The 2026 European Society of Cardiology (ESC) heart failure guidelines represent an important shift in how we think about this disease.1 Heart failure (HF) is no longer simply a syndrome treated once symptoms develop; it is a continuum from cardiovascular risk to cardiac change and overt disease. The greatest gains may come from identifying patients earlier, before irreversible changes occur. The question is no longer simply, “How should we treat HF?”, but “How early should we intervene, and can we prevent it?”
It is impossible to cover every change within such comprehensive guidelines in a single opinion piece. We, therefore, focus on four clinically important developments: the prevention-focused stages A–D, revised left ventricular ejection fraction (LVEF) classification, replacement of guideline-directed medical therapy (GDMT) with more precise terminology, and earlier referral in stage D.
From A to D: prevention becomes HF care
Europe has finally adopted the American A–D staging framework, introduced in the American Heart Association (AHA) HF guidelines in 2001.2 Stage A identifies people at risk without symptoms or objective cardiac abnormality; stage B (pre-HF) identifies objective abnormality without symptoms; stage C denotes current or previous symptomatic HF; and stage D denotes advanced disease. This prevention-forward approach places risk-factor control and early detection within the HF pathway, rather than at its periphery.
The patient conversation matters just as much as the classification itself. Telling an asymptomatic person that they have ‘stage B heart failure’ may provide the jolt needed to address blood pressure, cholesterol, weight, glycaemic control, alcohol, activity, sleep and nicotine exposure (life’s essential 83). Fear alone, however, is not a therapeutic strategy. Patients must understand that stage B is not symptomatic HF, that progression is not inevitable, and that specific actions can alter risk. Used well, the label creates agency; used carelessly, it creates anxiety.
Despite the potential, stage A/B HF remains under-recognised, under-researched and under-treated. These stages constitute the largely hidden burden of the HF iceberg, yet their prevalence, progression and optimal management remain poorly understood. Bidirectional trajectories between stages A and B add complexity, as a single screening time-point may not capture this fluctuating course.4 Uncertainties, therefore, remain: the true prevalence of these stages (including geographically5–8), who and how frequently to screen, which biomarker or imaging strategies are most effective, and whether specific interventions can prevent progression across such a heterogeneous population. Ireland’s STOP-HF programme9 may offer a potential model, and, importantly for health-policy and funding authorities, is likely to be cost-effective.10 In at-risk adults, natriuretic peptide (NP) screening linked to collaborative primary and specialist care reduced new left ventricular dysfunction and HF, as well as emergency cardiovascular hospitalisation.9
The implementation challenge is substantial. Population screening could generate considerable demand for NP testing, imaging, follow-up and specialist review, with uncertain benefit for some phenotypes. The real test is whether health systems will fund both the research and the clinical infrastructure required to shift from treating decompensation towards preventing progression, without overwhelming services that are already stretched managing stages C and D. Standardising the stages across Europe and the US will improve awareness, facilitate international research and help identify the mechanisms driving HF. This matters, as although several therapies reduce incident HF in selected high-risk groups, no agent is licensed specifically to prevent progression across stages A/B to C.11
New LVEF nomenclature: two phenotypes
Removing HF with mildly reduced ejection fraction (HFmrEF) simplifies classification by incorporating LVEF 41–49% within HF with reduced ejection fraction (HFrEF). However, a binary ‘reduced’ or ‘preserved’ framework may obscure HF with improved ejection fraction (HFimpEF). Patients whose LVEF normalises on therapy are not equivalent to those with de novo HF with preserved ejection fraction (HFpEF); recovery may represent remission, and treatment withdrawal may precipitate recurrent dysfunction. A contemporary LVEF may mistake therapeutic success as disease resolution. There is relief that the guidelines did not adopt the full 2025 consensus12 nomenclature: unchanged (HFuncEF), worsening (HFworEF), recovered (HFrecEF) and supranormal ejection fraction (HFsnEF), although its central argument remains valid – LVEF is dynamic. The same value may represent stability, recovery or deterioration, with different implications. Classification should, therefore, record previous, nadir and current LVEF, its direction and treatment context. Trajectory may be more useful than multiplying categories.
Guideline-directed medical therapy relabelled
The relabelling of guideline-directed medical therapy (GDMT) is a step forward. GDMT had become an umbrella term, applied indiscriminately across distinct classes of therapy.
Foundational medical therapy
Foundational medical therapy (FMT) describes class I treatments that reduce hospitalisation and/or death in broadly eligible patients: ‘everyone eligible gets this’. The recommendation for sacubitril/valsartan has expanded alongside the broader HFrEF classification to include patients with LVEF <50%. In those with HFpEF, mineralocorticoid-receptor antagonists are now FMT and are upgraded to a class I recommendation.
Additional medical therapy
Additional medical therapy (AMT) covers class IIa or IIb treatments, or class I therapies for symptoms, quality of life or defined subgroups: ‘this patient may benefit’. A welcome change within AMT includes an upgrade in the recommendation (to class IIa) to consider the use of cardiac glycosides (digoxin/digitoxin) in patients with HFrEF (LVEF <40%; sinus rhythm or atrial fibrillation) to reduce the risk of hospitalisation.13
Guideline-directed interventional therapy
Guideline-directed interventional therapy (GDIT) incorporates recommended devices and procedures in appropriate clinical situations. In this category, a significant change is the elevation of mitral valve transcatheter edge-to-edge repair to a class I recommendation. Separating foundational from subgroup-specific treatment is clarifying. It offers a stepwise approach in which recommendations follow the weight of evidence. Most encouragingly, the guidelines showcase expanding evidence-based HF therapies, enabling effective, phenotype-specific treatment for more patients than ever.
Stage D: class 1 recommendation for early referral
The stage D section contains a consequential shift. Advanced HF is defined by severe symptoms, limited exercise capacity, cardiac dysfunction or recurrent events, despite optimal FMT, AMT and GDIT. Early advanced-centre consultation is now a class I recommendation, supported by “I NEED HELP” and the rule of three.14,15 Durable left ventricular assist-device support is similarly upgraded to class I in selected advanced HFrEF, as a bridge to transplantation, candidacy or recovery, or as destination therapy; transplantation remains central for eligible patients.
This reframes stage D from an exhausted end point to a time-sensitive therapeutic window. Referral should precede irreversible organ dysfunction, profound frailty or recurrent cardiogenic shock. Specialist review must integrate advance care planning, symptom control and palliative care alongside transplantation or mechanical-support assessment. These are parallel pathways, not mutually exclusive choices.
Conclusion
The guideline’s greatest contribution may be its recognition of stage A–D and its wider horizon. Staging A–D makes prevention part of practice. Links between community detection, primary care, imaging, biomarkers and specialist services could shift HF from late rescue towards personalised prevention. The iceberg has been named; our challenge is now to address what lies beneath the surface.
Conflicts of interest
BW reports no disclosures relevant to the present work, but has previously received speaker/consulting fees for Novartis, travel grant from Novo Nordisk. EJ reports no disclosures relevant to the present work, but has previously received speaker and consulting fees from Pfizer, Bayer, Alynylam and is on the steering committee of FIRE-1. PC reports no disclosures relevant to the present work, but has previously received speaker/consultancy fees from Bayer, Boehringer Ingelheim, Novo Nordisk, Pharmacosmos, Vifor.
Funding
None.
Declaration of generative AI
During the preparation of this work, the authors used Claude.ai (Sonnet 5) for very minor refinement of language. AI was not used for concept formation. After using this tool, the authors reviewed and edited the content as needed and take full responsibility for the content of the published article.
References
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