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Heart failure specialist at the debated whether the role of ejection fraction calculations is relevant in the treatment of their patients.

Burkert Pieske, MD, of Charite University Medicine, Berlin, who took the "pro" position at the scheduled event, said, "Ejection fraction has become the single most important number in cardiology. We all know how to use it, how to apply it, and how to interpret it. It is part of our daily life. It can be obtained using any cardiac imaging device worldwide."

But Frank Ruschitzka, MD, of the University of Zurich's heart center, arguing the "con" side, was not so impressed. "Heart failure isn't a disease – it is hundreds of diseases," he said. "Ejection fraction was not developed through divine inspiration. It was developed so you could enrich your trial population at the time."

"Ejection fraction is an imprecise, arbitrary method of measuring disease in heart failure patients," he said. "But we do use a lot of arbitrary stuff and yet it is still helpful because we lack alternatives. And some of the alternatives mentioned are not ready yet for general use."

In the debate, Pieske leaned on the status quo. "Guidelines recommend the use of ejection fraction in classifying heart failure as a Class 1 indication. It is a reliable parameter. It is also used as a reliable predictor of survival. The lower the ejection fraction, the higher cardiovascular mortality is over time. It is a worldwide accepted risk predictor," he said.

"In the European guidelines of 2016, ejection fraction was used to differentiate heart failure phenotypes. Heart failure with reduced ejection fraction [HFrEF] below 40%; heart failure with preserved ejection fracture [HFpEF] – cutoff 50% and above, and then this in-between group from 40% to 49% of heart failure with mid-range ejection fraction [HFmrEF] where there is a relatively gray zone for what to do about treatment."

"In clinical trials, ejection fraction is one of the core factors in identifying patients who would do well on particular drugs. Without this measure, we cannot do heart failure trials, at the moment. Ejection fraction is the key measure to identify subsets of patients for specific therapies. It is also a cutoff number for devices such as implanted defibrillators that have a cutoff of 30% to 35% for use," he said.

Ruschitzka took issue with the gray area, suggesting this was where the use of ejection fraction failed heart failure patients. He argued that the accepted values for preserved ejection fraction are fraught with controversy. "I don't want to be told my ejection fraction is 50," making it part of the HFpEF universe. He noted that some trials consider HFpEF to be as low as 45% in clinical trials. That aura of uncertainty stains the acceptance of ejection fraction, he suggested.

"I think we could agree," Pieske said, "that ejection fraction stays, but we need additional measures to differentiate patients who may benefit from specific therapy. Do we need to enrich ejection fraction with other imaging parameters of cardiac structure and function, as well as underlying etiology and pathophysiology?"

He ticked off some of those measures: Speckle tracking or strain imaging; Doppler techniques; left ventricular volumes of remodeling index; peak power output to left ventricular mass; stroke volume index, and torsion, twist or untwist. "In my opinion, none of these are ready for prime time," he said.

Ruschitzka agreed, to an extent, but "we have to prospectively evaluate and test these other factors," he cautioned.

Debate moderator Mariell Jessup, MD, of the University of Pennsylvania and chief science and medical officer of the American Heart Association, offered a viewpoint of her own.

"The real question is not the ejection fraction that you start with, but how well the patients responds to therapy that is important," Jessup said. "If we knew that, we could triage the patients much more effectively. I don't think we have made a lot of progress in figuring out what is the response to therapy."

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