The quality of the evidence for gynaecomastia was moderate for spironolactone due to risk of bias which likely underestimated the incidence of the event, and very low for eplerenone due to risk of bias and imprecision (though regarding the latter, the committee noted that there was no serious imprecision in the confidence intervals around the estimated absolute effect). The quality of the evidence for hypotension was low due to risk of bias and imprecision. The quality of evidence for change in NYHA class was very low due to risk of bias, indirectness and imprecision, and so it did not weigh heavily in decision making. Chronic Heart Failure Treating Heart Failure NICE 2018. All rights reserved. Subject to Notice of rights. ISBN: 978-1-4731-3093-7 Trade-off between clinical benefits and harms The use of mineralocorticoid receptor antagonists (MRAs) led to a clinically important reduction in mortality and hospitalisations, and possibly an improvement in NYHA class. However, MRAs also led to a clinically important increase in the number of patients experiencing hyperkalaemia. There was also some evidence of worsening renal function and an increase in hypotension in patients using MRAs, though this evidence was mixed and mostly suggested a difference of insufficient magnitude to be clinically important. The use of spironolactone was associated with a clinically important increase in gynaecomastia. This was not the case for eplerenone, where the very low quality evidence suggested that there was no clinically important difference. The committee agreed that there was likely to be no clinically important difference between the eplerenone and placebo group. Overall, the beneficial effects of MRAs on mortality and hospitalisation outweighed the risk of hyperkalaemia and the possible impact on renal function. 