CARdiac Imaging and BIomarkers in the Diagnosis of Antibody Mediated Rejection in Heart Transplantation

This is a multicentric prospective study with experimental sample collection. Therapy and procedures will be performed according to clinical practice and current guidelines. Caring physicians will be blinded to the results of study specific assays, which will not be used to change standard cynical decision making.

Patients will be enrolled in the study at the time of the DSA assay performed in the context of standard surveillance (yearly monitoring for anti-HLA antibodies is recommended by current guidelines and is part of routine clinical practice). At study entry patients will receive blood sampling to assay dd-cfDNA (centralized laboratory) and T-reg populations (local laboratory). Clinical characteristics, medical history, and results of standard laboratory tests will be collected at baseline.

Inclusion criteria

• Age > 18 years

• Post heart transplantation follow-up between 1 and 15 y
• Ambulatory clinical stable
• Left ventricular ejection fraction (LVEF) > 40% (as assessed by complete cardiac ultrasound within 3 months before the enrolment)

Exclusion criteria

• Unplanned hospitalization for cardiovascular causes in the previous three months

• Biopsy-proven cellular (2R or greater) or AMR (pAMR> 1 ) in the previous 3 months
• Any contraindication to CMR
• Known pregnancy