The optimal frequency for monitoring renal function in people with heart failure is questioned in an extensive review of national and international heart failure guidelines.¹ The review describes the two-way link between cardiac and renal function, the association between decline in cardiac function with renal function (and vice versa) and how drugs used to manage heart failure can worsen the situation. Renal dysfunction due to diuretics, particularly in patients with heart failure, is a common cause of hospitalisation for adverse drug reactions in the UK. There is a lack of good evidence to inform heart failure guidelines on the optimal frequency for monitoring renal function. Current recommendations are largely based on expert opinion.

The review found that major guidelines on the management of heart failure (National Institute for Health and Care Excellence, Scottish Intercollegiate Guidelines Network, European Society of Cardiology American College of Cardiology Foundation and American Heart Association [ACCF/AHA]) recommend similar drug treatments but offer varying advice about frequency for monitoring renal function and thresholds for reviewing treatment. Recommendations are often non-specific, for example, guidelines advise that monitoring is done ‘periodically’, ‘frequently’, or ‘at the discretion of the clinician’.

The review’s authors conclude that, in light of the lack of studies specifically addressing optimal timing of monitoring renal function, the approach of current heart failure guidelines is essentially medication based. They suggest that, to rationalise guidance for monitoring renal function and to minimise risk of worsening renal function and acute kidney injury in vulnerable patients, a more effective and appropriate regimen would be patient-based. This should, they say, consider both medication and individual risk factors and suggest a monitoring interval based on a patient’s combined risk, facilitating early intervention (such as dose adjustment) to reduce risk of renal deterioration, hospital admission and mortality.

Comment: It is surprising that, for such a common problem, that there is a lack of evidence to support recommendations on the optimal frequency for monitoring renal function. Further guidance on practical patient-centred rather than drug-centred monitoring would be valuable.