Rest dyspnea dims as acute heart failure treatment target

PARIS – During the most recent pharmaceutical generation, drug development for heart failure largely focused on acute heart failure, and specifically on patients with rest dyspnea as the primary manifestation of their acute heart failure decompensation events.

That has now changed, agreed heart failure experts as they debated the upshot of sobering results from two neutral trials that failed to show a midterm mortality benefit in patients hospitalized for acute heart failure who underwent aggressive management of their congestion using 2 days of intravenous treatment with either of two potent vasodilating drugs. Results first reported in November 2016 failed to show a survival benefit from ularitide in the 2,100-patient TRUE-AHF (Efficacy and Safety of Ularitide for the Treatment of Acute Decompensated Heart Failure) trial (N Engl J Med. 2017 May 18;376[20]:1956-64). And results reported at a meeting of the Heart Failure Association of the ESC failed to show a survival benefit from serelaxin in more than 6,500 acute heart failure patients in the RELAX-AHF-2 (Efficacy, Safety and Tolerability of Serelaxin When Added to Standard Therapy in AHF) trial.

The failure of a 2-day infusion of serelaxin to produce a significant reduction in cardiovascular death in RELAX-AHF-2 was especially surprising because the predecessor trial, RELAX-AHF, which randomized only 1,160 patients and used a surrogate endpoint of dyspnea improvement, had shown significant benefit that hinted more clinically meaningful benefits might also result from serelaxin treatment (Lancet. 2013 Jan 5;381[9860]:29-39). The disappointing serelaxin and ularitide results also culminate a series of studies using several different agents or procedures to treat acute decompensated heart failure patients that all failed to produce a reduction in deaths.

^{Frontline Medical News}

Dr. Frank Ruschitzka

“This is a sea change; make no mistake. We will need a more targeted, selective approach. It was always a daunting proposition to believe that short-term infusion could have an effect 6 months later. We were misled by the analogy [of acute heart failure] to acute coronary syndrome,” said Dr. Ruschitzka, professor of medicine at the University of Zürich.

The right time to intervene

Meeting attendees offered several hypotheses to explain why the acute ularitide and serelaxin trials both failed to show a mortality benefit, with timing of treatment the most common denominator.

Acute heart failure “is an event, not a disease,” declared Milton Packer, MD, lead investigator of TRUE-AHF, during a session devoted to vasodilator treatment of acute heart failure. Acute heart failure decompensations “are fluctuations in a chronic disease. It doesn’t matter what you do during the episode – it matters what you do between acute episodes. We focus all our attention on which vasodilator and which dose of Lasix [furosemide], but we send patients home on inadequate chronic therapy. It doesn’t matter what you do to the dyspnea, the shortness of breath will get better. Do we need a new drug that makes dyspnea go away an hour sooner and doesn’t cost a fortune? What really matters is what patients do between acute episodes and how to prevent them, ” said Dr. Packer, distinguished scholar in cardiovascular science at Baylor University Medical Center in Dallas.

Dr. Packer strongly urged clinicians to put heart failure patients on the full regimen of guideline-directed drugs and at full dosages, a step he thinks would go a long way toward preventing a majority of decompensation episodes. “Chronic heart failure treatment has improved dramatically, but implementation is abysmal,” he said.

^{Mitchel L. Zoler/Frontlione Medical News}

Dr. G. Michael Felker

Of course, at this phase of their disease heart failure patients are usually at home, which more or less demands that the treatments they take are oral or at least delivered by subcutaneous injection.

“We’ve had a mismatch of candidate drugs, which have mostly been IV infusions, with a clinical setting where an IV infusion is challenging to use.”

“We are killing good drugs by the way we’re testing them,” commented Javed Butler, MD, who bemoaned the ignominious outcome of serelaxin treatment in RELAX-AHF-2. “The available data show it makes no sense to treat for just 2 days. We should take true worsening heart failure patients, those who are truly failing standard treatment, and look at new chronic oral therapies to try on them.” Oral drugs similar to serelaxin and ularitide could be used chronically, suggested Dr. Butler, professor of medicine and chief of cardiology at Stony Brook (N.Y.) School of Medicine.

Wrong patients with the wrong presentation

Perhaps just as big a flaw of the acute heart failure trials has been their target patient population, patients with rest dyspnea at the time of admission. “Why do we think that dyspnea is a clinically relevant symptom for acute heart failure?” Dr. Packer asked.

^{Mitchel L. Zoler/Frontlione Medical News}

Dr. John G.F. Cleland

Dr. Cleland and his associates analyzed data on 116,752 hospitalizations for acute heart failure in England and Wales during April 2007–March 2013, a database that included more than 90% of hospitals for these regions. “We found that a large proportion of admitted patients did not have breathlessness at rest as their primary reason for seeking hospitalization. For about half the patients, moderate or severe peripheral edema was the main problem,” he reported. Roughly a third of patients had rest dyspnea as their main symptom.

An unadjusted analysis also showed a stronger link between peripheral edema and the rate of mortality during a median follow-up of about a year following hospitalization, compared with rest dyspnea. Compared with the lowest-risk subgroup, the patients with severe peripheral edema (18% of the population) had more than twice the mortality. In contrast, the patients with the most severe rest dyspnea and no evidence at all of peripheral edema, just 6% of the population, had a 50% higher mortality rate than the lowest-risk patients.

”It’s peripheral edema rather than breathlessness that is the important determinant of length of stay and prognosis. The disastrous neutral trials for acute heart failure have all targeted the breathless subset of patients. Maybe a reason for the failures has been that they’ve been treating a problem that does not exist. The trials have looked at the wrong patients,” Dr. Cleland said.

‘We’ve told the wrong story to industry” about the importance of rest dyspnea to acute heart failure patients. “When we say acute heart failure, we mean an ambulance and oxygen and the emergency department and rapid IV treatment. That’s breathlessness. Patients with peripheral edema usually get driven in and walk from the car to a wheelchair and they wait 4 hours to be seen. I think that, following the TRUE-AHF and RELAX-AHF-2 results, we’ll see a radical change.”

But just because the focus should be on peripheral edema rather than dyspnea, that doesn’t mean better drugs aren’t needed, Dr. Cleland added.

“We need better treatments to deal with congestion. Once a patient is congested, we are not very good at getting rid of it. We depend on diuretics, which we don’t use properly. Ultimately I’d like to see agents as adjuncts to diuretics, to produce better kidney function.” But treatments for breathlessness are decent as they now exist: furosemide plus oxygen. When a simple, cheap drug works 80% of the time, it is really hard to improve on that.” The real unmet needs for treating acute decompensated heart failure are patients with rest dyspnea who don’t respond to conventional treatment, and especially patients with gross peripheral edema plus low blood pressure and renal dysfunction for whom no good treatments have been developed, Dr. Cleland said.

Another flaw in the patient selection criteria for the acute heart failure studies has been the focus on patients with elevated blood pressures, the logical target for vasodilator drugs that lower blood pressure, noted Dr. Felker. “But these are the patients at lowest risk. We’ve had a mismatch between the patients with the biggest need and the patients we actually study, which relates to the types of drugs we’ve developed.”

Acute heart failure remains a target

Despite all the talk of refocusing attention on chronic heart failure and peripheral edema, at least one expert remained steadfast in talking up the importance of new acute interventions.

^{Mitchel L. Zoler/Frontlione Medical News}

Dr. Milton Packer (left) and Dr. Alexandre Mebazaa

Part of the problem in believing that existing treatments can adequately manage heart failure and prevent acute decompensations is that about 75% of acute heart failure episodes either occur as the first presentation of heart failure, or occur in patients with heart failure with preserved ejection fraction (HFpEF), a type of heart failure that, until recently, had no chronic drug regimens with widely acknowledged efficacy for HFpEF. (The 2017 U.S. heart failure management guidelines update listed aldosterone receptor antagonists as a class IIb recommendation for treating HFpEF, the first time guidelines have sanctioned a drug class for treating HFpEF [Circulation. 2017 Apr 28. doi: 10.1161/CIR.0000000000000509].)

“For patients with heart failure with reduced ejection fraction, you can give optimal treatments and [decompensations] are prevented,” noted Dr. Mebazaa, a professor of anesthesiology and resuscitation at Lariboisière Hospital in Paris. “But for the huge number of HFpEF patients we have nothing. Acute heart failure will remain prevalent, and we still don’t have the right drugs to use on these patients.”

The TRUE-AHF trial was sponsored by Cardiorentis. RELAX-AHF-2 was sponsored by Novartis. Dr. Ruschitzka has been a speaker on behalf of Novartis, and has been a speaker for or consultant to several companies and was a coinvestigator for TRUE-AHF and received fees from Cardiorentis for his participation. Dr. Packer is a consultant to and stockholder in Cardiorentis and has been a consultant to several other companies. Dr. Felker has been a consultant to Novartis and several other companies and was a coinvestigator on RELAX-AHF-2. Dr. Butler has been a consultant to several companies. Dr. Cleland has received research support from Novartis, and he has been a consultant to and received research support from several other companies. Dr. Mebazaa has received honoraria from Novartis and Cardiorentis as well as from several other companies and was a coinvestigator on TRUE-AHF.

mzoler@frontlinemedcom.com

On Twitter @mitchelzoler