Improving the management of fluid retention can minimise symptoms of breathlessness due to congestion. Loop diuretics, such as furosemide or bumetanide, are the main agents used. Thiazide or thiazide-like diuretics are less often used on their own. Electrolyte balance, particularly potassium, should be monitored on a regular basis for all patients with chronic heart failure on diuretic therapy due to the added risk of developing hyponatremia (low blood sodium), which can cause serious neurological symptoms and even death. Renal function should also be monitored regularly to avoid worsening of renal impairment or causing acute renal failure. Diuretics improve symptoms of breathlessness and exercise performance in patients with heart failure.

ACE inhibitors improve survival in heart failure patients with left ventricular (LV) systolic dysfunction. The benefit is significant in patients with more severe LV systolic dysfunction symptoms. There is also good evidence to suggest that ACE inhibitors reduce exacerbations of heart failure and the risk of hospitalisation from it. They also reduce symptoms of fatigue and breathlessness in patients with heart failure and improve exercise capacity. ACE inhibitors should be initiated at a low dose and titrated upwards at short intervals (for example, every two weeks) until the optimal tolerated or target dose is achieved.

These agents are better tolerated than ACE inhibitors but the evidence for their use in heart failure is much weaker in comparison. ARBs should therefore be reserved for patients who are truly intolerant to ACE inhibitors. The addition of an ARB can also be considered for symptomatic chronic heart failure patients who are already taking conventional therapy.

Beta blockers are started on the lowest dose and gradually increased while monitoring heart rate, blood pressure and clinical status. Doses should be titrated upwards at no less than twoweekly intervals, aiming for the target dose or the highest tolerated dose. This slow increase, which the National Institute for Health and Care Excellence (NICE) calls “start slow, go slow”, is due to the fact that heart failure symptoms may be exacerbated during the initial period of therapy and patients need to be fully informed of the potential for this in order to minimise anxiety. These symptoms, which may include an increase in breathlessness and ankle oedema (swelling due to fluid retention), will subside with time.

Spironolactone and eplerenone act by blocking aldosterone, the steroid hormone that regulates salt and water in the body, thereby reducing water and salt retention. Spironolactone, added to conventional therapy, reduces both mortality and frequency of hospitalisation. The NICE guidance recommends that a licensed aldosterone antagonist may be added to the treatment regimen in patients with class III or IV heart failure, or those who have suffered a myocardial infarction (heart attack), if there are still symptoms despite optimal therapy with an ACEI plus beta blocker. Eplerenone is a newer aldosterone antagonist with a better side effect profile, as it is less likely to cause gynaecomastia (enlargement of male breast tissue). Other monitoring requirements are the same as spironolactone. It is licensed in post-myocardial infarction patients with heart failure and as an adjunct in chronic mild heart failure where the amount of blood being pumped out of the left ventricle with each contraction is 30 per cent or lower.

Ivabradine selectively and specifically inhibits the cardiac pacemaker, leading to a reduction in the heart rate. According to the NICE 2012 Technology appraisal, ivabradine is an option for treating mild to severe stable chronic heart failure in combination with standard therapy such as beta blockers, an ACEI, and an aldosterone antagonist (unless contraindicated or not tolerated).