Patiromer Use Could Help Heart Failure Patients Stay on Optimized RAASi Therapy

Javed Butler, MD

Data from the DIAMOND trial suggest use of patiromer (Veltassa) could help patients maintain optimized heart failure therapy, even if they have a history of hyperkalemia.

Presented at the American College of Cardiology’s 71st Annual Scientific Sessions, results of the phase 3b trial suggest use of patiromer was associated with a significant reduction in blood potassium levels among patients taking RAASi medications for heart failure.

“On the basis of these results, unless accessibility or affordability of medications is an issue, there’s no good reason not to use potassium binders to optimize heart failure medical therapy,” said Javed Butler, MD, MPH, MBA, president of Baylor, Scott & White Research Institute in Texas and distinguished professor of medicine at the University of Mississippi, in a statement from the ACC. “For cases where hyperkalemia is the dominant reason for not giving guideline-directed RAASi therapy, I think what we are achieving with patiromer is an enablement strategy to allow patients to get appropriate RAASi therapy while simultaneously lowering the risk of hyperkalemia.”

Although RAASi therapy carries a class 1 level of recommendation for us in patients with heart failure, patients with a history of or current hyperkalemia often have RAASi therapy discontinued or down titrated. With this in mind, investigators sought to assess whether treatment with patiromer, which is a novel potassium binder from Vifor Pharma, was associated with a lowering of serum potassium levels.

Led by Butler, the trial enrolled hyperkalemic and normokalemic patients with a history of hyperkalemia leading to RAASi reduction or discontinuation. Patients underwent a single-0blinded run-in phase that last ed up to 12 weeks. During this time period, patients were initiated on patiromer, had ACE/ARB/ARNi therapy optimized, and were initiated on or had MRA therapy optimized. In the treatment phase, patients were randomized to continued patiromer or placebo therapy.

Overall, 1194 patients entered the run-in phase and 878 underwent randomization, with 439 patients randomized to patiromer and 439 randomized to placebo therapy. The study cohort had a mean age of 66.9±10 years, 27% were women, a median follow-up of 266.6 days, and a mean ejection fraction at baseline was 33.5%. Of the 439 patients in each arm, 360 randomized to patiromer and 367 randomized to placebo therapy completed the study treatment.

The primary endpoint of interest for the study was the adjusted mean change in serum potassium levels to the end of the study period. Secondary endpoints included time to first event of hyperkalemia, time to reduction of MRA dose below the 50 mg target, investigator-reported adverse events of hyperkalemia, and win-ratio for morbidity and mortality adjusted hyperkalemia. Of note, hyperemia incidence was defined as a level above 5.5 mEq/L and investigators assessed both first and total events of hyperkalemia.

Upon analysis, results of the study suggested there was a between-group difference in serum potassium levels of -0.10 mEq/L (95% CI, -0.13 to -0.07) favoring patiromer. In adjusted models, the mean change from randomization to end of study among the placebo arm was 0.13 (95% CI, 0.09-0.16) and 0.03 (95% CI, -0.01 to 0.07). Analysis of secondary end points demonstrated use of patiromer was associated with a reduction in risk of hyperkalemia (HR, 0.63 [95% CI, 0.45 to 0.87]; P=.006) and a reduction in risk of total hyperkalemic events (HR, 0.66 [95% CI, 0.53-0.81]; P <.001).

“These results are further evidence for the use of potassium binders to optimize heart failure medical therapy”, added Butler, in a statement from Vifor Pharma, the study’s sponsor. “RAASi offers significant survival benefits for these patients, but due to risk of hyperkalemia these therapies are unfortunately underutilized in practice. For cases where hyperkalemia is the dominant reason for not giving guideline-directed RAASi therapy, Veltassa can be an enablement strategy to allow patients to get optimized RAASi therapy while simultaneously lowering the risk of hyperkalemia”.

This study, “Patiromer For The Management Of Hyperkalemia In Subjects Receiving Renin-Angiotensin-Aldosterone System Inhibitors For Heart Failure With Reduced Ejection Fraction,” was presented at ACC.22.