DAPAgliflozin for Renal protection in Heart Transplant recipients. Rationale and design of the randomized controlled DAPARHT trial

Background and aims: Heart transplantation is the preferred treatment for selected patients with end stage heart failure. Kidney function often declines after heart transplantation. Sodium-glucose cotransporter 2 inhibitors (SGLT2i) slow the decline in eGFR in different populations. However, the effect of SGLT2i on kidney function in heart transplant recipients is unknown. Methods: The Dapagliflozin for Renal protection in Heart Transplant recipients (DAPARHT) trial is an investigator initiated, double blind, randomized, placebo-controlled trial designed to assess dapagliflozin's effect on kidney function in heart transplant recipients. Adults heart transplanted at least one year prior to randomization are eligible. Exclusion criteria include an estimated glomerular filtration rate (eGFR) <25 mL/min/1.73 m², diabetes type I, and contraindication to study medication. Four hundred and thirty patients will be randomized 1:1 to receive 12 months blinded treatment with dapagliflozin 10 mg o.d. or placebo, followed by 24-months open-label treatment. The primary endpoint is the chronic slope of the eGFR from two weeks to 12 months after starting randomized treatment. The open-label phase evaluates dapagliflozin's long-term effects on kidney function, clinical outcomes, safety, and tolerability. Enrolment began in June 2022. As of December 18, 2024, 300 patients were enrolled. The mean baseline creatinine was 104 ± 28 µmol/L with corresponding eGFR of 66 ± 22 mL/min/1.73 m². Estimated last patient visit is in September, 2028. Conclusion: The DAPARHT trial will test whether dapagliflozin improves eGFR slope compared to placebo during one year of follow-up, providing the first randomized evidence of the efficacy of SGLT2i in heart transplant recipients. Trial Registration: Dapagliflozin for Renal protection in Heart Transplant recipients (DAPARHT), NCT05321706, clinicaltrials.gov.