ESC26: Heart attack reclassification rights gender imbalance
A new, universal definition for a heart attack or myocardial infarction (MI) recognises that there are many different underlying causes and could lead to better care for women.
The updated classification system proposed by four leading cardiovascular organisations, revealed at the European Society of Cardiology (ESC) congress in Munich, Germany, breaks away from the previous numerical system for categorising MIs – i.e. types 1 to 5 – which has been criticised for being overly complex and confusing.
The result is a system that breaks down the various types of MI into three categories, covering some which predominantly affect women and are often underdiagnosed and undertreated, such as spontaneous coronary artery dissection (SCAD).
The experts behind the framework reckon that it will lead to improved diagnosis and management of MI, a greater level of understanding for patients, and open up new avenues for research into improved therapies.
"People may think of an MI as a heart attack caused by a blocked coronary artery, but there are many different causes," ESC chair Prof Nicholas Mills of the University of Edinburgh in the UK told delegates at the conference.
The previous numerical system was "not always easy to apply in clinical practice, leading to inconsistencies in diagnosis and treatment," he added.
The new scheme includes three main categories. The first, primary MI, covers spontaneous acute coronary pathologies like atherothrombosis, vasospasm, or SCAD, where a sudden tear forms in the wall of the coronary artery.
SCAD is up to nine times more common in women than in men because female sex hormones and specific vascular conditions can weaken the vessel wall. Along with being underdiagnosed, the condition places women with SCAD at risk of getting inappropriate treatment, including some that may worsen their condition.
The second category covers secondary MI, where the cause is another acute illness, such as severe anaemia, respiratory failure, or sudden blood loss, while the third bundles together procedure-related MIs that occur within 30 days of a cardiac intervention.
The new classification introduces lower, gender-specific thresholds for troponin – a biomarker for heart damage – and encourages precise coronary imaging for non-clot heart attacks, which should help improve SCAD diagnosis. It also aligns with standardised International Classification of Disease (ICD) tracking data, which should result in better public health monitoring and healthcare system planning.
The ESC came together with the American College of Cardiology (ACC), the American Heart Association (AHA), and the World Heart Federation (WHF) to come up with the new classification system.
"Clinicians often do not use the previous numerical terminology…in patient discussions as it is rather complex," commented ACA/AHA chair Prof Kristin Newby.
"With the new approach, we can now talk with patients about the cause of their MI so that they can understand their condition and recognise why the next steps, such as further tests and treatments, are needed."
Heart failure definitions tweaked
In another change to cardiovascular classification systems, the ESC also saw the introduction of updated guidelines on heart failure.
The headline change is to the categorisation of heart failure based on left ventricular ejection fraction (LVEF), removing heart failure with mildly reduced ejection fraction and splitting patients. Now, patients are classified as either heart failure with reduced ejection fraction (HFrEF), with an LVEF of 50% or less, or heart failure with preserved ejection fraction (HFpEF) with LVEF above the 50% threshold.
There are also changes to the recommendations for drug therapies. Mineralocorticoid receptor antagonists like Bayer's Kerendia (finerenone) are now backed in chronic heart failure independent of LVEF, while Novo Nordisk's GLP-1 agonist semaglutide and Eli Lilly's dual GIP/GLP-1 agonist tirzepatide are recommended for patients with HFpEF and obesity.
