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Donor-Derived Cell-Free DNA as a Prognostic Biomarker After Heart Transplantation: The DEFINE-HT Study
Palak Shah1, Paul J Kim2, Kelly H Schlendorf3
1Inova Schar Heart and Vascular Institute, Falls Church, Virginia, USA.
Insights
Donor-derived cell-free DNA (dd-cfDNA) shows promise as a noninvasive biomarker for predicting adverse outcomes after heart transplantation. Elevated dd-cfDNA levels significantly increase the risk of treated rejection, graft dysfunction, or death within one year.
Area of Science:
- Cardiology
- Transplantation Immunology
- Molecular Diagnostics
Background:
- Donor-derived cell-free DNA fraction (dd-cfDNA%) and donor quantity score (DQS) are emerging noninvasive biomarkers for acute rejection in heart transplantation (HT).
- The prognostic capability of these biomarkers beyond traditional histopathology requires further investigation.
Purpose of the Study:
- To assess the association between donor-derived cell-free DNA (dd-cfDNA) levels and significant clinical outcomes in heart transplant recipients.
- The study evaluated a composite endpoint including treated rejection, graft dysfunction, retransplantation, or death within one year post-HT.
Main Methods:
- A prospective, observational study (DEFINE-HT) followed 110 adult heart transplant recipients for one year.
- Blood samples were collected for dd-cfDNA testing (Prospera Heart) during routine surveillance and for-cause evaluations.
- Time-varying Andersen-Gill models were used to analyze the relationship between dd-cfDNA and clinical events.
Main Results:
- 34.5% of patients experienced the composite endpoint, with treated rejection being the most common event (20%).
- Elevated dd-cfDNA% and DQS were significantly associated with treated rejection.
- Increases in dd-cfDNA% and DQS were linked to a higher risk of the composite endpoint (19% and 12% increased risk per SD increase, respectively).
- Above-threshold dd-cfDNA levels conferred a 4.42-fold increased risk of the composite endpoint.
Conclusions:
- The DEFINE-HT study suggests that dd-cfDNA can serve as a valuable prognostic biomarker for graft health in heart transplantation.
- Findings support the potential for dd-cfDNA monitoring to guide clinical management and inform future randomized trials comparing it with biopsy-based strategies.
Background:
Measurement of donor-derived cell-free DNA fraction (dd-cfDNA%) and donor quantity score (DQS) is a noninvasive biomarker of acute rejection in heart transplantation (HT). Its prognostic value beyond histopathology remains uncertain.
Objectives:
This study sought to evaluate associations between donor-derived cell-free DNA (dd-cfDNA) and clinically meaningful outcomes using a composite endpoint of treated rejection, graft dysfunction, retransplantation, or death within 1 year post-HT.
Methods:
The DEFINE-HT (Development of Noninvasive Cell-free DNA to Supplant Invasive Biopsy in Heart Transplantation) was a prospective, observational study following adult HT recipients at 10 U.S. centers for 1-year post-HT; blood was collected for dd-cfDNA testing (Prospera Heart) during surveillance and for-cause evaluations, independent of clinical decision-making. Treated rejection included biopsy-positive or biopsy-negative rejection requiring augmented immunomodulation. Graft dysfunction was defined as >10% decline in left ventricular ejection fraction from baseline to <50%. Time-varying Andersen-Gill models assessed associations between dd-cfDNA and events.
Results:
Among 110 patients (median age 55 years, 25.5% female, 22% Black), 38 (34.5%) met the primary composite endpoint: treated rejection (20%), graft dysfunction (10.9%), death (3.6%), and retransplantation (0%). Furthermore, 4.6% of endomyocardial biopsies demonstrated rejection and 90% of dd-cfDNA results were below threshold. dd-cfDNA% and DQS were higher in treated vs untreated biopsy-positive rejection (0.23% vs 0.085%; P = 0.045, and 27 vs 9 copies/mL; P = 0.012, respectively). No patients with graft dysfunction had biopsy-positive rejection despite elevated dd-cfDNA. One-intrapatient-SD increases in dd-cfDNA% and DQS were associated with 19% and 12% higher risk of the primary endpoint (P < 0.001). Above-threshold dd-cfDNA levels also conferred 4.42-fold increased risk of the composite endpoint (P < 0.001).
Conclusions:
DEFINE-HT supports the potential role of dd-cfDNA as a prognostic biomarker of graft health and informs a randomized trial comparing dd-cfDNA and biopsy-based monitoring. (Development of Noninvasive Cell-free DNA to Supplant Invasive Biopsy in Heart Transplantation [DEFINE-HT]; NCT05309382).
