27 August 2018

GPs at the heart of new guidelines

Cardio Clinical General practice

New Australian  guidelines have changed the ejection fraction categories of heart failure, with experts saying the move will eliminate diagnostic uncertainty.

Breaking from European recommendations, the new Heart Foundation and Cardiac Society of Australia and New Zealand (CSANZ) guidelines say patients with a clinical diagnosis of heart failure and left ventricular ejection fraction of 50% or less should now be considered to have “reduced” ejection fraction.

Previously people with an ejection fraction between 40 and 50% were classified as having mid-range LVEF, which had implications for treatment.

The guidelines committee said the margin of error from an echocardiogram examination raised questions over whether patients were being correctly identified as having mid-range, reduced or preserved ejection fraction.

In addition, evidence seemed to show that these previously labelled “mid-range” patients also benefited from blockade of the renin–angiotensin system, beta blockers and mineralocorticoid receptor antagonists (MRAs) just as those with an LVEF of less than 40% did, they said.

The evidence is now stronger in support of ACE inhibitors and beta-blockers for patients with an LVEF of 40% or less, and less strong but still recommended in those with an LVEF of between 40% to 50%, providing there are no contraindications.

Similarly, a mineralocorticoid receptor antagonist (MRA) is also recommended to patients with an LVEF of 40% or less unless contraindicated.

Another major shift in the guidelines was the recommendation that euvolaemic patients start both heart failure specific beta blockers and an ACE inhibitor or ARB at the same time. From there, it advised doctors to up-titrate the beta blocker first, because beta blockers have been shown to provide better benefits to mortality and functionality than the other drugs.

In terms of monitoring, the Australian guidelines recommend doing a full blood count and iron study in patients with persistent HFrEF in line with clinical judgment, as iron deficiency is common in this population.

Around one in two patients with heart failure are iron deficient (ferritin <100?g/L or ferritin 100-300?g/L with transferrin saturation <20%), but their symptoms and quality of life can be greatly improved with intravenous iron.

In accompanying guidelines for atrial fibrillation, experts backed NOACs as the oral anticoagulant of choice, over warfarin, in newly diagnosed patients.

Associate Professor Gary Kilov suggested GPs consider doing a database search to identify their patients who could be transitioned from warfarin to the newer agents.

“We’ve had NOACs or DOACs for over a decade now, and despite their proven superiority over warfarin in terms of safety, efficacy and ease of use, they remain underutilised,” the Tasmanian GP told Cardiology Today.

“There are individuals who’ve been diagnosed with atrial fibrillation who remain off treatment despite risk calculators indicating that [the drugs] would be of benefit.”

There were also patients who may be treated with suboptimal or subtherapeutic doses, he added.

“Given this, it may be prudent to consider doing a database search, a clinical audit, to identify individuals who may be at risk of developing atrial fibrillation or those who are on medication for atrial fibrillation but could do with a review of their medication and management of risk factors and comorbidities.”

GPs are also being asked to now opportunistically screen any individuals for AF in the clinic or community who are over age 65.

To simplify the treatment algorithm and standardise thresholds, cardiology experts have also dropped the sex category from the CHA2DS2-VA score.