PP.08.21

Abstract

Objective: The new cardiovascular magnetic resonance (CMR) T1 mapping sequences can be applied to quantify diffuse myocardial fibrosis. Also, new CMR analysis softwares allow for the accurate and reproducible measurement of myocardial strain. We aimed to use these two new developments in a pilot study in order to assess the association between presence of diffuse fibrosis and changes in myocardial strain. Design and method: 12 hypertensive patients (HT, 52 ± 7yrs, 10 males) with preserved ejection fraction and 12 controls (NT, 44 ± 10yrs, 8 males) underwent a CMR protocol at 3T that included black blood morphological sequences, cine sequences in the 2,3 and 4-chamber views as well as short axis series with typically 40 phases for each image acquisition, T1-mapping with two MOLLI acquisitions (3–3–5), before and 15 min after administration of a bolus of gadolinium-DTPA (0.1 mM/kg), and late gadolinium sequences in the same views as the cine sequences. All the scans were eventually analysed by two experienced observers with a dedicated software to obtain left ventricular volumes, ejection fraction and mass, precontrast myocardial T1 values, gadolinium partition coefficient (GPC) and extracellular volume fraction (ECV), a measure of diffuse myocardial fibrosis. Also, global longitudinal and radial myocardial strain and strain rate, as well as epicardium-endocardium strain gradient were measured. Results: All subjects had preserved systolic function and results are shown on the table. There was a trend towards increased ECV in HT though it did not reach statistical significance.Global londitudinal and radial strain (GLS, GRS), longitudinal strain rate (GLSR) and precontrast T1 were all lower in HT, while radial strain gradient between subendocardium and subepicardium (GRS endo-epi) was increased in HT. There was a significant inverse correlation of GLS and GRS with ECV, and of radial strain rate with ECV (all p < 0.05).Conclusions: In this pilot study we have found that there is an inverse correlation between global strain, a sensitive indicator of regional contractility, and myocardial extracellular volume fraction, a marker of diffuse fibrosis. This finding may have implications for early diagnosis of target organ damage in hypertensive patients.