Heart Failure Redefined With New Classifications, Staging

Debra L. Beck

March 08, 2021

The terminology and classification scheme for heart failure (HF) is changing in ways that experts hope will directly impact patient outcomes.

In a new consensus statement, a multisociety group of experts proposed a new universal definition of heart failure and made substantial revisions to the way in which the disease is staged and classified.

The authors of the statement, led by writing committee chair and immediate past president of the Heart Failure Society of America Biykem Bozkurt, MD, PhD, hope their efforts will go far to improve standardization of terminology, but more importantly will facilitate better management of the disease in ways that keep pace with current knowledge and advances in the field.

"There is a great need for reframing and standardizing the terminology across societies and different stakeholders, and importantly for patients because a lot of the terminology we were using was understood by academicians, but were not being translated in important ways to ensure patients are being appropriately treated," said Bozkurt, of Baylor College of Medicine, Houston.

The consensus statement was a group effort led by the HFSA, the Heart Failure Association of the European Society of Cardiology, and the Japanese Heart Failure Society, with endorsements from the Canadian Heart Failure Society, the Heart Failure Association of India, the Cardiac Society of Australia and New Zealand, and the Chinese Heart Failure Association.

The article was published March 1 in the Journal of Cardiac Failure and the European Journal of Heart Failure, authored by a writing committee of 38 individuals with domain expertise in HF, cardiomyopathy, and cardiovascular disease.

"This is a very thorough and very carefully written document that I think will be helpful for clinicians because they've tapped into important changes in the field that have occurred over the past 10 years and that now allow us to do more for patients than we could before," Eugene Braunwald, MD, said in an interview.

Braunwald and Elliott M. Antman, MD, both from TIMI Study Group at Brigham and Women's Hospital and Harvard Medical School in Boston, wrote an editorial that accompanied the European Journal of Heart Failure article.

A New Universal Definition

"[Heart failure] is a clinical syndrome with symptoms and or signs caused by a structural and/or functional cardiac abnormality and corroborated by elevated natriuretic peptide levels and/or objective evidence of pulmonary or systemic congestion."

This proposed definition, said the authors, is designed to be contemporary and simple "but conceptually comprehensive, with near universal applicability, prognostic and therapeutic viability, and acceptable sensitivity and specificity."

Both left and right HF qualifies under this definition, said the authors, but conditions that result in marked volume overload, such as chronic kidney disease, which may present with signs and symptoms of HF, do not.

"Although some of these patients may have concomitant HF, these patients have a primary abnormality that may require a specific treatment beyond that for HF," said the consensus statement authors.

For his part, Douglas L. Mann, MD, is happy to see what he considers a more accurate and practical definition for heart failure.

"We've had some wacky definitions in heart failure that haven't made sense for 30 years, the principal of which is the definition of heart failure that says it's the inability of the heart to meet the metabolic demands of the body," Mann, of Washington University, St. Louis, said in an interview.

"I think this description was developed thinking about people with end-stage heart failure, but it makes no sense in clinical practice. Does it make sense to say about someone with New York Heart Association class I heart failure that their heart can't meet the metabolic demands of the body?" said Mann, who was not involved with the writing of the consensus statement.

Proposed Revised Stages of the HF Continuum

Overall, minimal changes have been made to the HF stages, with tweaks intended to enhance understanding and address the evolving role of biomarkers.

The authors proposed an approach to staging of HF:

  • At-risk for HF (stage A), for patients at risk for HF but without current or prior symptoms or signs of HF and without structural or biomarkers evidence of heart disease.

  • Pre-HF (stage B), for patients without current or prior symptoms or signs of HF, but evidence of structural heart disease or abnormal cardiac function, or elevated natriuretic peptide levels

  • HF (stage C), for patients with current or prior symptoms and/or signs of HF caused by a structural and/or functional cardiac abnormality.

  • Advanced HF (stage D), for patients with severe symptoms and/or signs of HF at rest, recurrent hospitalizations despite guideline-directed management and therapy (GDMT), refractory or intolerant to GDMT, requiring advanced therapies such as consideration for transplant, mechanical circulatory support, or palliative care.

One notable change to the staging scheme is stage B, which the authors have reframed as "pre-heart failure."

"Pre-cancer is a term widely understood and considered actionable and we wanted to tap into this successful messaging and embrace the pre-heart failure concept as something that is treatable and preventable," said Bozkurt.

"We want patients and clinicians to understand that there are things we can do to prevent heart failure, strategies we didn't have before, like SGLT2 inhibitors in patients with diabetes at risk for HF," she added.

The revision also avoids the stigma of HF before the symptoms are manifest.

"Not calling it stage A and stage B heart failure you might say is semantics, but it's important semantics," said Braunwald. "When you're talking to a patient or a relative and tell them they have stageA heart failure, it's scares them unnecessarily. They don't hear the stage A or B part, just the heart failure part."

New Classifications According to LVEF

And finally, in what some might consider the most obviously needed modification, the document proposes a new and revised classification of HF according to left ventricular ejection fraction (LVEF). Most agree on how to classify heart failure with reduced ejection fraction (HFrEF) and heart failure with preserved ejection fraction (HFpEF), but although the middle range has long been understood to be a clinically relevant, it has no proper name or clear delineation.

"For standardization across practice guidelines, to recognize clinical trajectories in HF, and to facilitate the recognition of different heart failure entities in a sensitive and specific manner that can guide therapy, we want to formalize the heart failure categories according to ejection fraction," said Bozkurt.

To this end, the authors propose the following four classifications of EF:

  • HF with reduced EF (HFrEF): LVEF of up to 40%.

  • HF with mildly reduced EF (HFmrEF): LVEF of 41-49%.

  • HF with preserved EF (HFpEF)HF with an LVEF of at least 50%.

  • HF with improved EF (HFimpEF): HF with a baseline LVEF of 40% or less, an increase of at least 10 points from baseline LVEF, and a second measurement of LVEF of greater than 40%.

HFmrEF is usually a transition period, noted Bozkurt. "Patients with AF in this range may represent a population whose EF is likely to change, either increase or decrease over time and it's important to be cognizant of that trajectory. Understanding where your patient is headed is crucial for prognosis and optimization of guideline-directed treatment," she said.

Improved, Not Recovered, HF

The last classification of heart failure with improved ejection fraction (HFimpEF) represents an important change to the current classification scheme.

"We want to clarify what terms to use but also which not to use. For example, we don't want people to use recovered heart failure or heart failure in remission, partly because we don't want the medication to be stopped. We don't want to give the false message that there has been full recovery," said Bozkurt.

As seen in the TRED-HF trial, guideline-directed medical therapy should be continued in patients with HF with improved EF regardless of whether it has improved to a normal range of above 50% in subsequent measurements.

"This is a distinct group of people, and for a while the guidelines were lumping them in with HFpEF, which I think is totally wrong," said Mann.

"I think it's very important that we emphasize heart failure as a continuum, rather than a one-way street of [inevitable] progression. Because we do see improvements in ejection fraction and we do see that we can prevent heart failure if we do the right things, and this should be reflected in the terminology we use," he added.

Bozkurt stressed that HFimpEF only applies if the EF improves to above 40%. A move from an EF of 10%-20% would still see the patient classified as having HFrEF, but a patient whose EF improved from, say, 30% to 45% would be classified as HFimpEF.

"The reason for this, again, is because a transition from, say an EF of 10%-20% does not change therapy, but a move upward over 40% might, especially regarding decisions for device therapies, so the trajectory as well as the absolute EF is important," she added.

"Particularly in the early stages, people are responsive to therapy and it's possible in some cases to reverse heart failure, so I think this change helps us understand when that's happened," said Braunwald.

One Step Toward Universality

"The implementation of this terminology and nomenclature into practice will require a variety of tactics," said Bozkurt. "For example, the current ICD 10 codes need to incorporate the at-risk and pre–heart failure categories, as well as the mid-range EF, preserved, and improved EF classifications, because the treatment differs between those three domains."

In terms of how these proposed changes will be worked into practice guidelines, Bozkurt declined to comment on this to avoid any perception of conflict of interest as she is the cochair of the American College of Cardiology/American Heart Association HF guideline writing committee.

Braunwald and Antman suggest it may be premature to call the new terminology and classifications "universal." In an interview, Braunwald lamented the absence of the World Heart Federation, the ACC, and the AHA as active participants in this effort and suggested this paper is only the first step of a multistep process that requires input from many stakeholders.

"It's important that these organizations be involved, not just to bless it, but to contribute their expertise to the process," he said.

For his part, Mann hopes these changes will gain widespread acceptance and clinical traction. "The problem sometimes with guidelines is that they're so data driven that you just can't come out and say the obvious, so making a position statement is a good first step. And they got good international representation on this, so I think these changes will be accepted in the next heart failure guidelines."

To encourage further discussion and acceptance, Robert J. Mentz, MD, and Anuradha Lala, MD, editor-in-chief and deputy editor of the Journal of Cardiac Failure, respectively, announced a series of multidisciplinary perspective pieces to be published in the journal monthly, starting in May with editorials from Clyde W Yancy, MD, MSc, and Carolyn S.P. Lam, MBBS, PhD, both of whom were authors of the consensus statement.

Bozkurt reports being a consultant for Abbott, Amgen, Baxter, Bristol Myers Squibb, Liva Nova Relypsa/Vifor Pharma, Respicardia, and being on the registry steering committee for Sanofi-Aventis. Braunwald reports research grant support through Brigham and Women's Hospital from AstraZeneca, Daiichi Sankyo, Merck, and Novartis; and consulting for Amgen, Boehringer-Ingelheim/Lilly, Cardurion, MyoKardia, Novo Nordisk, and Verve.

J Card Fail. Published online February 7, 2021. Abstract

This article originally appeared on MDEdge.com.

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