NICE clinical guideline 108 updated and replaced NICE clinical guideline 5 (published July 2003). [2018] indicates that the evidence was reviewed and the recommendation added, updated or unchanged in 2018. [2016] refers to NICE technology appraisal guidance published in 2016. [2012] refers to NICE technology appraisal guidance published in 2012. [2010] indicates that the evidence was reviewed in 2010. [2010, amended 2018] indicates that the evidence was reviewed in 2010 but changes were made to the recommendation wording in 2018 that changed the meaning. [2003] indicates that the evidence was reviewed in 2003. [2003, amended 2018] indicates that the evidence was reviewed in 2003 but changes were made to the recommendation wording in 2018 that changed the meaning. [2003, amended 2010] indicates that the evidence was reviewed in 2003 but changes were made to the recommendation wording in 2010 that changed the meaning. 'Heart failure due to left ventricular systolic dysfunction (LVSD)' has been replaced in all recommendations by 'heart failure with reduced ejection fraction' in line with current terminology and the 2018 guideline scope. 'Aldosterone antagonists' has been replaced in all recommendations by 'mineralocorticoid receptor antagonists (MRAs') to clarify the function of the receptor, and in line with the 2018 guideline scope. 33 of 'African or African-Caribbean family origin' has been added to recommendation 1.2.7 because of the high incidence of heart failure with preserved ejection fraction in these populations. Recent evidence shows that NT-proBNP levels are lower in people of west African family background and are a confounder in the diagnosis of heart failure. Doppler 2D has been deleted from recommendations 1.2.8, 1.2.9 and 1.2.11 because all transthoracic echocardiography would have doppler 2D as a minimum and it is no longer necessary to specify this. 