A new study suggests that patients assigned to finerenone are more likely to experience an initial decline in estimated glomerular filtration rate (eGFR) between randomization and one month compared to placebo. The paper’s authors concluded that while an initial decline in eGFR was associated with worse subsequent outcomes in patients assigned to placebo, this association was not as strong in those assigned to finerenone. Discussing their findings in the January 21 issue of the Journal of the American College of Cardiology, the research team added, “An early decline in eGFR can be anticipated with finerenone and should not automatically lead to the discontinuation of finerenone, as with other effective treatments in patients with heart failure (HF). “This conclusion highlights the potential benefits of continuing finerenone despite early kidney function changes, emphasizing its role as a disease-modifying therapy.” FINEARTS-HF trial Led by Shingo Matsumoto, MD, PhD, from the University of Glasgow in the UK, the team undertook a prespecified analysis of the Bayer-sponsored Finerenone Trial to Investigate Efficacy and Safety Superior to Placebo in Patients with Heart Failure (FINEARTS-HF). Drawing data obtained from 5,587 patients who had an eGFR measurement at both baseline and 1 month, the team found 1,018 (18.2%) had experienced a ≥15% decline in eGFR. The proportion of patients experiencing a ≥15% decline in eGFR was 23.0% with finerenone and 13.4% with placebo (odds ratio [OR]: 1.95; 95% confidence interval [CI]: 1.69-2.24; P<0.001). After adjustment, an eGFR decline was associated with a higher risk of the primary outcome in patients assigned to placebo (adjusted rate ratio: 1.50; 95% CI: 1.20-1.89) versus those assigned to finerenone (adjusted rate ratio: 1.07; 95% CI: 0.84-1.35; Pinteraction= 0.04). By contrast, the efficacy of finerenone was consistent across the range of change in eGFR from baseline to 1 month (Pinteraction=0.50 for percent change in eGFR), and safety, including hyperkalemia, was similar regardless of an early eGFR decline. “Although an initial decline in eGFR was common in patients started on finerenone, the mean decrease between baseline to 1 month was small...supporting the suggestion of a similar underlying mechanism reflecting changes in glomerular hemodynamics",” the paper’s authors suggested. Common occurrence Kevin Damman, MD, PhD, from University Medical Center Groningen in the Netherlands highlighted the common occurrence of early declines in kidney function (pseudo-worsening renal function) that accompanied HF therapies. Citing mineralocorticoid receptor antagonist (MRAs) and sodium-glucose cotransporter 2 (SGLT2) inhibitors as examples, Dr Damman added that the observation was not necessarily indicative of poor clinical outcomes. “We have gotten to know this phenomenon as pseudo worsening renal function... in many studies this decline has not been associated with a higher risk of adverse events compared with patients that had the same worsening of GFR while randomized to placebo,” he said in his editorial commentary, which was also published Monday online alongside the paper. Dr. Damman also pointed out that, while finerenone led to a measurable early decline in eGFR, the decline did not diminish its therapeutic benefits in preventing HF events and cardiovascular deaths. Hemodynamic changes Commenting on any possible mechanism and comparisons with other therapies, Dr. Damman suggested that the decline in eGFR seen with finerenone was likely hemodynamic. This observation was similar to changes observed with angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs) and differs from the attenuation of long-term renal decline seen with SGLT2 inhibitors. "The early decline in eGFR is followed by a slow decline in eGFR that is similar to that observed in placebo," said Dr. Damman. Commenting on the implications of these findings both for monitoring and patient management, the editorial commentary highlighted that whilst early decline in eGFR was not harmful, clinicians must monitor for significant kidney function changes and hyperkalemia to ensure the continued benefit of therapy. "We need to monitor for substantial decline in eGFR and associated hyperkalemia... the standard approach should be to continue and/or up titrate MRA therapy because these drugs have now convincingly been shown to improve important clinical outcomes,” the editorialists wrote. Study methodology The FINEARTS-HF trial was a randomized and double-blind investigation in which participants were randomly assigned to receive either finerenone or a placebo. Overall, 5,587 patients had an eGFR measurement both at baseline and 1 month and were included in this analysis. Here 1,018 (18.2%) patients (72.9 ±9.5 years of which 535 (52.6%) were male) experienced a ≥15% decline in eGFR. Participants were followed for an average of 32 months to track heart failure events, cardiovascular deaths, and any side effects, including hyperkalemia. The primary outcomes were the composite of total HF events and cardiovascular death. Sources: Matsumoto S, Jhund PS, Henderson AD, et al. Initial Decline in Glomerular Filtration Rate With Finerenone in HFmrEF/HFpEF: A Prespecified Analysis of FINEARTS-HF. J Am Coll Cardiol. 2025;85:173–185. Damman K. When Kidney Function Declines But Therapy Still Works. The Case for Nonsteroidal MRA Therapy in Heart Failure. J Am Coll Cardiol. 2025;85:186–189. Image credit: SewcreamStudio – stock.adobe.com