Heart failure & cardiomyopathies
Acute cellular rejection after heart transplantation: validation of HEARTBiT, a transcriptomic biomarker
Authors' conclusion
HEARTBiT provides a reliable, minimally invasive rule-out signal for moderate-to-severe ACR across the first year post-HTx, particularly during the high-risk early post-operative period.
Study context
- Population
- Consecutive adult heart transplant recipients at four tertiary centres
- Participants
- 117 recipients · 336 visits
- Comparison
- HEARTBiT vs endomyocardial biopsy grades
- Outcome
- Diagnostic accuracy for moderate-to-severe ACR (ISHLT ≥2R)
Methodological detailsprospective, multicentre
- Prospective
- Multicentre
Performance
As reported in the abstract
Moderate-to-severe ACR (ISHLT ≥2R)
| Test or model | AUC overall | AUC ≤60 days | AUC >60 days | Sensitivity ≤60 days (cutoff >0.54) | Specificity ≤60 days (cutoff >0.54) | Sensitivity >60 days (cutoff >0.54) | Specificity >60 days (cutoff >0.54) |
|---|---|---|---|---|---|---|---|
| HEARTBiT | 0.78 (95% CI 0.70-0.86) | 0.78 (95% CI 0.65-0.90) | 0.80 (95% CI 0.72-0.87) | 89% | 56% | 100% | 49% |
HEARTBiT
AUC overall0.78 (95% CI 0.70-0.86)
AUC ≤60 days0.78 (95% CI 0.65-0.90)
AUC >60 days0.80 (95% CI 0.72-0.87)
Sensitivity ≤60 days (cutoff >0.54)89%
Specificity ≤60 days (cutoff >0.54)56%
Sensitivity >60 days (cutoff >0.54)100%
Specificity >60 days (cutoff >0.54)49%
Further findings
Moderate-to-severe acute cellular rejection (ACR) (ISHLT ≥2R) detection, by time post-HTx
- AUC early post-HTx (≤60 days), 95% CI 0.65-0.90
- 0.78
- AUC beyond 60 days, 95% CI 0.72-0.87
- 0.80
Sensitivity and specificity at pre-specified cutoff (>0.54)
- Sensitivity early (≤60 days)
- 89%
- Sensitivity beyond 60 days
- 100%
- Specificity early (≤60 days)
- 56%
- Specificity beyond 60 days
- 49%
- Missed ACR overall
- ≤1
Sensitivity and specificity beyond 60 days, exploratory time-varying threshold (>0.68)
- Sensitivity
- 83%
- Specificity
- 76%
- Exploratory
Score rise before histological ACR detection (serial trajectories)
- Slope-based AUC, 95% CI 0.60-0.96
- 0.78
- Exploratory analysis, 246 serial visits from 31 participants
Original publication
Acute cellular rejection after heart transplantation: validation of HEARTBiT, a transcriptomic biomarker. Eur Heart J. Published 29 September 2026. doi:10.
Summarised from the published abstract; every number is checked against it