The SGLT2 inhibitor dapagliflozin scored a clear win in a randomized, controlled trial with more than 300 U.S. patients with heart failure with preserved ejection fraction (HFpEF), showing a significant and clinically meaningful benefit for the primary endpoint, a KCCQ measure of symptoms and physical limitations, after 12 weeks of treatment.
These results in the PRESERVED-HF study follow closely on the heals of the initial report from the EMPEROR-Preserved trial that showed a benefit from a different sodium-glucose cotransporter 2 (SGLT2) inhibitor, empagliflozin (Jardiance) in nearly 6,000 randomized patients for the primary endpoint of preventing cardiovascular death or hospitalizations for heart failure.
In PRESERVED-HF, patients with HFpEF who received a standard, once-daily dose of dapagliflozin (Farxiga) had an average 5.8-point improvement in their condition as measured by the Kansas City Cardiomyopathy Questionnaire clinical summary score (KCCQ-CS), the study’s primary endpoint.
This is “the first study to demonstrate that an SGLT2 inhibitor dapagliflozin significantly improves symptoms, physical limitations, and 6-minute walking distance in patients with HFpEF,” Mikhail N. Kosiborod, MD, reported at the annual scientific meeting of the Heart Failure Society of America. The secondary endpoint of 6-minute walking distance “has been very difficult to improve in many previous studies of other treatments” tested in patients with HFpEF, noted Kosiborod, a cardiologist and codirector of the Cardiometabolic Center of Excellence at Saint Luke’s Mid-America Heart Institute.
The results are “highly complementary” to the findings from large outcome trials, such as the findings from EMPEROR-Preserved, he said, and collectively the recent findings from these studies of SGLT2 inhibitors in patients with HFpEF identify drugs in this class as a “new treatment option” for patients with a disorder that until now had no treatment with unequivocally proven efficacy and safety.
‘Impressive and Unprecedented’ Findings
The findings are “really impressive and unprecedented,” said Milton Packer, MD, a cardiologist at Baylor University Medical Center in Dallas who was not involved in the study. “This is the largest KCCQ benefit ever seen in either patients with HFpEF or in patients with heart failure with reduced ejection fraction,” said Packer, one of the investigators who led the EMPEROR-Preserved trial.
PRESERVED-HF randomized 324 patients diagnosed with heart failure and with a left ventricular ejection fraction of 45% or higher at any of 26 U.S. centers, with 304 patients completing the planned final analysis after 12 weeks on treatment. Patients could be in New York Heart Association (NYHA) functional class II-IV, they had to have a baseline N-terminal pro-brain natriuretic peptide (NT-proBNP) level of at least 225 pg/mL (or higher if they also had atrial fibrillation), and they required at least one of three markers of established heart failure: recent hospitalization for heart failure or an urgent outpatient visit that required treatment with an IV diuretic, elevated filling pressure measured by left or right catheterization, or structural heart disease detected by echocardiography.
The average age of the enrolled patients was 70 years, and they had been diagnosed with heart failure for about 3 years; 57% were women, 30% were African American, and their median body mass index was 35 kg/m2. Roughly 42% had NYHA class III or IV disease, 56% had type 2 diabetes, their median estimated glomerular filtration rate was about 55 mL/min per 1.73 m2, their median KCCQ-CS score at baseline was about 62, and their average 6-minute walk distance was 244 m.
These and other features of the enrolled population define a distinctly U.S. patient population, stressed Kosiborod, professor of medicine at the University of Missouri–Kansas City.
“The patients we enrolled are the patients we see in U.S. clinical practice,” he said in an interview. Importantly, the patient profile of a median BMI of 35 kg/m2, a median KCCQ-CS score of 62 — “quite low,” noted Kosiborod — and having more than 40% of patients in NYHA functional class III defines a study population with a substantially greater burden of obesity, symptoms, and functional impairment compared with those enrolled in prior trials involving patients with HFpEF such as EMPEROR-Preserved.
Results Complement Findings From Larger Trials
PRESERVED-HF was an investigator-initiated study designed to inform clinical practice, not as a pivotal trial like EMPEROR-Preserved, which aims to gather evidence to support a new indication for regulatory approval. (On Sept. 9, 2021, the Food and Drug Administration granted empagliflozin “breakthrough therapy” status for treating HFpEF based on the EMPEROR-Preserved results, which will fast-track the agency’s decision on this indication.)
Kosiborod noted that he and his associates designed PRESERVED-HF with adequate patient numbers to power a statistically valid assessment of effect on KCCQ-CS score. While the new findings will not by themselves lead to a new indication for dapagliflozin to treat patients with HFpEF, they will potentially complement the pending results of another trial, DELIVER, by showing efficacy and safety in a uniquely U.S. patient population. DELIVER is a pivotal, global trial of dapagliflozin in more than 6,000 patients with HFpEF that’s on track to report findings in 2022.
Kosiborod also stressed that dapagliflozin has U.S.-approved indications for treating patients with type 2 diabetes, and for patients with chronic kidney disease, and that a majority of patients enrolled in PRESERVED-HF had one or both of these conditions. That makes the new findings especially compelling for patients with either type 2 diabetes or chronic kidney disease and HFpEF who are not already receiving an SGLT2 inhibitor.
Other findings that he reported showed a range of benefits consistent with the primary endpoint, including the KCCQ overall summary score, which also showed a significant 4.5-point average increase over placebo after 12 weeks. Analysis by the percentage of patients achieving at least a 5-point improvement in the KCCQ clinical summary score (the threshold for a clinically meaningful improvement) showed that about 45% of patients treated with dapagliflozin reached this mark compared with roughly 35% of patients in the placebo arm, indicating a number needed to treat of nine to have one additional patient achieve this threshold after 12 weeks. Average improvement in 6-minute walk distance was about 20 m with dapagliflozin compared with placebo.
No Heterogeneity of Effect by Baseline Ejection Fraction
Subgroup analyses showed no heterogeneity of response across 12 different ways of subdividing the study population, including age, sex, race, diabetes status, and BMI. The median left ventricular ejection fraction among enrolled patients was 60%, and the findings showed identical KCCQ improvements among patients with ejection fractions less than the median and those with an ejection fraction above the median.
This last finding was especially relevant because the EMPEROR-Preserved results showed a possible signal of heterogeneity by ejection fraction and an attenuated effect among patients with HFpEF and an ejection fraction above the 60%–65% range, although the certainty of this finding is currently controversial.
The impact of empagliflozin on KCCQ clinical summary score in EMPEROR-Preserved showed an average incremental improvement of 1.32 points compared with placebo, a significant difference, but more modest than the increment from dapagliflozin treatment seen in PRESERVED-HF. Kosiborod hypothesized that this difference might be mostly because of the different patient populations enrolled in the two studies.
Kosiborod noted that a report on the PRESERVED-HF results will soon appear in Nature Medicine.
PRESERVED-HF was funded by AstraZeneca, which markets dapagliflozin (Farxiga), but the trials’ design and conduct were independent of this funding source. Kosiborod has been a consultant to AstraZeneca and numerous other companies, and he has received research funding from AstraZeneca and Boehringer Ingelheim. Packer has had financial relationships with AstraZeneca and numerous other companies.
Heart Failure Society of America (HFSA) Annual Scientific Meeting 2021.
This article originally appeared on MDEdge.com.
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