Organ Preservation and Reperfusion Influence on Outcome after Heart Transplantation

s S193 The purpose of the study was to evaluate T2, T1 and extracellular volume (ECV) quantification as novel tissue markers to diagnose acute cardiac rejection. Methods: CMR was prospectively performed in heart transplant patients before or just after routine EMB and before acute rejection therapy. Images were acquired on a 1.5 Tesla scanner including T2 mapping (T2 preparedSSFP) and T1 mapping using a modified look locker inversion recovery sequence ( MOLLI) at basal, mid and apical level in short axis view. T2 and T1 values were measured before and 15 minutes (for T1 mapping) after contrast administration. The results are expressed by the median and the 5th and the 95th percentiles. Results: twenty six patients (age 52±14 years) were included providing 40 comparisons CMR/EMB. Acute rejection (cellular, humoral or clinical symptoms) was diagnosed in 13 patients. Patients with AR had significantly higher global T2 values at 3 levels (58 ms [52-61] vs 55ms [49-55], P= 0.0049 at basal; 57 ms [54-61] vs 51 ms [5054], P= 0.0010 at median and 60 ms [54-66] vs 54 ms [50-57], P= 0.0119 at apical level). The area under the curve (AUC) for each level was: 0.78; 0.84 and 0.77 respectively. Patients with AR had significantly higher ECV at basal and median level: 35% [33-41] vs 27% [25-31] P= 0.0021 and 33% [28-38] vs 27%[24-31], P= 0.015 respectively. The AUC for each level was; 0.83 and 0.75 respectively. The sensitivity, specificity and diagnosis accuracy for basal T2 (cutoff : 58 ms) were 70%, 96 % and 79% respectively; basal ECV: (cutoff 31%) 89%, 77% and 81% respectively. The best AUC ( 0.88) was obtained when we combined basal T2 and basal ECV. Conclusion: In heart transplant patients, a combined CMR approach using T2 mapping and ECV quantification provides a high diagnostic accuracy for acute rejection diagnosis and could potentially decrease the number of routine EMB. Further studies are required to confirm these data.