1070Comparison of native T1 values in acute and chronic viral myocarditis

Background and objectives: Patients with viral myocarditis commonly display significant amounts of LGE. LGE pattern is commonly diffuse or patchy. Our aim was to assess native T1 values in the presence of self-limiting and resolved systemic inflammation by T1 mapping. Secondly, we hypothesized that increased T1 relaxation time provides marker of risk, by paralleling with aortic stiffness, an established marker of CV risk. Methods: Forty-five patients, with a clinical diagnosis of viral myocarditis, evidenced by recent flu-like illness, ECG changes, raise in inflammatory markers and troponin, were recruited into this study. Twenty-three healthy subjects served as controls. They underwent routine cardiac MRI protocol (1.5 and 3-Tesla). Native T1 values were measured in septal myocardium using ConSept technique. Central pulse wave velocity (PWV) was obtained by a free-breathing inplane phase contrast gradient echo sequence with high temporal resolution (120 phases/cycle) allowing for foot-to-foot measurement. Results: Native T1 values in all cases were increased in both acute and chronic myocarditis at both field strengths (controls vs. acute vs. chronic myocarditis; 1.5T: native T1 (msec): 945 ± 33 vs. 1107 ± 103 vs. 1016 ± 56, p < 0.01; 3T: 1058 ± 24 vs. 1175 ± 93 vs. 1112 ± 80, p < 0.01). Post-hoc tests revealed significantly greater native T1 in acute vs. chronic myocardium (1.5T: p = 0.04; 3T: p = 0.05). Both patients' groups had significantly raised central PWV (for both scanners, m/sec: 5.1 ± 1.6 vs. 7.5 ± 1.4 vs. 8.4 ± 2.6, p < 0.01), with no significant difference between the two types of myocarditis. Central PWV was increased in patients' groups (PWV, m/sec, 5 ± 0.8 vs. 8.6 ± 2.5 vs. 8.2 ± 2.1 vs. 8.9 ± 3, p < 0.01). There was a linear relationship between native T1 and PWV (r = 0.39, p < 0.001, Figure 1).