Т1 mapping in the evaluation of the risk factors for diffuse myocardial fibrosis in essential arterial hypertension

Abstract

Background : The assessment of diffuse myocardial fibrosis is necessary to plan the management of patients with various cardiovascular disorders, including hypertensive heart disease. The development of imaging techniques has enabled a non-invasive detection of left ventricular myocardial fibrosis by magnetic resonance imaging (MRI) with T1 mapping. Aim: By cardiac MRI, to identify risk factors for diffuse left ventricular myocardial fibrosis in patients with hypertensive heart disease. Materials and methods : This was a cross-sectional observational study in 50 outpatients with hypertensive heart disease, aged 46 to 82 years (median, 68 [64; 72] years) and bodyweight of 52 to 120 kg (median, 91 [80; 98] kg). Standard cardiac MRI with delayed contrast enhancement was performed with Optima MR450w GEM 1.5T (General Electric, USA). For assessment of diffuse myocardial fibrosis MRI mapping by 2D MOLLI (3-3-5) technique was used. The results were analyzed with Cvi42 software (Circle Cardiovascular Imaging Inc., USA). The potential risk factors included patients’ age, gender, bodyweight, and diastolic heart failure. Results: The mean time of T1 relaxation without contrast enhancement was 1122.64 ±63.67 ms, indicating the presence of myocardial fibrosis in 100% of the patients. Female patients had more advanced diffuse myocardial abnormalities (p < 0.001). In the elderly patients, there was a direct correlation between their age and degree of fibrosis (p = 0.006). There was an inverse correlation between higher bodyweight and increased extracellular volume. Heart rhythm disorders and diastolic heart failure had no impact on the changes in the mapping parameters of the left ventricular myocardium and MRI-assessed cardiac output values. No correlation between the myocardial fibrosis and dyslipidemia/hyperlipidemia was found. There was a direct correlation between the native T1 mapping values and extracellular volume fraction (p = 0.004) and an inverse correlation between low values of post-contrast T1 mapping and increased extracellular volume fraction (p = 0.05). Conclusion: Т1 mapping in patients with essential arterial hypertension allows for detection of diffuse myocardial fibrosis of the left ventricle, which is recognised as a major indicator of myocardial remodeling. Female gender, older age, and bodyweight were the factors associated with more advanced myocardial fibrosis.