Prospective study reveals cardiac MRI reliably rules out acute cellular rejection in early heart transplant recipients, highlighting potential to reduce invasive biopsies.
Key Points
To evaluate the diagnostic accuracy of cardiac magnetic resonance T1 mapping and extracellular volume quantification for detecting acute cellular rejection within the first 60 days following heart transplantation.
Conducted a prospective single-center study of 45 adult heart transplant recipients within 60 days post-transplantation.
Performed cardiac magnetic resonance imaging with native T1 mapping, extracellular volume (ECV) quantification, and late gadolinium enhancement (LGE) alongside surveillance endomyocardial biopsy as the reference standard.
Significant cellular rejection (grade ≥2R) occurred in 14 of 45 patients (31.1%), with significant elevations in native T1 (1048 ± 46.2 vs. 1006.6 ± 60.6 ms, p=0.028) and ECV (36.8 ± 5.3% vs. 33.2 ± 5.5%, p=0.043).
Standalone native T1 yielded an AUC of 0.700 (cutoff 1036.5 ms; sensitivity 64.3%, specificity 74.2%, PPV 52.9%, NPV 82.1%), while ECV yielded an AUC of 0.726 (cutoff 37.9%; sensitivity 57.1%, specificity 90.3%, PPV 72.7%, NPV 82.4%).
A multiparametric scan approach combining native T1 <1037 ms, ECV <38%, and absent LGE achieved a negative predictive value of 100% for ruling out significant rejection.