More than half of the nearly 6,000 patients with heart failure and HFpEF enrolled in EMPEROR-Preserved had CKD (although renal function was not an enrollment criterion), including 10% with an estimated glomerular filtration rate (eGFR) that fell in the range of 20-29 mL/min/1.73 m2, which categorized them as having stage 4 CKD.
The results showed, in a prespecified analysis, that treatment with empagliflozin led to a consistent, significant relative risk reduction compared with placebo in the primary endpoint of cardiovascular death or hospitalization for heart failure “across the full spectrum of kidney function, down to an eGFR of 20 mL/min/1.73m2,” said Faiez Zannad, MD, PhD, who presented the findings at the annual meeting of the American Society of Nephrology.
Among the 46.5% of enrolled patients without CKD, empagliflozin produced a significant 20% drop in the primary outcome relative to those who received placebo. Among the 53.5% of patients with CKD at time of randomization (defined as an eGFR <60 mL/min/1/73 m2 or a urinary albumin to creatinine ratio >300 mg/g), treatment with empagliflozin was associated with a significant 25% cut in the primary endpoint compared with placebo.
Empagliflozin was also “well tolerated” by patients with HFpEF, whether or not they also had CKD, “including patients with severely impaired kidney function,” said Dr. Zannad, a professor of cardiology therapeutics at the University of Lorraine in Nancy, France, at the virtual meeting.
An end to ‘renalism’
“This is a nail in the coffin for the concept of ‘renalism,’” the erroneous notion held by many clinicians and researchers that various treatments are not as effective and potentially more likely to cause adverse effects in patients with CKD compared with those with better renal function, commented Janani Rangaswami, MD, a nephrologist who is a professor and director of the cardiorenal program at George Washington University, Washington, D.C.
In addition to EMPEROR-Preserved, other large trials of agents from the SGLT2 inhibitor class bucked the premise of renalism and took the “groundbreaking step” of enrolling patients with moderate-severe CKD, noted Dr. Rangaswami in an interview. In particular, two trials took this approach when enrolling patients with heart failure with reduced ejection fraction (HFrEF), EMPEROR-Reduced (which also tested empagliflozin and matched the design of EMPEROR-Preserved) and DAPA-HF (which tested the SGLT2 inhibitor dapagliflozin [Farxiga, AstraZeneca]).
“It was a huge, bold step, especially in EMPEROR-Preserved and in EMPEROR-Reduced, which both enrolled patients with eGFRs as low as 20 mL/min/1.73m2,” Dr. Rangaswami said. DAPA-HF included patients with eGFRs as low as 30 mL/min/1.73m2.
EMPEROR-Reduced and DAPA-HF – published earlier this year – both had similar findings as EMPEROR-Preserved as reported by Dr. Zannad: consistent benefit from empagliflozin or dapagliflozin regardless of eGFR level and no signal of increased adverse events from treatment.
In fact, all three analyses show that patients with worse renal function had the highest risk for cardiovascular death and hospitalization for heart failure; hence, the beneficial impact from SGLT2 inhibitors is greatest in these patients.
These observations “make it easier to focus on the group with moderate-to-severe CKD,” both in the routine care setting as well as in future trials, said Dr. Rangaswami.
“This is a welcome trend that paves the way to test more treatments in patients with stage 4 and even stage 5 CKD, patients ... excluded from trials in the past,” she said.
In addition, the consistent benefit from SGLT2 inhibitors in these three heart failure trials regardless of CKD “means there is simply no room for renalism. There is no room for clinicians to say that because a patient’s eGFR is 30 mL/min/1.73m2 they are worried about starting an SGLT2 inhibitor,” she stressed.