Pericardial tissue characterization with quantitative methods in cardiac magnetic resonance in acute or recurrent pericarditis

Background: Cardiac Magnetic Resonance(CMR) is gaining importance for prognosis stratification of pericarditis,but data on quantitative evaluation of pericardial inflammation with CMR are currently limited. Aim of the study is to assess the utility of tissue characterization of pericardium with quantitative methods in outcome prediction of acute or recurrent pericarditis. Materials and methods: Consecutive patients who performed CMR for acute or recurrent pericarditis and > 6 months clinical follow up (FU) were enrolled. Quantitative evaluation of oedema and late gadolinium enhancement (LGE) amount on pericardium with different techniques and T1/T2 maximum values on inflamed pericardium with mapping were performed. The continuous variables are presented as mean ± SD or median (IQR) as appropriate. Univariate/multivariate Cox regressions were used to investigate the association between the different CMR quantitative parameters and clinical outcome. Results: Sixty-one patients(mean age:48 ± 18 years; male:41 %) were enrolled, whose 46 (75 %) with acute pericarditis. Pericardial LGE median amount was 31.2(9;54.5), 42.7(17.2;72.5) and 38.8(15.2;69)cm3 when measured with FWHM, 5 and 6 SD, respectively. Median pericardial T1 and T2 values were 1356(1305;1523)ms and 77(73;81)ms, respectively. At 12 months FU, 20(32 %) patients reached the composite outcome including recurrence, constrictive evolution and right heart failure. Quantitative LGE, but neither T1 nor T2 mapping values nor T2w image, was associated to pericarditis recurrence and composite outcome in global cohort and to pericarditis recurrence in acute pericarditis cohort. Conclusion: Quantitative LGE evaluation with different techniques, but not parametric mapping, showed an association with clinical outcome prediction in acute and recurrent pericarditis, confirming LGE currently represents the most accurate imaging marker with prognostic value in this setting.