process causing HFpEF. Spironolactone and eplerenone are mineralocorticoid receptors antagonists (MRAs) licensed for treatment of people with HFREF. 