Overall, the beneficial effects of MRAs on mortality and hospitalisation outweighed the risk of hyperkalaemia and the possible impact on renal function. The committee acknowledged that the quality of the evidence on the risk of hyperkalaemia and renal function impairment was affected by the risk of bias, which may have led to an underestimation of the actual risk of hyperkalaemia/renal impairment in this population (as there was a proportion of participants who discontinued the study drug but remained in the study, and due to the strict inclusion criteria). The potential underestimation of these risks is confirmed by the results of other studies, which suggest a higher rate of these adverse events in patients using MRAs . However, these risks can be managed by starting patients on appropriate doses, measuring patients potassium levels and renal function at baseline and monitoring those levels regularly, and appropriate dose adjustment (see NICE Acute Kidney Injury guideline CG169). Patients with chronic renal impairment and hence the lowest eGFR appear to be those who have the most to gain in terms of mortality benefit. There is, however, a small cohort of patients who may experience a clinically significant deterioration in renal function and this highlights the need for baseline measurement and meticulous monitoring and follow-up by someone with specific expertise in managing heart failure and acute kidney injury. The committee acknowledged the evidence of an increased risk of gynaecomastia in patients taking spironolactone, but noted that the majority of patients did not experience this adverse event. Clinicians should consider switching to eplerenone in patients who experience gynaecomastia while taking spironolactone. Switching should be considered as part of shared decision making, as the value placed on avoiding gynaecomastia varies from patient to patient. 