The committee was aware that post hoc analyses of the principle trial (TOPCAT) suggested a considerable degree of heterogeneity within the population recruited and that MRAs might habe differential effcts in the different groups. Due to the uncertainties around any possible benefit of MRAs on mortality and hospitalisations in this population, a lack of alternative treatments and the clinically important risk of deteriorating renal function and hyperkalaemia, the committee was uncertain about the affect of MRAs in HFPEF but aware they were used in clinical practice. Therefore it was decided not to make a clinical recommendation on the use of MRAs in this population pending further evidence. Trade-off between net clinical effects and costs No previously published economic evaluations were identified for chronic heart failure patients with preserved ejection fraction and therefore unit costs were presented to the committee for consideration. This included annual drug costs: spironolactone (25mg: 18, 50mg: 41) and eplerenone with a specialist nurse ( 45.50) and blood tests ( 3), and the costs of all cause hospitalisation ( 2,930) and acute kidney injury ( 2,337). The committee noted that there could be potential cost savings from a reduced number of all cause hospitalisations for those treated with MRAs; however, as mentioned above, the clinical evidence for this outcome is uncertain. The committee also noted the greater number of acute kidney injury (AKI) events occurring in those treated with MRAs and agreed that the high cost of AKI would likely outweigh any potential cost savings from Chronic Heart Failure Treating Heart Failure NICE 2018. All rights reserved. Subject to Notice of rights. ISBN: 978-1-4731-3093-7 Research recommendation No recommendation reduced hospitalisation. 