NEW ORLEANS – Treatment of patients with heart failure with preserved ejection fraction (HFpEF) with the SGLT2 inhibitor dapagliflozin (Farxiga) for 24 weeks produced significant and beneficial reductions in left-heart filling pressures in a mechanistic, randomized clinical study.
The findings "provide new insight into the mechanisms underlying the favorable clinical effects of dapagliflozin in patients with HFpEF," Barry A. Borlaug, MD, said at the joint scientific sessions of the American College of Cardiology and the World Heart Federation. "Elevations in left heart filling pressures at rest and during exercise are fundamental pathophysiologic features of HFpEF," he noted.
Results from prior studies documented the benefit of dapagliflozin for improving clinical outcomes in patients with HFpEF in the DELIVER trial, and for the related sodium-glucose cotransporter 2 (SGLT2) inhibitor empagliflozin (Jardiance) in the EMPEROR-Preserved trial. The new findings presented by Dr. Borlaug provide evidence from a placebo-controlled, prospective study for one way by which these SGLT2 inhibitors exert this benefit in patients with HFpEF.
The results of his single-center study showed that, in patients with HFpEF who also exhibited "severe" elevations in pulmonary capillary wedge pressure (PCWP) during exercise, 24 weeks of treatment with dapagliflozin led to a significant reduction in PCWP during exercise. The treatment produced an average 6.1–mm Hg drop from baseline compared with control patients who received placebo. A similar pattern occurred when these patients were at rest, when dapagliflozin treatment linked with a significant average reduction in PCWP from baseline of 3.5 mm Hg compared with controls.
Improving a 'specific and fundamental' feature of HFpEF
"This fantastic study looked at one of the fundamental aspects of HFpEF," said John R. Teerlink, MD, designated discussant for the study. "You've shown that dapagliflozin targets a specific and fundamental" manifestation of HFpEF by lowering PCWP, said Dr. Teerlink, director of Heart Failure at the San Francisco Veterans Affairs Medical Center.
However, Dr. Teerlink added, the study did not directly address the related question of what physiologic action of dapagliflozin produces this notable drop in PCWP.
"We're just starting to look at that," replied Dr. Borlaug, a cardiologist and professor at the Mayo Clinic in Rochester, Minn.
He reported finding an intriguing correlate in the current study linked to the cut in PCWP with dapagliflozin treatment. The SGLT2 inhibitor at a standard daily 10-mg dose produced an average 3.5-kg drop in body weight in the dapagliflozin-treated patients that significantly linked with the changes in PCWP both at rest and during exercise. Dapagliflozin-treated patients also showed a significant reduction from their baseline plasma volume compared with placebo-treated patients, but this "poorly correlated" with the dapagliflozin-linked cuts in PCWP, Dr. Borlaug said.
"I don't think this means weight loss is the cause of the hemodynamic benefit, but maybe it's an indicator. When patients [with HFpEF] lose weight, they are in a metabolic state that leads to good changes in hemodynamics," he suggested. "My guess is that there is probably a combination of many different little things [caused by dapagliflozin treatment of patients with HFpEF] that together result in the 20%-25% relative improvement we see in filling pressure."
An 'obese, cardiometabolic' HFpEF phenotype
The study enrolled patients with HFpEF and a left ventricular ejection fraction of at least 50%, a New York Heart Association functional class of 2 or 3, and a PCWP during exercise of at least 25 mm Hg. Of the 37 evaluable patients, about two-thirds of the patients were women, more than two-thirds were in functional class 3, about 70% were obese, and their average ejection fraction was about 62%. The study excluded patients with HFpEF who also had type 1 diabetes, cardiomyopathy, pericardial disease, or other causes of dyspnea or heart failure.
Dr. Teerlink asked about the generalizability of the findings, as the study cohort seemed to differ in certain respects from the patients enrolled in the DELIVER trial, and because of the many apparently distinct patient phenotypes that exist within the scope of HFpEF.
An "obese, cardiometabolic phenotype" predominated the study cohort, Dr. Borlaug said. "The patients we enrolled look like the HFpEF patients seen in U.S. clinics." However, he added that "in reality, many [HFpEF phenotypes] coexist in one patient. It's not that simple," that every patient with HFpEF can be categorized into a single HFpEF phenotype.
The researchers monitored PCWP invasively with high-fidelity micromanometer catheters.
The study was sponsored by AstraZeneca, the company that markets dapagliflozin (Farxiga). Dr. Borlaug has received research funding from AstraZeneca, as well as from Corvia, GlaxoSmithKline, Medtronic, Mesoblast, Novo Nordisk, and Tenax. Dr. Teerlink has had financial relationships with AstraZeneca, as well as with Amgen, Bayer, Boehringer Ingelheim, Bristol Myers Squibb, Cytokinetics, Medtronic, Merck, Novartis, Servier, and Windtree Therapeutics.
This article originally appeared on MDedge.com, part of the Medscape Professional Network.
Lead image: Sebastian Kaulitzki/Dreamstime
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Cite this: Dapagliflozin's HFpEF Benefit Tied to Lower Filling Pressure - Medscape - Mar 23, 2023.