RESUMO
BACKGROUND: Late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) enables high-resolution myocardial tissue characterization, showing the results of different injuries, especially in the early period after heart transplantation (HTX). OBJECTIVES: We sought to apply LGE-CMR to investigate the prevalence and patterns of infarct-atypical myocardial involvement and associated mechanisms in patients early and late after HTX. METHODS: LGE-CMR was performed on a 1.5-T MRI scanner (Philips, Best, the Netherlands) in 89 patients: group 1 (48 patients) less than 2.5 years after operation (1.2 ± 0.5 years) and group 2 (41 patients) later this period (8.2 ± 4.2 years). Following LGE-CMR, the presence, distribution, patterns of infarct-atypical LGE and possible associated mechanisms were assessed. RESULTS: 71 % of group 1 patients (34/48) showed infarctatypical LGE whereas 57 % of group 2 patients (22/41) were affected (p = 0.25). Fewer segments/patients were involved later after HTX (1.6 ± 2.0 vs. 2.9 ± 3.1 segments/ patient; p = 0.03), but only diffuse LGE-CMR pattern decreased significantly (11.5 % of affected segments in group 1 vs. 6.5 % in group 2; p\0.001). Group 2 had lower ischemic time (181 ± 53 vs. 208 ± 61 min; p = 0.03), the donors were younger (33 ± 13 vs. 41 ± 13 years; p = 0.01) and fewer donors were Toxoplasma gondii seropositive (4 vs. 22pts; p\0.001). CONCLUSION: Infarct-atypical LGE was found in a significant number of patients early post-HTX, however, fewer patients and myocardial segments per patient were affected later after HTX. Many potential factors seem to be involved, but the exact mechanisms are still unclear. Future studies are necessary to test prognostic implications associated with LGE-CMR patterns.
