Native T1 myocardial tissue characterisation in patients with pulmonary hypertension: findings from International T1 Multicentre Study

Abstract

Background Pulmonary hypertension is a severe disorder characterized by elevated pulmonary artery pressure leading to right ventricular (RV) failure and premature death. We have recently shown that high signal in septal myocardium by cardiovascular magnetic resonance (CMR) late gadolinium enhancement (LGE) imaging indicates more severe disease. This study investigated whether markers of interstitial septal changes by T1 mapping relate to parameters of biventricular function and structure and makers of disease severity in pulmonary hypertension. Methods Patients with a suspected or established diagnosis of pulmonary hypertension, based on a previous echocardiography or catheterisation, respectively, and control subjects underwent routine clinical CMR protocol (1.5 and 3 Tesla) and T1 mapping prior to and >20 minutes after administration of 0.2 mmol/kg of gadobutrol. T1 values were measured in mid-ventricular slices conservatively within septal myocardium. To transform native T1 values into a binary variable (normal/abnormal), the established cut-offs of >990ms at 1.5T or >1090ms at 3T, respectively, were used. For comparison of two and more than two normally distributed variables, Student’s t-test and one-way analysis of variance (ANOVA, with Bonferroni’s post-hoc test) as appropriate. Associations were explored by single and multivariate linear regressions. Results