Economic Evaluation of Patiromer in Patients with Concomitant Heart Failure and Chronic Kidney Disease in Italy

Background: Hyperkalaemia (HK), in patients with heart failure (HF) with and without chronic kidney disease (CKD), is potentially life-threatening. Risk of HK is further heightened in those patients receiving renin–angiotensin–aldosterone system inhibitors (RAASi), used to reduce cardiovascular morbidity and mortality in HF. Patiromer, an oral potassium (K+) binder, has been shown to reduce the risk of HK and enable optimal RAASi dosing. We evaluated the cost-effectiveness of patiromer in HF patients with CKD in the Italian setting, utilising results from the recent DIAMOND clinical trial, which assessed long-term use of patiromer in HK management. Methods: An established Markov model was adapted to include data from DIAMOND using the National Health Service (NHS) perspective. In DIAMOND, patients received patiromer during a run-in period (up to 12 weeks) to achieve optimal RAASi without HK. However, this led to low mean K+ concentrations in the placebo arm, resulting from a legacy effect of patiromer in the run-in phase of the trial. Therefore, the DIAMOND population was adjusted to a real-world population to better represent the K+ levels in the standard of care (SoC) arm. Mean K+ concentration for baseline and the patiromer arm was calculated from the overall population at baseline (screening phase) and after treatment (end of run-in period), respectively. Lifetime trajectories were estimated for quality-adjusted life years (QALYs), life years (LYs) and costs. Results: The economic evaluation model calculated a discounted total average cost per patient of €109,900 for patiromer and €64,847 for SoC. Patiromer generated a gain of 1.97 LYs (1.55 QALYs) compared with SoC. The incremental cost-effectiveness ratio (ICER) for patiromer was €29,060/QALY gained versus SoC. Conclusion: Applying DIAMOND data, patiromer is deemed to be cost-effective at a willingness-to pay threshold of €40,000 per QALY gained in Italy.