Conference Coverage

Empagliflozin failed to improve exercise capacity in heart failure



Empagliflozin showed favorable effects on diuretic use and congestion symptoms in patients with heart failure with reduced ejection fraction (HFrEF), but the oral sodium glucose cotransporter 2 (SGLT2) inhibitor did not improve the primary endpoint of improved exercise capacity in the EMPERIAL-Reduced trial, investigators reported at the European Society of Cardiology Heart Failure Discoveries virtual meeting.

Dr. William T. Abraham

In the matching EMPERIAL-Preserved trial, conducted in patients with heart failure with preserved ejection fraction (HFpEF), empagliflozin (Jardiance) produced modest improvements in diuretic use, as well as a reduction in unscheduled outpatient visits, compared with placebo-treated controls, although these trends failed to achieve statistical significance. And as in the EMPERIAL-Reduced trial, the SGLT2 inhibitor didn’t move the needle at all on the primary endpoint of improved exercise capacity as measured by 6-minute hall walk distance.

EMPERIAL-Reduced and -Preserved were identically designed, concurrent, phase 3, double-blind, 12-week randomized trials of empagliflozin versus placebo in 312 patients with HFrEF and 315 with HFpEF, defined in EMPERIAL-preserved as a left ventricular ejection fraction above 40%. The majority of participants had type 2 diabetes.

From a baseline median 6-minute walk distance of about 300 meters, the 6-minute walk distance at week 12 was actually 4.0 meters worse in the empagliflozin-treated HFrEF patients than it was in controls and a mere 4.0 meters better than with placebo in empagliflozin-treated patients with HFpEF, reported William T. Abraham, MD, professor of medicine, director of the division of cardiovascular medicine, and associate dean at Ohio State University, Columbus.

He indicated that the audience shouldn’t make too much of the failure to achieve the primary endpoint in the two trials in light of the studies’ major limitations: namely, their relatively small size for purposes of evaluating clinical outcomes and the relatively short 12-week duration.

“In many ways, I would say it’s remarkable that we can observe a positive signal, a favorable signal, in outcomes around congestion. In the case of HFrEF it’s statistically significant, and in HFpEF it’s a trend towards improvement. Of course, there are larger trials ongoing that may confirm these observations. Hopefully the EMPERIAL trials predict a good outcome for those ongoing trials,” Dr. Abraham said.

Piotr Ponikowski, MD, presented the study results for the secondary outcomes of congestion symptoms, diuretic use, and utilization of health care resources. In EMPERIAL-Reduced, intensification of diuretic therapy – often a prelude to acute decompensation and a trip to the hospital – occurred at a rate of 4.5% with empagliflozin and 16.1% with placebo, for a highly significant 73% relative risk reduction. Intensification of loop diuretics occurred in 2.6% of the empagliflozin group and 14.2% of controls, for a 82% risk reduction.

Dr. Piotr Ponikowski

“That’s a pretty significant effect,” observed Dr. Ponikowski, professor of cardiology and head of the department of heart diseases at the Medical University of Wroclaw (Poland).

Moreover, a congestion symptoms score comprising a summary of orthopnea, jugular veinous distention, and edema improved by 47% after 12 weeks on empagliflozin, a statistically significant and clinically meaningful improvement that grew in magnitude over time and at 12 weeks was twice as large, compared with the reduction in placebo group, he added.

There was a trend for fewer unscheduled outpatient visits in the empagliflozin arm of EMPERIAL-Reduced with a rate of 10.4%, compared with 25.8% in controls; however, this 26% reduction in relative risk did not achieve statistical significance.

Intensification of loop diuretics occurred in 9% of EMPERIAL-Preserved participants on empagliflozin and 13.5% on placebo, but this 34% reduction in risk didn’t reach significance.

Adverse events in the EMPERIAL trials were similar across the active treatment and placebo arms. The benign safety profile was similar to what was seen in the earlier major clinical trials of empagliflozin for treatment of type 2 diabetes.

Session chair Stephane Heymans, MD, PhD, of the University of Maastricht (the Netherlands) noted that a substantial minority of patients in EMPERIAL-Reduced were on the combined neprilysin inhibitor sacubitril and the angiotensin receptor blocker valsartan (Entresto), whereas far fewer were in EMPERIAL-Preserved. He wondered if this greater use of background sacubitril/valsartan could explain empagliflozin’s greater efficacy in EMPERIAL-Reduced.

Highly unlikely, according to the investigators.

“It looks like, as is the case with most of our heart failure therapies, that we do see incremental value here. If you met the criteria for these trials, it appears you derived benefit from empagliflozin regardless of whether you were on an angiotensin receptor neprilysin inhibitor or not. I think that speaks to the incremental benefit of SGLT2 inhibitors on top of current guideline-directed medical therapy,” Dr. Abraham said.

Dr. Ponikowski observed that the same point was underscored in the DAPA-HF trial of the SGLT2 inhibitor dapagliflozin (Farxiga) in patients with heart failure (DAPA-HF: N Engl J Med. 2019 Nov 21;381[21]:1995-2008).

“You’ll see that the mortality and morbidity and quality-of-life benefit is in those treated with dapagliflozin with or without angiotensin receptor neprilysin inhibition; so, regardless of background therapy. And the effect is especially clear in patients on both therapies,” the cardiologist said.

The EMPERIAL trials were sponsored by Boehringer Ingelheim. Dr. Abraham and Dr. Ponikowksi reported receiving consultant fees from the company for serving on the trials’ executive committee.

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